// Generic API client with authentication

import type { AuthUser } from '@/auth/types';
import { ApiError } from '@/types';

let onUnauthorized: (() => void) | null = null;

export function setOnUnauthorized(handler: () => void): void {
  onUnauthorized = handler;
}

export function fireUnauthorized(): void {
  if (onUnauthorized) {
    onUnauthorized();
  }
}

export interface RequestOptions {
  method?: 'GET' | 'POST' | 'PUT' | 'DELETE';
  params?: Record<string, string | number | boolean | Date | undefined>;
  body?: unknown;
}

/**
 * Build query string from parameters object
 */
function buildQueryString(params: Record<string, string | number | boolean | Date | undefined>): string {
  const queryString = new URLSearchParams();

  for (const [key, value] of Object.entries(params)) {
    if (value !== undefined && value !== null && value !== '') {
      if (value instanceof Date) {
        queryString.append(key, value.toISOString());
      } else {
        queryString.append(key, String(value));
      }
    }
  }

  return queryString.toString();
}

/**
 * Generic authenticated API request
 */
export async function apiRequest<T>(
  user: AuthUser,
  endpoint: string,
  options: RequestOptions = {}
): Promise<T> {
  const { method = 'GET', params, body } = options;

  let url = endpoint;
  if (params) {
    const queryString = buildQueryString(params);
    if (queryString) {
      url = `${endpoint}?${queryString}`;
    }
  }

  const fetchOptions: RequestInit = {
    method,
    headers: {
      Authorization: `Bearer ${user.accessToken}`,
      'Content-Type': 'application/json',
    },
  };

  if (body !== undefined) {
    fetchOptions.body = JSON.stringify(body);
  }

  const response = await fetch(url, fetchOptions);

  if (!response.ok) {
    if (response.status === 401) {
      fireUnauthorized();
    }
    throw new ApiError(`Error: ${response.status}`, response.status);
  }

  return response.json() as Promise<T>;
}