/**
 * JAWS Command Line Interface
 */


var aws         = require('aws-sdk'),
    exec        = require('child_process').exec,
    fs          = require('fs'),
    os          = require('os'),
    packageJson = require('./../package.json'),
    async       = require('async'),
    zip         = new require('node-zip')(),
    wrench      = require('wrench'),
    moment      = require('moment'),
    yaml        = require('js-yaml'),
    Q           = require('q'),
    prettysize  = require('prettysize'),
    replace     = require("replace"),
    path        = require('path');

var JAWS = function () {
    this.jawsLibDir = this._findLibDir(process.cwd());
    console.log('****** JAWS: found lib path at', this.jawsLibDir);

    // Require Admin ENV Variables
    require('dotenv').config({
        path: this.jawsLibDir + '/../.adminenv'
    });

    this.version   = packageJson.version;
    this.configYml = yaml.safeLoad(fs.readFileSync(this.jawsLibDir + '/../jaws.yml', 'utf8')).jaws;

    return this;
};


/**
 * JAWS: Run Lambda Function Locally
 */

JAWS.prototype.run = function (functionRootDirPath, callback) {
    // Check if in extension's root directory
    if (!fs.existsSync(functionRootDirPath + '/index.js')) {
        callback(new Error('****** JAWS:  Error - You must be in the root directory of your Lambda function to run it locally.'));
    }

    var extension = require(functionRootDirPath + '/index.js');
    var event     = require(functionRootDirPath + '/event.json');
    var metadata  = require(functionRootDirPath + '/lambda.json');

    console.log('****** JAWS: Running ' + metadata.FunctionName + ' Locally...');

    // Run Handler
    this._runHandler(extension.handler, event, callback);
};


JAWS.prototype._runHandler = function (handler, event, callback) {
    var context = {
        succeed: function (result) {
            callback(null, result);
        },
        fail: function (error) {
            console.error(error);
            callback(new Error(error.message));
        },
        done: function (error, result) {
            callback(error, result);
        }
    };

    handler(event, context);
};


/**
 * JAWS: Deploy Lambda Function
 */

JAWS.prototype.deploy = function (stage, functionDir) {
    var deferred = Q.defer();

    // Defaults
    var _this   = this;
    var regions = this.configYml.deploy.regions;

    // Get Lambda Config
    if (!fs.existsSync(functionDir + '/lambda.json')) {
        return Q.fcall(function () {
            throw new Error('****** JAWS Error: lambda.json is missing in this folder');
        });
    }
    var lambda_config          = require(functionDir + '/lambda.json');
    lambda_config.FunctionName = stage + "_" + lambda_config.FunctionName;

    console.log('****** JAWS: Deploying ' + lambda_config.FunctionName);

    var tmpCodeDir               = os.tmpdir() + lambda_config.FunctionName + '-' + moment().unix(),
        packageApiExcludesGlobal = _this.configYml.deploy.packageApiExcludes || [],
        packageApiExcludesLambda = lambda_config.packageApiExcludes || [],
        packageLibExcludesGlobal = _this.configYml.deploy.packageLibExcludes || [],
        packageLibExcludesLambda = lambda_config.packageLibExcludes || [],
        packageApiExcludes       = packageApiExcludesGlobal.concat(packageApiExcludesLambda),
        packageLibExclues        = packageLibExcludesGlobal.concat(packageLibExcludesLambda);

    console.log("\tCopying files to tmp dir " + tmpCodeDir);

    // Copy code from api/model/action dir to temp location
    wrench.copyDirSyncRecursive(functionDir, tmpCodeDir, {
        forceDelete: true,
        exclude: function (name, prefix) {
            var relPath = prefix.replace(functionDir, '');
            return _this._copyExclude(name, relPath, packageApiExcludes);
        }
    });

    //Fixup rel links to shared lib dir
    replace({
        regex: RegExp("require\\(['\"](../)*(../../../lib)['\"]\\)", "g"),
        replacement: "require('./lib')",
        paths: [tmpCodeDir + '/index.js'],
        recursive: true,
        silent: true
    });

    // Copy lib dir
    wrench.copyDirSyncRecursive(_this.jawsLibDir, tmpCodeDir + '/lib', {
        forceDelete: true,
        exclude: function (name, prefix) {
            var relPath = prefix.replace(_this.jawsLibDir, '');
            return _this._copyExclude(name, relPath, packageLibExclues);
        }
    });

    // Copy down ENV file
    var s3            = new aws.S3({
            apiVersion: '2006-03-01',
            accessKeyId: global.process.env.ADMIN_AWS_ACCESS_KEY_ID,
            secretAccessKey: global.process.env.ADMIN_AWS_SECRET_ACCESS_KEY
        }),
        targetEnvFile = fs.createWriteStream(tmpCodeDir + '/lib/.env'),
        s3EnvPath     = _this.configYml.deploy.envS3Location,
        firstSlash    = s3EnvPath.indexOf('/'),
        bucket        = s3EnvPath.substring(0, firstSlash),
        key           = s3EnvPath.substring(firstSlash + 1) + stage;

    console.log("\tDownolading ENV file s3://" + bucket + key);
    s3.getObject({Bucket: bucket, Key: key})
        .on("error", function (err) {
            console.error("\tError getting ENV file s3://" + bucket + key);
            deferred.reject(err);
        })
        .createReadStream().pipe(targetEnvFile);

    targetEnvFile
        .on('finish', function () {
            console.log("\tCompressing files...");

            _this._zip(lambda_config.FunctionName, tmpCodeDir, function (err, buffer) {
                if (err) {
                    return deferred.reject(err);
                }

                async.map(regions, function (region, cb) {
                    var lambda = new aws.Lambda({
                        apiVersion: '2015-03-31',
                        region: region,
                        accessKeyId: global.process.env.ADMIN_AWS_ACCESS_KEY_ID,
                        secretAccessKey: global.process.env.ADMIN_AWS_SECRET_ACCESS_KEY
                    });

                    // Define Params for New Lambda Function
                    var params = {
                        FunctionName: lambda_config.FunctionName,
                        Handler: lambda_config.Handler ? lambda_config.Handler : 'index.handler',
                        Role: lambda_config.Role ? lambda_config.Role : _this.configYml.iamRoles[stage],
                        Runtime: lambda_config.Runtime,
                        Description: lambda_config.Description ? lambda_config.Description : 'A Lambda function that was created with the JAWS framework',
                        MemorySize: lambda_config.MemorySize,
                        Timeout: lambda_config.Timeout
                    };

                    // Check If Lambda Function Exists Already
                    lambda.getFunction({
                        FunctionName: lambda_config.FunctionName
                    }, function (err, data) {

                        if (err && err.code !== 'ResourceNotFoundException') {
                            return deferred.reject(err);
                        }

                        if (!data || !data.Code) {
                            /**
                             * Create New Lambda Function
                             */

                            console.log("\tCreating in " + stage + " with params:");
                            console.log(params);

                            params.Code = {ZipFile: buffer};
                            lambda.createFunction(params, function (err, data) {
                                lambda_arn = data;
                                return cb(err, data);
                            });
                        } else {
                            //Update instead of delete so there is no downtime

                            /**
                             * Update existing (code and config)
                             */

                            console.log("\tUpdating existing Lambda function in " + stage + " with params:");
                            console.log(params);

                            lambda.updateFunctionCode({
                                FunctionName: params.FunctionName,
                                ZipFile: buffer
                            }, function (err, data) {
                                if (err) {
                                    return deferred.reject(err);
                                }

                                lambda.updateFunctionConfiguration({
                                    FunctionName: params.FunctionName,
                                    Description: params.Description,
                                    Handler: params.Handler,
                                    MemorySize: params.MemorySize,
                                    Role: params.Role,
                                    Timeout: params.Timeout
                                }, function (err, data) {
                                    return cb(err, data);
                                });
                            });
                        }
                    });

                }, function (err, results) {

                    if (err) {
                        return deferred.reject(err);
                    }

                    var functionArns = [];
                    for (var i in results) {
                        functionArns.push(results[i].FunctionArn);
                    }

                    deferred.resolve(functionArns);
                });
            });
        });

    return deferred.promise;
};

JAWS.prototype._zip = function (functionName, codeDirectory, callback) {
    var options = {
        type: 'nodebuffer',
        compression: 'DEFLATE',
        compressionOptions: {level: 9}
    };

    var files = wrench.readdirSyncRecursive(codeDirectory);
    files.forEach(function (file) {
        var filePath = [codeDirectory, file].join('/');
        var isFile   = fs.lstatSync(filePath).isFile();
        if (isFile) {
            var content = fs.readFileSync(filePath);
            zip.file(file, content);
        }
    });

    var data = zip.generate(options);

    if (data.length > 52428800) {
        return callback(new Error("Zip file is > the 50MB Lambda deploy limit (" + data.length + " bytes)"), null);
    }

    console.log("\tPackage is " + prettysize(data.length, false) + " (Max 50MB)");

    return callback(null, data);
};

JAWS.prototype._copyExclude = function (fileName, relPath, tests) {
    if (!tests.length) {
        return false;
    }

    return tests.some(function (sRegex) {
        var re       = new RegExp(sRegex),
            testFile = relPath + "/" + fileName,
            testFile = ('/' == testFile.charAt(0)) ? testFile.substr(1) : testFile,
            matches  = re.exec(testFile);

        return (matches && matches.length > 0);
    });
};

JAWS.prototype._findLibDir = function (startDir) {
    var packageName    = 'jaws-lib',
        libPackagePath = '/lib/package.json',
        foundPath      = false,
        previous       = "/";

    //Look ahead 1 folder cuz could be running from root for things like deploy all/multiple functions
    if (fs.existsSync(startDir + libPackagePath)) {
        var info = require(startDir + libPackagePath);
        if (packageName == info.name) {
            return path.dirname(startDir + libPackagePath);
        }
    }

    for (var i = 0; i < 20; i++) {
        previous     = previous + '../';
        var fullPath = startDir + previous + libPackagePath;

        if (fs.existsSync(fullPath)) {
            var info = require(fullPath);
            if (packageName == info.name) {
                foundPath = path.resolve(path.dirname(fullPath));
                break;
            }
        }
    }

    if (!foundPath) {
        throw new Error('***** JAWS Error: Can\'t find your jaws lib folder.  Did you rename it or create folders over 20 levels deep in your api folder?');
    }

    return foundPath;
};

/**
 * JAWS: Start "site" Server
 */

JAWS.prototype.server = function (serverDir) {

    // Check if in server root folder
    if (!fs.existsSync(serverDir + '/server.js')) return console.log('****** JAWS:  Error - You must be in the "site" directory of your JAWS application to run this command and start the server.');

    var child = exec('node server', function (error, stdout, stderr) {
        if (error !== null) console.log('exec error: ' + error);
    });

    child.stdout.pipe(process.stdout);
    child.stderr.pipe(process.stderr);
};

// Export
module.exports = new JAWS();