var gulp = require('gulp');
var handlebars = require('gulp-handlebars');
var declare = require('gulp-declare');
var concat = require('gulp-concat');
var wrap = require('gulp-wrap');
var livereload = require('gulp-livereload');
var path = require('path');
var streamqueue = require('streamqueue');
var stripbom = require('gulp-stripbom');
var compliler = require('handlebars');

var errorHandler = require('./helpers/errorHandler');
var paths = require('./helpers/paths.js');

console.log('Handlebars (gulp) Version: ', compliler.VERSION);
console.log('Handlebars (gulp) Compiler: ', compliler.COMPILER_REVISION);

gulp.task('handlebars', () => {
  var coreStream = gulp.src([
    paths.src.templates,
    '!*/**/*Partial.*'
  ])
    .pipe(stripbom({
      showLog: false
    }))
    .pipe(handlebars({
      handlebars: compliler
    }))
    .on('error', errorHandler)
    .pipe(declare({
      namespace: 'T',
      noRedeclare: true,
      processName: (filePath) => {
        filePath = path.relative(paths.src.root, filePath);

        return filePath.replace(/\\/g, '/')
          .toLocaleLowerCase()
          .replace('template', '')
          .replace('.js', '');
      }
    }));

  var partialStream = gulp.src([paths.src.partials])
    .pipe(stripbom({
      showLog: false
    }))
    .pipe(handlebars({
      handlebars: compliler
    }))
    .on('error', errorHandler)
    .pipe(wrap('Handlebars.template(<%= contents %>)'))
    .pipe(wrap('Handlebars.registerPartial(<%= processPartialName(file.relative) %>, <%= contents %>)', {}, {
      imports: {
        processPartialName: function(fileName) {
          return JSON.stringify(
            path.basename(fileName, '.js')
          );
        }
      }
    }));

  return streamqueue({
    objectMode: true
  },
      partialStream,
      coreStream
    ).pipe(concat('templates.js'))
    .pipe(gulp.dest(paths.dest.root))
    .pipe(livereload());
});