import { env } from '../config/env'

type RequestJsonOptions = Omit<RequestInit, 'body'> & {
  timeoutMs?: number
  body?: unknown
}

export class HttpError extends Error {
  public readonly status: number
  public readonly payload: string

  constructor(message: string, status: number, payload: string) {
    super(message)
    this.status = status
    this.payload = payload
  }
}

export function apiUrl(path: string): string {
  const normalizedPath = path.startsWith('/') ? path : `/${path}`
  if (!env.apiBaseUrl) {
    return normalizedPath
  }
  return `${env.apiBaseUrl}${normalizedPath}`
}

export async function requestJson<T>(path: string, options: RequestJsonOptions = {}): Promise<T> {
  const controller = new AbortController()
  const timeoutMs = options.timeoutMs ?? 8000

  const headers = new Headers(options.headers || {})
  const hasBody = options.body !== undefined
  if (hasBody && !headers.has('Content-Type')) {
    headers.set('Content-Type', 'application/json')
  }

  const timeout = setTimeout(() => {
    controller.abort()
  }, timeoutMs)

  try {
    const response = await fetch(apiUrl(path), {
      ...options,
      headers,
      body: hasBody ? JSON.stringify(options.body) : undefined,
      signal: controller.signal,
    })

    const text = await response.text()
    if (!response.ok) {
      throw new HttpError(`Request failed: ${response.status}`, response.status, text)
    }

    if (!text) {
      return {} as T
    }

    return JSON.parse(text) as T
  } finally {
    clearTimeout(timeout)
  }
}