'use strict';

/**
 * Serverless Endpoint Class
 * - options.path format is: "moduleFolder/functionFolder#functionName"
 */

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

class ServerlessEndpoint {

  /**
   * Constructor
   */

  constructor(Serverless, config) {

    // Validate required attributes
    if (!config.component || !config.module || !config.function || !config.endpointPath || !config.endpointMethod) throw new SError('Missing required config.component, config.module, config.function, config.endpointMethod, config.endpointPath');

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

    // Default properties
    _this.path                 = config.endpointPath;
    _this.method               = config.endpointMethod;
    _this.authorizationType    = 'none';
    _this.apiKeyRequired       = false;
    _this.requestParameters    = {};
    _this.requestTemplates     = {};
    _this.requestTemplates['application/json'] = '';
    _this.responses            = {};
    _this.responses['default'] = {
      statusCode: '200',
      responseParameters: {},
      responseModels: {},
      responseTemplates: {}
    };
    _this.responses['default']['application/json'] = '';
    _this.responses['400']     = {
      statusCode: '400'
    };
  }

  /**
   * Update Config
   * - Takes config.component, config.module, config.function
   */

  updateConfig(config) {

    if (!config) return;

    // Set sPath
    if (config.component || config.module || config.function || config.endpointPath || config.endpointMethod) {
      this._config.component      = config.component;
      this._config.module         = config.module;
      this._config.function       = config.function;
      this._config.endpointPath   = config.endpointPath;
      this._config.endpointMethod = config.endpointMethod;
      this._config.sPath          = SUtils.buildSPath({
        component: config.component,
        module:    config.module,
        function:  config.function,
        endpointPath:   config.endpointPath,
        endpointMethod: config.endpointMethod
      });
    }

    // 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, parse.module, parse.function);
    }
  }

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

  load() {

    let _this = this;

    return new BbPromise(function(resolve) {

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

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

      let functionJson = SUtils.readAndParseJsonSync(path.join(_this._config.fullPath, 's-function.json'));
      let endpoint = null;
      for (let i = 0; i < functionJson.endpoints.length; i++) {
        if (functionJson.endpoints[i].path === _this._config.endpointPath &&
          functionJson.endpoints[i].method === _this._config.endpointMethod) {
          endpoint = functionJson.endpoints[i];
        }
      }

      if (!endpoint) throw new SError('Endpoint was not found: ' + _this._config.sPath);

      // Merge
      _.assign(_this, endpoint);

      return resolve(_this);
    });
  }

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

  set(data) {

    // Merge
    _.assign(this, data);
    return this;
  }

  /**
   * Get
   * - Return data
   */

  get() {
    return SUtils.exportClassData(_.cloneDeep(this));
  }

  /**
   * Get Populated
   * - Fill in templates then variables
   * - Returns Promise
   */

  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('Endpoint could not be populated because no project path has been set on Serverless instance');

    // Return
    return SUtils.populate(_this._S, _this.get(), options.stage, options.region)
      .then(function(data) {
        return data;
      });
  }

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

  save() {

    let _this = this;

    return new BbPromise(function(resolve) {

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

      // Validate: Check function exists
      if (!SUtils.fileExistsSync(path.join(_this._config.fullPath, 's-function.json'))) {
        throw new SError('Endpoint could not be saved because its function does not exist');
      }

      // Check if endpoint exists, and replace it if so
      let functionJson = SUtils.readAndParseJsonSync(path.join(_this._config.fullPath, 's-function.json'));
      let endpoint = null;
      for (let i = 0; i < functionJson.endpoints.length; i++) {
        if (functionJson.endpoints[i].path === _this._config.endpointPath &&
          functionJson.endpoints[i].method === _this._config.endpointMethod) {
          endpoint = functionJson.endpoints[i];
          functionJson.endpoints[i] = _this.get();
        }
      }

      if (!endpoint) functionJson.endpoints.push(_this.get());

      // Save updated function file
      return SUtils.writeFile(path.join(_this._config.fullPath, 's-function.json'), JSON.stringify(functionJson, null, 2))
        .then(resolve);
    });
  }
}

module.exports = ServerlessEndpoint;