const apiBaseUrl = import.meta.env.VITE_API_BASE_URL ?? ''

export class ApiError extends Error {
  readonly status: number
  readonly details: unknown

  constructor(message: string, status: number, details: unknown) {
    super(message)
    this.name = 'ApiError'
    this.status = status
    this.details = details
  }
}

export async function getJson<T>(path: string): Promise<T> {
  return requestJson<T>(path, {
    method: 'GET',
  })
}

export async function sendJson<T>(path: string, method: 'POST' | 'PUT', body?: unknown): Promise<T> {
  return requestJson<T>(path, {
    method,
    headers: {
      'Content-Type': 'application/json',
    },
    body: body === undefined ? undefined : JSON.stringify(body),
  })
}

async function requestJson<T>(path: string, init: RequestInit): Promise<T> {
  const response = await fetch(`${apiBaseUrl}${path}`, {
    ...init,
    headers: {
      Accept: 'application/json',
      ...init.headers,
    },
  })

  const payload = await readResponsePayload(response)
  if (!response.ok) {
    throw new ApiError(`Request failed with status ${response.status}`, response.status, payload)
  }

  return payload as T
}

async function readResponsePayload(response: Response): Promise<unknown> {
  const contentType = response.headers.get('content-type') ?? ''
  if (!contentType.includes('application/json')) {
    return response.text()
  }
  return response.json()
}