/*
Copyright 2015, 2016 OpenMarket Ltd

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

'use strict';

var q = require('q');
var extend = require('./extend');
var dis = require('./dispatcher');
var MatrixClientPeg = require('./MatrixClientPeg');
var sdk = require('./index');
var Modal = require('./Modal');

function infoForImageFile(imageFile) {
    var deferred = q.defer();

    // Load the file into an html element
    var img = document.createElement("img");

    var reader = new FileReader();
    reader.onload = function(e) {
        img.src = e.target.result;

        // Once ready, returns its size
        img.onload = function() {
            deferred.resolve({
                w: img.width,
                h: img.height
            });
        };
        img.onerror = function(e) {
            deferred.reject(e);
        };
    };
    reader.onerror = function(e) {
        deferred.reject(e);
    };
    reader.readAsDataURL(imageFile);

    return deferred.promise;
}

class ContentMessages {
    constructor() {
        this.inprogress = [];
        this.nextId = 0;
    }

    sendContentToRoom(file, roomId, matrixClient) {
        var content = {
            body: file.name,
            info: {
                size: file.size,
            }
        };

        // if we have a mime type for the file, add it to the message metadata
        if (file.type) {
            content.info.mimetype = file.type;
        }

        var def = q.defer();
        if (file.type.indexOf('image/') == 0) {
            content.msgtype = 'm.image';
            infoForImageFile(file).then(function(imageInfo) {
                extend(content.info, imageInfo);
                def.resolve();
            });
        } else {
            content.msgtype = 'm.file';
            def.resolve();
        }

        var upload = {
            fileName: file.name,
            roomId: roomId,
            total: 0,
            loaded: 0
        };
        this.inprogress.push(upload);
        dis.dispatch({action: 'upload_started'});

        var error;
        var self = this;
        return def.promise.then(function() {
            upload.promise = matrixClient.uploadContent(file);
            return upload.promise;
        }).progress(function(ev) {
            if (ev) {
                upload.total = ev.total;
                upload.loaded = ev.loaded;
                dis.dispatch({action: 'upload_progress', upload: upload});
            }
        }).then(function(url) {
            content.url = url;
            return matrixClient.sendMessage(roomId, content);
        }, function(err) {
            error = err;
            if (!upload.canceled) {
                var desc = "The file '"+upload.fileName+"' failed to upload.";
                if (err.http_status == 413) {
                    desc = "The file '"+upload.fileName+"' exceeds this home server's size limit for uploads";
                }
                var ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
                Modal.createDialog(ErrorDialog, {
                    title: "Upload Failed",
                    description: desc
                });
            }
        }).finally(function() {
            var inprogressKeys = Object.keys(self.inprogress);
            for (var i = 0; i < self.inprogress.length; ++i) {
                var k = inprogressKeys[i];
                if (self.inprogress[k].promise === upload.promise) {
                    self.inprogress.splice(k, 1);
                    break;
                }
            }
            if (error) {
                dis.dispatch({action: 'upload_failed', upload: upload});
            }
            else {
                dis.dispatch({action: 'upload_finished', upload: upload});
            }
        });
    }

    getCurrentUploads() {
        return this.inprogress;
    }

    cancelUpload(promise) {
        var inprogressKeys = Object.keys(this.inprogress);
        var upload;
        for (var i = 0; i < this.inprogress.length; ++i) {
            var k = inprogressKeys[i];
            if (this.inprogress[k].promise === promise) {
                upload = this.inprogress[k];
                break;
            }
        }
        if (upload) {
            upload.canceled = true;
            MatrixClientPeg.get().cancelUpload(upload.promise);
        }
    }
}

if (global.mx_ContentMessage === undefined) {
    global.mx_ContentMessage = new ContentMessages();
}

module.exports = global.mx_ContentMessage;