/* Put everything inside the global mpl namespace */
window.mpl = {};

mpl.get_websocket_type = function() {
    if (typeof(WebSocket) !== 'undefined') {
        return WebSocket;
    } else if (typeof(MozWebSocket) !== 'undefined') {
        return MozWebSocket;
    } else {
        alert('Your browser does not have WebSocket support.' +
              'Please try Chrome, Safari or Firefox ≥ 6. ' +
              'Firefox 4 and 5 are also supported but you ' +
              'have to enable WebSockets in about:config.');
    };
}

mpl.figure = function(figure_id, websocket, ondownload, parent_element) {
    this.id = figure_id;

    this.ws = websocket;

    this.supports_binary = (this.ws.binaryType != undefined);

    if (!this.supports_binary) {
        var warnings = document.getElementById("mpl-warnings");
        if (warnings) {
            warnings.style.display = 'block';
            warnings.textContent = (
                "This browser does not support binary websocket messages. " +
                    "Performance may be slow.");
        }
    }

    this.imageObj = new Image();

    this.context = undefined;
    this.message = undefined;
    this.canvas = undefined;
    this.rubberband_canvas = undefined;
    this.rubberband_context = undefined;
    this.format_dropdown = undefined;

    this.image_mode = 'full';

    this.root = $('<div/>');
    this._root_extra_style(this.root)
    this.root.attr('style', 'display: inline-block');

    $(parent_element).append(this.root);

    this._init_header(this);
    this._init_canvas(this);
    this._init_toolbar(this);

    var fig = this;

    this.waiting = false;

    this.ws.onopen =  function () {
            fig.send_message("supports_binary", {value: fig.supports_binary});
            fig.send_message("send_image_mode", {});
            fig.send_message("refresh", {});
        }

    this.imageObj.onload = function() {
            if (fig.image_mode == 'full') {
                // Full images could contain transparency (where diff images
                // almost always do), so we need to clear the canvas so that
                // there is no ghosting.
                fig.context.clearRect(0, 0, fig.canvas.width, fig.canvas.height);
            }
            fig.context.drawImage(fig.imageObj, 0, 0);
        };

    this.imageObj.onunload = function() {
        this.ws.close();
    }

    this.ws.onmessage = this._make_on_message_function(this);

    this.ondownload = ondownload;
}

mpl.figure.prototype._init_header = function() {
    var titlebar = $(
        '<div class="ui-dialog-titlebar ui-widget-header ui-corner-all ' +
        'ui-helper-clearfix"/>');
    var titletext = $(
        '<div class="ui-dialog-title" style="width: 100%; ' +
        'text-align: center; padding: 3px;"/>');
    titlebar.append(titletext)
    this.root.append(titlebar);
    this.header = titletext[0];
}



mpl.figure.prototype._canvas_extra_style = function(canvas_div) {

}


mpl.figure.prototype._root_extra_style = function(canvas_div) {

}

mpl.figure.prototype._init_canvas = function() {
    var fig = this;

    var canvas_div = $('<div/>');

    canvas_div.attr('style', 'position: relative; clear: both; outline: 0');

    function canvas_keyboard_event(event) {
        return fig.key_event(event, event['data']);
    }

    canvas_div.keydown('key_press', canvas_keyboard_event);
    canvas_div.keyup('key_release', canvas_keyboard_event);
    this.canvas_div = canvas_div
    this._canvas_extra_style(canvas_div)
    this.root.append(canvas_div);

    var canvas = $('<canvas/>');
    canvas.addClass('mpl-canvas');
    canvas.attr('style', "left: 0; top: 0; z-index: 0; outline: 0")

    this.canvas = canvas[0];
    this.context = canvas[0].getContext("2d");

    var rubberband = $('<canvas/>');
    rubberband.attr('style', "position: absolute; left: 0; top: 0; z-index: 1;")

    var pass_mouse_events = true;

    canvas_div.resizable({
        start: function(event, ui) {
            pass_mouse_events = false;
        },
        resize: function(event, ui) {
            fig.request_resize(ui.size.width, ui.size.height);
        },
        stop: function(event, ui) {
            pass_mouse_events = true;
            fig.request_resize(ui.size.width, ui.size.height);
        },
    });

    function mouse_event_fn(event) {
        if (pass_mouse_events)
            return fig.mouse_event(event, event['data']);
    }

    rubberband.mousedown('button_press', mouse_event_fn);
    rubberband.mouseup('button_release', mouse_event_fn);
    // Throttle sequential mouse events to 1 every 20ms.
    rubberband.mousemove('motion_notify', mouse_event_fn);

    rubberband.mouseenter('figure_enter', mouse_event_fn);
    rubberband.mouseleave('figure_leave', mouse_event_fn);

    canvas_div.on("wheel", function (event) {
        event = event.originalEvent;
        event['data'] = 'scroll'
        if (event.deltaY < 0) {
            event.step = 1;
        } else {
            event.step = -1;
        }
        mouse_event_fn(event);
    });

    canvas_div.append(canvas);
    canvas_div.append(rubberband);

    this.rubberband = rubberband;
    this.rubberband_canvas = rubberband[0];
    this.rubberband_context = rubberband[0].getContext("2d");
    this.rubberband_context.strokeStyle = "#000000";

    this._resize_canvas = function(width, height) {
        // Keep the size of the canvas, canvas container, and rubber band
        // canvas in synch.
        canvas_div.css('width', width)
        canvas_div.css('height', height)

        canvas.attr('width', width);
        canvas.attr('height', height);

        rubberband.attr('width', width);
        rubberband.attr('height', height);
    }

    // Set the figure to an initial 600x600px, this will subsequently be updated
    // upon first draw.
    this._resize_canvas(600, 600);

    // Disable right mouse context menu.
    $(this.rubberband_canvas).bind("contextmenu",function(e){
        return false;
    });

    function set_focus () {
        canvas.focus();
        canvas_div.focus();
    }

    window.setTimeout(set_focus, 100);
}

mpl.figure.prototype._init_toolbar = function() {
    var fig = this;

    var nav_element = $('<div/>')
    nav_element.attr('style', 'width: 100%');
    this.root.append(nav_element);

    // Define a callback function for later on.
    function toolbar_event(event) {
        return fig.toolbar_button_onclick(event['data']);
    }
    function toolbar_mouse_event(event) {
        return fig.toolbar_button_onmouseover(event['data']);
    }

    for(var toolbar_ind in mpl.toolbar_items) {
        var name = mpl.toolbar_items[toolbar_ind][0];
        var tooltip = mpl.toolbar_items[toolbar_ind][1];
        var image = mpl.toolbar_items[toolbar_ind][2];
        var method_name = mpl.toolbar_items[toolbar_ind][3];

        if (!name) {
            // put a spacer in here.
            continue;
        }
        var button = $('<button/>');
        button.addClass('ui-button ui-widget ui-state-default ui-corner-all ' +
                        'ui-button-icon-only');
        button.attr('role', 'button');
        button.attr('aria-disabled', 'false');
        button.click(method_name, toolbar_event);
        button.mouseover(tooltip, toolbar_mouse_event);

        var icon_img = $('<span/>');
        icon_img.addClass('ui-button-icon-primary ui-icon');
        icon_img.addClass(image);
        icon_img.addClass('ui-corner-all');

        var tooltip_span = $('<span/>');
        tooltip_span.addClass('ui-button-text');
        tooltip_span.html(tooltip);

        button.append(icon_img);
        button.append(tooltip_span);

        nav_element.append(button);
    }

    var fmt_picker_span = $('<span/>');

    var fmt_picker = $('<select/>');
    fmt_picker.addClass('mpl-toolbar-option ui-widget ui-widget-content');
    fmt_picker_span.append(fmt_picker);
    nav_element.append(fmt_picker_span);
    this.format_dropdown = fmt_picker[0];

    for (var ind in mpl.extensions) {
        var fmt = mpl.extensions[ind];
        var option = $(
            '<option/>', {selected: fmt === mpl.default_extension}).html(fmt);
        fmt_picker.append(option)
    }

    // Add hover states to the ui-buttons
    $( ".ui-button" ).hover(
        function() { $(this).addClass("ui-state-hover");},
        function() { $(this).removeClass("ui-state-hover");}
    );

    var status_bar = $('<span class="mpl-message"/>');
    nav_element.append(status_bar);
    this.message = status_bar[0];
}

mpl.figure.prototype.request_resize = function(x_pixels, y_pixels) {
    // Request matplotlib to resize the figure. Matplotlib will then trigger a resize in the client,
    // which will in turn request a refresh of the image.
    this.send_message('resize', {'width': x_pixels, 'height': y_pixels});
}

mpl.figure.prototype.send_message = function(type, properties) {
    properties['type'] = type;
    properties['figure_id'] = this.id;
    this.ws.send(JSON.stringify(properties));
}

mpl.figure.prototype.send_draw_message = function() {
    if (!this.waiting) {
        this.waiting = true;
        this.ws.send(JSON.stringify({type: "draw", figure_id: this.id}));
    }
}


mpl.figure.prototype.handle_save = function(fig, msg) {
    var format_dropdown = fig.format_dropdown;
    var format = format_dropdown.options[format_dropdown.selectedIndex].value;
    fig.ondownload(fig, format);
}


mpl.figure.prototype.handle_resize = function(fig, msg) {
    var size = msg['size'];
    if (size[0] != fig.canvas.width || size[1] != fig.canvas.height) {
        fig._resize_canvas(size[0], size[1]);
        fig.send_message("refresh", {});
    };
}

mpl.figure.prototype.handle_rubberband = function(fig, msg) {
    var x0 = msg['x0'];
    var y0 = fig.canvas.height - msg['y0'];
    var x1 = msg['x1'];
    var y1 = fig.canvas.height - msg['y1'];
    x0 = Math.floor(x0) + 0.5;
    y0 = Math.floor(y0) + 0.5;
    x1 = Math.floor(x1) + 0.5;
    y1 = Math.floor(y1) + 0.5;
    var min_x = Math.min(x0, x1);
    var min_y = Math.min(y0, y1);
    var width = Math.abs(x1 - x0);
    var height = Math.abs(y1 - y0);

    fig.rubberband_context.clearRect(
        0, 0, fig.canvas.width, fig.canvas.height);

    fig.rubberband_context.strokeRect(min_x, min_y, width, height);
}

mpl.figure.prototype.handle_figure_label = function(fig, msg) {
    // Updates the figure title.
    fig.header.textContent = msg['label'];
}

mpl.figure.prototype.handle_cursor = function(fig, msg) {
    var cursor = msg['cursor'];
    switch(cursor)
    {
    case 0:
        cursor = 'pointer';
        break;
    case 1:
        cursor = 'default';
        break;
    case 2:
        cursor = 'crosshair';
        break;
    case 3:
        cursor = 'move';
        break;
    }
    fig.rubberband_canvas.style.cursor = cursor;
}

mpl.figure.prototype.handle_message = function(fig, msg) {
    fig.message.textContent = msg['message'];
}

mpl.figure.prototype.handle_draw = function(fig, msg) {
    // Request the server to send over a new figure.
    fig.send_draw_message();
}

mpl.figure.prototype.handle_image_mode = function(fig, msg) {
    fig.image_mode = msg['mode'];
}

mpl.figure.prototype.updated_canvas_event = function() {
    // Called whenever the canvas gets updated.
    this.send_message("ack", {});
}

// A function to construct a web socket function for onmessage handling.
// Called in the figure constructor.
mpl.figure.prototype._make_on_message_function = function(fig) {
    return function socket_on_message(evt) {
        if (evt.data instanceof Blob) {
            /* FIXME: We get "Resource interpreted as Image but
             * transferred with MIME type text/plain:" errors on
             * Chrome.  But how to set the MIME type?  It doesn't seem
             * to be part of the websocket stream */
            evt.data.type = "image/png";

            /* Free the memory for the previous frames */
            if (fig.imageObj.src) {
                (window.URL || window.webkitURL).revokeObjectURL(
                    fig.imageObj.src);
            }

            fig.imageObj.src = (window.URL || window.webkitURL).createObjectURL(
                evt.data);
            fig.updated_canvas_event();
            fig.waiting = false;
            return;
        }
        else if (typeof evt.data === 'string' && evt.data.slice(0, 21) == "data:image/png;base64") {
            fig.imageObj.src = evt.data;
            fig.updated_canvas_event();
            fig.waiting = false;
            return;
        }

        var msg = JSON.parse(evt.data);
        var msg_type = msg['type'];

        // Call the  "handle_{type}" callback, which takes
        // the figure and JSON message as its only arguments.
        try {
            var callback = fig["handle_" + msg_type];
        } catch (e) {
            console.log("No handler for the '" + msg_type + "' message type: ", msg);
            return;
        }

        if (callback) {
            try {
                // console.log("Handling '" + msg_type + "' message: ", msg);
                callback(fig, msg);
            } catch (e) {
                console.log("Exception inside the 'handler_" + msg_type + "' callback:", e, e.stack, msg);
            }
        }
    };
}

// from http://stackoverflow.com/questions/1114465/getting-mouse-location-in-canvas
mpl.findpos = function(e) {
    //this section is from http://www.quirksmode.org/js/events_properties.html
    var targ;
    if (!e)
        e = window.event;
    if (e.target)
        targ = e.target;
    else if (e.srcElement)
        targ = e.srcElement;
    if (targ.nodeType == 3) // defeat Safari bug
        targ = targ.parentNode;

    // jQuery normalizes the pageX and pageY
    // pageX,Y are the mouse positions relative to the document
    // offset() returns the position of the element relative to the document
    var x = e.pageX - $(targ).offset().left;
    var y = e.pageY - $(targ).offset().top;

    return {"x": x, "y": y};
};

/*
 * return a copy of an object with only non-object keys
 * we need this to avoid circular references
 * http://stackoverflow.com/a/24161582/3208463
 */
function simpleKeys (original) {
  return Object.keys(original).reduce(function (obj, key) {
    if (typeof original[key] !== 'object')
        obj[key] = original[key]
    return obj;
  }, {});
}

mpl.figure.prototype.mouse_event = function(event, name) {
    var canvas_pos = mpl.findpos(event)

    if (name === 'button_press')
    {
        this.canvas.focus();
        this.canvas_div.focus();
    }

    var x = canvas_pos.x;
    var y = canvas_pos.y;

    this.send_message(name, {x: x, y: y, button: event.button,
                             step: event.step,
                             guiEvent: simpleKeys(event)});

    /* This prevents the web browser from automatically changing to
     * the text insertion cursor when the button is pressed.  We want
     * to control all of the cursor setting manually through the
     * 'cursor' event from matplotlib */
    event.preventDefault();
    return false;
}

mpl.figure.prototype._key_event_extra = function(event, name) {
    // Handle any extra behaviour associated with a key event
}

mpl.figure.prototype.key_event = function(event, name) {

    // Prevent repeat events
    if (name == 'key_press')
    {
        if (event.which === this._key)
            return;
        else
            this._key = event.which;
    }
    if (name == 'key_release')
        this._key = null;

    var value = '';
    if (event.ctrlKey && event.which != 17)
        value += "ctrl+";
    if (event.altKey && event.which != 18)
        value += "alt+";
    if (event.shiftKey && event.which != 16)
        value += "shift+";

    value += 'k';
    value += event.which.toString();

    this._key_event_extra(event, name);

    this.send_message(name, {key: value,
                             guiEvent: simpleKeys(event)});
    return false;
}

mpl.figure.prototype.toolbar_button_onclick = function(name) {
    if (name == 'download') {
        this.handle_save(this, null);
    } else {
        this.send_message("toolbar_button", {name: name});
    }
};

mpl.figure.prototype.toolbar_button_onmouseover = function(tooltip) {
    this.message.textContent = tooltip;
};
