import axios, { AxiosError, type AxiosRequestConfig } from 'axios'

export type ApiError = {
  status: number
  message: string
  data?: unknown
}

export type ApiResponse<T> = {
  code: number
  msg: string
  data?: T | null
}

const defaultBaseUrl = import.meta.env.PROD ? '/api/v1' : 'http://localhost:8000/api/v1'
const baseURL = import.meta.env.VITE_API_BASE_URL || defaultBaseUrl

export const http = axios.create({
  baseURL,
  timeout: 30000,
})

function normalizePath(path: string) {
  if (path.startsWith('http://') || path.startsWith('https://')) return path
  return path.replace(/^\/+/, '')
}

function extractWrappedErrorMessage(data: unknown) {
  if (!data || typeof data !== 'object') return undefined
  const obj = data as Record<string, unknown>
  const msg = obj.msg
  const code = obj.code
  if (typeof msg === 'string' && typeof code === 'number') return `API ${code}: ${msg}`
  if (typeof msg === 'string') return msg
  return undefined
}

function toApiError(error: unknown): ApiError {
  if (axios.isAxiosError(error)) {
    const axiosError = error as AxiosError
    const status = axiosError.response?.status ?? 0
    const wrappedMsg = extractWrappedErrorMessage(axiosError.response?.data)
    const message =
      wrappedMsg ||
      (typeof axiosError.response?.data === 'string'
        ? axiosError.response.data
        : axiosError.message)

    return {
      status,
      message,
      data: axiosError.response?.data,
    }
  }

  return {
    status: 0,
    message: error instanceof Error ? error.message : String(error),
  }
}

export async function apiGet<T>(path: string, config?: AxiosRequestConfig) {
  try {
    const res = await http.get<T>(normalizePath(path), config)
    return res.data
  } catch (error) {
    throw toApiError(error)
  }
}

export function unwrapApiResponse<T>(value: unknown) {
  if (!value || typeof value !== 'object') return { ok: false as const, error: '响应不是对象' }
  const obj = value as Record<string, unknown>
  if (typeof obj.code !== 'number' || typeof obj.msg !== 'string') {
    return { ok: false as const, error: '响应缺少 code/msg 字段' }
  }
  const code = obj.code
  const msg = obj.msg
  const data = obj.data as T | null | undefined
  if (code !== 200) {
    return { ok: false as const, error: `API ${code}: ${msg}`, code, msg, data }
  }
  return { ok: true as const, data }
}

export async function apiGetWrapped<T>(path: string, config?: AxiosRequestConfig) {
  const raw = await apiGet<unknown>(path, config)
  const parsed = unwrapApiResponse<T>(raw)
  if (parsed.ok) return parsed.data as T
  if (parsed.error === '响应缺少 code/msg 字段') return raw as T
  const apiError: ApiError = {
    status: 0,
    message: parsed.error,
    data: raw,
  }
  throw apiError
}

export async function apiPost<TRes, TReq>(
  path: string,
  data: TReq,
  config?: AxiosRequestConfig,
) {
  try {
    const res = await http.post<TRes>(normalizePath(path), data, config)
    return res.data
  } catch (error) {
    throw toApiError(error)
  }
}

export async function apiPostWrapped<TRes, TReq>(
  path: string,
  data: TReq,
  config?: AxiosRequestConfig,
) {
  const raw = await apiPost<unknown, TReq>(path, data, config)
  const parsed = unwrapApiResponse<TRes>(raw)
  if (parsed.ok) return parsed.data as TRes
  if (parsed.error === '响应缺少 code/msg 字段') return raw as TRes
  const apiError: ApiError = {
    status: 0,
    message: parsed.error,
    data: raw,
  }
  throw apiError
}

export async function apiGetText(path: string, config?: AxiosRequestConfig) {
  try {
    const res = await http.get<string>(normalizePath(path), {
      ...config,
      responseType: 'text',
    })
    return res.data
  } catch (error) {
    throw toApiError(error)
  }
}