'use strict';

/**
 * Serverless Component Class
 */

const SError       = require('./ServerlessError'),
    SUtils           = require('./utils/index'),
    BbPromise        = require('bluebird'),
    path             = require('path'),
    _                = require('lodash'),
    fs               = require('fs');

class ServerlessComponent {

    /**
     * Constructor
     */

    constructor(Serverless, config) {

        // Validate required attributes
        if (!config.component) throw new SError('Missing required config.component');

        let _this     = this;
        _this._S      = Serverless;
        _this._config = {};
        _this.updateConfig(config);

        // Default Properties
        _this.name           = _this._config.component || 'component' + SUtils.generateShortId(6);
        _this.runtime        = config.runtime || 'nodejs';
        _this.custom         = {};
        _this.functions      = {};
        _this.templates      = {};
    }

    /**
     * Update Config
     * - Takes config.component
     */

    updateConfig(config) {

        if (!config) return;

        // Set sPath
        if (config.component) {
            this._config.component = config.component;
            this._config.sPath     = SUtils.buildSPath({
                component: config.component
            });
        }

        // Make full path
        if (this._S.config.projectPath && this._config.sPath) {
            let parse = SUtils.parseSPath(this._config.sPath);
            this._config.fullPath = path.join(this._S.config.projectPath, parse.component);
        }
    }

    /**
     * Load
     * - Load from source (i.e., file system);
     * - Returns promise
     */

    load() {

        let _this = this,
            skip  = ['node_modules', 'lib'],
            componentJson,
            componentContents;

        // Helper to instantiate functions
        let loadFn = function(fnName, fnKey, cPath) {
            let func = new _this._S.classes.Function(_this._S, {
                component: _this._config.component,
                cPath:    cPath ? cPath : null,
                function: fnName
            });

            return func.load()
                .then(function(instance) {
                    componentJson.functions[fnKey]= instance;
                    return componentJson.functions[fnKey];
                });
        };

        // Load component, then traverse component dirs to get all functions
        return BbPromise.try(function() {

                // Validate: Check project path is set
                if (!_this._S.config.projectPath) throw new SError('Component could not be loaded because no project path has been set on Serverless instance');

                // Validate: Check component exists
                if (!SUtils.fileExistsSync(path.join(_this._config.fullPath, 's-component.json'))) {
                    throw new SError('Component could not be loaded because it does not exist in your project: ' + _this._config.sPath);
                }

                componentJson           = SUtils.readAndParseJsonSync(path.join(_this._config.fullPath, 's-component.json'));
                componentJson.functions = {};
                componentContents       = fs.readdirSync(_this._config.fullPath);
                return componentContents;
            })
            .each(function(f, i) {

                // Skip node_modules and lib
                if (skip.indexOf(f.trim() == -1) return;

                // If s-function.json doesn't exist, look in 2 subfolders
                if (SUtils.fileExistsSync(path.join(_this._config.fullPath, componentContents[i], 's-function.json'))) {
                    let fnJson = SUtils.readAndParseJsonSync(path.join(_this._S.config.serverlessPath, componentContents[i], 's-function.json'));
                    return loadFn(fnJson.name, fnJson.name, null);
                } else {

                    // Loop through 1st level subfolders looking for more functions
                    return BbPromise.resolve(fs.readdirSync(path.join(_this._config.fullPath, componentContents[i])))
                        .each(function(sf1, i) {

                            // If s-function.json doesn't exist, look in 2 subfolders
                            if (SUtils.fileExistsSync(path.join(_this._config.fullPath, componentContents[i], sf1, 's-function.json'))) {
                                let fnJson = SUtils.readAndParseJsonSync(path.join(_this._S.config.serverlessPath, componentContents[i], sf1, 's-function.json'));
                                return loadFn(fnJson.name, fnJson.name, sf1 + '/' + fnJson.name);
                            } else {

                                // Loop through 2nd level subfolders looking for more functions
                                return BbPromise.resolve(fs.readdirSync(path.join(_this._config.fullPath, componentContents[i], sf1)))
                                    .each(function(sf2, i) {

                                        // If s-function.json doesn't exist, look in 2 subfolders
                                        if (SUtils.fileExistsSync(path.join(_this._config.fullPath, componentContents[i], sf1, sf2, 's-function.json'))) {
                                            let fnJson = SUtils.readAndParseJsonSync(path.join(_this._S.config.serverlessPath, componentContents[i], sf1, sf2, 's-function.json'));
                                            return loadFn(fnJson.name, fnJson.name, sf1 + '/' + sf2 + '/' + fnJson.name);
                                        }
                                    });
                            }
                        });
                }
            })
            .then(function() {

                // Get templates
                if (_this._config.fullPath && SUtils.fileExistsSync(path.join(_this._config.fullPath, 's-templates.json'))) {
                    componentJson.templates = require(path.join(_this._config.fullPath, 's-templates.json'));
                }
            })
            .then(function() {

                // Merge
                _.assign(_this, componentJson);
                return _this;
            });
    }

    /**
     * Set
     * - Set data
     * - Accepts a data object
     */

    set(data) {
        let _this = this;

        // Instantiate Components
        for (let prop in data.functions) {

            if (data.functions[prop] instanceof _this._S.classes.Function) {
                throw new SError('You cannot pass subclasses into the set method, only object literals');
            }

            let instance = new _this._S.classes.Function(_this._S, {
                component: _this._config.component,
                function:  data.functions[prop].name,
                cPath: prop.indexOf('/') !== -1 ? prop : null
            });
            data.functions[prop] = instance.set(data.functions[prop]);
        }

        // Merge in
        _this = _.extend(_this, data);
        return _this;
    }

    /**
     * Get
     * - Returns clone of data
     */

    get() {
        let clone = _.cloneDeep(this);
        for (let prop in this.functions) {
            clone.functions[prop] = this.functions[prop].get();
        }
        return SUtils.exportClassData(clone);
    }

    /**
     * getPopulated
     * - Fill in templates then variables
     */

    getPopulated(options) {
        let _this = this;

        options = options || {};

        // Validate: Check Stage & Region
        if (!options.stage || !options.region) throw new SError('Both "stage" and "region" params are required');

        // Validate: Check project path is set
        if (!_this._S.config.projectPath) throw new SError('Component could not be populated because no project path has been set on Serverless instance');

        // Populate
        let clone            = _this.get();
        clone                = SUtils.populate(_this._S.state.getMeta(), this.getTemplates(), clone, options.stage, options.region);
        clone.functions        = {};
        for (let prop in _this.functions) {
            clone.functions[prop] = _this.functions[prop].getPopulated(options);
        }

        return clone;
    }

    /**
     * Get Templates
     * - Returns clone of templates
     * - Inherits parent templates
     */

    getTemplates() {
        return _.merge(
            this.getProject().getTemplates(),
            _.cloneDeep(this.templates)
        );
    }

    /**
     * Save
     * - Saves data to file system
     * - Returns promise
     */

    save(options) {

        let _this = this;

        return new BbPromise.try(function() {

            // Validate: Check project path is set
            if (!_this._S.config.projectPath) throw new SError('Component could not be saved because no project path has been set on Serverless instance');

            // Create if does not exist
            if (!SUtils.fileExistsSync(path.join(_this._config.fullPath, 's-component.json'))) {
                return _this._create();
            }
        })
            .then(function() {

                // Save all nested modules
                if (options && options.deep) {
                    return BbPromise.try(function () {
                            return Object.keys(_this.functions);
                        })
                        .each(function(fnKey) {
                            return _this.functions[fnKey].save();
                        })
                }
            })
            .then(function() {

                // If templates, save templates
                if (_this.templates && Object.keys(_this.templates).length) {
                    return SUtils.writeFile(path.join(_this._config.fullPath, 's-templates.json'), _this.templates);
                }
            })
            .then(function() {

                let clone = _this.get();

                // Strip properties
                if (clone.functions) delete clone.functions;
                if (clone.templates) delete clone.templates;

                // Write file
                return SUtils.writeFile(path.join(_this._config.fullPath, 's-component.json'),
                    JSON.stringify(clone, null, 2));
            })
            .then(function() {
                return _this;
            })
    }

    /**
     * Create (scaffolding)
     * - Returns promise
     */

    _create() {

        let _this              = this,
            writeDeferred        = [];

        return BbPromise.try(function() {

            writeDeferred.push(
                fs.mkdirSync(_this._config.fullPath),
                fs.mkdirSync(path.join(_this._config.fullPath, 'lib'))
            );
            // Runtime: nodejs
            if (_this.runtime === 'nodejs') {
                let packageJsonTemplate = SUtils.readAndParseJsonSync(path.join(_this._S.config.serverlessPath, 'templates', 'nodejs', 'package.json')),
                    libJs = fs.readFileSync(path.join(_this._S.config.serverlessPath, 'templates', 'nodejs', 'index.js'));

                writeDeferred.push(
                    SUtils.writeFile(path.join(_this._config.fullPath, 'lib', 'index.js'), libJs),
                    SUtils.writeFile(path.join(_this._config.fullPath, 'package.json'), JSON.stringify(packageJsonTemplate, null, 2))
                );
            } else if (_this.runtime === 'python2.7') {
                let requirements = fs.readFileSync(path.join(_this._S.config.serverlessPath, 'templates', 'python2.7', 'requirements.txt')),
                    initPy = fs.readFileSync(path.join(_this._S.config.serverlessPath, 'templates', 'python2.7', '__init__.py')),
                    blankInitPy = fs.readFileSync(path.join(_this._S.config.serverlessPath, 'templates', 'python2.7', 'blank__init__.py'));

                writeDeferred.push(
                    fs.mkdirSync(path.join(_this._config.fullPath, 'vendored')),
                    SUtils.writeFile(path.join(_this._config.fullPath, 'lib', '__init__.py'), initPy),
                    SUtils.writeFile(path.join(_this._config.fullPath, 'vendored', '__init__.py'), blankInitPy),
                    SUtils.writeFile(path.join(_this._config.fullPath, 'requirements.txt'), requirements)
                );
            }

            return BbPromise.all(writeDeferred);
        });
    }

    /**
     * Get Project
     * - Returns reference to the instance
     */

    getProject() {
        return this._S.state.project;
    }
}

module.exports = ServerlessComponent;