// Copyright (c) 2015 Walter Bender
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the The GNU Affero General Public
// License as published by the Free Software Foundation; either
// version 3 of the License, or (at your option) any later version.
//
// You should have received a copy of the GNU Affero General Public
// License along with this library; if not, write to the Free Software
// Foundation, 51 Franklin Street, Suite 500 Boston, MA 02110-1335 USA
//

// FIXME: Use busy cursor

// A viewer for Turtle Blocks plugins
function PluginsViewer(canvas, stage, refreshCanvas, close, load) {
    this.canvas = canvas;
    this.stage = stage;
    this.refreshCanvas = refreshCanvas;
    this.closeViewer = close;
    this.loadPlugin = load;
    this.dict = {};
    this.pluginFiles = [];
    this.container = null;
    this.prev = null;
    this.next = null;
    this.page = 0; // 4x4 image matrix per page
    this.server = true;

    this.setServer = function(server) {
        this.server = server;
    }

    this.hide = function() {
        if (this.container !== null) {
            this.container.visible = false;
            this.refreshCanvas();
        }
    }

    this.show = function(scale) {
        this.scale = scale;
        this.page = 0;
        if (this.server) {
            try {
                var rawData = httpGet();
                var obj = JSON.parse(rawData);
                // console.log('json parse: ' + obj);
                // Look for svg
                for (var file in obj) {
                    if (fileExt(obj[file]) === 'svg') {
                        var name = fileBasename(obj[file]);
                        if (this.pluginFiles.indexOf(name) === -1) {
                            this.pluginFiles.push(name);
                        }
                    }
                }
                // and corresponding .json files
                for (var file in this.pluginFiles) {
                    var tbfile = this.pluginFiles[file] + '.json';
                    if (!tbfile in obj) {
                        this.pluginFiles.remove(this.pluginFiles[file]);
                    }
                }
            } catch (e) {
                console.log(e);
                return false;
            }
        } else {
            // FIXME: grab files from a local server?
            this.pluginFiles = SAMPLEPLUGINS;
        }
        console.log('found these projects: ' + this.pluginFiles.sort());

        if (this.container === null) {
            this.container = new createjs.Container();
            this.stage.addChild(this.container);
            this.container.x = Math.floor(((this.canvas.width / scale) - 650) / 2);
            this.container.y = 27;

            function processBackground(viewer, name, bitmap, extras) {
                viewer.container.addChild(bitmap);

                function processPrev(viewer, name, bitmap, extras) {
                    viewer.prev = bitmap;
                    viewer.container.addChild(viewer.prev);
                    viewer.prev.x = 270;
                    viewer.prev.y = 535;

                    function processNext(viewer, name, bitmap, scale) {
                        viewer.next = bitmap;
                        viewer.container.addChild(viewer.next);
                        viewer.next.x = 325;
                        viewer.next.y = 535;
                        viewer.container.visible = true;
                        viewer.refreshCanvas();
                        viewer.completeInit();
                        loadThumbnailContainerHandler(viewer);
                        return true;
                    }
                    makeViewerBitmap(viewer, NEXTBUTTON, 'viewer', processNext, null);
                }
                makeViewerBitmap(viewer, PREVBUTTON, 'viewer', processPrev, null);
            }
            makeViewerBitmap(this, BACKGROUND, 'viewer', processBackground, null);
        } else {
            this.container.visible = true;
            this.refreshCanvas();
            this.completeInit();
            return true;
        }
    }

    this.downloadImage = function(p, prepareNextImage) {
        var header = 'data:image/svg+xml;utf8,';
        var name = this.pluginFiles[p] + '.svg';
        // console.log('getting ' + name + ' from samples');
        if (this.server) {
            var data = header + httpGet(name);
        } else {
            var data = header + SAMPLESSVG[name];
        }
        var image = new Image();
        var viewer = this;

        image.onload = function() {
            bitmap = new createjs.Bitmap(data);
            bitmap.scaleX = 0.5;
            bitmap.scaleY = 0.5;
            viewer.container.addChild(bitmap);
            lastChild = last(viewer.container.children);
            viewer.container.swapChildren(bitmap, lastChild);

            viewer.dict[viewer.pluginFiles[p]] = bitmap;
            x = 5 + (p % 4) * 160;
            y = 55 + Math.floor((p % 16) / 4) * 120;
            viewer.dict[viewer.pluginFiles[p]].x = x;
            viewer.dict[viewer.pluginFiles[p]].y = y;
            viewer.dict[viewer.pluginFiles[p]].visible = true;
            viewer.refreshCanvas();
            if (prepareNextImage !== null) {
                prepareNextImage(viewer, p + 1);
            }
        }
        image.src = data;
    }

    this.completeInit = function() {
        var p = 0;
        this.prepareNextImage(this, p);
    }

    this.prepareNextImage = function(viewer, p) {
        // TODO: this.pluginFiles.sort()
        // Only download the images on the first page.
        if (p < viewer.pluginFiles.length && p < (viewer.page * 16 + 16)) {
            if (viewer.pluginFiles[p] in viewer.dict) {
                x = 5 + (p % 4) * 160;
                y = 55 + Math.floor((p % 16) / 4) * 120;
                viewer.dict[viewer.pluginFiles[p]].x = x;
                viewer.dict[viewer.pluginFiles[p]].y = y;
                viewer.dict[viewer.pluginFiles[p]].visible = true;
                viewer.prepareNextImage(viewer, p + 1)
            } else {
                viewer.downloadImage(p, viewer.prepareNextImage);
            }
        } else {
            if (viewer.page === 0) {
                viewer.prev.visible = false;
            }
            if ((viewer.page + 1) * 16 < viewer.pluginFiles.length) {
                viewer.next.visible = true;
            }
            viewer.refreshCanvas();
        }
    }
}


function hideCurrentPage(viewer) {
    var min = viewer.page * 16;
    var max = Math.min(viewer.pluginFiles.length, (viewer.page + 1) * 16);
    // Hide the current page.
    for (var p = min; p < max; p++) {
        viewer.dict[viewer.pluginFiles[p]].visible = false;
    }
    // Go back to previous page.
    viewer.page -= 1;
    if (viewer.page === 0) {
        viewer.prev.visible = false;
    }
    if ((viewer.page + 1) * 16 < viewer.pluginFiles.length) {
        viewer.next.visible = true;
    }
    // Show the current page.
    var min = viewer.page * 16;
    var max = Math.min(viewer.pluginFiles.length, (viewer.page + 1) * 16);
    for (var p = min; p < max; p++) {
        viewer.dict[viewer.pluginFiles[p]].visible = true;
    }
    viewer.refreshCanvas();
}


function showNextPage(viewer) {
    var min = viewer.page * 16;
    var max = Math.min(viewer.pluginFiles.length, (viewer.page + 1) * 16);
    // Hide the current page.
    for (var p = min; p < max; p++) {
        viewer.dict[viewer.pluginFiles[p]].visible = false;
    }
    // Advance to next page.
    viewer.page += 1;
    viewer.prev.visible = true;
    if ((viewer.page + 1) * 16 + 1 > viewer.pluginFiles.length) {
        viewer.next.visible = false;
    }
    viewer.prepareNextImage(viewer, max);
    viewer.refreshCanvas();
}


function viewerClicked(viewer, event) {
    var x = (event.stageX / viewer.scale) - viewer.container.x;
    var y = (event.stageY / viewer.scale) - viewer.container.y;
    if (x > 600 && y < 55) {
        viewer.hide();
        viewer.closeViewer();
    } else if (y > 535) {
        if (viewer.prev.visible && x < 325) {
            hideCurrentPage(viewer);
        } else if (viewer.next.visible && x > 325) {
            showNextPage(viewer)
        }
    } else {
        // Select a plugin.
        var col = Math.floor((x - 5) / 160);
        var row = Math.floor((y - 55) / 120);
        var p = row * 4 + col + 16 * viewer.page;
        if (p < viewer.pluginFiles.length) {
            viewer.hide();
            viewer.closeViewer();
            viewer.loadPlugin(viewer.pluginFiles[p] + '.json');
        }
    }
}


function loadThumbnailContainerHandler(viewer) {
    var hitArea = new createjs.Shape();
    var w = 650;
    var h = 590;
    var startX, startY, endX, endY;
    hitArea.graphics.beginFill('#FFF').drawRect(0, 0, w, h);
    hitArea.x = 0;
    hitArea.y = 0;
    viewer.container.hitArea = hitArea;

    var locked = false;

    viewer.container.on('click', function(event) {
        // We need a lock to "debouce" the click.
        if (locked) {
            console.log('debouncing click');
            return;
        }
        locked = true;
        setTimeout(function() {
            locked = false;
        }, 500);
        viewerClicked(viewer, event)
    });

    viewer.container.on('mousedown', function(event) {
        startX = event.stageX;
        startY = event.stageY;
        locked = true;
    });

    viewer.container.on('pressup', function(event) {
        endX = event.stageX;
        endY = event.stageY;
        if (endY > startY + 30 || endX > startX + 30) {
            // Down or right
            if (viewer.next.visible) {
                showNextPage(viewer);
            }
        }
        else if(endY < startY - 30 || endX < startX - 30) {
            // Up or left
            if (viewer.prev.visible) {
                hideCurrentPage(viewer);
            }
        }
        else {
            locked = false;
            viewerClicked(viewer, event)
        }
    });
}


function makeViewerBitmap(viewer, data, name, callback, extras) {
    // Async creation of bitmap from SVG data
    // Works with Chrome, Safari, Firefox (untested on IE)
    var img = new Image();
    img.onload = function() {
        bitmap = new createjs.Bitmap(img);
        callback(viewer, name, bitmap, extras);
    }
    img.src = 'data:image/svg+xml;base64,' + window.btoa(
        unescape(encodeURIComponent(data)));
}