/*
 * grunt-contrib-jst
 * http://gruntjs.com/
 *
 * Copyright (c) 2012 Tim Branyen, contributors
 * Licensed under the MIT license.
 * https://github.com/gruntjs/grunt-contrib-jst/blob/master/LICENSE-MIT
 */

module.exports = function(grunt) {
  "use strict";

  var _ = require("underscore");
  var helpers = require('grunt-contrib-lib').init(grunt);

  // filename conversion for templates
  var defaultProcessName = function(name) { return name; };

  grunt.registerMultiTask("jst", "Compile underscore templates to JST file", function() {

    var helpers = require("grunt-contrib-lib").init(grunt);
    var options = helpers.options(this, {namespace: "JST", templateSettings: {}});

    // assign filename transformation functions
    var processName = options.processName || defaultProcessName;

    grunt.verbose.writeflags(options, "Options");

    // TODO: ditch this when grunt v0.4 is released
    this.files = this.files || helpers.normalizeMultiTaskFiles(this.data, this.target);

    var compiled, srcFiles, src, filename;
    var output = [];
    var nsInfo = helpers.getNamespaceDeclaration(options.namespace);

    this.files.forEach(function(files) {
      srcFiles = grunt.file.expandFiles(files.src);
      srcFiles.forEach(function(file) {
        src = grunt.file.read(file);

        try {
          compiled = _.template(src, false, options.templateSettings).source;
        } catch (e) {
          grunt.log.error(e);
          grunt.fail.warn("JST failed to compile.");
        }

        filename = processName(file);
        output.push(nsInfo.namespace+"["+JSON.stringify(filename)+"] = "+compiled+";");
      });

      if(output.length > 0) {
        output.unshift(nsInfo.declaration);
        grunt.file.write(files.dest, output.join("\n\n"));
        grunt.log.writeln("File '" + files.dest + "' created.");
      }
    });


  });

};