import { type ISmartRequestOptions } from '../legacy/smartrequest.interfaces.js';
import { request, type IExtendedIncomingMessage } from '../legacy/smartrequest.request.js';
import * as plugins from '../legacy/smartrequest.plugins.js';

import type { HttpMethod, ResponseType, FormField } from './types/common.js';
import {
  type TPaginationConfig,
  PaginationStrategy,
  type OffsetPaginationConfig,
  type CursorPaginationConfig,
  type CustomPaginationConfig,
  type TPaginatedResponse
} from './types/pagination.js';
import { createPaginatedResponse } from './features/pagination.js';

/**
 * Modern fluent client for making HTTP requests
 */
export class SmartRequestClient<T = any> {
  private _url: string;
  private _options: ISmartRequestOptions = {};
  private _responseType: ResponseType = 'json';
  private _timeoutMs: number = 60000;
  private _retries: number = 0;
  private _queryParams: Record<string, string> = {};
  private _paginationConfig?: TPaginationConfig;

  /**
   * Create a new SmartRequestClient instance
   */
  static create<T = any>(): SmartRequestClient<T> {
    return new SmartRequestClient<T>();
  }

  /**
   * Set the URL for the request
   */
  url(url: string): this {
    this._url = url;
    return this;
  }

  /**
   * Set the HTTP method
   */
  method(method: HttpMethod): this {
    this._options.method = method;
    return this;
  }

  /**
   * Set JSON body for the request
   */
  json(data: any): this {
    if (!this._options.headers) {
      this._options.headers = {};
    }
    this._options.headers['Content-Type'] = 'application/json';
    this._options.requestBody = data;
    return this;
  }

  /**
   * Set form data for the request
   */
  formData(data: FormField[]): this {
    const form = new plugins.formData();

    for (const item of data) {
      if (Buffer.isBuffer(item.value)) {
        form.append(item.name, item.value, {
          filename: item.filename || 'file',
          contentType: item.contentType || 'application/octet-stream'
        });
      } else {
        form.append(item.name, item.value);
      }
    }

    if (!this._options.headers) {
      this._options.headers = {};
    }

    this._options.headers = {
      ...this._options.headers,
      ...form.getHeaders()
    };

    this._options.requestBody = form;
    return this;
  }

  /**
   * Set request timeout in milliseconds
   */
  timeout(ms: number): this {
    this._timeoutMs = ms;
    this._options.timeout = ms;
    this._options.hardDataCuttingTimeout = ms;
    return this;
  }

  /**
   * Set number of retry attempts
   */
  retry(count: number): this {
    this._retries = count;
    return this;
  }

  /**
   * Set HTTP headers
   */
  headers(headers: Record<string, string>): this {
    if (!this._options.headers) {
      this._options.headers = {};
    }
    this._options.headers = {
      ...this._options.headers,
      ...headers
    };
    return this;
  }

  /**
   * Set a single HTTP header
   */
  header(name: string, value: string): this {
    if (!this._options.headers) {
      this._options.headers = {};
    }
    this._options.headers[name] = value;
    return this;
  }

  /**
   * Set query parameters
   */
  query(params: Record<string, string>): this {
    this._queryParams = {
      ...this._queryParams,
      ...params
    };
    return this;
  }

  /**
   * Set response type
   */
  responseType(type: ResponseType): this {
    this._responseType = type;

    if (type === 'binary' || type === 'stream') {
      this._options.autoJsonParse = false;
    }

    return this;
  }

  /**
   * Configure pagination for requests
   */
  pagination(config: TPaginationConfig): this {
    this._paginationConfig = config;
    return this;
  }

  /**
   * Configure offset-based pagination (page & limit)
   */
  withOffsetPagination(config: Omit<OffsetPaginationConfig, 'strategy'> = {}): this {
    this._paginationConfig = {
      strategy: PaginationStrategy.OFFSET,
      pageParam: config.pageParam || 'page',
      limitParam: config.limitParam || 'limit',
      startPage: config.startPage || 1,
      pageSize: config.pageSize || 20,
      totalPath: config.totalPath || 'total'
    };

    // Add initial pagination parameters
    this.query({
      [this._paginationConfig.pageParam]: String(this._paginationConfig.startPage),
      [this._paginationConfig.limitParam]: String(this._paginationConfig.pageSize)
    });

    return this;
  }

  /**
   * Configure cursor-based pagination
   */
  withCursorPagination(config: Omit<CursorPaginationConfig, 'strategy'> = {}): this {
    this._paginationConfig = {
      strategy: PaginationStrategy.CURSOR,
      cursorParam: config.cursorParam || 'cursor',
      cursorPath: config.cursorPath || 'nextCursor',
      hasMorePath: config.hasMorePath || 'hasMore'
    };
    return this;
  }

  /**
   * Configure Link header-based pagination
   */
  withLinkPagination(): this {
    this._paginationConfig = {
      strategy: PaginationStrategy.LINK_HEADER
    };
    return this;
  }

  /**
   * Configure custom pagination
   */
  withCustomPagination(config: Omit<CustomPaginationConfig, 'strategy'>): this {
    this._paginationConfig = {
      strategy: PaginationStrategy.CUSTOM,
      hasNextPage: config.hasNextPage,
      getNextPageParams: config.getNextPageParams
    };
    return this;
  }

  /**
   * Make a GET request
   */
  async get<R = T>(): Promise<IExtendedIncomingMessage<R>> {
    return this.execute<R>('GET');
  }

  /**
   * Make a POST request
   */
  async post<R = T>(): Promise<IExtendedIncomingMessage<R>> {
    return this.execute<R>('POST');
  }

  /**
   * Make a PUT request
   */
  async put<R = T>(): Promise<IExtendedIncomingMessage<R>> {
    return this.execute<R>('PUT');
  }

  /**
   * Make a DELETE request
   */
  async delete<R = T>(): Promise<IExtendedIncomingMessage<R>> {
    return this.execute<R>('DELETE');
  }

  /**
   * Make a PATCH request
   */
  async patch<R = T>(): Promise<IExtendedIncomingMessage<R>> {
    return this.execute<R>('PATCH');
  }

  /**
   * Get paginated response
   */
  async getPaginated<ItemType = T>(): Promise<TPaginatedResponse<ItemType>> {
    if (!this._paginationConfig) {
      throw new Error('Pagination not configured. Call one of the pagination methods first.');
    }

    // Default to GET if no method specified
    if (!this._options.method) {
      this._options.method = 'GET';
    }

    const response = await this.execute();

    return createPaginatedResponse<ItemType>(
      response,
      this._paginationConfig,
      this._queryParams,
      (nextPageParams) => {
        // Create a new client with the same configuration but updated query params
        const nextClient = new SmartRequestClient<ItemType>();
        Object.assign(nextClient, this);
        nextClient._queryParams = nextPageParams;

        return nextClient.getPaginated<ItemType>();
      }
    );
  }

  /**
   * Get all pages at once (use with caution for large datasets)
   */
  async getAllPages<ItemType = T>(): Promise<ItemType[]> {
    const firstPage = await this.getPaginated<ItemType>();
    return firstPage.getAllPages();
  }

  /**
   * Execute the HTTP request
   */
  private async execute<R = T>(method?: HttpMethod): Promise<IExtendedIncomingMessage<R>> {
    if (method) {
      this._options.method = method;
    }

    this._options.queryParams = this._queryParams;

    // Handle retry logic
    let lastError: Error;

    for (let attempt = 0; attempt <= this._retries; attempt++) {
      try {
        if (this._responseType === 'stream') {
          return await request(this._url, this._options, true) as IExtendedIncomingMessage<R>;
        } else if (this._responseType === 'binary') {
          const response = await request(this._url, this._options, true);

          // Handle binary response
          const dataPromise = plugins.smartpromise.defer<Buffer>();
          const chunks: Buffer[] = [];

          response.on('data', (chunk: Buffer) => chunks.push(chunk));
          response.on('end', () => {
            const buffer = Buffer.concat(chunks);
            (response as IExtendedIncomingMessage<R>).body = buffer as any;
            dataPromise.resolve();
          });

          await dataPromise.promise;
          return response as IExtendedIncomingMessage<R>;
        } else {
          // Handle JSON or text response
          return await request(this._url, this._options) as IExtendedIncomingMessage<R>;
        }
      } catch (error) {
        lastError = error as Error;

        // If this is the last attempt, throw the error
        if (attempt === this._retries) {
          throw lastError;
        }

        // Otherwise, wait before retrying
        await new Promise(resolve => setTimeout(resolve, 1000));
      }
    }

    // This should never be reached due to the throw in the loop above
    throw lastError;
  }
}