/* -*- mode: js2; js2-basic-offset: 4; indent-tabs-mode: nil -*- */

const Clutter = imports.gi.Clutter;
const GTop = imports.gi.GTop;
const Lang = imports.lang;
const Mainloop = imports.mainloop;
const St = imports.gi.St;
const Shell = imports.gi.Shell;

const Main = imports.ui.main;
const Tweener = imports.ui.tweener;

const Gettext = imports.gettext.domain('gnome-shell-extensions');
const _ = Gettext.gettext;

const ExtensionUtils = imports.misc.extensionUtils;
const Me = ExtensionUtils.getCurrentExtension();
const Convenience = Me.imports.convenience;

const INDICATOR_UPDATE_INTERVAL = 500;
const INDICATOR_NUM_GRID_LINES = 3;

const ITEM_LABEL_SHOW_TIME = 0.15;
const ITEM_LABEL_HIDE_TIME = 0.1;
const ITEM_HOVER_TIMEOUT = 300;

const Indicator = new Lang.Class({
    Name: 'SystemMonitor.Indicator',

    _init: function() {
        this._initValues();
        this.drawing_area = new St.DrawingArea({ reactive: true });
        this.drawing_area.connect('repaint', Lang.bind(this, this._draw));
        this.drawing_area.connect('button-press-event', function() {
            let app = Shell.AppSystem.get_default().lookup_app('gnome-system-monitor.desktop');
            app.open_new_window(-1);
        });

        this.actor = new St.Bin({ style_class: "extension-systemMonitor-indicator-area",
                                  reactive: true, track_hover: true,
				  x_fill: true, y_fill: true });
        this.actor.add_actor(this.drawing_area);

        this._timeout = Mainloop.timeout_add(INDICATOR_UPDATE_INTERVAL, Lang.bind(this, function () {
            this._updateValues();
            this.drawing_area.queue_repaint();
            return true;
        }));
    },

    showLabel: function() {
        if (this.label == null)
            return;

        this.label.opacity = 0;
        this.label.show();

        let [stageX, stageY] = this.actor.get_transformed_position();

	let itemWidth = this.actor.allocation.x2 - this.actor.allocation.x1;
        let itemHeight = this.actor.allocation.y2 - this.actor.allocation.y1;

	let labelWidth = this.label.width;
        let labelHeight = this.label.height;
        let xOffset = Math.floor((itemWidth - labelWidth) / 2)

        let x = stageX + xOffset;

        let node = this.label.get_theme_node();
        let yOffset = node.get_length('-y-offset');

        let y = stageY - this.label.get_height() - yOffset;

        this.label.set_position(x, y);
        Tweener.addTween(this.label,
                         { opacity: 255,
                           time: ITEM_LABEL_SHOW_TIME,
                           transition: 'easeOutQuad',
                         });
    },

    setLabelText: function(text) {
        if (this.label == null)
            this.label = new St.Label({ style_class: 'extension-systemMonitor-indicator-label'});

        this.label.set_text(text);
        Main.layoutManager.addChrome(this.label);
        this.label.hide();
    },

    hideLabel: function () {
        Tweener.addTween(this.label,
                         { opacity: 0,
                           time: ITEM_LABEL_HIDE_TIME,
                           transition: 'easeOutQuad',
                           onComplete: Lang.bind(this, function() {
                               this.label.hide();
                           })
                         });
    },

    destroy: function() {
        Mainloop.source_remove(this._timeout);

        this.actor.destroy();
	if (this.label)
	    this.label.destroy();
    },

    _initValues: function() {
    },

    _updateValues: function() {
    },

    _draw: function(area) {
        let [width, height] = area.get_surface_size();
        let themeNode = this.actor.get_theme_node();
        let cr = area.get_context();

        //draw the background grid
        let color = themeNode.get_color(this.gridColor);
        let gridOffset = Math.floor(height / (INDICATOR_NUM_GRID_LINES + 1));
        for (let i = 1; i <= INDICATOR_NUM_GRID_LINES; ++i) {
                cr.moveTo(0, i * gridOffset + .5);
                cr.lineTo(width, i * gridOffset + .5);
        }
        Clutter.cairo_set_source_color(cr, color);
        cr.setLineWidth(1);
        cr.setDash([4,1], 0);
        cr.stroke();
        
        //draw the foreground

        function makePath(values, reverse, nudge) {
            if (nudge == null) {
                nudge = 0;
            }
            //if we are going in reverse, we are completing the bottom of a chart, so use lineTo
            if (reverse) {
                cr.lineTo(values.length - 1, (1 - values[values.length - 1]) * height + nudge);
                for (let k = values.length - 2; k >= 0; --k) {
                    cr.lineTo(k, (1 - values[k]) * height + nudge);
                }
            } else {
                cr.moveTo(0, (1 - values[0]) * height + nudge);
                for (let k = 1; k < values.length; ++k) {
                    cr.lineTo(k, (1 - values[k]) * height + nudge);
                }

            }
        }
        
        let renderStats = this.renderStats;

        // Make sure we don't have more sample points than pixels
        renderStats.map(Lang.bind(this, function(k){
            let stat = this.stats[k];
            if (stat.values.length > width) {
                stat.values = stat.values.slice(stat.values.length - width, stat.values.length);
            }
        }));

        for (let i = 0; i < renderStats.length; ++i) {
            let stat = this.stats[renderStats[i]];
            // We outline at full opacity and fill with 40% opacity
            let outlineColor = themeNode.get_color(stat.color);
            let color = new Clutter.Color(outlineColor);
            color.alpha = color.alpha * .4;
           
            // Render the background between us and the next level
            makePath(stat.values, false);
            // If there is a process below us, render the cpu between us and it, otherwise, 
            // render to the bottom of the chart
            if (i == renderStats.length - 1) {
                cr.lineTo(stat.values.length - 1, height);
                cr.lineTo(0, height);
                cr.closePath();
            } else {
                let nextStat = this.stats[renderStats[i+1]];
                makePath(nextStat.values, true);
            }
            cr.closePath()
            Clutter.cairo_set_source_color(cr, color);
            cr.fill();
            
            // Render the outline of this level
            makePath(stat.values, false, .5);
            Clutter.cairo_set_source_color(cr, outlineColor);
            cr.setLineWidth(1.0);
            cr.setDash([], 0);
            cr.stroke();
        }
    }
});

const CpuIndicator = new Lang.Class({
    Name: 'SystemMonitor.CpuIndicator',
    Extends: Indicator,

    _init: function() {
        this.parent();

        this.gridColor = '-grid-color';
        this.renderStats = [ 'cpu-user', 'cpu-sys', 'cpu-iowait' ];
        
        // Make sure renderStats is sorted as necessary for rendering
        let renderStatOrder = {'cpu-total': 0, 'cpu-user': 1, 'cpu-sys': 2, 'cpu-iowait': 3};
        this.renderStats = this.renderStats.sort(function(a,b) {
            return renderStatOrder[a] - renderStatOrder[b];
        });

	this.setLabelText(_("CPU"));
    },

    _initValues: function() {
        this._prev = new GTop.glibtop_cpu;
        GTop.glibtop_get_cpu(this._prev);

        this.stats = { 
                       'cpu-user': {color: '-cpu-user-color', values: []},
                       'cpu-sys': {color: '-cpu-sys-color', values: []},
                       'cpu-iowait': {color: '-cpu-iowait-color', values: []},
                       'cpu-total': {color: '-cpu-total-color', values: []} 
                     };
    },

    _updateValues: function() {
        let cpu = new GTop.glibtop_cpu;
        let t = 0.0;
        GTop.glibtop_get_cpu(cpu);
        let total = cpu.total - this._prev.total;
        let user = cpu.user - this._prev.user;
        let sys = cpu.sys - this._prev.sys;
        let iowait = cpu.iowait - this._prev.iowait;
        let idle = cpu.idle - this._prev.idle;

        t += iowait / total;
        this.stats['cpu-iowait'].values.push(t);
        t += sys / total;
        this.stats['cpu-sys'].values.push(t);
        t += user / total;
        this.stats['cpu-user'].values.push(t);
        this.stats['cpu-total'].values.push(1 - idle / total);
        
        this._prev = cpu;
    }
});

const MemoryIndicator = new Lang.Class({
    Name: 'SystemMonitor.MemoryIndicator',
    Extends: Indicator,
    
    _init: function() {
        this.parent();

        this.gridColor = '-grid-color';
        this.renderStats = [ 'mem-user', 'mem-other', 'mem-cached' ];
        
        // Make sure renderStats is sorted as necessary for rendering
        let renderStatOrder = { 'mem-cached': 0, 'mem-other': 1, 'mem-user': 2 };
        this.renderStats = this.renderStats.sort(function(a,b) {
            return renderStatOrder[a] - renderStatOrder[b];
        });

	this.setLabelText(_("Memory"));
    },

    _initValues: function() {
        this.mem = new GTop.glibtop_mem;
        this.stats = {
                        'mem-user': { color: "-mem-user-color", values: [] },
                        'mem-other': { color: "-mem-other-color", values: [] },
                        'mem-cached': { color: "-mem-cached-color", values: [] }
                     };
    },

    _updateValues: function() {
        GTop.glibtop_get_mem(this.mem);

        let t = this.mem.user / this.mem.total;
        this.stats['mem-user'].values.push(t);
        t += (this.mem.used - this.mem.user - this.mem.cached) / this.mem.total;
        this.stats['mem-other'].values.push(t);
        t += this.mem.cached / this.mem.total;
        this.stats['mem-cached'].values.push(t);
    }
});

const INDICATORS = [CpuIndicator, MemoryIndicator];

const Extension = new Lang.Class({
    Name: 'SystemMonitor.Extension',

    _init: function() {
	Convenience.initTranslations();

	this._showLabelTimeoutId = 0;
	this._resetHoverTimeoutId = 0;
	this._labelShowing = false;
    },

    enable: function() {
	this._box = new St.BoxLayout({ style_class: 'extension-systemMonitor-container',
				       x_align: Clutter.ActorAlign.START,
				       x_expand: true });
	this._indicators = [ ];

	for (let i = 0; i < INDICATORS.length; i++) {
	    let indicator = new (INDICATORS[i])();

            indicator.actor.connect('notify::hover', Lang.bind(this, function() {
		this._onHover(indicator);
	    }));
	    this._box.add_actor(indicator.actor);
	    this._indicators.push(indicator);
	}

	Main.messageTray.actor.add_actor(this._box);
    },

    disable: function() {
	this._indicators.forEach(function(i) { i.destroy(); });
	this._box.destroy();
    },

    _onHover: function (item) {
        if (item.actor.get_hover()) {
            if (this._showLabelTimeoutId == 0) {
                let timeout = this._labelShowing ? 0 : ITEM_HOVER_TIMEOUT;
                this._showLabelTimeoutId = Mainloop.timeout_add(timeout,
                    Lang.bind(this, function() {
                        this._labelShowing = true;
                        item.showLabel();
                        return false;
                    }));
                if (this._resetHoverTimeoutId > 0) {
                    Mainloop.source_remove(this._resetHoverTimeoutId);
                    this._resetHoverTimeoutId = 0;
                }
            }
        } else {
            if (this._showLabelTimeoutId > 0)
                Mainloop.source_remove(this._showLabelTimeoutId);
            this._showLabelTimeoutId = 0;
            item.hideLabel();
            if (this._labelShowing) {
                this._resetHoverTimeoutId = Mainloop.timeout_add(ITEM_HOVER_TIMEOUT,
                    Lang.bind(this, function() {
                        this._labelShowing = false;
                        return false;
                    }));
            }
        }
    },
});

function init() {
    return new Extension();
}