import { Installer } from "@xmcl/installer";
import { downloadFileWork, got } from "@xmcl/net";
import Task from "@xmcl/task";
import Unzip from "@xmcl/unzip";
import { JavaExecutor, MinecraftFolder, MinecraftLocation, vfs } from "@xmcl/util";
import { ResolvedLibrary, Version } from "@xmcl/version";
import * as path from "path";
import { Readable } from "stream";

async function findMainClass(lib: string) {
    const zip = await Unzip.open(lib, { lazyEntries: true });
    const [manifest] = await zip.filterEntries(["META-INF/MANIFEST.MF"]);
    let mainClass: string | undefined;
    if (manifest) {
        const content = await zip.readEntry(manifest).then((b) => b.toString());
        const mainClassPair = content.split("\n").map((l) => l.split(": ")).filter((arr) => arr[0] === "Main-Class")[0];
        if (mainClassPair) {
            mainClass = mainClassPair[1].trim();
        }
    }
    zip.close();
    return mainClass;
}

export namespace ForgeInstaller {
    export interface VersionMeta {
        installer: {
            md5: string;
            sha1: string;
            path: string;
        };
        universal: {
            md5: string;
            sha1: string;
            path: string;
        };
        mcversion: string;
        version: string;
    }

    export const DEFAULT_FORGE_MAVEN = "http://files.minecraftforge.net";

    export interface InstallProfile {
        spec: number;
        profile: string;
        version: string;
        json: string;
        path: string;
        minecraft: string;
        data: {
            [key: string]: {
                client: string,
                server: string,
            },
        };
        processors: Array<{
            jar: string,
            classpath: string[],
            args: string[],
            outputs?: {
                [key: string]: string,
            },
        }>;
        libraries: Version.NormalLibrary[];
    }

    export interface Diagnosis {
        /**
         * When this flag is true, please reinstall totally
         */
        badInstall: boolean;
        /**
         * When only this is not empty
         */
        badProcessedFiles: Array<InstallProfile["processors"][number]>;
        badVersionJson: boolean;
        /**
         * When this is not empty, please use `postProcessInstallProfile`
         */
        missingInstallDependencies: Version.NormalLibrary[];

        missingBinpatch: boolean;

        /**
         * Alt for badProcessedFiles
         */
        missingSrgJar: boolean;
        /**
         * Alt for badProcessedFiles
         */
        missingMinecraftExtraJar: boolean;
        /**
         * Alt for badProcessedFiles
         */
        missingForgePatchesJar: boolean;
    }

    /**
     * Diagnose for specific forge version. Majorly for the current installer forge. (mcversion >= 1.13)
     *
     * Don't use this with the version less than 1.13
     * @param versionOrProfile If the version string present, it will try to find the installer profile under version folder. Otherwise it will use presented installer profile to diagnose
     * @param minecraft The minecraft location.
     */
    export async function diagnoseForgeVersion(versionOrProfile: string | InstallProfile, minecraft: MinecraftLocation): Promise<Diagnosis> {
        const version = typeof versionOrProfile === "string" ? versionOrProfile : versionOrProfile.version;
        const mc = MinecraftFolder.from(minecraft);
        const verRoot = mc.getVersionRoot(version);
        const versionJsonPath = mc.getVersionJson(version);

        const diag: Diagnosis = {
            badProcessedFiles: [],
            missingInstallDependencies: [],
            badVersionJson: false,
            missingBinpatch: false,
            badInstall: false,
            missingSrgJar: false,
            missingMinecraftExtraJar: false,
            missingForgePatchesJar: false,
        };

        let prof: InstallProfile | undefined;
        if (typeof versionOrProfile === "string") {
            const installProfPath = path.join(verRoot, "install_profile.json");
            if (await vfs.exists(installProfPath)) {
                prof = JSON.parse(await vfs.readFile(installProfPath).then((b) => b.toString()));
            }
        } else {
            prof = versionOrProfile;
        }
        if (prof) {
            const processedProfile = postProcessInstallProfile(mc, prof);
            for (const proc of processedProfile.processors) {
                if (proc.outputs) {
                    let bad = false;
                    for (const file in proc.outputs) {
                        if (! await vfs.validate(file, { algorithm: "sha1", hash: proc.outputs[file].replace(/\'/g, "") })) {
                            bad = true;
                            break;
                        }
                    }
                    if (bad) {
                        diag.badProcessedFiles.push(proc);
                    }
                }
            }
            // if we have to process file, we have to check if the forge deps are ready
            if (diag.badProcessedFiles.length !== 0) {
                const libValidMask = await Promise.all(processedProfile.libraries.map(async (lib) => {
                    const artifact = lib.downloads.artifact;
                    const libPath = mc.getLibraryByPath(artifact.path);
                    if (await vfs.exists(libPath)) {
                        return artifact.sha1 ? vfs.validate(libPath) : true;
                    }
                    return false;
                }));
                const missingLibraries = processedProfile.libraries.filter((_, i) => !libValidMask[i]);
                diag.missingInstallDependencies.push(...missingLibraries);

                const validClient = await vfs.stat(processedProfile.data.BINPATCH.client).then((s) => s.size !== 0).catch((_) => false);
                if (!validClient) {
                    diag.missingBinpatch = true;
                    diag.badInstall = true;
                }
            }
        }
        if (await vfs.exists(versionJsonPath)) {
            const versionJSON: Version = JSON.parse(await vfs.readFile(versionJsonPath).then((b) => b.toString()));
            if (versionJSON.arguments && versionJSON.arguments.game) {
                const args = versionJSON.arguments.game;
                const forgeVersion = args.indexOf("--fml.forgeVersion") + 1;
                const mcVersion = args.indexOf("--fml.mcVersion") + 1;
                const mcpVersion = args.indexOf("--fml.mcpVersion") + 1;
                if (!forgeVersion || !mcVersion || !mcpVersion) {
                    diag.badVersionJson = true;
                    diag.badInstall = true;
                } else {
                    const srgPath = mc.getLibraryByPath(`net/minecraft/client/${mcVersion}-${mcpVersion}/client-${mcVersion}-${mcpVersion}-srg.jar`);
                    const extraPath = mc.getLibraryByPath(`net/minecraft/client/${mcVersion}/client-${mcVersion}-extra.jar`);
                    const forgePatchPath = mc.getLibraryByPath(`net/minecraftforge/forge/${mcVersion}-${forgeVersion}/forge-${mcVersion}-${forgeVersion}-client.jar`);
                    diag.missingSrgJar = await vfs.missing(srgPath);
                    diag.missingMinecraftExtraJar = await vfs.missing(extraPath);
                    diag.missingForgePatchesJar = await vfs.missing(forgePatchPath);
                }
            } else {
                diag.badVersionJson = true;
                diag.badInstall = true;
            }
        } else {
            diag.badVersionJson = true;
            diag.badInstall = true;
        }

        return diag;
    }

    /**
     * Post processing function for new forge installer (mcversion >= 1.13). You can use this with `ForgeInstaller.diagnose`.
     *
     * @param mc The minecraft location
     * @param proc The processor
     * @param java The java executor
     */
    export async function postProcess(mc: MinecraftFolder, proc: InstallProfile["processors"][number], java: JavaExecutor) {
        const jarRealPath = mc.getLibraryByPath(Version.getLibraryInfo(proc.jar).path);
        const mainClass = await findMainClass(jarRealPath);
        if (!mainClass) { throw new Error(`Cannot find main class for processor ${proc.jar}.`); }
        const cp = [...proc.classpath, proc.jar].map(Version.getLibraryInfo).map((p) => mc.getLibraryByPath(p.path)).join(path.delimiter);
        const cmd = ["-cp", cp, mainClass, ...proc.args];
        await java(cmd);
        let failed = false;
        if (proc.outputs) {
            for (const file in proc.outputs) {
                if (! await vfs.validate(file, { algorithm: "sha1", hash: proc.outputs[file].replace(/\'/g, "") })) {
                    console.error(`Fail to process ${proc.jar} @ ${file} since its validation failed.`);
                    failed = true;
                }
            }
        }
        if (failed) {
            console.error(`Java arguments: ${JSON.stringify(cmd)}`);
            throw new Error(`Fail to process post processing since its validation failed.`);
        }
    }

    function postProcessInstallProfile(mc: MinecraftFolder, installProfile: InstallProfile) {
        function processValue(v: string) {
            if (v.match(/^\[.+\]$/g)) {
                const targetId = v.substring(1, v.length - 1);
                return mc.getLibraryByPath(Version.getLibraryInfo(targetId).path);
            }
            return v;
        }
        function processMapping(data: InstallProfile["data"], m: string) {
            m = processValue(m);
            if (m.match(/^{.+}$/g)) {
                const key = m.substring(1, m.length - 1);
                m = data[key].client;
            }
            return m;
        }
        const profile: InstallProfile = JSON.parse(JSON.stringify(installProfile));
        profile.data.MINECRAFT_JAR = {
            client: mc.getVersionJar(profile.minecraft),
            server: "",
        };
        for (const key in profile.data) {
            const value = profile.data[key];
            value.client = processValue(value.client);
            value.server = processValue(value.server);

            if (key === "BINPATCH") {
                const verRoot = mc.getVersionRoot(profile.version);
                value.client = path.join(verRoot, value.client);
                value.server = path.join(verRoot, value.server);
            }
        }
        for (const proc of profile.processors) {
            proc.args = proc.args.map((a) => processMapping(profile.data, a));
            if (proc.outputs) {
                const replacedOutput: InstallProfile["processors"][0]["outputs"] = {};
                for (const key in proc.outputs) {
                    replacedOutput[processMapping(profile.data, key)] = processMapping(profile.data, proc.outputs[key]);
                }
                proc.outputs = replacedOutput;
            }
        }

        return profile;
    }

    /**
     * Install for forge installer step 2 and 3.
     * @param version The version string or installer profile
     * @param minecraft The minecraft location
     */
    export function installByInstallerPartialTask(version: string | InstallProfile, minecraft: MinecraftLocation, option: {
        java?: JavaExecutor,
    } & Installer.LibraryOption = {}) {
        return Task.create("installForge", async (context) => {
            const mc = MinecraftFolder.from(minecraft);
            let prof: InstallProfile;
            let ver: Version;
            if (typeof version === "string") {
                const versionRoot = mc.getVersionRoot(version);
                prof = await vfs.readFile(path.join(versionRoot, "install_profile.json")).then((b) => b.toString()).then(JSON.parse);
            } else {
                prof = version;
            }
            ver = await vfs.readFile(mc.getVersionJson(prof.version)).then((b) => b.toString()).then(JSON.parse);
            await installByInstallerPartialWork(mc, prof, ver, option.java || JavaExecutor.createSimple("java"), option)(context);
        });
    }

    /**
     * Install for forge installer step 2 and 3.
     * @param version The version string or installer profile
     * @param minecraft The minecraft location
     */
    export async function installByInstallerPartial(version: string | InstallProfile, minecraft: MinecraftLocation, option: {
        java?: JavaExecutor,
    } & Installer.LibraryOption = {}) {
        return installByInstallerPartialTask(version, minecraft, option).execute();
    }

    function installByInstallerPartialWork(mc: MinecraftFolder, profile: InstallProfile, versionJson: Version, java: JavaExecutor, installLibOption: Installer.LibraryOption) {
        return async (context: Task.Context) => {
            profile = postProcessInstallProfile(mc, profile);

            const parsedLibs = Version.resolveLibraries([...profile.libraries, ...versionJson.libraries]);
            await context.execute("downloadLibraries", Installer.installLibrariesDirectTask(parsedLibs, mc, installLibOption).work);

            await context.execute("postProcessing", async (ctx) => {
                ctx.update(0, profile.processors.length);
                let i = 0;
                const errs: Error[] = [];
                for (const proc of profile.processors) {
                    try {
                        await postProcess(mc, proc, java);
                    } catch (e) {
                        errs.push(e);
                    }
                    ctx.update(i += 1, profile.processors.length);
                }
                i += 1;
                ctx.update(i, profile.processors.length);

                if (errs.length !== 0) {
                    throw new Error(`Fail to post processing`);
                }
            });
        };
    }

    function installByInstallerTask(version: VersionMeta, minecraft: MinecraftLocation, maven: string, installLibOption: Installer.LibraryOption, java: JavaExecutor, tempDir?: string, clearTempDir: boolean = true) {
        return async (context: Task.Context) => {
            const mc = typeof minecraft === "string" ? new MinecraftFolder(minecraft) : minecraft;
            const forgeVersion = `${version.mcversion}-${version.version}`;
            let versionId: string;

            const installerURLFallback = `${maven}/maven/net/minecraftforge/forge/${forgeVersion}/forge-${forgeVersion}-installer.jar`;
            const installerURL = `${maven}${version.installer.path}`;

            function downloadInstallerTask(installer: string, dest: string) {
                return async (ctx: Task.Context) => {
                    let inStream;
                    if (await vfs.validate(dest, { algorithm: "md5", hash: version.installer.md5 }, { algorithm: "sha1", hash: version.installer.sha1 })) {
                        inStream = vfs.createReadStream(dest);
                    }
                    if (!inStream) {
                        inStream = got.stream(installer, {
                            method: "GET",
                            headers: { connection: "keep-alive" },
                        }).on("error", () => { })
                            .on("downloadProgress", (progress) => { ctx.update(progress.transferred, progress.total as number); });

                        inStream.pipe(vfs.createWriteStream(dest));
                    }

                    return inStream.pipe(Unzip.createParseStream({ lazyEntries: true }))
                        .wait();
                };
            }

            const temp = tempDir || await vfs.mkdtemp(mc.root + path.sep);
            await vfs.ensureDir(temp);
            const installJar = path.join(temp, "forge-installer.jar");
            let profile!: InstallProfile;
            let versionJson!: Version;

            async function processVersion(zip: Unzip.ZipFile, installProfileEntry: Unzip.Entry, versionEntry: Unzip.Entry, clientDataEntry: Unzip.Entry) {
                profile = await zip.readEntry(installProfileEntry).then((b) => b.toString()).then(JSON.parse);
                versionJson = await zip.readEntry(versionEntry).then((b) => b.toString()).then(JSON.parse);
                versionId = versionJson.id;

                const rootPath = mc.getVersionRoot(versionJson.id);
                const jsonPath = path.join(rootPath, `${versionJson.id}.json`);
                const installJsonPath = path.join(rootPath, `install_profile.json`);
                const clientDataPath = path.join(rootPath, profile.data.BINPATCH.client);

                await vfs.ensureFile(jsonPath);
                await vfs.writeFile(installJsonPath, JSON.stringify(profile));
                await vfs.writeFile(jsonPath, JSON.stringify(versionJson));

                await vfs.ensureFile(clientDataPath);
                const stream = await zip.openEntry(clientDataEntry);
                await vfs.waitStream(stream.pipe(vfs.createWriteStream(clientDataPath)));
            }
            async function processExtractLibrary(s: Readable, p: string) {
                const file = mc.getLibraryByPath(p);
                await vfs.ensureFile(file);
                await vfs.waitStream(s.pipe(vfs.createWriteStream(file)));
            }
            try {
                let zip: Unzip.LazyZipFile;
                try {
                    zip = await context.execute("downloadInstaller", downloadInstallerTask(installerURL, installJar));
                } catch {
                    zip = await context.execute("downloadInstaller", downloadInstallerTask(installerURLFallback, installJar));
                }

                const [forgeEntry, forgeUniversalEntry, clientDataEntry, installProfileEntry, versionEntry] = await zip.filterEntries([
                    `maven/net/minecraftforge/forge/${forgeVersion}/forge-${forgeVersion}.jar`,
                    `maven/net/minecraftforge/forge/${forgeVersion}/forge-${forgeVersion}-universal.jar`,
                    "data/client.lzma",
                    "install_profile.json",
                    "version.json"]);

                if (!forgeEntry) {
                    throw new Error("Missing forge jar entry");
                }
                if (!forgeUniversalEntry) {
                    throw new Error("Missing forge universal entry");
                }
                if (!installProfileEntry) {
                    throw new Error("Missing install profile");
                }
                if (!versionEntry) {
                    throw new Error("Missing version entry");
                }

                await processExtractLibrary(await zip.openEntry(forgeEntry), forgeEntry.fileName);
                await processExtractLibrary(await zip.openEntry(forgeUniversalEntry), forgeUniversalEntry.fileName);
                await processVersion(zip, installProfileEntry, versionEntry, clientDataEntry);

                await installByInstallerPartialWork(mc, profile, versionJson, java, installLibOption)(context);

                return versionId!;
            } catch (e) {
                if (clearTempDir) {
                    await vfs.remove(temp);
                }
                throw e;
            }
        };
    }

    function installByUniversalTask(version: VersionMeta, minecraft: MinecraftLocation, maven: string, checkDependecies: boolean) {
        return async (context: Task.Context) => {
            const mc = typeof minecraft === "string" ? new MinecraftFolder(minecraft) : minecraft;
            const forgeVersion = `${version.mcversion}-${version.version}`;
            const jarPath = mc.getLibraryByPath(`net/minecraftforge/forge/${forgeVersion}/forge-${forgeVersion}.jar`);
            let fullVersion: string;
            let realJarPath: string;

            const universalURLFallback = `${maven}/maven/net/minecraftforge/forge/${forgeVersion}/forge-${forgeVersion}-universal.jar`;
            const universalURL = `${maven}${version.universal.path}`;

            await context.execute("installForgeJar", async () => {
                if (await vfs.exists(jarPath)) {
                    const valid = await vfs.validate(jarPath, { algorithm: "md5", hash: version.universal.md5 }, { algorithm: "sha1", hash: version.universal.sha1 });
                    if (valid) {
                        return;
                    }
                }

                try {
                    await context.execute("downloadJar", downloadFileWork({ url: universalURL, destination: jarPath }));
                } catch  {
                    await context.execute("redownloadJar", downloadFileWork({ url: universalURLFallback, destination: jarPath }));
                }
            });

            await context.execute("installForgeJson", async () => {
                const zip = await Unzip.open(jarPath, { lazyEntries: true });
                const [versionEntry] = await zip.filterEntries(["version.json"]);

                if (versionEntry) {
                    const buf = await zip.readEntry(versionEntry);
                    const raw = JSON.parse(buf.toString());
                    const id = raw.id;
                    fullVersion = id;
                    const rootPath = mc.getVersionRoot(fullVersion);
                    realJarPath = mc.getLibraryByPath(Version.getLibraryInfo(raw.libraries.find((l: any) => l.name.startsWith("net.minecraftforge:forge"))).path);

                    await vfs.ensureDir(rootPath);
                    await vfs.writeFile(path.join(rootPath, `${id}.json`), buf);
                } else {
                    throw new Error(`Cannot install forge json for ${version.version} since the version json is missing!`);
                }
            });

            if (realJarPath! !== jarPath) {
                await vfs.ensureFile(realJarPath!);
                await vfs.copyFile(jarPath, realJarPath!);
                await vfs.unlink(jarPath);
            }

            if (checkDependecies) {
                const resolvedVersion = await Version.parse(minecraft, fullVersion!);
                context.execute("installDependencies", Installer.installDependenciesTask(resolvedVersion).work);
            }

            return fullVersion!;
        };
    }

    /**
     * Install forge to target location.
     * Installation task for forge with mcversion >= 1.13 requires java installed on your pc.
     * @param version The forge version meta
     */
    export function install(version: VersionMeta, minecraft: MinecraftLocation, option?: {
        maven?: string,
        forceCheckDependencies?: boolean,
        java?: JavaExecutor,
        tempDir?: string,
        clearTempDirAfterInstall?: boolean,
    }) {
        return installTask(version, minecraft, option).execute();
    }

    /**
     * Install forge to target location.
     * Installation task for forge with mcversion >= 1.13 requires java installed on your pc.
     * @param version The forge version meta
     */
    export function installTask(version: VersionMeta, minecraft: MinecraftLocation, option: {
        maven?: string,
        forceInstallDependencies?: boolean,
        java?: JavaExecutor,
        tempDir?: string,
        clearTempDirAfterInstall?: boolean,
    } & Installer.LibraryOption = {}): Task<string> {
        let byInstaller = true;
        try {
            const minorVersion = Number.parseInt(version.mcversion.split(".")[1], 10);
            byInstaller = minorVersion >= 13;
        } catch { }
        const work = byInstaller ? installByInstallerTask(version, minecraft, option.maven || DEFAULT_FORGE_MAVEN, option, option.java || JavaExecutor.createSimple("java"), option.tempDir, option.clearTempDirAfterInstall)
            : installByUniversalTask(version, minecraft, option.maven || DEFAULT_FORGE_MAVEN, option.forceInstallDependencies === true);
        return Task.create("installForge", work);
    }
}

export * from "./forgeweb";

export default ForgeInstaller;