const AWS = require("aws-sdk");
const db = require("./mongo");
const utils = require("./utils");

function _getRgName(provision) {
    let rgName = provision.scenario.toUpperCase();
    rgName = rgName.replace(/AZQMI/g, 'QMI');
    rgName = rgName + "-" + provision._id.toString();
    return rgName;
}

function _getRegion(provision) {
    let region = "eu-west-1";
    if ( provision.deployOpts.location === 'East US') {
        region = "us-east-1";
    } else if ( provision.deployOpts.location === 'Southeast Asia' ) {
        region = "ap-southeast-1";
    }
    return region;
}

function _getDbIndentifier(provision) {
    var out;
    if ( provision.outputs['db_instance_id'] ) {      
        out = provision.outputs['db_instance_id'];
    } else if (provision.outputs['db_instance_endpoint']) {
        out  = provision.outputs['db_instance_endpoint'].split(".")[0];
    }
    return out;
}

async function stopDbInstance(provision, triggerUserId, isSendEmailAfter) {
    if (provision.statusVms === 'Stopped' || provision.statusVms === 'Stopping'){
        return;
    }
    var identifier = _getDbIndentifier(provision);

    if ( !identifier ) {
        return;
    }
    
    await db.provision.update(provision._id.toString(), {"statusVms": "Stopping" });

    db.event.add({ user: triggerUserId, provision: provision._id, type: `db.stopping` });

    return new Promise((resolve, reject) => {
        let region = _getRegion(provision);
        var rds = new AWS.RDS({apiVersion: '2014-10-31', region: region});
        var params = {
            DBInstanceIdentifier: identifier 
        };
        console.log(`AWSCLI# DB (${identifier}) stopping...`);
        rds.stopDBInstance(params, async function(err, data) {
            if (err) {
                console.log("AWSCLI# ERROR stopping DB: "+identifier, err.stack);
                await db.provision.update(provision._id.toString(), {"statusVms": "Running" }); 
                reject(err);
            } else {
                console.log(`AWSCLI# DB (${identifier}) stopped!`); 
                resolve(data);
            }
        });
    });

} 

async function startDbInstance(provision, triggerUserId) {
    if (provision.statusVms === 'Running' || provision.statusVms === 'Starting'){
        return;
    }
    
    var identifier = _getDbIndentifier(provision);

    if ( !identifier ) {
        return;
    }

    await db.provision.update(provision._id.toString(), {"statusVms": "Starting" });
    db.event.add({ user: triggerUserId, provision: provision._id, type: `db.starting` });

    return new Promise((resolve, reject) => {
        let region = _getRegion(provision);
        var rds = new AWS.RDS({apiVersion: '2014-10-31', region: region});
        var params = {
            DBInstanceIdentifier: identifier 
        };
        console.log(`AWSCLI# DB (${identifier}) starting...`);
        
        rds.startDBInstance(params, async function(err, data) {
            
            if (err) {
                console.log("AWSCLI# ERROR starting DB: "+identifier, err.stack);
                await db.provision.update(provision._id.toString(), {"statusVms": "Stopped" });
                reject(err);
            } else {   
                console.log(`AWSCLI# DB (${identifier}) starting (2)...`);
                rds.waitFor('dBInstanceAvailable', params, async function(err, data) {
                    if (err) {
                        console.log("AWSCLI# ERROR waiting for DB to become available: "+identifier, err.stack);
                        reject(err);
                    } else {    
                        console.log(`AWSCLI# DB (${identifier}) started!`);
                        await utils.afterStartVms( provision, triggerUserId, "db" ); 
                    }
                });   
                resolve(data);
            }
        });
        
    });
}

function deallocate(provision, triggerUserId, isSendEmailAfter) {
    
    let rgName = _getRgName(provision);
    let region = _getRegion(provision);

    console.log("AWSCLI# Stopping EC2s for resource group: "+rgName);

    return new Promise((resolve, reject) => {

        var ec2 = new AWS.EC2({apiVersion: '2016-11-15', region: region});

        var params = {
            DryRun: false,
            Filters: [
                {
                    Name: 'tag:Name',
                    Values: [ `fort-${provision._id}` ]
                },
            ]
        };

        ec2.describeInstances(params, async function (err, data) {
            if (err) {
                console.log("AWSCLI# ERROR describing EC2s: "+rgName, err.stack);
                await db.provision.update(provision._id.toString(), {"statusVms": "Running" });
                reject(err);
            } else if (data && data.Reservations && data.Reservations.length) {    
                
                var ec2Ids = data.Reservations[0].Instances.map(ec2=> ec2.InstanceId);
                console.log("AWSCLI# Stopping Ec2s ids...", ec2Ids);
                params = {
                    DryRun: false,
                    InstanceIds: ec2Ids
                };

                ec2.stopInstances(params, async function(err1, data) {
                    if (err1) { 
                        console.log("AWSCLI# ERROR stopping EC2s: "+rgName, err1.stack);
                        await db.provision.update(provision._id.toString(), {"statusVms": "Running" });
                        reject(err1);
                    } else  {    
                        console.log("AWSCLI# Ec2s stopped!");
                        await utils.afterStopVms( provision, triggerUserId, isSendEmailAfter );
                        resolve(data);
                    }
                });
            } else {
                console.log("AWSCLI# No Ec2 Instances found: "+rgName);
                resolve(data);
            }  
        });
    });
}

function start(provision, triggerUserId) {
   
    let rgName = _getRgName(provision);
    let region = _getRegion(provision);

    console.log("AWSCLI# Stopping EC2s for resource group: "+rgName);

    return new Promise((resolve, reject) => {

        var ec2 = new AWS.EC2({apiVersion: '2016-11-15', region: region});
        var params = {
            DryRun: false,
            Filters: [
                {
                    Name: 'tag:Name',
                    Values: [ `fort-${provision._id}` ]
                },
            ]
        };
        
        ec2.describeInstances(params, async function (err, data) {
            if (err) {
                console.log("AWSCLI# ERROR describing EC2s: "+rgName, err.stack);
                await db.provision.update(provision._id.toString(), {"statusVms": "Stopped" });
                reject(err);
            } else if (data && data.Reservations && data.Reservations.length) {       
                var ec2Ids = data.Reservations[0].Instances.map(ec2=> ec2.InstanceId);
                console.log("AWSCLI# Starting Ec2s ids...", ec2Ids);
                params = {
                    DryRun: false,
                    InstanceIds: ec2Ids
                };

                ec2.startInstances(params, async function(err1, data) {
                    if (err1) {
                        console.log("AWSCLI# ERROR starting EC2s: "+rgName, err1.stack);
                        await db.provision.update(provision._id.toString(), {"statusVms": "Stopped" });
                        reject(err1);
                    } else {
                        console.log("AWSCLI# Ec2s started!");
                        await utils.afterStartVms( provision, triggerUserId );
                        resolve(data);
                    }
                });     
            } else {
                console.log("AWSCLI# No Ec2 Instances found: "+rgName);
                resolve(data);
            }
        });
    });
}

module.exports.deallocate = deallocate;
module.exports.start = start;
module.exports.stopDbInstance = stopDbInstance;
module.exports.startDbInstance = startDbInstance;