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 uncommentShader = require("./gulp-removeShaderComments");
var expect = require('gulp-expect-file');
var optimisejs = require('gulp-optimize-js');

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

var shadersStream;

var extendsSearchRegex = /var\s__extends[\s\S]+?\};/g;
var decorateSearchRegex = /var\s__decorate[\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(expect.real({ errorOnFailure: true }, shadersDef.files)).
            pipe(uncommentShader()).
            pipe(srcToVariable("BABYLON.Effect.ShadersStore", true, shadersName)
            );
    });
    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'),
            experimentalDecorators: true
        }));
    //If this gulp task is running on travis, file the build!
    if (process.env.TRAVIS) {
        var error = false;
        tsResult.on('error', function () {
            error = true;
        }).on('end', function () {
            if (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'),
            experimentalDecorators: true
        }));
    return tsResult.js
        .pipe(sourcemaps.write("./")) // sourcemaps are written.
        .pipe(gulp.dest(config.build.srcOutputDirectory));
});

gulp.task("default", ["shaders"], function () {
    return merge2(
        gulp.src(config.core.files).        
            pipe(expect.real({ errorOnFailure: true }, config.core.files)),
        shadersStream)
        .pipe(concat(config.build.filename))
        .pipe(cleants())
        .pipe(replace(extendsSearchRegex, ""))
        .pipe(replace(decorateSearchRegex, ""))
        .pipe(addModuleExports("BABYLON"))
        .pipe(gulp.dest(config.build.outputDirectory))
        .pipe(rename(config.build.minFilename))
        .pipe(uglify())
        .pipe(optimisejs())
        .pipe(gulp.dest(config.build.outputDirectory));
});

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

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

/**
 * 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"]);
});