import crypto from 'node:crypto';
import fs from 'node:fs';
import fsp from 'node:fs/promises';
import path from 'node:path';

export const REQUIRED_PORTAL_RUNTIME_PATHS = Object.freeze([
  'server.mjs',
  'memind-canary-proxy.mjs',
  'deepseek-no-think-proxy.mjs',
  'wechat-mp.bundle.mjs',
  'mindspace-sandbox-mcp.mjs',
  'tkmind-search-mcp.mjs',
  'tkmind-excel-mcp.mjs',
  'mindspace-public-links.mjs',
  'dist',
  'package.json',
  'scripts/run-memind-portal-prod.sh',
  'scripts/run-memind-portal-candidate.sh',
  'scripts/run-memind-canary-proxy-prod.sh',
  'scripts/run-deepseek-compat-proxy-candidate.sh',
  'scripts/goosed-canary.compose.yml',
  'scripts/check-mindspace-public-links.mjs',
  'scripts/load-env.mjs',
  'scripts/wechat-mp-menu.mjs',
  'scripts/memind-portal-tunnel.sh',
]);

export const FORBIDDEN_PORTAL_RUNTIME_PATHS = Object.freeze([
  '.env',
  '.git',
  'data',
  'dist/dev',
  'dist/hello-john.html',
  'users',
  'logs',
  'MindSpace',
  '.tailscale',
  'public/plaza-covers',
]);

export async function removeForbiddenPortalRuntimePaths(artifactPath) {
  const root = path.resolve(artifactPath);
  const segments = root.split(path.sep);
  if (path.basename(root) !== 'portal' || !segments.includes('.runtime')) {
    throw new Error('Refusing to sanitize a path outside an explicit .runtime/portal directory');
  }
  for (const relative of FORBIDDEN_PORTAL_RUNTIME_PATHS) {
    await fsp.rm(path.join(root, relative), { recursive: true, force: true });
  }
}

export function assertPortalRuntimePath(artifactPath, {
  repoRoot,
} = {}) {
  const expected = path.resolve(repoRoot, '.runtime', 'portal');
  const actual = path.resolve(artifactPath);
  if (actual !== expected) {
    throw new Error(`Portal release gate artifact must be ${expected}`);
  }
  return actual;
}

async function sha256File(filePath) {
  const hash = crypto.createHash('sha256');
  await new Promise((resolve, reject) => {
    const stream = fs.createReadStream(filePath);
    stream.on('data', (chunk) => hash.update(chunk));
    stream.on('error', reject);
    stream.on('end', resolve);
  });
  return hash.digest('hex');
}

async function walk(root, current = root) {
  const entries = await fsp.readdir(current, { withFileTypes: true });
  entries.sort((a, b) => a.name.localeCompare(b.name));
  const result = [];
  for (const entry of entries) {
    const absolute = path.join(current, entry.name);
    const relative = path.relative(root, absolute).split(path.sep).join('/');
    const stat = await fsp.lstat(absolute);
    if (stat.isDirectory()) {
      result.push({ type: 'dir', path: relative, mode: stat.mode & 0o777 });
      result.push(...await walk(root, absolute));
    } else if (stat.isFile()) {
      result.push({
        type: 'file',
        path: relative,
        mode: stat.mode & 0o777,
        size: stat.size,
        sha256: await sha256File(absolute),
      });
    } else if (stat.isSymbolicLink()) {
      const target = await fsp.readlink(absolute);
      const resolved = path.resolve(path.dirname(absolute), target);
      const relativeResolved = path.relative(root, resolved);
      if (path.isAbsolute(target) || relativeResolved.startsWith(`..${path.sep}`) || relativeResolved === '..') {
        throw new Error(`Artifact symlink escapes root: ${relative}`);
      }
      result.push({ type: 'symlink', path: relative, target });
    } else {
      throw new Error(`Unsupported artifact entry: ${relative}`);
    }
  }
  return result;
}

export async function hashArtifact(artifactPath) {
  const absolute = path.resolve(artifactPath);
  const stat = await fsp.stat(absolute);
  if (stat.isFile()) {
    return {
      sha256: await sha256File(absolute),
      kind: 'file',
      files: 1,
      bytes: stat.size,
    };
  }
  if (!stat.isDirectory()) {
    throw new Error(`Artifact must be a file or directory: ${absolute}`);
  }
  const entries = await walk(absolute);
  const hash = crypto.createHash('sha256');
  for (const entry of entries) {
    hash.update(JSON.stringify(entry));
    hash.update('\n');
  }
  return {
    sha256: hash.digest('hex'),
    kind: 'directory-tree',
    files: entries.filter((entry) => entry.type === 'file').length,
    bytes: entries.reduce((sum, entry) => sum + (entry.size ?? 0), 0),
    entries,
  };
}

export async function inspectPortalRuntime(artifactPath) {
  const root = path.resolve(artifactPath);
  const stat = await fsp.stat(root);
  if (!stat.isDirectory()) {
    throw new Error('Portal runtime inspection requires a directory artifact');
  }
  const missing = [];
  for (const relative of REQUIRED_PORTAL_RUNTIME_PATHS) {
    try {
      await fsp.access(path.join(root, relative));
    } catch {
      missing.push(relative);
    }
  }
  const forbidden = [];
  for (const relative of FORBIDDEN_PORTAL_RUNTIME_PATHS) {
    try {
      await fsp.access(path.join(root, relative));
      forbidden.push(relative);
    } catch {
      // Expected: runtime artifacts must not contain persisted production state.
    }
  }
  return {
    missing,
    forbidden,
    passed: missing.length === 0 && forbidden.length === 0,
  };
}