/**
 * NB: All tasks are initialized lazily, even plugins are required lazily,
 * running 1 task does not require all tasks' files
 */

const gulp = require('gulp');
const glob = require('glob');
const path = require('path');
const fs = require('fs');
const assert = require('assert');
const runSequence = require('run-sequence');
const ll   = require('gulp-ll');

const config = require('config');
const mongoose = require('lib/mongoose');

process.on('uncaughtException', function(err) {
  console.error(err.message, err.stack, err.errors);
  process.exit(255);
});

const jsSources = [
  'handlers/**/*.js', 'modules/**/*.js', 'tasks/**/*.js', '*.js'
];



function lazyRequireTask(path) {
  var args = [].slice.call(arguments, 1);
  return function(callback) {
    var task = require(path).apply(this, args);

    return task(callback);
  };
}

function requireModuleTasks(moduleName) {

  let dir = path.join(path.dirname(require.resolve(moduleName)), 'tasks');
  let taskFiles = fs.readdirSync(dir);

  let hasDeps;
  try {
    fs.accessSync(path.join(dir, '.deps.json'));
    hasDeps = true;

  } catch(e) {
    hasDeps = false;
  }

  let deps = hasDeps ? require(path.join(dir, '.deps.json')) : {};

  for(let taskFile of taskFiles) {
    // migrate:myTask

    let taskName = taskFile.split('.')[0];
    if (taskName === '') continue; // ignore .files

    let taskNameFull = moduleName.replace(/\//g, ':') + ':' + taskName;

    // console.log("task", taskNameFull, "deps", deps[taskName] || [], "path", path.join(dir, taskFile) );

    gulp.task(taskNameFull, deps[taskName] || [], lazyRequireTask(path.join(dir, taskFile)) );
  }

}

ll.tasks('nodemon', 'client:webpack', 'server');

// usage: gulp db:load --from fixture/init --harmony
gulp.task('db:load', lazyRequireTask('./tasks/dbLoad'));
gulp.task('db:clear', lazyRequireTask('./tasks/dbClear'));

gulp.task("nodemon", lazyRequireTask('./tasks/nodemon', {
  // shared client/server code has require('template.jade) which precompiles template on run
  // so I have to restart server to pickup the template change
  ext:    "js,jade",

  nodeArgs: process.env.NODE_DEBUG  ? ['--debug'] : [],
  script: "./bin/server.js",
  //ignoreRoot: ['.git', 'node_modules'].concat(glob.sync('{handlers,modules}/**/client')), // ignore handlers' client code
  ignore: ['**/client/', '**/photoCut/'], // ignore handlers' client code
  watch:  ["handlers", "modules"]
}));

gulp.task("client:livereload", lazyRequireTask("./tasks/livereload", {
  // watch files *.*, not directories, no need to reload for new/removed files,
  // we're only interested in changes

  watch: [
    "public/pack/**/*.*",
    // not using this file, using only styles.css (extracttextplugin)
    "!public/pack/styles.js",
    // this file changes every time we update styles
    // don't watch it, so that the page won't reload fully on style change
    "!public/pack/head.js"
  ]
}));


requireModuleTasks('migrate');
requireModuleTasks('tutorial');
requireModuleTasks('quiz');

var testSrcs = ['{handlers,modules}/**/test/**/*.js'];
// on Travis, keys are required for E2E Selenium tests
// for PRs there are no keys, so we disable E2E
if (!process.env.TEST_E2E || process.env.CI && process.env.TRAVIS_SECURE_ENV_VARS=="false") {
  testSrcs.push('!{handlers,modules}/**/test/e2e/*.js');
}

gulp.task("test", lazyRequireTask('./tasks/test', {
  src: testSrcs,
  reporter: 'spec',
  timeout: 100000 // big timeout for webdriver e2e tests
}));


gulp.task('watch', lazyRequireTask('./tasks/watch', {
  root:        __dirname,
  // for performance, watch only these dirs under root
  dirs: ['assets', 'styles'],
  taskMapping: [
    {
      watch: 'assets/**',
      task:  'client:sync-resources'
    }
  ]
}));

gulp.task('deploy', function(callback) {
  runSequence("deploy:build", "deploy:update", callback);
});

gulp.task("client:sync-resources", lazyRequireTask('./tasks/syncResources', {
  assets: 'public'
}));

// show errors if encountered
gulp.task('client:compile-css',
  lazyRequireTask('./tasks/compileCss', {
    src: './styles/base.styl',
    dst: './public/styles',
    publicDst: process.env.STATIC_HOST + '/styles/',  // from browser point of view
    manifest: path.join(config.manifestRoot, 'styles.versions.json'),
    assetVersioning: config.assetVersioning
  })
);


gulp.task('client:minify', lazyRequireTask('./tasks/minify'));
gulp.task('client:resize-retina-images', lazyRequireTask('./tasks/resizeRetinaImages'));

gulp.task('client:webpack', lazyRequireTask('./tasks/webpack'));
// gulp.task('client:webpack-dev-server', lazyRequireTask('./tasks/webpackDevServer'));


gulp.task('build', function(callback) {
  runSequence("client:sync-resources", 'client:webpack', callback);
});

gulp.task('server', lazyRequireTask('./tasks/server'));

// no build
gulp.task('edit', ['tutorial:importWatch', "client:sync-resources", 'client:livereload', 'server']);


gulp.task('dev', function(callback) {
  runSequence("client:sync-resources", ['nodemon', 'client:livereload', 'client:webpack', 'watch'], callback);
});

gulp.task('cache:clean', lazyRequireTask('./tasks/cacheClean'));

gulp.task('config:nginx', lazyRequireTask('./tasks/configNginx'));

// when queue finished successfully or aborted, close db
// orchestrator events (sic!)
gulp.on('stop', function() {
  mongoose.disconnect();
});

gulp.on('err', function(gulpErr) {
  if (gulpErr.err) {
    // cause
    console.error("Gulp error details", [gulpErr.err.message, gulpErr.err.stack, gulpErr.err.errors].filter(Boolean));
  }
  mongoose.disconnect();
});