var gulp = require("gulp");
var uglify = require("gulp-uglify");
var typescript = require("gulp-typescript");
var sourcemaps = require("gulp-sourcemaps");
var srcToVariable = require("./gulp-srcToVariable");
var addModuleExports = require("./gulp-addModuleExports");
var merge2 = require("merge2");
var concat = require("gulp-concat");
var rename = require("gulp-rename");
var cleants = require('gulp-clean-ts-extends');
var changed = require('gulp-changed');
var runSequence = require('run-sequence');
var replace = require("gulp-replace")

var config = require("./config.json");

var shadersStream;
var workersStream;

var extendsSearchRegex = /var\s__extends[\s\S]+?\};/g

//function to convert the shaders' filenames to variable names.
function shadersName(filename) {
    return filename.replace('.fragment', 'Pixel')
      .replace('.vertex', 'Vertex')
      .replace('.fx', 'Shader');
}

gulp.task("shaders", function(cb) {
    shadersStream = config.shadersDirectories.map(function(shadersDef) {
        return gulp.src(shadersDef.files).pipe(srcToVariable(shadersDef.variable, true, shadersName));
    });
    cb();
});

gulp.task("workers", function(cb) {
    workersStream = config.workers.map(function(workerDef) {
        return gulp.src(workerDef.files).pipe(uglify()).pipe(srcToVariable(workerDef.variable));
    });
    cb();
});

/*
Compiles all typescript files and creating a declaration file.
*/
gulp.task('typescript-compile', function() {  
  var tsResult = gulp.src(config.core.typescript)
                .pipe(typescript({ 
                    noExternalResolve: true, 
                    target: 'ES5', 
                    declarationFiles: true,
                    typescript: require('typescript')
                })).on('error', function(error) {
                    console.log('Typescript compile failed');
                    process.exit(1);
                });
    return merge2([
        tsResult.dts
            .pipe(concat(config.build.declarationFilename))
            .pipe(gulp.dest(config.build.outputDirectory)),
        tsResult.js
            .pipe(gulp.dest(config.build.srcOutputDirectory))
    ]);
});

gulp.task('typescript-sourcemaps', function() {
    var tsResult = gulp.src(config.core.typescript)
                .pipe(sourcemaps.init()) // sourcemaps init. currently redundant directory def, waiting for this - https://github.com/floridoo/gulp-sourcemaps/issues/111
                .pipe(typescript({ 
                    noExternalResolve: true, 
                    target: 'ES5', 
                    declarationFiles: true,
                    typescript: require('typescript')
                }));
    return tsResult.js
            .pipe(sourcemaps.write("./")) // sourcemaps are written.
            .pipe(gulp.dest(config.build.srcOutputDirectory));
});

gulp.task("buildNoWorker", ["shaders"], function () {
    return merge2(
        gulp.src(config.core.files, config.extras.files),
        shadersStream
    )
    .pipe(concat(config.build.minNoWorkerFilename))
    .pipe(cleants())
    .pipe(replace(extendsSearchRegex, ""))
    .pipe(addModuleExports("BABYLON"))
    .pipe(uglify())
    .pipe(gulp.dest(config.build.outputDirectory))
});

gulp.task("build", ["workers", "shaders"], function () {
    return merge2(
        gulp.src(config.core.files, config.extras.files),    
        shadersStream,
        workersStream
    )
    .pipe(concat(config.build.filename))
    .pipe(cleants())
    .pipe(replace(extendsSearchRegex, ""))
    .pipe(addModuleExports("BABYLON"))
    .pipe(gulp.dest(config.build.outputDirectory))
    .pipe(rename(config.build.minFilename))
    .pipe(uglify())
    .pipe(gulp.dest(config.build.outputDirectory))
});

gulp.task("typescript", function(cb) {
    runSequence("typescript-compile", "default");
});

/**
 * The default task, call the tasks: build
 */
gulp.task('default', function() {
    return runSequence("buildNoWorker", "build");
});

/**
 * Watch task, will call the default task if a js file is updated.
 */
gulp.task('watch', function() {
  gulp.watch(config.core.typescript, ['build']);
});

/**
 * Watch typescript task, will call the default typescript task if a typescript file is updated.
 */
gulp.task('watch-typescript', function() {
  gulp.watch(config.core.typescript, ["typescript-compile", "build"]);
});