var EEPROM = function(srcId, endpoint, authorization) {
    var obj = {
        srcId: parseInt(srcId),
        endpoint: endpoint,
        authorization: authorization,
    };

    obj.setEndpoint = function(endpoint) {
        obj.endpoint = (endpoint || '').toString();
    };

    obj.setAuthorization = function(authorization) {
        obj.authorization = (authorization || '').toString();
    };

    obj.deleteUpload = function(fileInfo) {
        return new EEPROM.EEPROMDeleteTask(
            obj.authorization,
            fileInfo
        );
    };

    obj.createUpload = function(file) {
        return new EEPROM.EEPROMUploadTask(
            obj.srcId,
            obj.endpoint,
            obj.authorization,
            file
        );
    };

    return obj;
};
EEPROM.ERR_GENERIC = 'generic';
EEPROM.ERR_INVALID = 'invalid';
EEPROM.ERR_AUTH = 'auth';
EEPROM.ERR_ACCESS = 'access';
EEPROM.ERR_DMCA = 'dmca';
EEPROM.ERR_GONE = 'gone';
EEPROM.ERR_SERVER = 'server';
EEPROM.ERR_SIZE = 'size';

EEPROM.EEPROMFile = function(fileInfo) {
    var obj = {
        id: (fileInfo.id || '').toString(),
        url: (fileInfo.url || '').toString(),
        urlf: (fileInfo.urlf || '').toString(),
        thumb: (fileInfo.thumb || '').toString(),
        name: (fileInfo.name || '').toString(),
        type: (fileInfo.type || '').toString(),
        size: parseInt(fileInfo.size || 0),
        user: parseInt(fileInfo.user || 0),
        hash: (fileInfo.hash || '').toString(),
        created: (fileInfo.created || null),
        accessed: (fileInfo.accessed || null),
        expires: (fileInfo.expires || null),
        deleted: (fileInfo.deleted || null),
        dmca: (fileInfo.dmca || null),
    };

    obj.isImage = function() { return obj.type.indexOf('image/') === 0; };
    obj.isAudio = function() { return obj.type === 'application/x-font-gdos' || obj.type.indexOf('audio/') === 0; };
    obj.isVideo = function() { return obj.type.indexOf('video/') === 0; };
    obj.isMedia = function() { return obj.isImage() || obj.isAudio() || obj.isVideo(); };

    return obj;
};

EEPROM.EEPROMDeleteTask = function(authorization, fileInfo) {
    var obj = {
        authorization: authorization,
        fileInfo: fileInfo,
        onSuccess: undefined,
        onFailure: undefined,
    };

    var xhr = obj.xhr = new XMLHttpRequest;
    obj.xhr.addEventListener('readystatechange', function() {
        if(xhr.readyState !== 4)
            return;

        if(xhr.status !== 204) {
            obj.errorCode = EEPROM.ERR_GENERIC;

            switch(xhr.status) {
                case 401:
                    obj.errorCode = EEPROM.ERR_AUTH;
                    break;
                case 403:
                    obj.errorCode = EEPROM.ERR_ACCESS;
                    break;
                case 404:
                case 410:
                    obj.errorCode = EEPROM.ERR_GONE;
                    break;
                case 500:
                case 503:
                    obj.errorCode = EEPROM.ERR_SERVER;
                    break;
            }

            if(obj.onFailure)
                obj.onFailure(obj.errorCode);
            return;
        }

        if(obj.onSuccess)
            obj.onSuccess();
    });

    obj.start = function() {
        xhr.open('DELETE', obj.fileInfo.urlf);
        xhr.setRequestHeader('Authorization', obj.authorization);
        xhr.send();
    };

    return obj;
};

EEPROM.EEPROMUploadTask = function(srcId, endpoint, authorization, file) {
    var obj = {
        aborted: false,
        endpoint: endpoint,
        authorization: authorization,
        onComplete: undefined,
        onFailure: undefined,
        onProgress: undefined,
        failureResponse: undefined,
    };

    var xhr = obj.xhr = new XMLHttpRequest,
        fd = obj.formData = new FormData;

    fd.append('src', srcId);
    fd.append('file', file);

    var reportUploadProgress = function(ev) {
        if(obj.onProgress)
            obj.onProgress({
                loaded: ev.loaded,
                total: ev.total,
                progress: Math.ceil((ev.loaded / ev.total) * 100),
            });
    };

    xhr.upload.addEventListener('loadstart', reportUploadProgress);
    xhr.upload.addEventListener('progress', reportUploadProgress);
    xhr.upload.addEventListener('load', reportUploadProgress);

    xhr.addEventListener('readystatechange', function() {
        if(this.readyState !== 4)
            return;

        if(this.status !== 201) {
            obj.failureResponse = {
                userAborted: obj.aborted,
                error: EEPROM.ERR_GENERIC,
            };

            switch(this.status) {
                case 400:
                case 405:
                    obj.failureResponse.error = EEPROM.ERR_INVALID;
                    break;
                case 401:
                    obj.failureResponse.error = EEPROM.ERR_AUTH;
                    break;
                case 403:
                    obj.failureResponse.error = EEPROM.ERR_ACCESS;
                    break;
                case 404:
                case 410:
                    obj.failureResponse.error = EEPROM.ERR_GONE;
                    break;
                case 451:
                    obj.failureResponse.error = EEPROM.ERR_DMCA;
                    break;
                case 413:
                    obj.failureResponse.error = EEPROM.ERR_SIZE;
                    obj.failureResponse.maxSize = parseInt(this.getResponseHeader('X-EEPROM-Max-Size'));
                    break;
                case 500:
                case 503:
                    obj.failureResponse.error = EEPROM.ERR_SERVER;
                    break;
            }

            if(obj.onFailure)
                obj.onFailure(obj.failureResponse);
            return;
        }

        obj.fileInfo = new EEPROM.EEPROMFile(JSON.parse(this.responseText));

        if(obj.onComplete)
            obj.onComplete(obj.fileInfo);
    });

    obj.abort = function() {
        obj.aborted = true;
        xhr.abort();
    };

    obj.start = function() {
        xhr.open('POST', obj.endpoint);
        xhr.setRequestHeader('Authorization', obj.authorization);
        xhr.send(fd);
    };

    return obj;
};