// ============================================================
// ZCLAW SaaS Admin — 类型化 HTTP 客户端
// ============================================================

import { getToken, logout } from './auth'
import type {
  AccountPublic,
  ApiError,
  ConfigItem,
  CreateTokenRequest,
  DashboardStats,
  LoginRequest,
  LoginResponse,
  Model,
  OperationLog,
  PaginatedResponse,
  Provider,
  RelayTask,
  TokenInfo,
  UsageByModel,
  UsageRecord,
} from './types'

// ── 错误类 ────────────────────────────────────────────────

export class ApiRequestError extends Error {
  constructor(
    public status: number,
    public body: ApiError,
  ) {
    super(body.message || `Request failed with status ${status}`)
    this.name = 'ApiRequestError'
  }
}

// ── 基础请求 ──────────────────────────────────────────────

const BASE_URL = process.env.NEXT_PUBLIC_SAAS_API_URL || 'http://localhost:8080'

async function request<T>(
  method: string,
  path: string,
  body?: unknown,
): Promise<T> {
  const token = getToken()
  const headers: Record<string, string> = {
    'Content-Type': 'application/json',
  }
  if (token) {
    headers['Authorization'] = `Bearer ${token}`
  }

  const res = await fetch(`${BASE_URL}${path}`, {
    method,
    headers,
    body: body ? JSON.stringify(body) : undefined,
  })

  if (res.status === 401) {
    logout()
    if (typeof window !== 'undefined') {
      window.location.href = '/login'
    }
    throw new ApiRequestError(401, { error: 'unauthorized', message: '登录已过期，请重新登录' })
  }

  if (!res.ok) {
    let errorBody: ApiError
    try {
      errorBody = await res.json()
    } catch {
      errorBody = { error: 'unknown', message: `请求失败 (${res.status})` }
    }
    throw new ApiRequestError(res.status, errorBody)
  }

  // 204 No Content
  if (res.status === 204) {
    return undefined as T
  }

  return res.json() as Promise<T>
}

// ── API 客户端 ────────────────────────────────────────────

export const api = {
  // ── 认证 ──────────────────────────────────────────────
  auth: {
    async login(data: LoginRequest): Promise<LoginResponse> {
      return request<LoginResponse>('POST', '/api/auth/login', data)
    },

    async register(data: {
      username: string
      password: string
      email: string
      display_name?: string
    }): Promise<LoginResponse> {
      return request<LoginResponse>('POST', '/api/auth/register', data)
    },

    async me(): Promise<AccountPublic> {
      return request<AccountPublic>('GET', '/api/auth/me')
    },
  },

  // ── 账号管理 ──────────────────────────────────────────
  accounts: {
    async list(params?: {
      page?: number
      page_size?: number
      search?: string
      role?: string
      status?: string
    }): Promise<PaginatedResponse<AccountPublic>> {
      const qs = buildQueryString(params)
      return request<PaginatedResponse<AccountPublic>>('GET', `/api/accounts${qs}`)
    },

    async get(id: string): Promise<AccountPublic> {
      return request<AccountPublic>('GET', `/api/accounts/${id}`)
    },

    async update(
      id: string,
      data: Partial<Pick<AccountPublic, 'display_name' | 'email' | 'role'>>,
    ): Promise<AccountPublic> {
      return request<AccountPublic>('PATCH', `/api/accounts/${id}`, data)
    },

    async updateStatus(
      id: string,
      data: { status: AccountPublic['status'] },
    ): Promise<void> {
      return request<void>('PATCH', `/api/accounts/${id}/status`, data)
    },
  },

  // ── 服务商管理 ────────────────────────────────────────
  providers: {
    async list(params?: {
      page?: number
      page_size?: number
    }): Promise<PaginatedResponse<Provider>> {
      const qs = buildQueryString(params)
      return request<PaginatedResponse<Provider>>('GET', `/api/providers${qs}`)
    },

    async create(data: Partial<Omit<Provider, 'id' | 'created_at' | 'updated_at'>>): Promise<Provider> {
      return request<Provider>('POST', '/api/providers', data)
    },

    async update(
      id: string,
      data: Partial<Omit<Provider, 'id' | 'created_at' | 'updated_at'>>,
    ): Promise<Provider> {
      return request<Provider>('PATCH', `/api/providers/${id}`, data)
    },

    async delete(id: string): Promise<void> {
      return request<void>('DELETE', `/api/providers/${id}`)
    },
  },

  // ── 模型管理 ──────────────────────────────────────────
  models: {
    async list(params?: {
      page?: number
      page_size?: number
      provider_id?: string
    }): Promise<PaginatedResponse<Model>> {
      const qs = buildQueryString(params)
      return request<PaginatedResponse<Model>>('GET', `/api/models${qs}`)
    },

    async create(data: Partial<Omit<Model, 'id'>>): Promise<Model> {
      return request<Model>('POST', '/api/models', data)
    },

    async update(id: string, data: Partial<Omit<Model, 'id'>>): Promise<Model> {
      return request<Model>('PATCH', `/api/models/${id}`, data)
    },

    async delete(id: string): Promise<void> {
      return request<void>('DELETE', `/api/models/${id}`)
    },
  },

  // ── API 密钥 ──────────────────────────────────────────
  tokens: {
    async list(params?: {
      page?: number
      page_size?: number
    }): Promise<PaginatedResponse<TokenInfo>> {
      const qs = buildQueryString(params)
      return request<PaginatedResponse<TokenInfo>>('GET', `/api/tokens${qs}`)
    },

    async create(data: CreateTokenRequest): Promise<TokenInfo> {
      return request<TokenInfo>('POST', '/api/tokens', data)
    },

    async revoke(id: string): Promise<void> {
      return request<void>('DELETE', `/api/tokens/${id}`)
    },
  },

  // ── 用量统计 ──────────────────────────────────────────
  usage: {
    async daily(params?: { days?: number }): Promise<UsageRecord[]> {
      const qs = buildQueryString(params)
      return request<UsageRecord[]>('GET', `/api/usage/daily${qs}`)
    },

    async byModel(params?: { days?: number }): Promise<UsageByModel[]> {
      const qs = buildQueryString(params)
      return request<UsageByModel[]>('GET', `/api/usage/by-model${qs}`)
    },
  },

  // ── 中转任务 ──────────────────────────────────────────
  relay: {
    async list(params?: {
      page?: number
      page_size?: number
      status?: string
    }): Promise<PaginatedResponse<RelayTask>> {
      const qs = buildQueryString(params)
      return request<PaginatedResponse<RelayTask>>('GET', `/api/relay/tasks${qs}`)
    },

    async get(id: string): Promise<RelayTask> {
      return request<RelayTask>('GET', `/api/relay/tasks/${id}`)
    },
  },

  // ── 系统配置 ──────────────────────────────────────────
  config: {
    async list(params?: {
      category?: string
    }): Promise<ConfigItem[]> {
      const qs = buildQueryString(params)
      return request<ConfigItem[]>('GET', `/api/config${qs}`)
    },

    async update(id: string, data: { value: string | number | boolean }): Promise<ConfigItem> {
      return request<ConfigItem>('PATCH', `/api/config/${id}`, data)
    },
  },

  // ── 操作日志 ──────────────────────────────────────────
  logs: {
    async list(params?: {
      page?: number
      page_size?: number
      action?: string
    }): Promise<PaginatedResponse<OperationLog>> {
      const qs = buildQueryString(params)
      return request<PaginatedResponse<OperationLog>>('GET', `/api/logs${qs}`)
    },
  },

  // ── 仪表盘 ────────────────────────────────────────────
  stats: {
    async dashboard(): Promise<DashboardStats> {
      return request<DashboardStats>('GET', '/api/stats/dashboard')
    },
  },
}

// ── 工具函数 ──────────────────────────────────────────────

function buildQueryString(params?: Record<string, unknown>): string {
  if (!params) return ''
  const entries = Object.entries(params).filter(
    ([, v]) => v !== undefined && v !== null && v !== '',
  )
  if (entries.length === 0) return ''
  const qs = entries
    .map(([k, v]) => `${encodeURIComponent(k)}=${encodeURIComponent(String(v))}`)
    .join('&')
  return `?${qs}`
}