#!/usr/bin/env node
/**
 * 依赖方向检查（任务 A1.2）。
 *
 * 拦三类反向依赖：
 *   1. 包之间越界——core 引用具体 Provider、业务包直连 Provider、客户端引用服务端
 *   2. 相对路径逃出包边界
 *   3. 引擎包被 server/agent 之外的模块引用（ADR-0006）
 *
 * 用法：node scripts/check-dependency-direction.mjs [仓库根目录]
 * 退出码 0 = 无违规，1 = 有违规。
 */
import { existsSync } from 'node:fs';
import { readFile, readdir, stat } from 'node:fs/promises';
import { dirname, join, relative, resolve, sep } from 'node:path';
import process from 'node:process';
import { pathToFileURL } from 'node:url';

/** 包 → 允许依赖的包。新增包必须在这里登记，否则视为违规。 */
export const PACKAGE_RULES = {
  '@aps/contracts': { allow: [] },
  '@aps/provider-sdk': { allow: ['@aps/contracts'] },
  '@aps/server': { allow: ['@aps/contracts', '@aps/provider-sdk'] },
  '@aps/client-app': { allow: ['@aps/contracts'] },
  '@aps/desktop': { allow: ['@aps/contracts', '@aps/client-app'] },
  '@aps/provider-aps': { allow: ['@aps/contracts', '@aps/provider-sdk'] },
};

/** 引擎包：只有 server/agent 允许引用（ADR-0006）。 */
export const ENGINE_PACKAGES = ['@earendil-works/pi-agent-core', '@earendil-works/pi-ai'];

const ENGINE_ALLOWED_PREFIX = 'server/agent/';
const SOURCE_EXTENSIONS = new Set(['.ts', '.tsx', '.mts', '.cts', '.js', '.mjs', '.cjs']);
const SKIP_DIRS = new Set(['node_modules', 'dist', '.git', 'coverage', '__pycache__']);

async function workspacePatterns(root) {
  const file = join(root, 'pnpm-workspace.yaml');
  if (!existsSync(file)) throw new Error(`未找到 ${file}`);
  const text = await readFile(file, 'utf8');
  const patterns = [];
  for (const line of text.split(/\r?\n/)) {
    const trimmed = line.trim();
    if (trimmed.startsWith('- ')) patterns.push(trimmed.slice(2).trim().replace(/^['"]|['"]$/g, ''));
  }
  return patterns;
}

export async function workspacePackages(root) {
  const dirs = [];
  for (const pattern of await workspacePatterns(root)) {
    if (pattern.includes('*')) {
      const base = pattern.replace(/\/\*+$/, '');
      const entries = await readdir(join(root, base), { withFileTypes: true }).catch(() => []);
      for (const entry of entries) if (entry.isDirectory()) dirs.push(`${base}/${entry.name}`);
    } else {
      dirs.push(pattern);
    }
  }
  return [...new Set(dirs)];
}

async function collectSources(dir, nestedRoots, acc = []) {
  let entries;
  try {
    entries = await readdir(dir, { withFileTypes: true });
  } catch {
    return acc;
  }
  for (const entry of entries) {
    const full = join(dir, entry.name);
    if (entry.isDirectory()) {
      if (SKIP_DIRS.has(entry.name)) continue;
      if (nestedRoots.has(full)) continue; // 嵌套包由它自己那轮检查
      await collectSources(full, nestedRoots, acc);
    } else if (SOURCE_EXTENSIONS.has(entry.name.slice(entry.name.lastIndexOf('.')))) {
      acc.push(full);
    }
  }
  return acc;
}

function extractSpecifiers(text) {
  const found = new Set();
  const patterns = [
    /(?:^|[^\w$.])import\s+(?:[^'";]*?\sfrom\s+)?['"]([^'"]+)['"]/g,
    /import\s*\(\s*['"]([^'"]+)['"]\s*\)/g,
    /require\s*\(\s*['"]([^'"]+)['"]\s*\)/g,
  ];
  for (const pattern of patterns) {
    let match;
    while ((match = pattern.exec(text)) !== null) found.add(match[1]);
  }
  return [...found];
}

const allowText = (rule) => (rule.allow.length ? rule.allow.join('、') : '无');

/** 返回违规清单；空数组表示通过。 */
export async function findViolations(root) {
  const packages = await workspacePackages(root);
  const nestedRoots = new Set(packages.map((rel) => join(root, rel)));
  const violations = [];

  for (const rel of packages) {
    const pkgDir = join(root, rel);
    const manifestPath = join(pkgDir, 'package.json');
    if (!existsSync(manifestPath)) {
      violations.push({ package: rel, file: `${rel}/package.json`, specifier: '', reason: '工作区目录缺少 package.json' });
      continue;
    }
    const manifest = JSON.parse(await readFile(manifestPath, 'utf8'));
    const name = manifest.name ?? rel;
    const rule = PACKAGE_RULES[name];
    if (!rule) {
      violations.push({ package: name, file: `${rel}/package.json`, specifier: '', reason: '未登记的包名：先在 PACKAGE_RULES 里写明它允许依赖谁' });
      continue;
    }

    const declared = [
      ...Object.keys(manifest.dependencies ?? {}),
      ...Object.keys(manifest.devDependencies ?? {}),
      ...Object.keys(manifest.peerDependencies ?? {}),
    ];
    for (const dep of declared) {
      if (dep.startsWith('@aps/') && dep !== name && !rule.allow.includes(dep)) {
        violations.push({ package: name, file: `${rel}/package.json`, specifier: dep, reason: `声明了不允许的依赖（允许：${allowText(rule)}）` });
      }
    }

    for (const file of await collectSources(pkgDir, nestedRoots)) {
      const relFile = relative(root, file).split(sep).join('/');
      const text = await readFile(file, 'utf8');
      for (const specifier of extractSpecifiers(text)) {
        if (specifier.startsWith('@aps/')) {
          if (specifier === name) continue;
          if (!rule.allow.includes(specifier)) {
            violations.push({ package: name, file: relFile, specifier, reason: `不允许引用该包（允许：${allowText(rule)}）` });
          }
          continue;
        }
        const engineHit = ENGINE_PACKAGES.find((pkg) => specifier === pkg || specifier.startsWith(`${pkg}/`));
        if (engineHit) {
          if (!relFile.startsWith(ENGINE_ALLOWED_PREFIX)) {
            violations.push({ package: name, file: relFile, specifier, reason: `引擎包只能由 ${ENGINE_ALLOWED_PREFIX} 引用（ADR-0006）` });
          }
          continue;
        }
        if (specifier.startsWith('.')) {
          const target = resolve(dirname(file), specifier);
          const inside = target === pkgDir || target.startsWith(pkgDir + sep);
          if (!inside) violations.push({ package: name, file: relFile, specifier, reason: '相对路径逃出包边界' });
        }
      }
    }
  }
  return violations;
}

async function main() {
  const root = resolve(process.argv[2] ?? process.cwd());
  if (!(await stat(root)).isDirectory()) throw new Error(`${root} 不是目录`);
  const violations = await findViolations(root);
  if (violations.length === 0) {
    console.log(`依赖方向检查通过（根目录：${root}）`);
    return;
  }
  console.error(`依赖方向检查发现 ${violations.length} 处违规：`);
  for (const v of violations) {
    console.error(`  [${v.package}] ${v.file}${v.specifier ? ` → ${v.specifier}` : ''}：${v.reason}`);
  }
  process.exitCode = 1;
}

if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
  await main();
}