import { spawn } from 'node:child_process';
import { mkdtemp, mkdir, readFile, readdir, rm, stat, writeFile } from 'node:fs/promises';
import { arch, platform, tmpdir } from 'node:os';
import { dirname, join, relative, resolve, sep } from 'node:path';
import { pathToFileURL } from 'node:url';
import { Arch, Platform, build } from 'electron-builder';
import {
  parseProbeArgs,
  resolvePiRuntime,
  runProbe,
  validatePiIdentity,
} from './probe-pi-runtime.mjs';
import { runLocalProviderContracts } from './probe-pi-provider-contracts.mjs';
import {
  PI_RUNTIME_MANIFEST,
  defaultPiBundleTarget,
  stagePiRuntimeBundle,
} from './lib/pi-runtime-bundle.mjs';

const PRODUCT_NAME = 'MakelorePiProbe';
const ARTIFACT_LABEL = 'controlled-electron-builder-dir-extra-resources';

async function pathExists(path) {
  try {
    await stat(path);
    return true;
  } catch {
    return false;
  }
}

function currentTarget() {
  let platformTarget;
  if (platform() === 'win32') platformTarget = Platform.WINDOWS;
  else if (platform() === 'darwin') platformTarget = Platform.MAC;
  else if (platform() === 'linux') platformTarget = Platform.LINUX;
  else throw new Error(`Unsupported packaging platform: ${platform()}`);
  const architecture = Arch[arch()];
  if (architecture == null) throw new Error(`Unsupported packaging architecture: ${arch()}`);
  return { platformTarget, architecture };
}

async function findPackagedExecutable(root) {
  const matches = [];
  const visit = async (directory) => {
    for (const entry of await readdir(directory, { withFileTypes: true })) {
      const path = join(directory, entry.name);
      if (entry.isDirectory()) await visit(path);
      else if (
        (platform() === 'win32' && entry.name === `${PRODUCT_NAME}.exe`)
        || (platform() === 'darwin'
          && entry.name === PRODUCT_NAME
          && directory.endsWith(`${sep}Contents${sep}MacOS`))
        || (platform() === 'linux' && entry.name === PRODUCT_NAME)
      ) matches.push(path);
    }
  };
  await visit(root);
  if (matches.length !== 1) {
    throw new Error(`Expected one packaged ${PRODUCT_NAME} executable, found ${matches.length}`);
  }
  return matches[0];
}

export function packagedResourcesDirectory(executable, currentPlatform = platform()) {
  return currentPlatform === 'darwin'
    ? resolve(executable, '..', '..', 'Resources')
    : join(dirname(executable), 'resources');
}

function runCommand(executable, args, options = {}) {
  return new Promise((resolvePromise, reject) => {
    const child = spawn(executable, args, {
      cwd: options.cwd,
      env: options.env ?? process.env,
      stdio: ['ignore', 'pipe', 'pipe'],
      windowsHide: true,
    });
    let stdout = '';
    let stderr = '';
    child.stdout.on('data', (chunk) => { stdout += chunk.toString(); });
    child.stderr.on('data', (chunk) => { stderr += chunk.toString(); });
    child.once('error', reject);
    child.once('exit', (code, signal) => {
      if (code === 0) resolvePromise({ stdout, stderr });
      else reject(new Error(
        `${executable} exited with code ${code ?? 'null'} signal ${signal ?? 'none'}: ${stderr || stdout}`,
      ));
    });
  });
}

export async function inspectPackagedClosure(executable, resourcesDirectory, assets) {
  const script = String.raw`
    const fs = require('node:fs');
    const path = require('node:path');
    const resources = process.env.PI_PROBE_RESOURCES_DIRECTORY;
    if (!resources) throw new Error('PI_PROBE_RESOURCES_DIRECTORY is required');
    const root = path.join(resources, 'pi-runtime');
    const packageJson = JSON.parse(fs.readFileSync(path.join(root, 'package.json'), 'utf8'));
    const runtimeManifestPath = path.join(root, '${PI_RUNTIME_MANIFEST}');
    const runtimeManifest = fs.existsSync(runtimeManifestPath)
      ? JSON.parse(fs.readFileSync(runtimeManifestPath, 'utf8'))
      : null;
    const shrinkwrap = JSON.parse(fs.readFileSync(path.join(root, 'npm-shrinkwrap.json'), 'utf8'));
    const assets = JSON.parse(process.env.PI_PROBE_ASSETS_JSON);
    const libc = process.platform === 'linux'
      ? (process.report?.getReport?.().header?.glibcVersionRuntime ? 'glibc' : 'musl')
      : undefined;
    const constraintMatches = (constraints, current) => {
      if (!constraints || constraints.length === 0 || !current) return true;
      const positive = constraints.filter((value) => !value.startsWith('!'));
      const negative = constraints.filter((value) => value.startsWith('!')).map((value) => value.slice(1));
      return !negative.includes(current) && (positive.length === 0 || positive.includes(current));
    };
    const supportsCurrentPlatform = (entry) => constraintMatches(entry.os, process.platform)
      && constraintMatches(entry.cpu, process.arch)
      && constraintMatches(entry.libc, libc);
    const missingPackages = [];
    const relocatedPackages = [];
    let expectedPackages = 0;
    let platformSkippedPackages = 0;
    for (const [packagePath, entry] of Object.entries(shrinkwrap.packages || {})) {
      if (!packagePath || entry.dev) continue;
      if (!supportsCurrentPlatform(entry)) {
        platformSkippedPackages += 1;
        continue;
      }
      expectedPackages += 1;
      const exactPath = path.join(root, ...packagePath.split('/'));
      if (fs.existsSync(exactPath)) continue;
      const nestedMarker = '/node_modules/';
      const packageTail = packagePath.includes(nestedMarker)
        ? packagePath.slice(packagePath.lastIndexOf(nestedMarker) + nestedMarker.length)
        : packagePath.slice('node_modules/'.length);
      const nameParts = packageTail.split('/');
      const packageName = nameParts[0].startsWith('@') ? nameParts.slice(0, 2).join('/') : nameParts[0];
      const flattenedPath = path.join(root, 'node_modules', ...packageName.split('/'));
      const flattenedPackageJson = path.join(flattenedPath, 'package.json');
      if (fs.existsSync(flattenedPackageJson)) {
        const flattenedVersion = JSON.parse(fs.readFileSync(flattenedPackageJson, 'utf8')).version;
        if (flattenedVersion === entry.version) {
          relocatedPackages.push({ from: packagePath, to: 'node_modules/' + packageName, version: entry.version });
          continue;
        }
      }
      missingPackages.push(packagePath);
    }
    const missingAssets = assets.filter((asset) => !fs.existsSync(path.join(root, ...asset.split('/'))));
    process.stdout.write(JSON.stringify({
      packageName: packageJson.name,
      packageVersion: packageJson.version,
      runtimeManifestExists: Boolean(runtimeManifest),
      runtimeManifestTarget: runtimeManifest?.target ?? null,
      cliExists: fs.existsSync(path.join(root, 'dist', 'cli.js')),
      lockedPackages: Math.max(0, Object.keys(shrinkwrap.packages || {}).length - 1),
      expectedPackages,
      platformSkippedPackages,
      missingPackages,
      relocatedPackages,
      assetCount: assets.length,
      missingAssets,
      nativeAssetsOutsideAsar: assets.filter((asset) => asset.endsWith('.node')).length,
    }));
  `;
  const { stdout } = await runCommand(executable, ['-e', script], {
    env: {
      ...process.env,
      ELECTRON_RUN_AS_NODE: '1',
      PI_PROBE_RESOURCES_DIRECTORY: resourcesDirectory,
      PI_PROBE_ASSETS_JSON: JSON.stringify(assets),
    },
  });
  const result = JSON.parse(stdout.trim());
  if (
    !result.cliExists
    || !result.runtimeManifestExists
    || result.missingPackages.length > 0
    || result.missingAssets.length > 0
  ) {
    throw new Error(`Packaged Pi closure is incomplete: ${JSON.stringify(result)}`);
  }
  return result;
}

function assertControlledOutput(projectRoot, outputDirectory) {
  const relativePath = relative(projectRoot, outputDirectory);
  if (!relativePath || relativePath.startsWith('..') || resolve(projectRoot, relativePath) !== outputDirectory) {
    throw new Error(`Refusing uncontrolled packaged-probe output: ${outputDirectory}`);
  }
  if (relativePath.split(sep).join('/') !== 'release/pi-runtime-probe') {
    throw new Error(`Unexpected packaged-probe output directory: ${outputDirectory}`);
  }
}

async function buildControlledArtifact(projectRoot, appDirectory, runtimeDirectory, outputDirectory) {
  const electronPackage = JSON.parse(await readFile(join(projectRoot, 'node_modules', 'electron', 'package.json'), 'utf8'));
  const { platformTarget, architecture } = currentTarget();
  const buildResources = join(appDirectory, 'build-resources');
  await mkdir(buildResources, { recursive: true });
  await writeFile(join(appDirectory, 'package.json'), `${JSON.stringify({
    name: 'makelore-pi-production-shape-probe',
    version: '1.0.0',
    main: 'main.js',
  }, null, 2)}\n`);
  await writeFile(join(appDirectory, 'main.js'), 'process.exit(0);\n');
  const builderArtifacts = await build({
    // Keep the probe application minimal while copying the permanent stage to
    // the same resources/pi-runtime location used by the product configuration.
    projectDir: appDirectory,
    targets: platformTarget.createTarget('dir', architecture),
    publish: 'never',
    config: {
      appId: 'app.niancode.desktop.pi-probe',
      productName: PRODUCT_NAME,
      electronVersion: electronPackage.version,
      electronDist: join(projectRoot, 'node_modules', 'electron', 'dist'),
      directories: {
        output: outputDirectory,
        buildResources,
      },
      files: [
        'main.js',
        'package.json',
      ],
      extraResources: [
        {
          from: runtimeDirectory,
          to: 'pi-runtime',
          filter: ['**/*', '!node_modules{,/**/*}'],
        },
        {
          from: join(runtimeDirectory, 'node_modules'),
          to: 'pi-runtime/node_modules',
          filter: ['**/*'],
        },
      ],
      asar: true,
      npmRebuild: false,
      win: {
        executableName: PRODUCT_NAME,
        signAndEditExecutable: false,
        verifyUpdateCodeSignature: false,
      },
      mac: {
        identity: null,
        hardenedRuntime: false,
      },
      linux: {
        executableName: PRODUCT_NAME,
      },
    },
  });
  return builderArtifacts;
}

export async function runPackagedProbe(options, projectRoot = process.cwd()) {
  const resolvedProjectRoot = resolve(projectRoot);
  const outputDirectory = resolve(resolvedProjectRoot, 'release', 'pi-runtime-probe');
  assertControlledOutput(resolvedProjectRoot, outputDirectory);
  const scratchRoot = await mkdtemp(join(tmpdir(), 'makelore-pi-packaged-probe-'));
  const appDirectory = join(scratchRoot, 'app');
  const runtimeDirectory = join(scratchRoot, 'runtime');
  try {
    const sourceRuntime = await resolvePiRuntime(resolvedProjectRoot);
    const identity = await validatePiIdentity(sourceRuntime);
    const runtimeManifest = await stagePiRuntimeBundle({
      projectRoot: resolvedProjectRoot,
      sourcePackageRoot: sourceRuntime.packageRoot,
      destination: runtimeDirectory,
      target: defaultPiBundleTarget(),
    });
    const stagedClosure = {
      lockfileVersion: runtimeManifest.lockfileVersion,
      expectedPackages: runtimeManifest.productionPackages.length,
      platformSkippedPackages: runtimeManifest.platformSkippedPackages,
      assets: runtimeManifest.runtimeAssets,
      omittedPublishedDevDependencies: runtimeManifest.staging.omittedPublishedDevDependencies,
      manifest: runtimeManifest,
    };
    await rm(outputDirectory, { recursive: true, force: true, maxRetries: 5, retryDelay: 200 });
    await mkdir(dirname(outputDirectory), { recursive: true });
    const builderArtifacts = await buildControlledArtifact(
      resolvedProjectRoot,
      appDirectory,
      runtimeDirectory,
      outputDirectory,
    );
    const executable = await findPackagedExecutable(outputDirectory);
    const resourcesDirectory = packagedResourcesDirectory(executable);
    const appAsar = join(resourcesDirectory, 'app.asar');
    const packagedRuntime = join(resourcesDirectory, 'pi-runtime');
    const cliPath = join(packagedRuntime, 'dist', 'cli.js');
    if (!await pathExists(appAsar)) throw new Error(`Packaged app.asar is missing: ${appAsar}`);
    const packagedClosure = await inspectPackagedClosure(
      executable,
      resourcesDirectory,
      stagedClosure.assets,
    );
    const runtime = await runProbe({
      ...options,
      reportPath: undefined,
      stage: false,
      keepStage: false,
      electronExecutablePath: executable,
      cliPath,
      artifactLabel: ARTIFACT_LABEL,
    }, resolvedProjectRoot);
    const providerContracts = await runLocalProviderContracts({
      ...options,
      reportPath: undefined,
      stage: false,
      keepStage: false,
      electronExecutablePath: executable,
      cliPath,
      artifactLabel: ARTIFACT_LABEL,
    }, resolvedProjectRoot);
    const report = {
      schemaVersion: 1,
      generatedAt: new Date().toISOString(),
      identity,
      artifact: {
        label: ARTIFACT_LABEL,
        outputDirectory,
        executable,
        appAsar,
        runtimeRoot: packagedRuntime,
        builderArtifacts,
      },
      stagedClosure,
      packagedClosure,
      runtime,
      providerContracts,
      result: runtime.result,
      decision: 'incomplete',
    };
    if (options.reportPath) {
      await mkdir(dirname(options.reportPath), { recursive: true });
      await writeFile(options.reportPath, `${JSON.stringify(report, null, 2)}\n`);
    }
    return report;
  } finally {
    await rm(scratchRoot, { recursive: true, force: true, maxRetries: 5, retryDelay: 200 });
  }
}

async function main() {
  const options = parseProbeArgs(process.argv.slice(2));
  if (options.help) {
    process.stdout.write('Usage: node scripts/probe-pi-packaged-runtime.mjs [probe options]\n');
    return;
  }
  if (options.stage || options.keepStage || options.electronExecutablePath) {
    throw new Error('Packaged probe owns staging and runtime paths; do not pass staging or runtime override flags');
  }
  const report = await runPackagedProbe(options);
  process.stdout.write(`${JSON.stringify(report, null, 2)}\n`);
  if (report.result === 'fail') process.exitCode = 1;
}

const isMain = process.argv[1]
  && pathToFileURL(resolve(process.argv[1])).href === import.meta.url;
if (isMain) {
  main().catch((error) => {
    process.stderr.write(`${error.stack ?? error.message}\n`);
    process.exit(1);
  });
}