/// <reference path="./deno.types.ts" />
import * as types from './types.js';
import { CoreResponse } from './response.js';
import { CoreRequest as AbstractCoreRequest } from '../core_base/request.js';

/**
 * Cache for HttpClient instances keyed by socket path
 * This prevents creating multiple clients for the same socket
 */
const httpClientCache = new Map<string, Deno.HttpClient>();

/**
 * Deno implementation of Core Request class using native fetch with unix socket support via HttpClient
 */
export class CoreRequest extends AbstractCoreRequest<
  types.IDenoRequestOptions,
  CoreResponse
> {
  private timeoutId: ReturnType<typeof setTimeout> | null = null;
  private abortController: AbortController | null = null;
  private createdClient: Deno.HttpClient | null = null;
  private requestDataFunc: ((req: any) => void) | null;

  constructor(
    url: string,
    options: types.IDenoRequestOptions = {},
    requestDataFunc: ((req: any) => void) | null = null,
  ) {
    super(url, options);
    this.requestDataFunc = requestDataFunc;

    // Check for unsupported Node.js-specific options
    if (options.agent) {
      throw new Error(
        'Node.js specific option (agent) is not supported in Deno implementation',
      );
    }

    // Handle Node.js stream conversion if requestDataFunc is provided
    if (requestDataFunc && (options as any).__nodeStream) {
      // Convert Node.js stream to web ReadableStream for Deno
      const nodeStream = (options as any).__nodeStream;

      // Create web ReadableStream from Node.js stream
      this.options.requestBody = new ReadableStream({
        async start(controller) {
          nodeStream.on('data', (chunk: any) => {
            controller.enqueue(new Uint8Array(chunk));
          });
          nodeStream.on('end', () => {
            controller.close();
          });
          nodeStream.on('error', (err: any) => {
            controller.error(err);
          });
        },
      });
    }

    // Throw error if raw streaming function is provided (not supported in Deno)
    if (requestDataFunc && (options as any).__rawStreamFunc) {
      throw new Error(
        'Raw streaming with .raw() is not supported in Deno. Use .stream() with web ReadableStream instead.',
      );
    }
  }

  /**
   * Get or create an HttpClient for unix socket communication
   */
  private getHttpClient(): Deno.HttpClient | undefined {
    // If client was explicitly provided, use it
    if (this.options.client) {
      return this.options.client;
    }

    // Check if we need a unix socket client
    const socketPath = this.options.socketPath ||
      (CoreRequest.isUnixSocket(this.url)
        ? CoreRequest.parseUnixSocketUrl(this.url).socketPath
        : null);

    if (!socketPath) {
      return undefined; // Use default client
    }

    // Check cache first
    if (httpClientCache.has(socketPath)) {
      return httpClientCache.get(socketPath);
    }

    // Create new HttpClient for this socket
    const client = Deno.createHttpClient({
      proxy: {
        url: `unix://${socketPath}`,
      },
    });

    // Cache it
    httpClientCache.set(socketPath, client);
    this.createdClient = client;

    return client;
  }

  /**
   * Build the full URL with query parameters
   */
  private buildUrl(): string {
    // For unix sockets, we need to extract the HTTP path part
    if (CoreRequest.isUnixSocket(this.url)) {
      const { path } = CoreRequest.parseUnixSocketUrl(this.url);

      // Build URL for the HTTP request (the hostname doesn't matter for unix sockets)
      if (
        !this.options.queryParams ||
        Object.keys(this.options.queryParams).length === 0
      ) {
        return `http://localhost${path}`;
      }

      const url = new URL(`http://localhost${path}`);
      Object.entries(this.options.queryParams).forEach(([key, value]) => {
        url.searchParams.append(key, value);
      });
      return url.toString();
    }

    // Regular HTTP/HTTPS URL
    if (
      !this.options.queryParams ||
      Object.keys(this.options.queryParams).length === 0
    ) {
      return this.url;
    }

    const url = new URL(this.url);
    Object.entries(this.options.queryParams).forEach(([key, value]) => {
      url.searchParams.append(key, value);
    });
    return url.toString();
  }

  /**
   * Convert our options to fetch RequestInit
   */
  private buildFetchOptions(): RequestInit & { client?: Deno.HttpClient } {
    const fetchOptions: RequestInit & { client?: Deno.HttpClient } = {
      method: this.options.method,
      headers: this.options.headers,
      credentials: this.options.credentials,
      mode: this.options.mode,
      cache: this.options.cache,
      redirect: this.options.redirect,
      referrer: this.options.referrer,
      referrerPolicy: this.options.referrerPolicy,
      integrity: this.options.integrity,
      keepalive: this.options.keepAlive,
      signal: this.options.signal,
    };

    // Set the HttpClient (for unix sockets or custom configurations)
    const client = this.getHttpClient();
    if (client) {
      fetchOptions.client = client;
    }

    // Handle request body
    if (this.options.requestBody !== undefined) {
      if (
        typeof this.options.requestBody === 'string' ||
        this.options.requestBody instanceof ArrayBuffer ||
        this.options.requestBody instanceof Uint8Array ||
        this.options.requestBody instanceof FormData ||
        this.options.requestBody instanceof URLSearchParams ||
        this.options.requestBody instanceof ReadableStream ||
        // Check for Buffer (Deno provides Buffer via Node.js compatibility)
        (typeof Buffer !== 'undefined' && this.options.requestBody instanceof Buffer)
      ) {
        fetchOptions.body = this.options.requestBody as BodyInit;

        // If streaming, we need to set duplex mode
        if (this.options.requestBody instanceof ReadableStream) {
          (fetchOptions as any).duplex = 'half';
        }
      } else {
        // Convert objects to JSON
        fetchOptions.body = JSON.stringify(this.options.requestBody);
        // Set content-type if not already set
        if (!fetchOptions.headers) {
          fetchOptions.headers = { 'Content-Type': 'application/json' };
        } else if (fetchOptions.headers instanceof Headers) {
          if (!fetchOptions.headers.has('Content-Type')) {
            fetchOptions.headers.set('Content-Type', 'application/json');
          }
        } else if (
          typeof fetchOptions.headers === 'object' &&
          !Array.isArray(fetchOptions.headers)
        ) {
          const headersObj = fetchOptions.headers as Record<string, string>;
          if (!headersObj['Content-Type']) {
            headersObj['Content-Type'] = 'application/json';
          }
        }
      }
    }

    // Handle timeout
    if (this.options.timeout || this.options.hardDataCuttingTimeout) {
      const timeout =
        this.options.hardDataCuttingTimeout || this.options.timeout;
      this.abortController = new AbortController();
      this.timeoutId = setTimeout(() => {
        if (this.abortController) {
          this.abortController.abort();
        }
      }, timeout);
      fetchOptions.signal = this.abortController.signal;
    }

    return fetchOptions;
  }

  /**
   * Fire the request and return a CoreResponse
   */
  async fire(): Promise<CoreResponse> {
    const response = await this.fireCore();
    return new CoreResponse(response);
  }

  /**
   * Fire the request and return the raw Response
   */
  async fireCore(): Promise<Response> {
    const url = this.buildUrl();
    const options = this.buildFetchOptions();

    try {
      const response = await fetch(url, options);
      // Clear timeout on successful response
      this.clearTimeout();
      return response;
    } catch (error) {
      // Clear timeout on error
      this.clearTimeout();
      if (error.name === 'AbortError') {
        throw new Error('Request timed out');
      }
      throw error;
    }
  }

  /**
   * Clear the timeout and abort controller
   * Note: We don't close the HttpClient here as it's cached for reuse
   */
  private clearTimeout(): void {
    if (this.timeoutId) {
      clearTimeout(this.timeoutId);
      this.timeoutId = null;
    }
    if (this.abortController) {
      this.abortController = null;
    }
  }

  /**
   * Static factory method to create and fire a request
   */
  static async create(
    url: string,
    options: types.IDenoRequestOptions = {},
  ): Promise<CoreResponse> {
    const request = new CoreRequest(url, options);
    return request.fire();
  }

  /**
   * Static method to clear the HttpClient cache
   * Call this when you want to force new clients to be created
   */
  static clearClientCache(): void {
    httpClientCache.forEach((client) => {
      client.close();
    });
    httpClientCache.clear();
  }
}

/**
 * Convenience exports for backward compatibility
 */
export const isUnixSocket = CoreRequest.isUnixSocket;
export const parseUnixSocketUrl = CoreRequest.parseUnixSocketUrl;