const API_BASE_URL = import.meta.env.VITE_API_BASE_URL ?? "";

export function apiUrl(path: string): string {
  return `${API_BASE_URL}${path}`;
}

export class ApiHttpError extends Error {
  readonly code: string;
  readonly details?: unknown;

  constructor(message: string, code = "REQUEST_ERROR", details?: unknown) {
    super(message);
    this.name = "ApiHttpError";
    this.code = code;
    this.details = details;
  }
}

async function parseResponse<T>(response: Response): Promise<T> {
  const payload = await response.json().catch(() => ({}));
  if (!response.ok) {
    const legacyError = typeof payload?.error === "object" && payload?.error !== null ? payload.error : null;
    const code = typeof payload?.error === "string" ? payload.error : legacyError?.code ?? "REQUEST_ERROR";
    const message = payload?.message ?? legacyError?.message ?? `Request failed (${response.status})`;
    const details = payload?.details ?? legacyError?.details;
    throw new ApiHttpError(message, code, details);
  }
  return payload.data as T;
}

export async function apiGet<T>(path: string): Promise<T> {
  const response = await fetch(apiUrl(path));
  return parseResponse<T>(response);
}

export async function apiPost<T>(path: string, body?: object): Promise<T> {
  const response = await fetch(apiUrl(path), {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: body ? JSON.stringify(body) : undefined,
  });
  return parseResponse<T>(response);
}

export async function apiPatch<T>(path: string, body?: object): Promise<T> {
  const response = await fetch(apiUrl(path), {
    method: "PATCH",
    headers: { "Content-Type": "application/json" },
    body: body ? JSON.stringify(body) : undefined,
  });
  return parseResponse<T>(response);
}

export async function apiDelete<T>(path: string): Promise<T> {
  const response = await fetch(apiUrl(path), {
    method: "DELETE",
  });
  return parseResponse<T>(response);
}

export async function apiMultipart<T>(path: string, form: FormData): Promise<T> {
  const response = await fetch(apiUrl(path), {
    method: "POST",
    body: form,
  });
  return parseResponse<T>(response);
}