var winston = require('winston');
var crypto = require('crypto');
var xml = require('xml');
var url = require('url');
var http = require('http');
var xml2js = require('xml2js').parseString;
var LRU = require("lru-cache");

var config;
var callbackReport;
var aaa;
var logger;
var options;
var taskCache = LRU({max: 2000});

var maxRetry = 10;
var sleepBeforeRetry = 30;

function start(_config, _callbackReport, options) {
    config = _config;
    callbackReport = _callbackReport
    
    if (options && options.aaa) {
            aaa = options.aaa;
    }
    
    if (options && options.logger) {
        logger = options.logger;
    } else {
        logger = new winston.Logger({
            transports: [
              new (winston.transports.Console)()
            ]
        });
    }
}

function calculateSignature(params) {
    var passwordHash = crypto.createHash('sha1').update(params.password).digest().toString('hex');
    var plain = params.trxtype + params.prdcode + params.value + params.msisdn + params.trxid + params.uid + passwordHash;
    var signature = crypto.createHash('sha256').update(plain).digest().toString('hex');
    
    try {
        logger.verbose('Signature calculated', {plain: plain, signature: signature});
    }
    catch(err) {}
    
    return signature;
}

function createXmlPayload(params) {
    var payload = "<?xml version=\"1.0\" ?>\n" + xml({
        ciwaru: [
            {trxtype: params.trxtype},
            {prdcode: params.prdcode},
            {value: params.value},
            {msisdn: params.msisdn},
            {trxid: params.trxid},
            {uid: params.uid},
            {hash: calculateSignature(params)}
        ]
    });
    
    logger.verbose("Payload: " + payload);
    return payload;
}

function getSNFromMessage(message) {
    try {
        var sn_match = message.match(/SN: (\w+)/);
        return sn_match[1];
    }
    catch(err) {
        return '';
    }
}

function hasSuccessKeywords(message) {
    var keywords = ['SUKSES', 'Finish'];
    
    var count = keywords.length;
    for (var i=0; i < count; i++) {
        if (message.indexOf(keywords[i]) >= 0) {
            return true;
        }
    }
    return false;
}

function supplierRcToST24Rc(rc) {
    var rcs = {
        '0001': '40',
        '0019': '13', // produk tidak tersedia
    }
    
    if (rcs[rc]) {
        return rcs[rc];
    } else {
        return;
    }
}

function topupResponseHandler(body) {
    //logger.info('Got reply from partner', {body: body});
    xml2js(body, function(err, result) {
        if (err) {
            logger.warn('Got invalid XML from partner', {err: err, body: body});
        }
        logger.info('XML message from partner', {result: result});
        
        var rc = '68';
        var message = result.ciwaru.msg[0];
        
        var trxid = 0;
        try {
            trxid = result.ciwaru.reqnum[0];
        } 
        catch(err) {
            trxid = result.ciwaru.trxid[0];
        }
        
        var task = taskCache.get(trxid);
        if (!task) {
            logger.warn('Got reply for undefined task');
            return;
        }
        
        if (message.indexOf('PENDING') >= 0) {
            rc = '68';
        }
        else if (hasSuccessKeywords(message)) {
            var sn = getSNFromMessage(result.ciwaru.msg);
            message = 'SN=' + sn + '; ' + message;
            rc = '00';
        } else {
            rc  = supplierRcToST24Rc(result.ciwaru.rc[0]);
            if (!rc) {
                rc = '68';
            }
        }
        
        if ((task.retry == maxRetry) || (rc != '68')) {
            callbackReport(trxid, rc, message);
        } else {
            logger.info('Not reporting to AAA for duplicate 68', {task: task});
        }
        
        if (rc == '68') {
            task.retry--;
            taskCache.set(trxid, task);
                
            if (task.retry) {
                logger.info('Got pending status, retrying in ' +  sleepBeforeRetry + 's');
                setTimeout(topupRequest, sleepBeforeRetry * 1000, task, task.retry);
            }
            else {
                logger.warn('Maximum retry for pending status exceeded', {task: task});
            }
        } else {
            taskCache.del(trxid);
        }
    });
}

function topupRequest(task, retry) {
        
    if (retry === undefined) {
        task.retry = maxRetry;
    }
    
    taskCache.set(task.requestId, task);
    
    var remoteProduct = task.remoteProduct.split(',');
    
    var params = {
        trxtype: '01',
        prdcode: remoteProduct[0],
        value: remoteProduct[1],
        msisdn: task.destination,
        trxid: task.requestId,
        uid: config.h2h_out.userid,
        password: config.h2h_out.password,
    };
    
    var postBody = createXmlPayload(params);
    
    var partnerUrl = url.parse(config.h2h_out.partner);
    var postRequest = {
        host: partnerUrl.hostname,
        path: partnerUrl.path,
        port: partnerUrl.port,
        method: "POST",
        headers: {
            'Content-Type': 'text/xml',
            'Content-Length': Buffer.byteLength(postBody)
        }
    };
    
    logger.info('POST to partner', {postRequest: postRequest});
    var req = http.request(postRequest, function( res ) {
        
        logger.info('Status code: ' + res.statusCode );
        var buffer = "";
        res.on( "data", function( data ) { buffer = buffer + data; } );
        res.on( "end", function( data ) {             
                topupResponseHandler(buffer);
        });
    });
    
    req.on('error', function(e) {
        logger.warn('problem with request: ' + e.message);
        callbackReport(task['requestId'], '40', e.message);
    });

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

exports.start = start;
exports.topupRequest = topupRequest;
exports.calculateSignature = calculateSignature;
exports.createXmlPayload = createXmlPayload;
exports.getSNFromMessage = getSNFromMessage;