const ByteArray = imports.byteArray;
const Desklet = imports.ui.desklet;
const Settings = imports.ui.settings;
const Mainloop = imports.mainloop;
const Lang = imports.lang;
const Clutter = imports.gi.Clutter;
const Gio = imports.gi.Gio;
const Cairo = imports.cairo;
const St = imports.gi.St;
const GLib = imports.gi.GLib;
const Gettext = imports.gettext;

const GIB_TO_KIB = 1048576; // 1 GiB = 1,048,576 kiB
const GB_TO_B = 1000000000; // 1 GB  = 1,000,000,000 B
const GIB_TO_MIB = 1024;    // 1 GiB = 1,042 MiB
const KB_TO_B = 1000;       // 1 KB  = 1,000 B
const KIB_TO_B = 1024;      // 1 KiB = 1,024 B

const CPU_TEMP_MIN =  20;    // Minimum CPU temperature
const CPU_TEMP_MAX = 100;    // Maximum CPU temperature
const CPU_FANSPEED_MAX = 4000; // CPU fan graph full-scale speed
const CPU_FAN_RETRY_MIN = 5;   // Initial retry delay in seconds
const CPU_FAN_RETRY_MAX = 300; // Maximum retry delay in seconds
const CPU_FAN_RETRY_MULTIPLIER = 2;

const UUID = "system-monitor-graph@mount";
const DESKLET_PATH = imports.ui.deskletManager.deskletMeta[UUID].path;

// Borrowed from battery@schorschii
const UPowerInterface = `<node>
  <interface name="org.freedesktop.UPower.Device">
    <property name="TimeToEmpty" type="x" access="read" />
    <property name="TimeToFull" type="x" access="read" />
  </interface>
</node>`;

const UPowerProxy = Gio.DBusProxy.makeProxyWrapper(UPowerInterface);
const UPowerBusName = "org.freedesktop.UPower";

Gettext.bindtextdomain(UUID, GLib.get_home_dir() + "/.local/share/locale");

function _(str) {
  return Gettext.dgettext(UUID, str);
}

function SystemMonitorGraph(metadata, desklet_id) {
  this._init(metadata, desklet_id);
}

function main(metadata, desklet_id) {
  return new SystemMonitorGraph(metadata, desklet_id);
}

function spawnAsyncWithOutput(argv, callback) {
    // callback(success, output_string)
    try {
        let [success, child_pid, std_in, std_out, std_err] = GLib.spawn_async_with_pipes(
            null,
            argv,
            null,
            GLib.SpawnFlags.DO_NOT_REAP_CHILD | GLib.SpawnFlags.LEAVE_DESCRIPTORS_OPEN,
            null
        );

        GLib.close(std_in);
        GLib.close(std_err);
        GLib.child_watch_add(GLib.PRIORITY_DEFAULT, child_pid, function(pid, wait_status) {
            GLib.spawn_close_pid(child_pid);
        });
        if (!success) {
            global.log('spawnAsyncWithOutput: spawn failed for command: ' + argv.join(' '));
            callback(false, null);
            return;
        }
        let ioChannel = GLib.IOChannel.unix_new(std_out);
        let tag = GLib.io_add_watch(
            ioChannel, GLib.PRIORITY_DEFAULT,
            GLib.IOCondition.IN | GLib.IOCondition.HUP,
            function(channel, condition) {
                let out_string = null;
                if (condition !== GLib.IOCondition.HUP) {
                    let [status, out] = channel.read_to_end();
                    out_string = out.toString();
                }
                GLib.source_remove(tag);
                channel.shutdown(true);
                callback(true, out_string);
            }
        );
    } catch(error) {
        callback(false, null);
    }
}

SystemMonitorGraph.prototype = {
    __proto__: Desklet.Desklet.prototype,

    _init: function(metadata, desklet_id) {
        Desklet.Desklet.prototype._init.call(this, metadata, desklet_id);

        // initialize settings
        this.settings = new Settings.DeskletSettings(this, this.metadata["uuid"], desklet_id);
        this.settings.bindProperty(Settings.BindingDirection.IN, "type", "type", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "cpu-variable", "cpu_variable", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "temperature-units-cpu", "temperature_units_cpu", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "data-prefix-ram", "data_prefix_ram", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "data-prefix-swap", "data_prefix_swap", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "data-prefix-hdd", "data_prefix_hdd", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "data-prefix-gpumem", "data_prefix_gpumem", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "data-prefix-network", "data_prefix_network", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "network-interface", "network_interface", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "battery-name", "battery_name", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "filesystem", "filesystem", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "filesystem-label", "filesystem_label", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "gpu-manufacturer", "gpu_manufacturer", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "gpu-variable", "gpu_variable", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "temperature-units-gpu", "temperature_units_gpu", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "gpu-id", "gpu_id", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "refresh-interval", "refresh_interval", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "duration", "duration", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "background-color", "background_color", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "h-midlines", "h_midlines", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "v-midlines", "v_midlines", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "scale-size", "scale_size", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "midline-color", "midline_color", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "text-color", "text_color", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "line-color-cpu", "line_color_cpu", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "line-color-ram", "line_color_ram", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "line-color-swap", "line_color_swap", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "line-color-hdd", "line_color_hdd", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "line-color-gpu", "line_color_gpu", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "line-color-network-down", "line_color_network_down", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "line-color-network-up", "line_color_network_up", this.on_setting_changed);
        this.settings.bindProperty(Settings.BindingDirection.IN, "line-color-battery", "line_color_battery", this.on_setting_changed);


        // initialize desklet GUI
        this.setupUI();
    },

    setupUI: function(){
        // initialize this.canvas
        this.canvas = new Clutter.Actor();
        this.canvas.remove_all_children();
        this.text1 = new St.Label();
        this.text2 = new St.Label();
        this.text3 = new St.Label();
        this.canvas.add_actor(this.text1);
        this.canvas.add_actor(this.text2);
        this.canvas.add_actor(this.text3);
        this.setContent(this.canvas);

        // flag to indicate the first loop of the Desklet
        this.first_run = true;
        // update loop for Desklet
        this.update();
    },

    update: function() {
        // monitors a given variable and plot its graph
        this.update_draw();
        // call this.update() every in refresh_interval seconds
        this.timeout = Mainloop.timeout_add_seconds(this.refresh_interval, Lang.bind(this, this.update));
    },

    update_draw: function() {
        // values needed in first run
        if (this.first_run){
            this.n_values = Math.floor(this.duration / this.refresh_interval)  + 1;
            this.values = new Array(this.n_values).fill(0.0);
            this.cpu_cpu_tot = 0;
            this.cpu_cpu_idl = 0;
            this.hdd_cpu_tot = 0;
            this.hdd_hdd_tot = 0;
            // values to graph
            this.cpu_use     = 0;
            this.ram_values  = new Array(2).fill(0.0);
            this.swap_values = new Array(2).fill(0.0);
            this.hdd_values  = new Array(4).fill(0.0);
            this.gpu_use     = NaN;
            this.gpu_mem     = new Array(2).fill(0.0);
            // network monitoring values
            this.net_down_values = new Array(this.n_values).fill(0.0);
            this.net_up_values = new Array(this.n_values).fill(0.0);
            this.last_net_rx = 0;
            this.last_net_tx = 0;
            this.net_down_speed = 0;
            this.net_up_speed = 0;
            this.net_max_scale = 1; // Auto-scaling for network graph
            // battery values
            this.battery_percent  = NaN;
            this.battery_status   = "";
            this.battery_time     = "";
            // temperature values
            this.cpu_temperature = NaN;
            this.gpu_temperature = NaN;
            // cpu fan values
            this.cpu_fan_rpm = NaN;
            this.cpu_fan_file = "";
            this.cpu_fan_discovery_complete = false;

            // set colors
            switch (this.type) {
              case "cpu":
                  this.line_color = this.line_color_cpu;
                  break;
              case "ram":
                  this.line_color = this.line_color_ram;
                  break;
              case "swap":
                  this.line_color = this.line_color_swap;
                  break;
              case "hdd":
                  this.line_color = this.line_color_hdd;
                  break;
              case "gpu":
                  this.line_color = this.line_color_gpu;
                  break;
              case "network":
                  this.line_color = this.line_color_network_down; // Use download color for border
                  this.line_color_down = this.line_color_network_down;
                  this.line_color_up = this.line_color_network_up;
                  break;
              case "battery":
                  this.line_color = this.line_color_battery;
                  break;
            }

            // set files
            // find file for overall CPU temperature
            let cpu_path_temp = "/sys/class/hwmon/";
            // test for Intel ("Package id 0")
            this.get_temperature_file_by_label(cpu_path_temp, 'Package id 0', (result) => {
                if (result !== "") {
                    this.cpu_temperature_file = result;
                } else {
                    // test for AMD ("Tct1")
                    this.get_temperature_file_by_label(cpu_path_temp, 'Tctl', (result) => {
                        this.cpu_temperature_file = result;
                    });
                }
            });
            if (this.type == "cpu" && this.cpu_variable == "fan") {
                this.rediscover_cpu_fan();
            }
            // find file for overall AMD GPU temperature
            let gpu_path_temp = "/sys/class/drm/card" + this.gpu_id + "/device/hwmon/";
            this.get_temperature_file_by_label(gpu_path_temp, 'edge', (result) => {
                this.gpu_amd_temperature_file = result;
            });

            this.first_run = false;
        }

        // Desklet proportions
        let unit_size = 15 * this.scale_size * global.ui_scale;  // pixels
        var line_width = unit_size / 15;
        var margin_up = 3 * unit_size;
        var graph_w = 20 * unit_size;
        var graph_h =  4 * unit_size;
        let desklet_w = graph_w + (2 * unit_size);
        let desklet_h = graph_h + (4 * unit_size);
        var h_midlines = this.h_midlines;
        var v_midlines = this.v_midlines;
        let text1_size = (4 * unit_size / 3) / global.ui_scale;
        let text2_size = (4 * unit_size / 3) / global.ui_scale;
        let text3_size = (3 * unit_size / 3) / global.ui_scale;
        var radius = 2 * unit_size / 3;;
        var degrees = Math.PI / 180.0;

        let n_values = this.n_values;
        let values = this.values;
        let graph_step = graph_w / (n_values -1);

        var value = 0.0;
        var text1 = '';
        var text2 = '';
        var text3 = '';
        var line_colors = this.parse_rgba_settings(this.line_color);

        // current values
        switch (this.type) {
          case "cpu":
              switch (this.cpu_variable) {
                  case "usage":
                      this.get_cpu_use();
                      value = this.cpu_use / 100;
                      text1 = _("CPU");
                      text2 = Math.round(this.cpu_use).toString() + "%";
                      break;

                  case "temperature":
                      this.get_cpu_temperature(this.cpu_temperature_file);
                      // scale CPU temperature based on [CPU_TEMP_MIN, CPU_TEMP_MAX]
                      value = 1.0 * (this.cpu_temperature - CPU_TEMP_MIN) / (CPU_TEMP_MAX - CPU_TEMP_MIN);
                      value = value < 0 ? 0 : value > 1 ? 1 : value;
                      text1 = _("CPU Temperature");
                      if (this.temperature_units_cpu == "C") {
                          text2 = this.cpu_temperature.toString() + "°C";
                      } else if (this.temperature_units_cpu == "F") {
                          text2 = Math.round(this.cpu_temperature * 9 / 5 + 32).toString() + "°F";
                      }
                      break;

                  case "fan":
                      this.get_cpu_fan_speed(this.cpu_fan_file);
                      value = isNaN(this.cpu_fan_rpm) ? 0 : this.cpu_fan_rpm / CPU_FANSPEED_MAX;
                      value = value < 0 ? 0 : value > 1 ? 1 : value;
                      text1 = _("CPU Fan");
                      text2_size = Math.max(1, text2_size - 1);
                      if (!isNaN(this.cpu_fan_rpm)) {
                          if (this.cpu_fan_rpm >= 1) {
                              text2 = this.cpu_fan_rpm + " " + _("RPM");
                              text3 = "🟢 " + _("On");
                          } else {
                              text3 = "🔴 " + _("Off");
                          }
                      } else if (this.cpu_fan_discovery_complete) {
                          text2 = _("Not detected");
                      } else {
                          text2 = _("Detecting...");
                      }
                      break;
              }
              break;

          case "ram":
              this.get_ram_values();
              let ram_use = 100 * this.ram_values[1] / this.ram_values[0];
              value = ram_use / 100;
              let ram_prefix = "";
              if (this.data_prefix_ram == 1) {
                  // decimal prefix
                  ram_prefix =  _("GB");
              } else {
                  // binary prefix
                  ram_prefix =  _("GiB");
              }
              text1 = _("RAM");
              text2 = Math.round(ram_use).toString() + "%"
              text3 = this.ram_values[1].toFixed(1) + " / "
                    + this.ram_values[0].toFixed(1) + " " + ram_prefix;
              break;

          case "swap":
            this.get_swap_values();
            let swap_use = 100 * this.swap_values[1] / this.swap_values[0];
            value = swap_use / 100;
            let swap_prefix = "";
            if (this.data_prefix_swap == 1) {
                // decimal prefix
                swap_prefix =  _("GB");
            } else {
                // binary prefix
                swap_prefix =  _("GiB");
            }
            text1 = _("Swap");
            text2 = Math.round(swap_use).toString() + "%"
            text3 = this.swap_values[1].toFixed(1) + " / "
                  + this.swap_values[0].toFixed(1) + " " + swap_prefix;
            break;

          case "hdd":
              let dir_path = decodeURIComponent(this.filesystem.replace("file://", "").trim());
              if(dir_path == null || dir_path == "") dir_path = "/";
              this.get_hdd_values(dir_path);
              let hdd_use = Math.min(this.hdd_values[1], 100); //already in %
              value = hdd_use / 100;
              let hdd_prefix = "";
              if (this.data_prefix_hdd == 1) {
                  // decimal prefix
                  hdd_prefix =  _("GB");
              } else {
                  // binary prefix
                  hdd_prefix =  _("GiB");
              }
              text1 = this.filesystem_label;
              if (text1 == "") text1 = this.hdd_values[0].toString();
              text2 = Math.round(hdd_use).toString() + "%"
              text3 = this.hdd_values[3].toFixed(0) + " " + hdd_prefix + " " + _("free of") + " "
                    + this.hdd_values[2].toFixed(0) + " " + hdd_prefix;
              break;

          case "gpu":
              switch (this.gpu_variable) {
                  case "usage":
                      switch (this.gpu_manufacturer) {
                          case "nvidia":
                              this.get_nvidia_gpu_use();
                              break;
                          case "amdgpu":
                              this.get_amdgpu_gpu_use();
                              break;
                      }
                      value = this.gpu_use / 100;
                      text1 = _("GPU Usage");
                      text2 = Math.round(this.gpu_use).toString() + "%";
                      break;
                  case "memory":
                      switch (this.gpu_manufacturer) {
                          case "nvidia":
                              this.get_nvidia_gpu_mem();
                              break;
                          case "amdgpu":
                              this.get_amdgpu_gpu_mem();
                              break;
                      }
                      let gpu_mem_use = 100 * this.gpu_mem[1] / this.gpu_mem[0];
                      value = gpu_mem_use / 100;
                      let gpumem_prefix = "";
                      if (this.data_prefix_gpumem == 1) {
                          // decimal prefix
                          gpumem_prefix =  _("GB");
                      } else {
                          // binary prefix
                          gpumem_prefix =  _("GiB");
                      }
                      text1 = _("GPU Memory");
                      text2 = Math.round(gpu_mem_use).toString() + "%"
                      text3 = this.gpu_mem[1].toFixed(1) + " / "
                            + this.gpu_mem[0].toFixed(1) + " " + gpumem_prefix;
                      break;
                  case "temperature":
                      switch (this.gpu_manufacturer) {
                          case "nvidia":
                              this.get_nvidia_gpu_temperature();
                              break;
                          case "amdgpu":
                              this.get_amdgpu_gpu_temperature(this.gpu_amd_temperature_file);
                              break;
                      }
                      value = 1.0 * (this.gpu_temperature - CPU_TEMP_MIN) / (CPU_TEMP_MAX - CPU_TEMP_MIN);
                      value = value < 0 ? 0 : value > 1 ? 1 : value;
                      text1 = _("GPU Temperature");
                      if (this.temperature_units_gpu == "C") {
                          text2 = this.gpu_temperature.toString() + "°C";
                      } else if (this.temperature_units_gpu == "F") {
                          text2 = Math.round(this.gpu_temperature * 9 / 5 + 32).toString() + "°F";
                      }
                      break;
              }
              break;

          case "network":
              this.get_network_values();
              // For network, we don't use the single 'value' variable as we have dual lines
              value = 0; // Not used for network type
              text1 = _("Network");
              
              // Format speeds with appropriate units
              let down_speed_formatted = this.format_network_speed(this.net_down_speed);
              let up_speed_formatted = this.format_network_speed(this.net_up_speed);
              
              text2 = "";
              text3 = "↓ " + down_speed_formatted + "  ↑ " + up_speed_formatted;
              break;

          case "battery":
              this.get_battery_use();
              value = this.battery_percent / 100.0;
              text1 = _("Battery");
              text2 = this.battery_percent + "%";
              let prefix = (this.battery_status == "Charging") ? "⚡ " : (this.battery_percent <= 20 ? "🪫 " : "🔋 ");
              text3 = (this.battery_status == "Full") ? "🔋 " + _("Fully charged") :
                (this.battery_status == "Not charging") ? "🔌 " + _("Not charging") :
                (this.battery_status == "" || this.battery_status == "Unknown") ? "" :
                prefix + this.battery_time + _(" hrs");
              break;
        }

        // For non-network types, concatenate new value to the main values array
        if (this.type !== "network") {
            values.push(isNaN(value) ? 0 : value);
            values.shift();
            this.values = values;
        }

        var background_colors = this.parse_rgba_settings(this.background_color);
        var midline_colors = this.parse_rgba_settings(this.midline_color);



        // draws graph
        let canvas = new Clutter.Canvas();
        canvas.set_size(desklet_w, desklet_h);
        canvas.connect('draw', (canvas, ctx, desklet_w, desklet_h) => {
            ctx.save();
            ctx.setOperator(Cairo.Operator.CLEAR);
            ctx.paint();
            ctx.restore();
            ctx.setOperator(Cairo.Operator.OVER);
            ctx.setLineWidth(2 * line_width);

            // desklet background
            ctx.setSourceRGBA(background_colors[0], background_colors[1], background_colors[2], background_colors[3]);
            ctx.newSubPath();
            ctx.arc(desklet_w - radius, radius, radius, -90 * degrees, 0 * degrees);
            ctx.arc(desklet_w - radius, desklet_h - radius, radius, 0 * degrees, 90 * degrees);
            ctx.arc(radius, desklet_h - radius, radius, 90 * degrees, 180 * degrees);
            ctx.arc(radius, radius, radius, 180 * degrees, 270 * degrees);
            ctx.closePath();
            ctx.fill();

            // graph V and H midlines
            ctx.setSourceRGBA(midline_colors[0], midline_colors[1], midline_colors[2], 1);
            ctx.setLineWidth(line_width);
            for (let i = 1; i<v_midlines; i++){
                ctx.moveTo((i * graph_w / v_midlines) + unit_size, margin_up);
                ctx.relLineTo(0, graph_h);
                ctx.stroke();
            }
            for (let i = 1; i<h_midlines; i++){
                ctx.moveTo(unit_size, margin_up + i * (graph_h / h_midlines));
                ctx.relLineTo(graph_w, 0);
                ctx.stroke();
            }

            if (this.type === "network") {
                // Draw dual-line network graph
                this.draw_network_graph(ctx, unit_size, margin_up, graph_w, graph_h, graph_step, n_values, line_width);
            } else {
                // timeseries and area
                ctx.setLineWidth(2 * line_width);
                ctx.setSourceRGBA(line_colors[0], line_colors[1], line_colors[2], 1);
                ctx.moveTo(unit_size, margin_up + graph_h - (values[0] * graph_h));
                for (let i = 1; i<n_values; i++){
                    ctx.lineTo(unit_size + (i * graph_step), margin_up + graph_h - (values[i] * graph_h));
                }
                ctx.strokePreserve();
                ctx.lineTo(unit_size + graph_w, margin_up + graph_h);
                ctx.lineTo(unit_size, margin_up + graph_h);
                ctx.closePath();
                ctx.setSourceRGBA(line_colors[0], line_colors[1], line_colors[2], 0.4);
                ctx.fill();
            }

            // graph border (redrawn on top)
            ctx.setLineWidth(2 * line_width);
            ctx.setSourceRGBA(line_colors[0], line_colors[1], line_colors[2], 1);
            ctx.rectangle(unit_size, margin_up, graph_w, graph_h);
            ctx.stroke();

            return false;
        });

        // labels: set text, style and position
        this.text1.set_text(text1);
        this.text1.style = "font-size: " + text1_size + "px;"
                         + "color: " + this.text_color + ";";
        this.text1.set_position(
            Math.round(unit_size),
            Math.round((2.5 * unit_size) - this.text1.get_height())
        );
        this.text2.set_text(text2);
        this.text2.style = "font-size: " + text2_size + "px;"
                         + "color: " + this.text_color + ";";
        this.text2.set_position(
            Math.round(this.text1.get_width() + (2 * unit_size)),
            Math.round((2.5 * unit_size) - this.text2.get_height())
        );
        this.text3.set_text(text3);
        this.text3.style = "font-size: " + text3_size + "px;"
                         + "color: " + this.text_color + ";";
        this.text3.set_position(
            Math.round((21 * unit_size) - this.text3.get_width()),
            Math.round((2.5 * unit_size) - this.text3.get_height()));


        // update canvas
        canvas.invalidate();
        this.canvas.set_content(canvas);
        this.canvas.set_size(desklet_w, desklet_h);
    },

    draw_network_graph: function(ctx, unit_size, margin_up, graph_w, graph_h, graph_step, n_values, line_width) {
        // Parse colors for download and upload
        var down_colors = this.parse_rgba_settings(this.line_color_down);
        var up_colors = this.parse_rgba_settings(this.line_color_up);
        
        // Robust array bounds checking
        if (!this.net_down_values || !this.net_up_values || 
            this.net_down_values.length === 0 || this.net_up_values.length === 0) {
            return; // Skip drawing if arrays are not properly initialized
        }
        
        // Filter out invalid values and find maximum
        let valid_down_values = this.net_down_values.filter(v => !isNaN(v) && isFinite(v) && v >= 0);
        let valid_up_values = this.net_up_values.filter(v => !isNaN(v) && isFinite(v) && v >= 0);
        
        let max_down = valid_down_values.length > 0 ? Math.max(...valid_down_values) : 0;
        let max_up = valid_up_values.length > 0 ? Math.max(...valid_up_values) : 0;
        let current_max = Math.max(max_down, max_up);
        
        // Improved Y-axis scaling with speed range detection
        let target_scale = this.calculate_optimal_scale(current_max);
        
        // Smooth scale transitions with different rates for up/down
        if (target_scale > this.net_max_scale) {
            // Scale up quickly for new peaks
            this.net_max_scale = target_scale;
        } else {
            // Scale down gradually with 98% retention for stability
            this.net_max_scale = Math.max(target_scale, this.net_max_scale * 0.98);
        }
        
        // Ensure minimum scale to avoid division by zero
        if (this.net_max_scale < 1024) this.net_max_scale = 1024; // Minimum 1 KiB/s scale
        
        ctx.setLineWidth(2 * line_width);
        
        // Draw download line with area fill
        ctx.setSourceRGBA(down_colors[0], down_colors[1], down_colors[2], 1);
        ctx.moveTo(unit_size, margin_up + graph_h - this.safe_scale_value(this.net_down_values[0], graph_h));
        for (let i = 1; i < n_values; i++) {
            ctx.lineTo(unit_size + (i * graph_step), margin_up + graph_h - this.safe_scale_value(this.net_down_values[i], graph_h));
        }
        ctx.strokePreserve();
        // Add area fill for download
        ctx.lineTo(unit_size + graph_w, margin_up + graph_h);
        ctx.lineTo(unit_size, margin_up + graph_h);
        ctx.closePath();
        ctx.setSourceRGBA(down_colors[0], down_colors[1], down_colors[2], 0.3);
        ctx.fill();
        
        // Draw upload line with area fill
        ctx.setSourceRGBA(up_colors[0], up_colors[1], up_colors[2], 1);
        ctx.moveTo(unit_size, margin_up + graph_h - this.safe_scale_value(this.net_up_values[0], graph_h));
        for (let i = 1; i < n_values; i++) {
            ctx.lineTo(unit_size + (i * graph_step), margin_up + graph_h - this.safe_scale_value(this.net_up_values[i], graph_h));
        }
        ctx.strokePreserve();
        // Add area fill for upload
        ctx.lineTo(unit_size + graph_w, margin_up + graph_h);
        ctx.lineTo(unit_size, margin_up + graph_h);
        ctx.closePath();
        ctx.setSourceRGBA(up_colors[0], up_colors[1], up_colors[2], 0.3);
        ctx.fill();
    },

    // Helper function for safe value scaling
    safe_scale_value: function(value, graph_h) {
        if (!value || isNaN(value) || !isFinite(value) || value < 0) {
            return 0; // Return 0 for invalid values
        }
        let scaled = (value / this.net_max_scale) * graph_h;
        // Clamp to graph bounds
        return Math.max(0, Math.min(graph_h, scaled));
    },

    // Calculate optimal scale based on speed ranges
    calculate_optimal_scale: function(current_max) {
        if (current_max <= 0) return 1024; // 1 KiB/s minimum
        
        // Define speed range thresholds (in bytes/sec)
        const speed_ranges = [
            1024,           // 1 KiB/s
            10240,          // 10 KiB/s
            102400,         // 100 KiB/s
            1048576,        // 1 MiB/s
            10485760,       // 10 MiB/s
            50000000,       // 50 MiB/s
            104857600,      // 100 MiB/s
            250000000,      // 250 MiB/s
            500000000,      // 500 MiB/s
            1073741824,     // 1 GiB/s
            10737418240     // 10 GiB/s
        ];
        
        // Find appropriate scale with 20% headroom
        let target = current_max * 1.2;
        
        for (let scale of speed_ranges) {
            if (target <= scale) {
                return scale;
            }
        }
        
        // For very high speeds, use next power of 2
        let power = Math.ceil(Math.log2(target));
        return Math.pow(2, power);
        
    },

    format_network_speed: function(speed_bytes_per_sec) {
        // Enhanced error handling for speed formatting
        if (!speed_bytes_per_sec || isNaN(speed_bytes_per_sec) || !isFinite(speed_bytes_per_sec) || speed_bytes_per_sec < 0) {
            if (this.data_prefix_network == 2) {
                return "0 " + _("b") + "/s";
            } else {
                return "0 " + _("B") + "/s";
            }
        }
        
        // Convert bytes per second to appropriate units
        let speed = speed_bytes_per_sec;
        let unit = "";
        
        if (this.data_prefix_network == 2) {
            // Decimal prefix (1000-based) bit
            speed = speed * 8;
            if (speed >= 1000000000) {
                speed = speed / 1000000000;
                unit = _("Gb") + "/s";
            } else if (speed >= 1000000) {
                speed = speed / 1000000;
                unit = _("Mb") + "/s";
            } else if (speed >= 1000) {
                speed = speed / 1000;
                unit = _("Kb") + "/s";
            } else {
                unit = _("b") + "/s";
            }
        } else if (this.data_prefix_network == 1) {
            // Decimal prefix (1000-based) bytes
            if (speed >= 1000000000) {
                speed = speed / 1000000000;
                unit = _("GB") + "/s";
            } else if (speed >= 1000000) {
                speed = speed / 1000000;
                unit = _("MB") + "/s";
            } else if (speed >= 1000) {
                speed = speed / 1000;
                unit = _("KB") + "/s";
            } else {
                unit = _("B") + "/s";
            }
        } else {
            // Binary prefix (1024-based) bytes
            if (speed >= 1073741824) { // 1024^3
                speed = speed / 1073741824;
                unit = _("GiB") + "/s";
            } else if (speed >= 1048576) { // 1024^2
                speed = speed / 1048576;
                unit = _("MiB") + "/s";
            } else if (speed >= 1024) {
                speed = speed / 1024;
                unit = _("KiB") + "/s";
            } else {
                unit = _("B") + "/s";
            }
        }
        
        // Format with appropriate decimal places
        if (speed >= 10) {
            return Math.round(speed).toString() + " " + unit;
        } else {
            return speed.toFixed(1) + " " + unit;
        }
    },

    on_setting_changed: function() {
        // settings changed; instant refresh
        if (this.timeout) {
            Mainloop.source_remove(this.timeout);
        }
        this.first_run = true;
        this.update();
   },

    on_desklet_removed: function() {
        if (this.timeout) {
            Mainloop.source_remove(this.timeout);
        }
    },

    cpu_file: Gio.file_new_for_path('/proc/stat'),
    get_cpu_use: function() {
        // https://rosettacode.org/wiki/Linux_CPU_utilization
        this.cpu_file.load_contents_async(null, (file, response) => {
            let [success, contents, tag] = file.load_contents_finish(response);
            if(success) {
                let cpu_values = ByteArray.toString(contents).split("\n")[0].split(/\s+/);
                let cpu_idl = parseFloat(cpu_values[4]);
                let cpu_tot = 0;
                for (let i = 1; i<10; i++){
                  cpu_tot += parseFloat(cpu_values[i])
                }
                this.cpu_use = 100 * (1 - (cpu_idl - this.cpu_cpu_idl) / (cpu_tot - this.cpu_cpu_tot));
                this.cpu_cpu_tot = cpu_tot;
                this.cpu_cpu_idl = cpu_idl;
            }
            GLib.free(contents);
        });
    },

    ram_swap_file: Gio.file_new_for_path('/proc/meminfo'),
    get_ram_values: function() {
        // used  = total - available
        // while meminfo says "kb" the unit is kibibytes
        this.ram_swap_file.load_contents_async(null, (file, response) => {
            let [success, contents, tag] = file.load_contents_finish(response);
            if(success) {
                let mem = ByteArray.toString(contents);
                let mem_tot = parseInt(mem.match(/(MemTotal):\D+(\d+)/)[2]);
                let mem_usd = mem_tot - parseInt(mem.match(/(MemAvailable):\D+(\d+)/)[2]);
                let ram_tot
                let ram_usd
                if (this.data_prefix_ram == 1) {
                    // decimal prefix
                    ram_tot = mem_tot * 1024 / GB_TO_B;
                    ram_usd = mem_usd * 1024 / GB_TO_B;
                } else {
                    // binary prefix
                    ram_tot = mem_tot / GIB_TO_KIB;
                    ram_usd = mem_usd / GIB_TO_KIB;
                }
                this.ram_values = [ram_tot, ram_usd];
            }
            GLib.free(contents);
        });
    },

    get_swap_values: function() {
        // used  = total - available
        // while meminfo says "kb" the unit is kibibytes
        this.ram_swap_file.load_contents_async(null, (file, response) => {
            let [success, contents, tag] = file.load_contents_finish(response);
            if(success) {
                let mem = ByteArray.toString(contents);
                let mem_tot = parseInt(mem.match(/(SwapTotal):\D+(\d+)/)[2]);
                let mem_usd = mem_tot - parseInt(mem.match(/(SwapFree):\D+(\d+)/)[2]);
                let swap_tot
                let swap_usd
                if (this.data_prefix_swap == 1) {
                    // decimal prefix
                    swap_tot = mem_tot * 1024 / GB_TO_B;
                    swap_usd = mem_usd * 1024 / GB_TO_B;
                } else {
                    // binary prefix
                    swap_tot = mem_tot / GIB_TO_KIB;
                    swap_usd = mem_usd / GIB_TO_KIB;
                }
                this.swap_values = [swap_tot, swap_usd];
            }
            GLib.free(contents);
        });
    },

    hdd_file: Gio.file_new_for_path('/proc/diskstats'),
    get_hdd_values: function(dir_path) {
        // while df says "1K" it means 1 kibibyte
        let subprocess = new Gio.Subprocess({
        argv: ['/bin/df', dir_path],
        flags: Gio.SubprocessFlags.STDOUT_PIPE|Gio.SubprocessFlags.STDERR_PIPE,
        });
        subprocess.init(null);
        subprocess.wait_async(null, (sourceObject, res) => {
            let [, stdout, stderr] = sourceObject.communicate_utf8(null, null);
            let df_line = stdout.match(/.+/g)[1];
            let df_values = df_line.split(/\s+/); // split by space
            // values for partition space
            var hdd_tot;
            var hdd_fre;
            if (this.data_prefix_hdd == 1) {
                // decimal prefix
                hdd_tot = parseFloat(df_values[1]) * 1024 / GB_TO_B;
                hdd_fre = parseFloat(df_values[3]) * 1024 / GB_TO_B;
            } else {
                // binary prefix
                hdd_tot = parseFloat(df_values[1]) / GIB_TO_KIB;
                hdd_fre = parseFloat(df_values[3]) / GIB_TO_KIB;
            }
            // get IO utilization of partition
            let dev_fs = df_values[0];
            let fs = dev_fs.split(/\/+/)[2];
            try {
                fs = GLib.file_read_link(dev_fs).split(/\/+/)[1];
            }
            catch (e) {
            }
            let re = new RegExp(fs + '.+');
            // https://stackoverflow.com/questions/4458183/how-the-util-of-iostat-is-computed
            this.cpu_file.load_contents_async(null, (file, response) => {
                let [cpu_success, cpu_contents, cpu_tag] = file.load_contents_finish(response);
                if(!cpu_success) return;
                let cpu_line = ByteArray.toString(cpu_contents).match(/cpu\s.+/)[0];
                // get total CPU time
                let cpu_values = cpu_line.split(/\s+/);
                let hdd_cpu_tot = 0;
                for (let i = 1; i<10; i++){
                    hdd_cpu_tot += parseFloat(cpu_values[i])
                }
                this.hdd_file.load_contents_async(null, (file, response) => {
                    let [hdd_success, hdd_contents, hdd_tag] = file.load_contents_finish(response);
                    if(!hdd_success) return;
                    let hdd_line = ByteArray.toString(hdd_contents).match(re)[0];
                    // get total of IO times
                    let hdd_hdd_tot = hdd_line.split(/\s+/)[10];
                    // update HDD use
                    let hdd_use = 100 * (hdd_hdd_tot - this.hdd_hdd_tot) / (hdd_cpu_tot - this.hdd_cpu_tot);
                    // update global values
                    this.hdd_cpu_tot = hdd_cpu_tot;
                    this.hdd_hdd_tot = hdd_hdd_tot;
                    this.hdd_values = [fs, hdd_use, hdd_tot, hdd_fre];
                    GLib.free(hdd_contents);
                });
                GLib.free(cpu_contents);
            });
        });
    },

    network_file: Gio.file_new_for_path('/proc/net/dev'),
    get_network_values: function() {
        // Enhanced error handling for network monitoring
        try {
            this.network_file.load_contents_async(null, (file, response) => {
                try {
                    let [success, contents, tag] = file.load_contents_finish(response);
                    if (!success) {
                        global.log('Network monitoring: Failed to read /proc/net/dev');
                        return;
                    }
                    
                    let lines = ByteArray.toString(contents).split('\n');
                    let total_rx = 0;
                    let total_tx = 0;
                    
                    // Skip header lines (first 2 lines)
                    for (let i = 2; i < lines.length; i++) {
                        let line = lines[i].trim();
                        if (line === '') continue;
                        
                        let parts = line.split(/[:\s]+/);
                        if (parts.length < 11) continue;
                        
                        let interface_name = parts[0];
                        
                        // Skip loopback interface
                        if (interface_name === 'lo') continue;
                        
                        // If specific interface is configured, only monitor that one
                        if (this.network_interface && this.network_interface.trim() !== '') {
                            if (interface_name !== this.network_interface.trim()) continue;
                        }
                        
                        // Parse RX and TX bytes (columns 1 and 9 after interface name)
                        let rx_bytes = parseInt(parts[1]) || 0;
                        let tx_bytes = parseInt(parts[9]) || 0;
                        
                        // Validate parsed values
                        if (isNaN(rx_bytes) || isNaN(tx_bytes) || rx_bytes < 0 || tx_bytes < 0) {
                            continue;
                        }
                        
                        total_rx += rx_bytes;
                        total_tx += tx_bytes;
                    }
                    
                    // Calculate deltas (bytes per second) with enhanced validation
                    if (this.last_net_rx > 0 && this.last_net_tx > 0) {
                        // Check for counter rollover (unlikely but possible)
                        let rx_delta = total_rx >= this.last_net_rx ? 
                            (total_rx - this.last_net_rx) / this.refresh_interval : 0;
                        let tx_delta = total_tx >= this.last_net_tx ? 
                            (total_tx - this.last_net_tx) / this.refresh_interval : 0;
                        
                        // Sanity check for unrealistic speeds (> 10 GiB/s)
                        const MAX_REASONABLE_SPEED = 10 * 1024 * 1024 * 1024; // 10 GiB/s
                        if (rx_delta > MAX_REASONABLE_SPEED) rx_delta = 0;
                        if (tx_delta > MAX_REASONABLE_SPEED) tx_delta = 0;
                        
                        // Store current speeds with validation
                        this.net_down_speed = Math.max(0, rx_delta);
                        this.net_up_speed = Math.max(0, tx_delta);
                        
                        // Ensure arrays are initialized
                        if (!this.net_down_values || !this.net_up_values) {
                            this.net_down_values = new Array(this.n_values).fill(0.0);
                            this.net_up_values = new Array(this.n_values).fill(0.0);
                        }
                        
                        // Add to time series arrays
                        this.net_down_values.push(this.net_down_speed);
                        this.net_up_values.push(this.net_up_speed);
                        this.net_down_values.shift();
                        this.net_up_values.shift();
                    }
                    
                    // Update last values for next calculation
                    this.last_net_rx = total_rx;
                    this.last_net_tx = total_tx;
                    
                    GLib.free(contents);
                    
                } catch (error) {
                    global.log('Network monitoring error: ' + error.toString());
                }
            });
        } catch (error) {
            global.log('Network monitoring file access error: ' + error.toString());
        }
    },

    parse_rgba_settings: function(color_str) {
        let colors = color_str.match(/\((.*?)\)/)[1].split(","); // get contents inside brackets: "rgb(...)"
        let r = parseInt(colors[0])/255;
        let g = parseInt(colors[1])/255;
        let b = parseInt(colors[2])/255;
        let a = 1;
        if (colors.length > 3) a = colors[3];
        return [r, g, b, a];
    },

    get_nvidia_gpu_use: function() {
        spawnAsyncWithOutput(
            ['/usr/bin/nvidia-smi', '--query-gpu=utilization.gpu', '--format=csv', '--id='+ this.gpu_id],
            (success, out_string) => {
                if (!success || !out_string) {
                    this.gpu_use = 0;
                    return;
                }
                this.gpu_use = parseInt(out_string.match(/[^\r\n]+/g)[1]);
            }
        );
    },

    get_nvidia_gpu_mem: function() {
        spawnAsyncWithOutput(
            ['/usr/bin/nvidia-smi', '--query-gpu=memory.total,memory.used', '--format=csv', '--id=' + this.gpu_id],
            (success, out_string) => {
                if (!success || !out_string) {
                    this.gpu_mem[0] = 0;
                    this.gpu_mem[1] = 0;
                    return;
                }
                let items = out_string.split(/\r?\n/)[1].split(',');
                if (this.data_prefix_gpumem == 1) {
                    this.gpu_mem[0] = parseInt(items[0]) * 1024 * 1024 / GB_TO_B;
                    this.gpu_mem[1] = parseInt(items[1]) * 1024 * 1024 / GB_TO_B;
                } else {
                    this.gpu_mem[0] = parseInt(items[0]) / GIB_TO_MIB;
                    this.gpu_mem[1] = parseInt(items[1]) / GIB_TO_MIB;
                }
            }
        );
    },

    get_nvidia_gpu_temperature: function() {
        spawnAsyncWithOutput(
            ['/usr/bin/nvidia-smi', '--query-gpu=temperature.gpu', '--format=csv', '--id='+ this.gpu_id],
            (success, out_string) => {
                if (!success || !out_string) {
                    this.gpu_temperature = 0;
                    return;
                }
                this.gpu_temperature = parseInt(out_string.match(/[^\r\n]+/g)[1]);
            }
        );
    },

    get_amdgpu_gpu_use: function() {
      // Sysfs directory with files related to the chosen gpu
      let gpu_dir = "/sys/class/drm/card" + this.gpu_id + "/device/";

      // File gpu_busy_percent contains the percentage of time that the gpu is busy
      // expresed as an integer number from 0 to 100
      Gio.File.new_for_path(gpu_dir + "gpu_busy_percent").load_contents_async(null, (file, response) => {
        let [success, contents, tag] = file.load_contents_finish(response);
        if(success) {
          this.gpu_use = parseInt(ByteArray.toString(contents));
        }
        GLib.free(contents);
      });
    },

    get_amdgpu_gpu_mem: function() {
      // Sysfs directory with files related to the chosen gpu
      let gpu_dir = "/sys/class/drm/card" + this.gpu_id + "/device/";

      // File mem_info_vram_total contains the total amount of gpu VRAM in bytes
      Gio.File.new_for_path(gpu_dir + "mem_info_vram_total").load_contents_async(null, (file, response) => {
        let [success, contents, tag] = file.load_contents_finish(response);
        if(success) {
          let mem_tot = parseInt(ByteArray.toString(contents));
          if (this.data_prefix_gpumem == 1) {
            this.gpu_mem[0] = mem_tot / GB_TO_B;
          } else {
            this.gpu_mem[0] = mem_tot / 1024 / 1024 / GIB_TO_MIB;
          }
        }
        GLib.free(contents);
      });

      // File mem_info_vram_used contains the used amount of gpu VRAM in bytes
      Gio.File.new_for_path(gpu_dir + "mem_info_vram_used").load_contents_async(null, (file, response) => {
        let [success, contents, tag] = file.load_contents_finish(response);
        if(success) {
          let mem_usd = parseInt(ByteArray.toString(contents));
          if (this.data_prefix_gpumem == 1) {
            this.gpu_mem[1] = mem_usd / GB_TO_B;
          } else {
            this.gpu_mem[1] = mem_usd / 1024 / 1024 / GIB_TO_MIB;
          }
        }
        GLib.free(contents);
      });
    },

    get_amdgpu_gpu_temperature: function(temperature_file) {
        if(temperature_file == null || temperature_file == "") return;
        // File contains temperature, integer number in celsius * 1000
        Gio.file_new_for_path(temperature_file).load_contents_async(null, (file, response) => {
            try {
                let [success, contents, tag] = file.load_contents_finish(response);
                if (success) {
                    this.gpu_temperature = Math.round(parseInt(ByteArray.toString(contents)) / 1000);
                }
                GLib.free(contents);
            } catch(error) {
                global.log('GPU AMD temperature file read error: ' + error.toString());
            }
        });
    },

    get_battery_use: function() {
        // Sysfs directory for battery info
        let battery_dir = "/sys/class/power_supply/" + this.battery_name + "/";
        // D-Bus object path for the battery device in the UPower daemon
        let bus_path = "/org/freedesktop/UPower/devices/battery_" + this.battery_name;

        // File capacity contains the battery charge percentage, integer number from 0 to 100
        Gio.file_new_for_path(battery_dir + "capacity").load_contents_async(null, (file, response) => {
            try {
                let [success, contents, tag] = file.load_contents_finish(response);
                if (success) {
                    let percent = parseInt(ByteArray.toString(contents));
                    this.battery_percent = percent >= 100 ? 100 : percent;
                }
                GLib.free(contents);
            } catch(error) {
                global.log('Battery capacity file read error: ' + error.toString());
            }
        });

        // File status contains the battery charge status, string
        Gio.file_new_for_path(battery_dir + "status").load_contents_async(null, (file, response) => {
            try {
                let [success, contents, tag] = file.load_contents_finish(response);
                if (success) {
                    this.battery_status = ByteArray.toString(contents).trim();
                }
                GLib.free(contents);
            } catch(error) {
                global.log('Battery status file read error: ' + error.toString());
            }
        });

        try {
            let upower_proxy = new UPowerProxy(Gio.DBus.system, UPowerBusName, bus_path);
            let time_sec = (this.battery_status == "Charging") ? upower_proxy.TimeToFull : upower_proxy.TimeToEmpty;
            this.battery_time = this.formatTime(time_sec);
        } catch(error) {
            global.log('Battery time file open error: ' + error.toString());
        }
    },

    formatTime: function(timeSec) {
        let totalMinutes = Math.round(timeSec / 60);
        let minutes = String(Math.floor(totalMinutes % 60)).padStart(2, '0');
        let hours = String(Math.floor(totalMinutes / 60)).padStart(2, '0');
        let result = `${hours}:${minutes}`;
        return (result == "00:00") ? "--:--" : result;
	},

    get_cpu_temperature: function(temperature_file) {
        if(temperature_file == null || temperature_file == "") return;
        // File contains temperature, integer number in celsius * 1000
        Gio.file_new_for_path(temperature_file).load_contents_async(null, (file, response) => {
            try {
                let [success, contents, tag] = file.load_contents_finish(response);
                if (success) {
                    this.cpu_temperature = Math.round(parseInt(ByteArray.toString(contents)) / 1000);
                }
                GLib.free(contents);
            } catch(error) {
                global.log('CPU temperature file read error: ' + error.toString());
            }
        });
    },

    get_cpu_fan_file: function(callback) {
        // Prefer explicitly labelled CPU fans, then known laptop cooling drivers.
        // Do not guess from an unrelated, unlabelled hwmon fan.
        let argv = ['/bin/sh', '-c', "for fan_file in $({ grep -s -i -l -d skip -E 'cpu|processor' /sys/class/hwmon/hwmon*/fan*_label | sed 's/_label/_input/'; grep -s -l -d skip -E '^(dell_smm|thinkpad)$' /sys/class/hwmon/hwmon*/name | sed 's#/name#/fan1_input#'; }); do [ -r \"$fan_file\" ] && { printf '%s' \"$fan_file\"; break; }; done"];
        spawnAsyncWithOutput(argv, (success, output) => {
            callback(success && output ? output.trim() : "");
        });
    },

    schedule_cpu_fan_retry: function() {
        if (this.cpu_fan_retry_delay == null) this.cpu_fan_retry_delay = CPU_FAN_RETRY_MIN;
        this.cpu_fan_file = "";
        this.cpu_fan_rpm = NaN;
        this.cpu_fan_discovery_complete = true;
        this.cpu_fan_next_discovery_time = GLib.get_monotonic_time()
            + (this.cpu_fan_retry_delay * GLib.USEC_PER_SEC);
        this.cpu_fan_retry_delay = Math.min(
            this.cpu_fan_retry_delay * CPU_FAN_RETRY_MULTIPLIER,
            CPU_FAN_RETRY_MAX);
    },

    rediscover_cpu_fan: function() {
        // Clear a stale hwmon path first. Missing or failed sensors are retried
        // with bounded backoff instead of spawning another lookup every refresh.
        if (this.cpu_fan_discovery_in_progress) return;
        if (this.cpu_fan_retry_delay == null) this.cpu_fan_retry_delay = CPU_FAN_RETRY_MIN;
        this.cpu_fan_discovery_in_progress = true;
        this.cpu_fan_file = "";
        this.cpu_fan_rpm = NaN;
        this.cpu_fan_discovery_complete = false;
        this.get_cpu_fan_file((result) => {
            this.cpu_fan_discovery_in_progress = false;
            if (result == "") {
                this.schedule_cpu_fan_retry();
            } else {
                this.cpu_fan_file = result;
                this.cpu_fan_discovery_complete = true;
                this.cpu_fan_next_discovery_time = 0;
            }
        });
    },

    get_cpu_fan_speed: function(fan_file) {
        if(fan_file == null || fan_file == "") {
            if (this.cpu_fan_discovery_complete
                && GLib.get_monotonic_time() >= this.cpu_fan_next_discovery_time) {
                this.rediscover_cpu_fan();
            }
            return;
        }
        Gio.file_new_for_path(fan_file).load_contents_async(null, (file, response) => {
            try {
                let [success, contents, tag] = file.load_contents_finish(response);
                if (success) {
                    let rpm = parseInt(ByteArray.toString(contents).trim());
                    this.cpu_fan_rpm = isNaN(rpm) ? NaN : Math.max(0, rpm);
                    this.cpu_fan_retry_delay = CPU_FAN_RETRY_MIN;
                    this.cpu_fan_next_discovery_time = 0;
                } else {
                    this.schedule_cpu_fan_retry();
                }
                GLib.free(contents);
            } catch(error) {
                this.schedule_cpu_fan_retry();
                global.log('CPU fan speed file read error: ' + error.toString());
            }
        });
    },

    get_temperature_file_by_label: function(path, label, callback) {
        // search for temperture file: 'path'/*/temp*_input associated to file path/*/temp*_label with content 'label'
        let argv = ['/bin/sh', '-c', "grep -s -l -d skip '" + label + "' " + path + "*/temp*_label | sed 's/_label/_input/' | head -n 1"];
        spawnAsyncWithOutput(argv, (success, output) => {
            if (success && output && output.trim() !== "") {
                callback(output.trim());
            } else {
                global.log('Temperature file search error for label: ' + label);
                callback("");
            }
        });
    },
};