const fs = require('../core/fs.js');
const async = require('async');
const utils = require('../utils/utils.js');
const webpack = require("webpack");
const constants = require('../constants');
const File = require('../core/file');

require("babel-preset-react");
require("babel-preset-es2015");
require("babel-preset-es2016");
require("babel-preset-es2017");

let pipeline;

// Override process.chdir so that we have a partial-implementation PWD for Windows
const realChdir = process.chdir;
process.chdir = (...args) => {
  if (!process.env.PWD) {
    process.env.PWD = process.cwd();
  }
  realChdir(...args);
};

class Pipeline {

  constructor(options) {
    this.buildDir = options.buildDir;
    this.contractsFiles = options.contractsFiles;
    this.assetFiles = options.assetFiles;
    this.pipelinePlugins = options.pipelinePlugins;
    this.pluginImports = options.pluginImports;
    this.web3Location = options.web3Location;
    this.providerCode = options.providerCode;

    this.interceptLogs();
  }

  interceptLogs() {
    const context = {};
    context.console = console;

    context.console.log  = this.log;
    context.console.warn  = this.log;
    context.console.info  = this.log;
    context.console.debug  = this.log;
    context.console.trace  = this.log;
    context.console.dir  = this.log;
  }

  log() {
    process.send({result: constants.pipeline.log, message: arguments});
  }

  build(abi, contractsJSON, path, callback) {
    let self = this;

    this.buildContracts(contractsJSON);

    self.buildWeb3JS(function(err) {
      if (err) {
        return callback(err);
      }

      let importsList = {};

      importsList["Embark/EmbarkJS"] = fs.dappPath(".embark", 'embark.js');
      importsList["Embark/web3"] = fs.dappPath(".embark", 'web3_instance.js');

      self.pluginImports.forEach(function (importObject) {
          let [importName, importLocation] = importObject;
          importsList[importName] = importLocation;
      });

      for (let contractName in contractsJSON) {
          let contractCode = self.buildContractJS(contractName);
          let filePath = fs.dappPath(".embark", contractName + '.js');
          fs.writeFileSync(filePath, contractCode);
          importsList["Embark/contracts/" + contractName] = filePath;
      }

      // limit:1 due to issues when downloading required files such as web3.js
      async.eachOfLimit(self.assetFiles, 1, function (files, targetFile, cb) {
        // limit:1 due to issues when downloading required files such as web3.js
        async.mapLimit(files, 1,
          function(file, fileCb) {
            file = new File(file); // Re-instantiate a File as through the process, we lose its prototype
            self.log("reading " + file.filename);

            if (file.filename.indexOf('.js') >= 0) {

              let realCwd;

              async.waterfall([

                function findImports(next) {
                  self.webpackRun(file.filename, {}, false, importsList, false, next);
                },

                function changeCwd(next) {
                  realCwd = utils.pwd();
                  process.chdir(fs.embarkPath(''));
                  next();
                },

                //function findImportsPhase2(next) {
                //  console.log("====> findImports_2");
                //  self.webpackRun(file.filename, {
                //    externals: function(context, request, callback) {
                //      if (request === utils.joinPath(fs.dappPath(), file.filename)) {
                //        callback();
                //      } else {
                //        //if (request.indexOf('Embark/contracts/') === 0) {
                //        //  let contractName = request.split('/')[2];
                //        //  let contractCode = self.buildContractJS(contractName);
                //        //  let filePath = utils.joinPath(fs.dappPath(), ".embark", contractName + '.js');
                //        //  fs.writeFileSync(filePath, contractCode);
                //        //  importsList[request] = filePath;
                //        //}
                //        callback(null, "amd " + Math.random());
                //      }
                //    }
                //  }, true, importsList, next);
                //},

                function runWebpack(next) {
                  self.webpackRun(file.filename, {}, true, importsList, true, next);
                },

                function changeCwdBack(next) {
                  process.chdir(realCwd);
                  next();
                },

                function checkFile(next) {
                  fs.access('./.embark/' + file.filename, (err) => {
                    if (err) {
                      self.log("couldn't find file: " + file.filename);
                      return next("couldn't find file: " + file.filename);
                    }
                    next();
                  });
                },

                function readFile(next) {
                  fs.readFile('./.embark/' + file.filename, (err, data) => {
                    if (err) {
                      return next(err);
                    }
                    next(null, data.toString());
                  });
                },

                function runPluginsOnContent(fileContent, next) {
                  self.runPlugins(file, fileContent, next);
                }

              ], function(err, contentFile) {
                if (err) {
                  process.chdir(realCwd);
                  self.log(err);
                  return fileCb(err);
                }

                fileCb(null, contentFile);
              });
            } else {
              file.content(function(fileContent) {
                self.runPlugins(file, fileContent, fileCb);
              });
            }
          },
          function (err, contentFiles) {
            if (err) {
              self.log('errors found while generating ' + targetFile);
            }
            let dir = targetFile.split('/').slice(0, -1).join('/');
            self.log("creating dir " + self.buildDir + dir);
            fs.mkdirpSync(self.buildDir + dir);

            // if it's a directory
            if (targetFile.slice(-1) === '/' || targetFile.indexOf('.') === -1) {
              let targetDir = targetFile;

              if (targetDir.slice(-1) !== '/') {
                targetDir = targetDir + '/';
              }

              contentFiles.map(function (file) {
                let filename = file.filename.replace(file.basedir + '/', '');
                self.log("writing file " + (self.buildDir + targetDir + filename).bold.dim);

                fs.copySync(file.path, self.buildDir + targetDir + filename, {overwrite: true});
              });
            } else {
              let content = contentFiles.map(function (file) {
                if (file === undefined) {
                  return "";
                }
                return file.content;
              }).join("\n");

              self.log("writing file " + (self.buildDir + targetFile).bold.dim);
              fs.writeFileSync(self.buildDir + targetFile, content);
            }
            cb();
          }
        );
      },
        function (_err, _results) {
          callback();
        });
    });
  }

  runPlugins(file, fileContent, fileCb) {
    const self = this;
    if (self.pipelinePlugins.length <= 0) {
      return fileCb(null, {content: fileContent, filename: file.filename, path: file.path, basedir: file.basedir, modified: true});
    }
    async.eachSeries(self.pipelinePlugins,
      function(plugin, pluginCB) {
        if (file.options && file.options.skipPipeline) {
          return pluginCB();
        }

        fileContent = plugin.runPipeline({targetFile: file.filename, source: fileContent});
        file.modified = true;
        pluginCB();
      },
      function (err) {
        if (err) {
          self.log(err.message);
        }
        return fileCb(null, {content: fileContent, filename: file.filename, path: file.path, basedir: file.basedir, modified: true});
      }
    );
  }

  webpackRun(filename, options, includeModules, importsList, detectErrors, callback) {
    let defaultOptions = {
      entry: fs.dappPath(filename),
      output: {
        libraryTarget: 'umd',
        path: fs.dappPath('.embark'),
        filename: filename
      },
      resolve: {
        alias: importsList,
        modules: [
          fs.embarkPath('node_modules'),
          fs.dappPath('node_modules')
        ]
      },
      externals: function(context, request, callback) {
        callback();
      }
    };

    let webpackOptions =  utils.recursiveMerge(defaultOptions, options);

    if (includeModules) {
      webpackOptions.module = {
        rules: [
          {
            test: /\.css$/,
            use: [{loader: "style-loader"}, {loader: "css-loader"}]
          },
          {
            test: /\.scss$/,
            use: [{loader: "style-loader"}, {loader: "css-loader"}]
          },
          {
            test: /\.(png|woff|woff2|eot|ttf|svg)$/,
            loader: 'url-loader?limit=100000'
          },
          {
            test: /\.js$/,
            loader: "babel-loader",
            exclude: /(node_modules|bower_components)/,
            options: {
              presets: ['babel-preset-es2016', 'babel-preset-es2017', 'babel-preset-react'].map(require.resolve),
              plugins: ["babel-plugin-webpack-aliases"].map(require.resolve),
              compact: false
            }
          }
        ]
      };
    }

    webpack(webpackOptions).run((_err, _stats) => {
      if (_err) {
        console.log('ERROS');
        console.log(_err);
      }
      if (!detectErrors) {
        return callback();
      }

      if (_stats.hasErrors()) {
        return callback(_stats.toJson().errors.join("\n"));
      }
      callback();
    });
  }

  buildContracts(contractsJSON) {
    fs.mkdirpSync(fs.dappPath(this.buildDir, 'contracts'));

    for (let className in contractsJSON) {
      let contract = contractsJSON[className];
      fs.writeJSONSync(fs.dappPath(this.buildDir, 'contracts', className + ".json"), contract, {spaces: 2});
    }
  }

  buildContractJS(contractName) {
    let contractJSON = fs.readFileSync(fs.dappPath(this.buildDir, 'contracts', contractName + '.json')).toString();

    let contractCode = "";
    contractCode += "import web3 from 'Embark/web3';\n";
    contractCode += "import EmbarkJS from 'Embark/EmbarkJS';\n";
    contractCode += "let " + contractName + "JSONConfig = " + contractJSON + ";\n";
    contractCode += "let " + contractName + " = new EmbarkJS.Contract(" + contractName + "JSONConfig);\n";

    contractCode += "\n__embarkContext.execWhenReady(function() {\n";
    contractCode += "\n" + contractName + ".setProvider(web3.currentProvider);\n";
    contractCode += "\n});\n";

    contractCode += "export default " + contractName + ";\n";

    return contractCode;
  }

  buildWeb3JS(cb) {
    const self = this;
    let code = "";

    async.waterfall([
      function getImports(next) {
        self.web3Location = self.web3Location.replace(/\\/g, '/'); // Import paths must always have forward slashes
        code += "\nimport Web3 from '" + self.web3Location + "';\n";

        code += "\n if (typeof web3 !== 'undefined') {";
        code += "\n } else {";
        code += "\n var web3 = new Web3();\n";
        code += "\n }";

        code += self.providerCode;
        code += "\nglobal.__embarkContext = __mainContext.__loadManagerInstance;\n";
        code += "\nwindow.web3 = web3;\n";
        code += "\nexport default web3;\n";

        next();
      },
      function makeDirectory(next) {
        fs.mkdirp(fs.dappPath(".embark"), (err, _result) => {
          next(err);
        });
      },
      function writeFile(next) {
        fs.writeFile(fs.dappPath(".embark", 'web3_instance.js'), code, next);
      }
    ], cb);
  }

}


process.on('message', (msg) => {
  if (msg.action === constants.pipeline.init) {
    pipeline = new Pipeline(msg.options);
    return process.send({result: constants.pipeline.initiated});
  }

  if (msg.action === constants.pipeline.build) {
    return pipeline.build(msg.abi, msg.contractsJSON, msg.path, (err, result) => {
      process.send({result: constants.pipeline.built, error: err, data: result});
    });
  }
});


process.on('exit', () => {
  process.exit(0);
});