import type { ApiResponse } from './types'

const TOKEN_KEY = 'gen2d_token'

export function getToken(): string | null {
  return localStorage.getItem(TOKEN_KEY)
}

export function setToken(token: string): void {
  localStorage.setItem(TOKEN_KEY, token)
}

export function clearToken(): void {
  localStorage.removeItem(TOKEN_KEY)
}

export class ApiError extends Error {
  code: number
  constructor(code: number, message: string) {
    super(message)
    this.code = code
  }
}

async function request<T>(url: string, options: RequestInit = {}): Promise<T> {
  const token = getToken()
  const headers: Record<string, string> = {
    'Content-Type': 'application/json',
    ...(options.headers as Record<string, string>),
  }
  if (token) {
    headers['Authorization'] = `Bearer ${token}`
  }

  const res = await fetch(url, {
    ...options,
    headers,
    credentials: 'include',
  })

  const json: ApiResponse<T> = await res.json()

  if (json.code !== 0) {
    throw new ApiError(json.code, json.message)
  }

  return json.data
}

export function get<T>(url: string): Promise<T> {
  return request<T>(url)
}

export function post<T>(url: string, body?: unknown): Promise<T> {
  return request<T>(url, {
    method: 'POST',
    body: body ? JSON.stringify(body) : undefined,
  })
}

export function put<T>(url: string, body?: unknown): Promise<T> {
  return request<T>(url, {
    method: 'PUT',
    body: body ? JSON.stringify(body) : undefined,
  })
}