/**
 * Adapter Service — 读写 IM Adapter 配置文件
 *
 * 配置文件：~/.claude/adapters.json
 * 原子写入：先写临时文件，再 rename
 */

import * as fs from 'fs/promises'
import * as path from 'path'
import * as os from 'os'
import { ApiError } from '../middleware/errorHandler.js'

export type PairedUser = {
  userId: string | number
  displayName: string
  pairedAt: number
}

export type PairingState = {
  code?: string | null
  expiresAt?: number | null
  createdAt?: number | null
}

export type AdapterFileConfig = {
  serverUrl?: string
  defaultProjectDir?: string
  pairing?: PairingState
  telegram?: {
    botToken?: string
    allowedUsers?: number[]
    pairedUsers?: PairedUser[]
    defaultWorkDir?: string
  }
  feishu?: {
    appId?: string
    appSecret?: string
    encryptKey?: string
    verificationToken?: string
    allowedUsers?: string[]
    pairedUsers?: PairedUser[]
    defaultWorkDir?: string
    streamingCard?: boolean
  }
  wechat?: {
    accountId?: string
    botToken?: string
    baseUrl?: string
    userId?: string
    allowedUsers?: string[]
    pairedUsers?: PairedUser[]
    defaultWorkDir?: string
  }
}

function getConfigPath(): string {
  const configDir = process.env.CLAUDE_CONFIG_DIR || path.join(os.homedir(), '.claude')
  return path.join(configDir, 'adapters.json')
}

function maskSecret(value: string | undefined): string | undefined {
  if (!value) return value
  if (value.length <= 4) return '****'
  return '****' + value.slice(-4)
}

function isMasked(value: string | undefined): boolean {
  return !!value && value.startsWith('****')
}

class AdapterService {
  /** 读取原始配置（不脱敏） */
  async getRawConfig(): Promise<AdapterFileConfig> {
    try {
      const raw = await fs.readFile(getConfigPath(), 'utf-8')
      return JSON.parse(raw) as AdapterFileConfig
    } catch (err: unknown) {
      if ((err as NodeJS.ErrnoException).code === 'ENOENT') {
        return {}
      }
      throw ApiError.internal(`Failed to read adapter config: ${err}`)
    }
  }

  /** 读取配置（敏感字段脱敏） */
  async getConfig(): Promise<AdapterFileConfig> {
    const config = await this.getRawConfig()
    if (config.telegram?.botToken) {
      config.telegram.botToken = maskSecret(config.telegram.botToken)
    }
    if (config.feishu) {
      if (config.feishu.appSecret) config.feishu.appSecret = maskSecret(config.feishu.appSecret)
      if (config.feishu.encryptKey) config.feishu.encryptKey = maskSecret(config.feishu.encryptKey)
      if (config.feishu.verificationToken) config.feishu.verificationToken = maskSecret(config.feishu.verificationToken)
    }
    if (config.wechat?.botToken) {
      config.wechat.botToken = maskSecret(config.wechat.botToken)
    }
    if (config.pairing?.code) {
      config.pairing.code = '******'
    }
    return config
  }

  /** 更新配置（浅合并，敏感字段如果是脱敏值则保留原值） */
  async updateConfig(patch: Partial<AdapterFileConfig>): Promise<void> {
    const current = await this.getRawConfig()

    // 保留已存储的密钥（如果前端传回的是脱敏值）
    if (patch.telegram && isMasked(patch.telegram.botToken)) {
      patch.telegram.botToken = current.telegram?.botToken
    }
    if (patch.feishu) {
      if (isMasked(patch.feishu.appSecret)) patch.feishu.appSecret = current.feishu?.appSecret
      if (isMasked(patch.feishu.encryptKey)) patch.feishu.encryptKey = current.feishu?.encryptKey
      if (isMasked(patch.feishu.verificationToken)) patch.feishu.verificationToken = current.feishu?.verificationToken
    }
    if (patch.wechat && isMasked(patch.wechat.botToken)) {
      patch.wechat.botToken = current.wechat?.botToken
    }
    if (patch.pairing && isMasked(patch.pairing.code ?? undefined)) {
      patch.pairing.code = current.pairing?.code
    }

    const merged: AdapterFileConfig = {
      ...current,
      ...patch,
      telegram: patch.telegram ? { ...current.telegram, ...patch.telegram } : current.telegram,
      feishu: patch.feishu ? { ...current.feishu, ...patch.feishu } : current.feishu,
      wechat: patch.wechat ? { ...current.wechat, ...patch.wechat } : current.wechat,
      pairing: patch.pairing !== undefined ? { ...current.pairing, ...patch.pairing } : current.pairing,
    }

    await this.writeConfig(merged)
  }

  private async writeConfig(data: AdapterFileConfig): Promise<void> {
    const filePath = getConfigPath()
    const dir = path.dirname(filePath)
    await fs.mkdir(dir, { recursive: true })

    const tmpFile = `${filePath}.tmp.${Date.now()}`
    try {
      await fs.writeFile(tmpFile, JSON.stringify(data, null, 2) + '\n', 'utf-8')
      await fs.rename(tmpFile, filePath)
    } catch (err) {
      await fs.unlink(tmpFile).catch(() => {})
      throw ApiError.internal(`Failed to write adapter config: ${err}`)
    }
  }
}

export const adapterService = new AdapterService()