import { i18n } from '@/plugins/i18n'

/** 请求基础 URL，默认 https://api.xtrader.vip，可通过环境变量 VITE_API_BASE_URL 覆盖 */
export const BASE_URL =
  (import.meta as { env?: { VITE_API_BASE_URL?: string } }).env?.VITE_API_BASE_URL ??
  'https://api.xtrader.vip'

const FALLBACK_BASE =
  typeof window !== 'undefined' ? window.location.origin : 'https://api.xtrader.vip'

/** 生成 WebSocket URL，与 REST API 同源 */
function getWsUrl(path: string): string {
  const base = BASE_URL || FALLBACK_BASE
  const url = new URL(base)
  const protocol = url.protocol === 'https:' ? 'wss:' : 'ws:'
  return `${protocol}//${url.host}${path.startsWith('/') ? path : `/${path}`}`
}

/** CLOB WebSocket URL */
export function getClobWsUrl(): string {
  return getWsUrl('/clob/ws')
}

/** User WebSocket URL（订单/持仓/余额推送） */
export function getUserWsUrl(): string {
  return getWsUrl('/clob/ws/user')
}

/**
 * 过滤空值后构建 query 对象，供 GET 请求使用
 * - undefined/null 跳过
 * - 空字符串 '' 跳过
 * - 空数组 [] 跳过
 * - NaN 跳过
 */
export function buildQuery(
  params: Record<string, string | number | string[] | number[] | undefined | null>,
): Record<string, string | number | string[] | number[]> {
  const result: Record<string, string | number | string[] | number[]> = {}
  for (const [k, v] of Object.entries(params)) {
    if (v === undefined || v === null) continue
    if (typeof v === 'string' && v === '') continue
    if (Array.isArray(v) && v.length === 0) continue
    if (typeof v === 'number' && !Number.isFinite(v)) continue
    result[k] = v
  }
  return result
}

export interface RequestConfig {
  /** 请求头，如 { 'x-token': token, 'x-user-id': userId } */
  headers?: Record<string, string>
}

/**
 * 带 x-token 等自定义头的 GET 请求
 */
export async function get<T = unknown>(
  path: string,
  params?: Record<string, string | number | string[] | number[] | undefined>,
  config?: RequestConfig,
): Promise<T> {
  const url = new URL(path, BASE_URL || window.location.origin)
  if (params) {
    Object.entries(params).forEach(([key, value]) => {
      if (value === undefined) return
      if (Array.isArray(value)) {
        value.forEach((v) => url.searchParams.append(key, String(v)))
      } else {
        url.searchParams.set(key, String(value))
      }
    })
  }
  const headers: Record<string, string> = {
    'Content-Type': 'application/json',
    'Accept-Language': i18n.global.locale.value as string,
    ...config?.headers,
  }
  const res = await fetch(url.toString(), { method: 'GET', headers })
  if (!res.ok) {
    throw new Error(`HTTP ${res.status}: ${res.statusText}`)
  }
  return res.json() as Promise<T>
}

/**
 * 带 x-token 等自定义头的 POST 请求
 */
export async function post<T = unknown>(
  path: string,
  body?: unknown,
  config?: RequestConfig,
): Promise<T> {
  const url = new URL(path, BASE_URL || window.location.origin)
  const headers: Record<string, string> = {
    'Content-Type': 'application/json',
    'Accept-Language': i18n.global.locale.value as string,
    ...config?.headers,
  }
  const res = await fetch(url.toString(), {
    method: 'POST',
    headers,
    body: body !== undefined ? JSON.stringify(body) : undefined,
  })
  if (!res.ok) {
    throw new Error(`HTTP ${res.status}: ${res.statusText}`)
  }
  return res.json() as Promise<T>
}