import { existsSync, readFileSync, readdirSync } from 'node:fs'
import { join, resolve } from 'node:path'

export const STANDALONE_PACKAGE_NAME = 'crawler-plugin-admin-frontend-vue'

/** 后台壳层允许存在的源码目录（任务 1 冻结的工作区边界，供验收脚本复用）。 */
export const ADMIN_SOURCE_DIRS = [
  'src/layout',
  'src/router',
  'src/styles',
  'src/types',
  'src/config',
  'src/pages',
] as const

export const REQUIRED_MANIFEST_FILES = [
  'package.json',
  'index.html',
  'vite.config.ts',
  'tsconfig.json',
  'src/main.ts',
  'src/App.vue',
] as const

// 客户端工程耦合标记：后台工程内出现即代表越界。用带路径/产物语义的标记，
// 避免与本工程自身包名后缀（…admin-frontend-vue）误匹配。扫描时排除本文件自身。
export const FORBIDDEN_COUPLING_TOKENS = [
  'new_web_source',
  'frontend-vue/',
  'app_client',
] as const

const SELF_SCAN_EXCLUSIONS = new Set(['src/config/workspace.ts'])
const SCAN_EXTENSIONS = /\.(ts|tsx|vue|css|html|json|js)$/

export function walk(rootDir: string, base = ''): string[] {
  const found: string[] = []
  for (const entry of readdirSync(join(rootDir, base), { withFileTypes: true })) {
    if (['node_modules', 'dist', '.git', 'tests'].includes(entry.name)) continue
    const rel = base ? `${base}/${entry.name}` : entry.name
    if (entry.isDirectory()) found.push(...walk(rootDir, rel))
    else if (SCAN_EXTENSIONS.test(entry.name)) found.push(rel)
  }
  return found
}

function fileExists(rootDir: string, path: string): boolean {
  return existsSync(join(rootDir, path))
}

/** 从当前目录向上定位独立后台工程根目录，找不到时给出可操作错误。 */
export function resolveWorkspaceRoot(cwd = process.cwd()): string {
  let dir = resolve(cwd)
  for (let i = 0; i < 6; i += 1) {
    if (fileExists(dir, 'package.json')) return dir
    const parent = resolve(dir, '..')
    if (parent === dir) break
    dir = parent
  }
  throw new Error(`在 ${cwd} 向上 6 层内找不到 package.json，请在 admin-frontend-vue 工程目录内执行`)
}

export interface WorkspacePackage {
  name: string
  private: boolean
  scripts: Record<string, string>
  dependencies: Record<string, string>
  devDependencies: Record<string, string>
}

export function readWorkspacePackage(rootDir = resolveWorkspaceRoot()): WorkspacePackage {
  const raw = JSON.parse(readFileSync(join(rootDir, 'package.json'), 'utf8')) as Partial<WorkspacePackage> & { private?: boolean }
  return {
    name: raw.name || '',
    private: raw.private !== false,
    scripts: raw.scripts || {},
    dependencies: raw.dependencies || {},
    devDependencies: raw.devDependencies || {},
  }
}

/** 校验独立工程边界，返回违规清单（空数组 = 边界成立）。 */
export function collectBoundaryViolations(rootDir = resolveWorkspaceRoot()): string[] {
  const violations: string[] = []
  const pkgPath = join(rootDir, 'package.json')
  const pkg: WorkspacePackage = fileExists(rootDir, 'package.json')
    ? readWorkspacePackage(rootDir)
    : { name: '', private: false, scripts: {}, dependencies: {}, devDependencies: {} }
  if (!fileExists(rootDir, 'package.json')) violations.push(`缺少必需清单文件 package.json（在 ${pkgPath}）`)

  if (pkg.name !== STANDALONE_PACKAGE_NAME) {
    violations.push(`package.name 应为 ${STANDALONE_PACKAGE_NAME}，实际为 ${pkg.name || '(空)'}`)
  }
  if (!pkg.private) violations.push('package.private 应为 true（后台工程不允许被外部发布依赖）')

  for (const file of REQUIRED_MANIFEST_FILES) {
    if (!fileExists(rootDir, file)) violations.push(`缺少必需清单文件 ${file}`)
  }
  for (const dir of ADMIN_SOURCE_DIRS) {
    if (!fileExists(rootDir, dir)) violations.push(`缺少允许源码目录 ${dir}`)
  }

  for (const file of walk(rootDir)) {
    if (SELF_SCAN_EXCLUSIONS.has(file)) continue
    const content = readFileSync(join(rootDir, file), 'utf8')
    for (const token of FORBIDDEN_COUPLING_TOKENS) {
      if (content.includes(token)) {
        violations.push(`${file} 引用了客户端耦合 token "${token}"，超出后台工程边界`)
      }
    }
  }
  return violations
}