var http = require('http');
var https = require('https');

/**
 * Module for verifying users to EVE characters. Hint: chain the successCallback of verifyCode
 * to a call to getCharacterInfo.
 * config: {
 *    ccpSsoHostname: "sisilogin.testeveonline.com",
 *    ccpSecretKey: '{client_id}:{client_secret}'// Base64 encoded use https://www.base64encode.org/
 * }
 */
var ccpVerify = function (config) {
    // some static properties used in the requests
    this.basicAuthHeader = 'Basic ' + config.ccpSecretKey
    this.formUrlEncodedHeader = 'application/x-www-form-urlencoded';
    this.config = config;
}

/**
 * Verifies a given authorization code as coming from CCP.
 * authCode: the code to verify
 * successCallback: function, taking the resultant acess token as parameter
 * failCallback: function, taking an error message as parameter
 */
ccpVerify.prototype.verifyCode = function (authCode, successCallback, failCallback) {

    var options = {
        hostname: this.config.ccpSsoHostname,
        path: '/oauth/token',
        method: 'POST',
        headers: {
            'Authorization': this.basicAuthHeader,
            'Content-Type': this.formUrlEncodedHeader
        }
    }

    var requestBody = 'grant_type=authorization_code&code=' + authCode;

    var req = https.request(options, function (res) {
        var statusCode = res.statusCode;

        res.on('data', function (d) {
            var data;
            try {
                data = JSON.parse(d);
            }
            catch (e) {
                console.error(e);
                data = { error_description: 'Unknown error' };
            }

            if (!data.access_token) {
                failCallback(data.error_description);
            }
            else {
                successCallback(data.access_token);
            }
        });
    });
    req.on('error', function (e) {
        failCallback({ error_description: 'Unknown error' });
    });

    req.write(requestBody);
    req.end();
};

/**
 * Gets character info associated with a given access token.
 * accessToken: an access token linked to a user
 * successCallback: function, takes an object representing the character as parameter
 * failCallback: function, takes an error message as parameter
 */
ccpVerify.prototype.getCharacterInfo = function (accessToken, successCallback, failCallback) {
    var config = this.config;

    var options = {
        hostname: this.config.ccpSsoHostname,
        path: '/oauth/verify',
        method: 'GET',
        headers: {
            'Authorization': 'Bearer ' + accessToken
        }
    }

    var req = https.request(options, function (res) {
        var statusCode = res.statusCode;

        res.on('data', function (d) {
            var data;
            try {
                data = JSON.parse(d);
            }
            catch (e) {
                data = { error_description: 'Unknown error' };
            }

            if (!data.CharacterID) {
                failCallback(data.error_description);
            }
            else {
                successCallback(data);
            }
        });
    });
    req.on('error', function (e) {
        failCallback({ error_description: 'Unknown error' });
    });

    req.end();
}



module.exports = ccpVerify;