import { type ApiClientConfig, ApiError, type RequestConfig } from './types';

import { dev } from '$app/environment';
import { DEFAULT_CONFIG } from './constants';
import { delay } from './utils';
import { hcWithType } from '@cio/api/rpc-types';
import { get } from 'svelte/store';
import { currentOrg } from '$lib/utils/store/org';
import type { Cookies } from '@sveltejs/kit';
import { env } from '$env/dynamic/public';
import { getCioCookieString } from '$lib/utils/functions/cookies';

export const getRequestBaseUrl = () => {
  if (typeof window === 'undefined') {
    // When on the server, we want to hit the private url which is the docker container of `api` or the private network url of `api`.
    // if that isn't set then it will fallback to the public url of the `api`
    return process.env.PRIVATE_SERVER_URL || env.PUBLIC_SERVER_URL;
  }

  // Self-hosted: dashboard and API are on different subdomains of the
  // operator's apex. Browser calls go straight to PUBLIC_SERVER_URL;
  // cookies cross subdomains via AUTH_COOKIE_DOMAIN. No Worker proxy.
  if (env.PUBLIC_IS_SELFHOSTED === 'true' || dev) {
    return env.PUBLIC_SERVER_URL ?? '';
  }

  // Cloud (multi-tenant): same-origin via the Cloudflare Worker `/proxy`
  // prefix so auth cookies stay host-only on whichever tenant or BYOD
  // domain the user is currently visiting. The Worker strips `/proxy`
  // before forwarding to the API.
  return `${window.location.origin}/proxy`;
};

function mergeAbortSignals(...signals: Array<AbortSignal | null | undefined>) {
  const activeSignals = signals.filter((signal): signal is AbortSignal => Boolean(signal));

  if (activeSignals.length === 0) {
    return undefined;
  }

  if (activeSignals.length === 1) {
    return activeSignals[0];
  }

  const controller = new AbortController();

  const abortWithSignal = (signal: AbortSignal) => {
    if (controller.signal.aborted) {
      return;
    }

    controller.abort(signal.reason);
  };

  for (const signal of activeSignals) {
    if (signal.aborted) {
      abortWithSignal(signal);
      break;
    }

    signal.addEventListener('abort', () => abortWithSignal(signal), { once: true });
  }

  return controller.signal;
}

class ApiClient {
  private config: Required<ApiClientConfig>;

  constructor(config: ApiClientConfig = {}) {
    this.config = { ...DEFAULT_CONFIG, ...config };
  }

  private async makeRequest(input: RequestInfo | URL, requestConfig: RequestConfig = {}): Promise<Response> {
    const { timeout = this.config.timeout, retries = this.config.retries, ...fetchConfig } = requestConfig;

    // The Hono RPC client already builds a full URL using the base it was
    // constructed with (PRIVATE_SERVER_URL on the server, `${origin}/proxy`
    // in the browser — see `getRequestBaseUrl()` above). Forward it as-is.
    const fullUrl = typeof input === 'string' ? input : input.toString();

    // Prepare headers
    const headers = new Headers(fetchConfig.headers);

    // Add default headers
    if (!headers.has('Accept')) {
      headers.set('Accept', 'application/json');
    }

    // Add organization ID header if available
    const org = get(currentOrg);
    if (org?.id) {
      headers.set('cio-org-id', org.id);
    }

    // Handle body serialization and content-type
    let requestBody = fetchConfig.body;
    const isFormData = fetchConfig.body instanceof FormData;

    if (fetchConfig.body && typeof fetchConfig.body === 'object' && !isFormData) {
      // Auto-stringify objects (except FormData)
      requestBody = JSON.stringify(fetchConfig.body);
      if (!headers.has('Content-Type')) {
        headers.set('Content-Type', 'application/json');
      }
    } else if (fetchConfig.body && !headers.has('Content-Type')) {
      // Set content-type for other body types if not already set
      if (typeof fetchConfig.body === 'string') {
        headers.set('Content-Type', 'text/plain');
      }
    }

    if (isFormData) {
      // Let the browser set the multipart boundary, but keep auth/org headers.
      headers.delete('Content-Type');
    }

    // Create abort controller for timeout
    const timeoutController = new AbortController();
    const timeoutId = setTimeout(() => timeoutController.abort(), timeout);

    const requestInit: RequestInit = {
      ...fetchConfig,
      headers,
      body: requestBody,
      signal: mergeAbortSignals(fetchConfig.signal, timeoutController.signal)
    };

    let lastError: Error | null = null;

    // Retry logic with exponential backoff
    for (let attempt = 0; attempt <= retries; attempt++) {
      try {
        const response = await this.config.customFetch(fullUrl, requestInit);

        clearTimeout(timeoutId);

        await this.config.onResponse(response);

        if (response.ok) {
          return response;
        }

        if (response.status === 401) {
          await this.config.onAuthError();
          throw new ApiError('Authentication failed', response.status, response.statusText, response);
        }

        if (response.status >= 400 && response.status < 500) {
          const errorText = await response.text().catch(() => 'Unknown error');
          throw new ApiError(errorText, response.status, response.statusText, response);
        }

        if (response.status >= 500) {
          const error = new ApiError(response.statusText, response.status, response.statusText, response);

          if (attempt === retries) {
            throw error;
          }

          lastError = error;
          await delay(this.config.retryDelay * Math.pow(2, attempt));
          continue;
        }

        // Other status codes
        throw new ApiError(`Unexpected status: ${response.statusText}`, response.status, response.statusText, response);
      } catch (error) {
        clearTimeout(timeoutId);

        // Handle abort (timeout)
        if (error instanceof Error && error.name === 'AbortError') {
          if (!timeoutController.signal.aborted) {
            throw error;
          }

          throw new ApiError('Request timeout', 408, 'Request Timeout');
        }

        // Handle network errors - retryable
        if (error instanceof TypeError && error.message.includes('fetch')) {
          const networkError = new ApiError('Network error', 0, 'Network Error');

          if (attempt === retries) {
            await this.config.onNetworkError(networkError);
            throw networkError;
          }

          lastError = networkError;
          await delay(this.config.retryDelay * Math.pow(2, attempt));
          continue;
        }

        // Re-throw non-retryable errors
        throw error;
      }
    }

    // If we get here, all retries failed
    throw lastError || new ApiError('Request failed after all retries');
  }

  // Generic request method - handles all HTTP methods
  async request(input: RequestInfo | URL, config: RequestConfig = {}): Promise<Response> {
    return this.makeRequest(input, config);
  }

  // Update configuration
  updateConfig(newConfig: Partial<ApiClientConfig>): void {
    this.config = { ...this.config, ...newConfig };
  }
}

// Create default instance
export const apiClient = new ApiClient();

// RPC client using the new fetch wrapper
export const classroomio = hcWithType(getRequestBaseUrl(), {
  fetch: async (input: RequestInfo | URL, requestInit?: RequestInit) => {
    return apiClient.request(input, requestInit);
  },
  init: {
    credentials: 'include' // Required for sending cookies cross-origin
  }
});

// Utility functions for common use cases
export const createApiClient = (config: ApiClientConfig) => new ApiClient(config);

// Re-export utility functions for convenience
export {
  handleJsonResponse,
  handleTextResponse,
  isApiError,
  isNetworkError,
  isAuthError,
  isClientError,
  isServerError,
  isTimeoutError,
  safeRequest,
  safeRequestText,
  safeRequestRaw,
  type Result
} from './utils';

export type { InferResponseType, InferRequestType } from '@cio/api/rpc-types';

// Export base API classes
export { BaseApi, BaseApiWithErrors } from './base.svelte';

/**
 * Gets headers with cookies and organization ID for API calls
 * Use this in load functions (+page.server.ts, +layout.server.ts) to pass user session cookies
 * and organization ID to API calls. This ensures authentication and organization context work correctly.
 *
 * @param cookies Cookies object from SvelteKit load function
 * @param orgId Organization ID to include in headers
 * @returns Headers object with cookie string and cio-org-id header
 *
 * @example
 * ```typescript
 * export const load = async ({ cookies, parent }) => {
 *   const { org } = await parent();
 *   const response = await classroomio.organization.$get(
 *     { query: { siteName } },
 *     getApiHeaders(cookies, org?.id)
 *   );
 * };
 * ```
 */
export function getApiHeaders(
  cookies: Cookies,
  orgId?: string
): { headers: { cookie: string; 'cio-org-id'?: string } } {
  const cioCookies = getCioCookieString(cookies);

  console.log('cioCookies', cioCookies);
  console.log('cookies', cookies.getAll());
  const headers: { cookie: string; 'cio-org-id'?: string } = {
    cookie: cioCookies || ''
  };

  console.log('headers', headers);
  console.log('orgId', orgId);

  if (orgId) {
    headers['cio-org-id'] = orgId;
  }

  return { headers };
}