/**
 *
 * Copyright (c) 2026 Aspose.PDF Cloud
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

import * as request from "request";
import { Configuration } from "./configuration";
import { invokeApiMethod } from "./requestHelper";

/**
 * Authentication logic for api calls
 */
export interface IAuthentication {
    /**
     * Apply authentication settings to header and query params.
     */
    applyToRequest(requestOptions: request.Options, configuration: Configuration): void;

    /**
     * Handle 401 response.
     */
    handle401response(configuration: Configuration);
}

/**
 * Implements OAuth authentication 
 */
export class OAuth implements IAuthentication {
    private accessToken: string;

     /**
      * Apply authentication settings to header and query params.
      */
    public async applyToRequest(requestOptions: request.Options, configuration: Configuration): Promise<void> {
        if (this.accessToken == null) {
            await this._requestToken(configuration);
        }

        if (requestOptions && requestOptions.headers) {
            requestOptions.headers.Authorization = "Bearer " + this.accessToken;
        }

        return Promise.resolve();
    }

    /**
     * Handle 401 response.
     */
    public async handle401response(configuration: Configuration) {
        await this._requestToken(configuration);
    }

    private async _requestToken(configuration: Configuration): Promise<void> {
        console.log("baseUrl: " + configuration.baseUrl);
        var tokenUrl = configuration.baseUrl.replace("/v3.0", "") + "/connect/token";
        console.log("tokenUrl: " + tokenUrl);
        const requestOptions: request.Options = {
            method: "POST",
            json: true,
            uri: tokenUrl,
            headers: {'Content-Type': 'application/x-www-form-urlencoded'},
            form: {
                grant_type: "client_credentials",
                client_id: configuration.clientId,
                client_secret: configuration.clientSecret,
            },
        };
        
        try {
            const response = await invokeApiMethod(requestOptions, configuration, true);
            if (!response.body.access_token || response.body.access_token.trim() == "") {
                this._handleResponseError(response)
            }

            this.accessToken = response.body.access_token;
        }
        catch(err) {
            if (err.response) {
                this._handleResponseError(err.response)
            } else {
                throw err
            }
        }

        return Promise.resolve();
    }

    private _handleResponseError(response: request.RequestResponse) {
        if (typeof response.body == 'string' && response.body.trim() != '') {
            throw new Error(response.body)
        } else {
            throw new Error(`empty token (${JSON.stringify(response.body)})`)
        }
    }
}