import {is_debug} from "../main_window";

const request = require('request');
const querystring = require('querystring');
const fs = require('fs-extra');
const os = require('os');
const UUID = require('pure-uuid');
import * as path from "path";
import * as zlib from "zlib";
import * as tar from "tar-stream";
import {Arguments, process_args} from "../../shared/process-arguments";
import {parse_version} from "../../shared/version";

import * as electron from "electron";
import MessageBoxOptions = Electron.MessageBoxOptions;
import {current_version, execute_graphical} from "../app-updater";

const TIMEOUT = 10000;
let local_path = undefined;

interface RemoteURL {
    (): string;
    cached?: string;
}
const remote_url: RemoteURL = () => {
    if(remote_url.cached)
        return remote_url.cached;
    const default_path = is_debug ? "http://localhost/home/TeaSpeak/Web-Client/client-api/environment/" : "https://clientapi.teaspeak.de/";
    return remote_url.cached = (process_args.has_value(...Arguments.SERVER_URL) ? process_args.value(...Arguments.SERVER_URL) : default_path);
};

function data_directory() : string {
    return electron.app.getPath('userData');
}

function cache_directory() : string {
    return path.join(data_directory(), "cache", "ui");
}

function working_directory() : string {
    return path.join(data_directory(), "tmp", "ui");
}

export interface VersionedFile {
    name: string,
    hash: string,
    path: string,
    type: string,

    local_url: () => Promise<String>
}

function generate_tmp() : Promise<String> {
    if(local_path) return Promise.resolve(local_path);

    const id = new UUID(4).format();
    const directory = path.join(os.tmpdir(), "TeaClient-" + id) + "/";

    return fs.mkdirs(directory).then(() => {
        local_path = directory;
        global["browser-root"] = local_path;
        console.log("Local browser path: %s", local_path);
        return Promise.resolve(local_path);
    });
}

function get_raw_app_files() : Promise<VersionedFile[]> {
    return generate_tmp().then(path => new Promise<VersionedFile[]>((resolve, reject) => {
            const url = remote_url() + "api.php?" + querystring.stringify({
                type: "files",
            });
            console.debug("Requesting file list from %s", url);
            request.get(url, {
                timeout: TIMEOUT
            }, (error, response, body: string) => {
                response = response || {statusCode: -1};

                if(error) { reject(error); return; }
                if(response.statusCode != 200) { setImmediate(reject, "invalid status code " + response.statusCode + " for " + url); return; }
                if(response.headers["info-version"] != 1) { setImmediate(reject, "Invalid response version (" + response.headers["info-version"] + "). Update your app manually!"); return; }
                if(!body) {
                    setImmediate(reject, "invalid body. (Missing)");
                    return;
                }
                let result: VersionedFile[] = [];

                body.split("\n").forEach(entry => {
                    if(entry.length == 0) return;

                    let info = entry.split("\t");
                    if(info[0] == "type") return;

                    result.push({
                        type: info[0],
                        hash: info[1],
                        path: info[2],
                        name: info[3]
                    } as VersionedFile);
                });
                setImmediate(resolve, result);
            });
        })
    );
}

function download_raw_app_files() : Promise<VersionedFile[]> {
    return get_raw_app_files().then(response => {
        for(let file of response) {
            const full_path = path.join(local_path, file.path, file.name);
            file.local_url = () => fs.mkdirs(path.dirname(full_path)).then(() => new Promise<String>((resolve, reject) => {
                const write_stream = fs.createWriteStream(full_path);
                request.get(remote_url() + "api.php?" + querystring.stringify({
                    type: "file",
                    path: file.path,
                    name: file.name
                }), {
                    timeout: TIMEOUT
                }).on('response', function(response) {
                    if(response.statusCode != 200) {
                        setImmediate(reject, "invalid status code " + response.statusCode + " for file " + file.name + " (" + file.path + ")");
                        return;
                    }
                }).on('complete', event => {
                }).on('error', error => {
                    setImmediate(reject, error);
                }).pipe(write_stream)
                    .on('finish', event => {
                        setImmediate(resolve, file.path + "/" + file.name);
                    });
            }));
        }
        return Promise.resolve(response);
    }).catch(error => {
        console.log("Failed to get file list: %o", error);
        return Promise.reject("Failed to get file list (" + error + ")");
    })
}

interface LocalUICache {
    fetch_history?: FetchStatus;
    versions?: LocalUICacheEntry[];

    remote_index?: UIVersion[] | UIVersion;
    remote_index_channel?: string; /* only set if the last status was a channel only*/

    local_index?: UIVersion;
}

interface FetchStatus {
    timestamp: number;
    /**
     * 0 = success
     * 1 = connect fail
     * 2 = internal fail
     */
    status: number;
}

interface LocalUICacheEntry {
    version: UIVersion;
    download_timestamp: number;
    tar_file: string;
    checksum: string; /* SHA512 */
}

export interface UIVersion {
    channel: string;
    version: string;
    git_hash: string;
    timestamp: number;

    required_client?: string;
    filename?: string;

    client_shipped?: boolean;
}

function ui_file_path(version: UIVersion) : string {
    if(version.client_shipped) {
        const app_path = electron.app.getAppPath();
        if(!app_path.endsWith(".asar"))
            return undefined;

        return path.join(path.join(path.dirname(app_path), "ui"), version.filename);
    }

    const file_name = "ui_" + version.channel + "_" + version.version + "_" + version.git_hash + "_" + version.timestamp + ".tar.gz";
    return path.join(cache_directory(), file_name);
}

let _ui_load_cache: LocalUICache;
async function ui_load_cache() : Promise<LocalUICache> {
    if(_ui_load_cache) return _ui_load_cache;

    const file = path.join(cache_directory(), "data.json");
    if(!fs.existsSync(file)) return {} as LocalUICache;

    console.log("Loading UI cache file %s", file);
    _ui_load_cache = await fs.readJson(file) as LocalUICache;
    return _ui_load_cache;
}

async function client_shipped_ui() : Promise<UIVersion | undefined> {
    const app_path = electron.app.getAppPath();
    if(!app_path.endsWith(".asar"))
        return undefined;

    const base_path = path.join(path.dirname(app_path), "ui");
    console.debug("Looking for client shipped UI pack at %s", base_path);
    if(!(await fs.pathExists(base_path)))
        return undefined;

    const info: {
        channel: string,
        version: string,
        git_hash: string,
        required_client: string,
        timestamp: number,
        filename: string
    } = await fs.readJson(path.join(base_path, "default_ui_info.json")) as any;

    return {
        channel: info.channel,
        client_shipped: true,

        filename: info.filename,
        git_hash: info.git_hash,
        required_client: info.required_client,
        timestamp: info.timestamp,
        version: info.version,
    }
}

async function ui_save_cache(cache: LocalUICache) {
    const file = path.join(cache_directory(), "data.json");
    if(!fs.existsSync(path.dirname(file)))
        await fs.mkdirs(path.dirname(file));
    await fs.writeJson(file, cache);
}

async function get_ui_pack(channel?: string) : Promise<UIVersion[] | UIVersion> {
    return await new Promise<UIVersion[] | UIVersion>((resolve, reject) => {
        const url = remote_url() + "api.php?" + querystring.stringify({
            type: "ui-info"
        });
        request.get(url, {
            timeout: TIMEOUT
        }, (error, response, body: string) => {
            try {
                response = response || {statusCode: -1};

                if(error) { throw error; }
                if(response.statusCode != 200) { throw "invalid status code " + response.statusCode + " for " + url; }
                if(!body) throw "invalid response body";

                let result: UIVersion[] = [];

                const json = JSON.parse(body) || {success: false, msg: "invalid body"};
                if(!json["success"]) throw "Failed to get ui info: " + json["msg"];

                for(const entry of json["versions"]) {
                    if(!channel || entry["channel"] == channel)
                        result.push({
                            channel: entry["channel"],
                            version: entry["version"],
                            git_hash: entry["git-ref"],
                            timestamp: entry["timestamp"],
                            required_client: entry["required_client"]
                        });
                }

                if(result.length == 0 && channel) result.push(undefined);
                const res = channel ? result[0] : result;
                ui_load_cache().then(async cache => {
                    cache.fetch_history = cache.fetch_history || {} as any;
                    cache.fetch_history.timestamp = Date.now();
                    cache.fetch_history.status = 0;
                    cache.remote_index = res as any;
                    cache.remote_index_channel = channel;
                    await ui_save_cache(cache);
                }).catch(error => {
                    console.warn("Failed to save UI cache info: %o", error);
                    resolve(res);
                }).then(err => resolve(res));
            } catch(error) {
                reject(error);
            }
        });
    })
}

async function download_ui_pack(version: UIVersion) : Promise<void> {
    const directory = cache_directory();
    const file = ui_file_path(version);
    await fs.mkdirs(directory);

    await new Promise((resolve, reject) => {
        request.get(remote_url() + "api.php?" + querystring.stringify({
            type: "ui-download",
            "git-ref": version.git_hash,
            version: version.version,
            timestamp: version.timestamp,
            channel: version.channel
        }), {
            timeout: TIMEOUT
        }).on('response', function(response) {
            if(response.statusCode != 200) { reject("Failed to download UI files (Status code " + response.statusCode + ")"); }
        }).on('error', error => {
            reject("Failed to download UI files: " + error);
        }).pipe(fs.createWriteStream(file)).on('finish', () => {
            ui_load_cache().then(cache => {
                cache.versions.push({
                    checksum: "undefined",
                    tar_file: file,
                    download_timestamp: Date.now(),
                    version: version
                });
                return ui_save_cache(cache);
            }).catch(error => resolve()).then(() => resolve());

        });
    });
}

function ui_pack_exists(version: UIVersion) : boolean {
    return fs.existsSync(ui_file_path(version));
}

async function unpack_cached(version: UIVersion) : Promise<string> {
    const file = ui_file_path(version);
    if(!fs.existsSync(file)) throw "missing file";

    const target_dir = path.join(working_directory(), version.channel + "_" + version.timestamp);
    if(fs.existsSync(target_dir)) fs.removeSync(target_dir);

    await fs.mkdirs(target_dir);

    const gunzip = zlib.createGunzip();
    const extract = tar.extract();
    const fpipe = fs.createReadStream(file);

    extract.on('entry', function(header: tar.Headers, stream, next) {
        if(header.type == 'file') {
            const target_file = path.join(target_dir, header.name);
            if(!fs.existsSync(path.dirname(target_file))) fs.mkdirsSync(path.dirname(target_file));

            stream.on('end', () => setImmediate(next));
            const wfpipe = fs.createWriteStream(target_file);
            stream.pipe(wfpipe);
        } else if(header.type == 'directory') {
            if(fs.existsSync(path.join(target_dir, header.name)))
                setImmediate(next);
            fs.mkdirs(path.join(target_dir, header.name)).catch(error => {
                console.warn("Failed to create unpacking fir " + path.join(target_dir, header.name));
                console.error(error);
            }).then(() => setImmediate(next));
        } else {
            console.warn("Invalid ui tar ball entry type (" + header.type + ")");
            return;
        }
    });

    const finish_promise = new Promise(resolve => {
        extract.on('finish', resolve);
        extract.on('error', event => {
            if(!event) return;
            throw event;
        });
    });

    fpipe.pipe(gunzip).pipe(extract);
    await finish_promise;

    return target_dir;
}

export async function cleanup() {
    if(await fs.pathExists(local_path))
        await fs.remove(local_path);
}

export async function load_files(channel: string, static_cb: (message: string, index: number) => any) : Promise<String> {
    const type = parseInt(process_args.has_value(Arguments.UPDATER_UI_LOAD_TYPE) ? process_args.value(Arguments.UPDATER_UI_LOAD_TYPE) : "-1");
    if(type == 0 || !is_debug) {
        console.log("Loading ui package");

        static_cb("Fetching info", 0);
        const cache = await ui_load_cache();
        console.log("Local cache: %o", cache);

        let ui_info: UIVersion;
        try {
            ui_info = await get_ui_pack(channel) as UIVersion;
        } catch(error) {
            if(error instanceof Error)
                console.error("Failed to fetch ui info: %s. Using cached info!", error.message);
            else
                console.error("Failed to fetch ui info: %o. Using cached info!", error);
        }
        if(!ui_info) {
            if(cache && !process_args.has_flag(Arguments.UPDATER_UI_NO_CACHE)) {
                if(Array.isArray(cache.remote_index)) {
                    for(const index of cache.remote_index) {
                        if(index && index.channel == "release") {
                            ui_info = index;
                            break;
                        }
                    }
                } else {
                    //TODO: test channel?
                    ui_info = cache.remote_index;
                }
            }
            if(ui_info) {
                console.debug("Found local UI pack.");
            } else {
                //Test for the client shipped ui pack
                try {
                    console.info("Looking for client shipped UI pack.");
                    ui_info = await client_shipped_ui();
                    if(!ui_info)
                        throw "failed to load info";
                    console.info("Using client shipped UI pack because we've no active internet connection.")
                } catch(error) {
                    console.warn("Failed to load client shipped UI pack: %o", error);
                    throw "Failed to load UI pack from cache!\nPlease ensure a valid internet connection.";
                }
            }
        }

        static_cb("Searching cache for file", .33);
        console.log("Loading UI from data: %o. Target path: %s", ui_info, ui_file_path(ui_info));
        if(ui_info.required_client && !process_args.has_flag(Arguments.DEBUG)) {
            const ui_vers = parse_version(ui_info.required_client);
            console.log("Checking required client version (Required: %s, Version: %s)", ui_vers.toString(true), (await current_version()).toString(true));
            if(ui_vers.newer_than(await current_version())) {
                const local_available = cache && cache.local_index ? ui_pack_exists(cache.local_index) : undefined;

                const result = await electron.dialog.showMessageBox({
                    type: "question",
                    message:
                        "Local client is outdated.\n" +
                        "Newer UI packs (>= " + ui_info.version + ") require client " + ui_info.required_client + "\n" +
                        "Do you want to upgrade?",
                    title: "Client outdated!",
                    buttons: ["yes", local_available ? "ignore and use last possible (" + cache.local_index.version + ")" : "close client"]
                } as MessageBoxOptions);
                if(result.response == 0) {
                    await execute_graphical(channel, true);
                    throw "client outdated";
                } else {
                    if(!local_available) {
                        electron.app.exit(1);
                        return;
                    }

                    ui_info = cache.local_index;
                }
            }
        }

        if(!ui_pack_exists(ui_info)) {
            console.log("Ui version does not locally exists. Downloading new one");
            static_cb("Downloading files", .34);
            await download_ui_pack(ui_info);
            console.log("Download completed!");
        }

        console.log("Unpacking cached ui info");
        static_cb("Unpacking files", .66);
        const target_path = await unpack_cached(ui_info);
        cache.local_index = ui_info;
        await ui_save_cache(cache);

        console.log("Unpacked. Target path: %s", target_path);
        static_cb("UI loaded", 1);

        return path.join(target_path, "index.html");
    } else {
        console.log("Loading file by file");

        static_cb("Fetching files", 0);
        let files;
        try {
            files = await download_raw_app_files()
        } catch (error) {
            throw "Failed to get file list: " + error;
        }
        console.log("Get raw files:");
        let futures: Promise<void>[] = [];
        let finish_count = 0;
        static_cb("Downloading files", 0);

        for(const file of files) {
            console.log("Start downloading %s (%s)", file.name, file.path);

            const start = Date.now();
            futures.push(file.local_url().then(data => {
                finish_count++;
                console.log("Downloaded %s (%s) (%ims)", file.name, file.path, Date.now() - start);
                static_cb("Downloading files", finish_count / files.length);
            }));

            //await new Promise(resolve => setTimeout(resolve, 1000));
        }

        try {
            await Promise.all(futures);
        } catch (error) {
            throw "Failed to download files: " + error;
        }
        return await generate_tmp() + "index.html"; /* entry point */
    }
}