import {
  IHttpClientAdaptor,
  Method,
  RequestConfig,
  ResponseType,
  HttpResponse,
} from './Adaptors';
import { FetchClientAdaptor } from './FetchClientAdaptor';
import {
  HttpRequestStrategy,
  DefaultHttpRequestStrategy,
} from './HttpRequestStrategies';
import { Logger } from './Logger';
import { AbortError } from './errors/AbortError';
import { ABORT_MESSAGE, ERROR_URL } from './strings';

/** Config used for setting up http calls */
export interface ApiConfig {
  /** If specified, a new axios instance is used instead of the one instantiated in the HttpClient's constructor */
  noGlobal?: boolean;
  /** The headers that will be used in the HTTP call. Global headers will be added to these.
   *  // TODO: Test when noGlobal is true if global headers are added to the request
   */
  headers?: Record<string, string>;
  /** The body of the request that will be sent */
  data?: any;
  /** The type of response that will be expected */
  responseType?: ResponseType;
  /** The query parameters that will be sent with the HTTP call */
  params?: any;
  /** The encoding of the response */
  responseEncoding?: string;
  /** The strategy to use for this request, if not provided then the request that was provided with the HttpClient will be used */
  httpRequestStrategy?: HttpRequestStrategy;
}

/**
 * HttpClient configuration options
 */
export interface HttpClientOptions {
  /** The strategy that will be used to handle http requests */
  httpRequestStrategy?: HttpRequestStrategy;
  /** The logger the HttpClient will use */
  logger?: Logger;
  baseUrl?: string;
}

/** Typed wrapper around axios that standardizes making HTTP calls and handling responses */
export class HttpClient {
  private logger: Logger | undefined;
  private httpRequestStrategy: HttpRequestStrategy;
  private baseUrl: string;

  constructor(
    private httpClientAdaptor: IHttpClientAdaptor = new FetchClientAdaptor(),
    options: HttpClientOptions = {},
  ) {
    const { httpRequestStrategy, logger, baseUrl = '' } = options;
    this.httpRequestStrategy =
      httpRequestStrategy ?? new DefaultHttpRequestStrategy();
    this.logger = logger;
    this.baseUrl = baseUrl;
  }

  /**
   * Sets the logger for the instance
   * @param {Logger|undefined} logger
   */
  public setLogger(logger: Logger | undefined) {
    this.logger = logger;
  }

  /** HTTP GET request */
  public get<T = unknown>(
    url: string,
    config: ApiConfig = {},
    cancelToken?: AbortController,
  ): Promise<T> {
    const method: Method = 'get';
    return this.dataRequest<T>(url, method, config, cancelToken);
  }

  /** HTTP POST request */
  public post<T = unknown>(
    url: string,
    config: ApiConfig = {},
    cancelToken?: AbortController,
  ): Promise<T> {
    const method: Method = 'post';
    return this.dataRequest<T>(url, method, config, cancelToken);
  }

  /** HTTP PUT request */
  public put<T = unknown>(
    url: string,
    config: ApiConfig = {},
    cancelToken?: AbortController,
  ): Promise<T> {
    const method: Method = 'put';
    return this.dataRequest<T>(url, method, config, cancelToken);
  }

  /** HTTP DELETE request */
  public delete<T = unknown>(
    url: string,
    config: ApiConfig = {},
    cancelToken?: AbortController,
  ): Promise<T> {
    const method: Method = 'delete';
    return this.dataRequest<T>(url, method, config, cancelToken);
  }

  /** HTTP PATCH request */
  public patch<T = unknown>(
    url: string,
    config: ApiConfig = {},
    cancelToken?: AbortController,
  ): Promise<T> {
    const method: Method = 'patch';
    return this.dataRequest<T>(url, method, config, cancelToken);
  }

  /**
   *  HTTP request that returns the body of the HTTP response
   *
   *  If a cancel token is passed in it will be aborted on request error.
   *
   *  @returns {Promise<T>} body of the HTTP response
   */
  public async dataRequest<T = unknown>(
    url: string,
    method: Method,
    config: ApiConfig = {},
    cancelToken?: AbortController,
  ): Promise<T> {
    const response = await this.request<T>(url, method, config, cancelToken);
    return response.data;
  }

  /**
   *  HTTP request
   *
   *  If a cancel token is passed in it will be aborted on request error.
   *
   *  @returns {Promise<HttpResponse<T>>} HttpResponse
   */
  public async request<T = unknown>(
    url: string,
    method: Method,
    config: ApiConfig = {},
    cancelToken?: AbortController,
  ): Promise<HttpResponse<T>> {
    if (cancelToken?.signal.aborted) {
      throw new AbortError(ABORT_MESSAGE);
    }
    try {
      return await this.doRequest<T>(url, method, config, cancelToken);
    } catch (e) {
      let message = `The ${method} request to ${url} failed`;
      if (e && typeof e === 'object' && 'status' in e) {
        message += ` with status ${e.status}`;
      }
      cancelToken?.abort(message);
      throw e;
    }
  }

  private async doRequest<T = unknown>(
    url: string,
    method: Method,
    config: ApiConfig = {},
    cancelToken?: AbortController,
  ): Promise<HttpResponse<T>> {
    if (typeof url !== 'string') throw new Error(ERROR_URL);
    const {
      headers,
      data,
      params,
      responseEncoding,
      responseType,
      httpRequestStrategy,
      noGlobal,
    } = config;

    const strategyToUse = httpRequestStrategy ?? this.httpRequestStrategy;

    const requestConfig: RequestConfig = {
      url: this.baseUrl + url,
      method,
      headers,
      data,
      params,
      responseEncoding,
      responseType,
      cancelToken,
      noGlobal,
    };

    try {
      const request = this.httpClientAdaptor.buildRequest<T>(requestConfig);
      this.logger?.debug(`HTTP - method: ${method}; url: ${url}`);
      const response = await strategyToUse.request<T>(request);
      this.logger?.debug(
        `HTTP ${response.status} - method: ${method}; url: ${url}`,
      );
      return response;
    } catch (e) {
      this.logger?.error(`HTTP error - method: ${method}; url: ${url}`, e);
      throw e;
    }
  }
}