'use strict';

const crypto = require('crypto');
const fs = require('fs');
const path = require('path');

const BOOTSTRAP_MARKER = '/* hot-update-builder:bootstrap */';
const NATIVE_PLATFORMS = new Set([
    'android',
    'ios',
    'mac',
    'windows',
    'linux',
    'native',
    'openharmony',
    'harmonyos-next',
]);

const BOOTSTRAP_SCRIPT = `${BOOTSTRAP_MARKER}
(function () {
    if (typeof window.jsb === 'object') {
        var hotUpdateSearchPaths = localStorage.getItem('HotUpdateSearchPaths');
        if (hotUpdateSearchPaths) {
            var paths = JSON.parse(hotUpdateSearchPaths);
            jsb.fileUtils.setSearchPaths(paths);

            var fileList = [];
            var storagePath = paths[0] || '';
            var tempPath = storagePath + '_temp/';
            var baseOffset = tempPath.length;

            if (jsb.fileUtils.isDirectoryExist(tempPath) && !jsb.fileUtils.isFileExist(tempPath + 'project.manifest.temp')) {
                jsb.fileUtils.listFilesRecursively(tempPath, fileList);
                fileList.forEach(srcPath => {
                    var relativePath = srcPath.substr(baseOffset);
                    var dstPath = storagePath + relativePath;

                    if (srcPath[srcPath.length] == '/') {
                        jsb.fileUtils.createDirectory(dstPath)
                    }
                    else {
                        if (jsb.fileUtils.isFileExist(dstPath)) {
                            jsb.fileUtils.removeFile(dstPath)
                        }
                        jsb.fileUtils.renameFile(srcPath, dstPath);
                    }
                })
                jsb.fileUtils.removeDirectory(tempPath);
            }
        }
    }
})();
`;

async function packageHotUpdate({
    buildOptions,
    buildResult,
    remoteUrl,
    version,
    projectPath,
}) {
    if (!buildResult?.dest) {
        throw new Error('[热更新打包] 构建结果缺少 dest 路径。');
    }

    const platform = String(buildOptions?.platform || '').toLowerCase();
    if (!NATIVE_PLATFORMS.has(platform)) {
        throw new Error(`[热更新打包] 平台 ${platform || '<unknown>'} 不是支持热更新的原生平台。`);
    }
    if (buildOptions?.md5Cache) {
        throw new Error('[热更新打包] 请关闭构建发布面板中的 MD5 Cache；AssetsManager Manifest 已负责文件版本校验。');
    }

    const normalizedUrl = normalizeRemoteUrl(remoteUrl);
    const normalizedVersion = normalizeVersion(version);
    const buildRoot = path.resolve(buildResult.dest);
    const dataRoot = await findNativeDataRoot(buildRoot);
    const mainScriptPath = path.join(dataRoot, 'main.js');

    await injectBootstrap(mainScriptPath);

    const projectInfo = await readProjectInfo(projectPath);
    const assetFiles = await collectPayloadFiles(dataRoot);
    const assets = {};
    let totalBytes = 0;

    for (const file of assetFiles) {
        const stat = await fs.promises.stat(file.absolutePath);
        const descriptor = {
            size: stat.size,
            md5: await calculateMd5(file.absolutePath),
        };
        if (path.extname(file.absolutePath).toLowerCase() === '.zip') {
            descriptor.compressed = true;
        }
        assets[encodeURI(file.relativePath)] = descriptor;
        totalBytes += stat.size;
    }

    const manifest = {
        packageUrl: normalizedUrl,
        remoteManifestUrl: new URL('project.manifest', normalizedUrl).toString(),
        remoteVersionUrl: new URL('version.manifest', normalizedUrl).toString(),
        version: normalizedVersion,
        engineVersion: projectInfo.creator?.version || '',
        assets,
        searchPaths: [],
    };
    const versionManifest = {
        packageUrl: manifest.packageUrl,
        remoteManifestUrl: manifest.remoteManifestUrl,
        remoteVersionUrl: manifest.remoteVersionUrl,
        version: manifest.version,
        engineVersion: manifest.engineVersion,
    };

    // Manifest 放入 data 根目录，Make 阶段会随原生包一起发布。
    const localManifestPath = path.join(dataRoot, 'project.manifest');
    await writeJsonAtomic(localManifestPath, manifest);
    await writeJsonAtomic(path.join(dataRoot, 'version.manifest'), versionManifest);

    // 每个版本独立输出，目录可以直接上传到面板中配置的 URL。
    const remotePackagePath = path.join(buildRoot, 'hot-update', normalizedVersion);
    await createRemotePackage({
        buildRoot,
        dataRoot,
        remotePackagePath,
        manifest,
        versionManifest,
        assetFiles,
    });

    return {
        version: normalizedVersion,
        localManifestPath,
        remotePackagePath,
        fileCount: assetFiles.length,
        totalBytes,
    };
}

function normalizeRemoteUrl(value) {
    const input = String(value || '').trim();
    let parsed;
    try {
        parsed = new URL(input);
    } catch {
        throw new Error(`[热更新打包] 热更新 URL 无效：${input || '<empty>'}`);
    }
    if (parsed.protocol !== 'http:' && parsed.protocol !== 'https:') {
        throw new Error('[热更新打包] 热更新 URL 仅支持 http:// 或 https://。');
    }
    parsed.hash = '';
    parsed.search = '';
    if (!parsed.pathname.endsWith('/')) {
        parsed.pathname += '/';
    }
    return parsed.toString();
}

function normalizeVersion(value) {
    const normalized = String(value || '').trim();
    if (!/^\d+(?:\.\d+){1,3}$/.test(normalized)) {
        throw new Error(`[热更新打包] 版本号无效：${normalized || '<empty>'}`);
    }
    return normalized;
}

async function findNativeDataRoot(buildRoot) {
    const candidates = [path.join(buildRoot, 'data'), path.join(buildRoot, 'assets')];
    for (const candidate of candidates) {
        if (await isDirectory(path.join(candidate, 'src')) && await isDirectory(path.join(candidate, 'assets'))) {
            return candidate;
        }
    }
    throw new Error(`[热更新打包] 在 ${buildRoot} 下找不到原生构建资源目录（data 或 assets）。`);
}

async function injectBootstrap(mainScriptPath) {
    let source;
    try {
        source = await fs.promises.readFile(mainScriptPath, 'utf8');
    } catch (error) {
        throw new Error(`[热更新打包] 无法读取 ${mainScriptPath}：${error.message}`);
    }
    if (source.includes(BOOTSTRAP_MARKER)) {
        return;
    }
    await writeTextAtomic(mainScriptPath, BOOTSTRAP_SCRIPT + source);
}

async function collectPayloadFiles(dataRoot) {
    const relativeFiles = [];
    for (const directory of ['src', 'assets', 'jsb-adapter']) {
        const absoluteDirectory = path.join(dataRoot, directory);
        if (await isDirectory(absoluteDirectory)) {
            await walkFiles(absoluteDirectory, dataRoot, relativeFiles);
        }
    }

    // Creator 3.8 将 application.js 放在 data 根目录，旧版生成器会漏掉它。
    const applicationScript = path.join(dataRoot, 'application.js');
    if (await isFile(applicationScript)) {
        relativeFiles.push({
            absolutePath: applicationScript,
            relativePath: 'application.js',
        });
    }

    relativeFiles.sort((a, b) => a.relativePath.localeCompare(b.relativePath));
    return relativeFiles;
}

async function walkFiles(directory, root, output) {
    const entries = await fs.promises.readdir(directory, { withFileTypes: true });
    entries.sort((a, b) => a.name.localeCompare(b.name));
    for (const entry of entries) {
        if (entry.name.startsWith('.')) {
            continue;
        }
        const absolutePath = path.join(directory, entry.name);
        if (entry.isDirectory()) {
            await walkFiles(absolutePath, root, output);
        } else if (entry.isFile()) {
            output.push({
                absolutePath,
                relativePath: path.relative(root, absolutePath).replace(/\\/g, '/'),
            });
        }
    }
}

async function createRemotePackage({
    buildRoot,
    dataRoot,
    remotePackagePath,
    manifest,
    versionManifest,
    assetFiles,
}) {
    assertPathInside(buildRoot, remotePackagePath);
    const stagingPath = path.join(buildRoot, 'hot-update', `.staging-${process.pid}-${Date.now()}`);
    assertPathInside(buildRoot, stagingPath);
    await fs.promises.mkdir(stagingPath, { recursive: true });

    try {
        for (const file of assetFiles) {
            const destination = path.join(stagingPath, ...file.relativePath.split('/'));
            await fs.promises.mkdir(path.dirname(destination), { recursive: true });
            await fs.promises.copyFile(file.absolutePath, destination);
        }
        await writeJsonAtomic(path.join(stagingPath, 'project.manifest'), manifest);
        await writeJsonAtomic(path.join(stagingPath, 'version.manifest'), versionManifest);

        await fs.promises.mkdir(path.dirname(remotePackagePath), { recursive: true });
        await fs.promises.rm(remotePackagePath, { recursive: true, force: true });
        await fs.promises.rename(stagingPath, remotePackagePath);
    } catch (error) {
        await fs.promises.rm(stagingPath, { recursive: true, force: true });
        throw error;
    }
}

function assertPathInside(parent, child) {
    const relative = path.relative(path.resolve(parent), path.resolve(child));
    if (!relative || relative.startsWith('..') || path.isAbsolute(relative)) {
        throw new Error(`[热更新打包] 拒绝操作构建目录外的路径：${child}`);
    }
}

function calculateMd5(filePath) {
    return new Promise((resolve, reject) => {
        const hash = crypto.createHash('md5');
        const stream = fs.createReadStream(filePath);
        stream.on('error', reject);
        stream.on('data', (chunk) => hash.update(chunk));
        stream.on('end', () => resolve(hash.digest('hex')));
    });
}

async function readProjectInfo(projectPath) {
    const packagePath = path.join(projectPath, 'package.json');
    try {
        return JSON.parse(await fs.promises.readFile(packagePath, 'utf8'));
    } catch {
        return {};
    }
}

async function writeJsonAtomic(filePath, value) {
    await writeTextAtomic(filePath, `${JSON.stringify(value, null, 2)}\n`);
}

async function writeTextAtomic(filePath, content) {
    await fs.promises.mkdir(path.dirname(filePath), { recursive: true });
    const tempPath = `${filePath}.${process.pid}.${Date.now()}.tmp`;
    await fs.promises.writeFile(tempPath, content, 'utf8');
    await fs.promises.rename(tempPath, filePath);
}

async function isDirectory(target) {
    try {
        return (await fs.promises.stat(target)).isDirectory();
    } catch {
        return false;
    }
}

async function isFile(target) {
    try {
        return (await fs.promises.stat(target)).isFile();
    } catch {
        return false;
    }
}

module.exports = {
    BOOTSTRAP_MARKER,
    collectPayloadFiles,
    normalizeRemoteUrl,
    normalizeVersion,
    packageHotUpdate,
};