var extend              = require('extend'),
    runSequence         = require('run-sequence'),
    fs                  = require('fs'),
    moment              = require('moment'),
    less                = require('gulp-less'),
    cssmin              = require('gulp-cssmin'),
    csscomb             = require('gulp-csscomb'),
    autoprefixer        = require('gulp-autoprefixer'),
    concat              = require('gulp-concat'),
    header              = require('gulp-header'),
    uglify              = require('gulp-uglify'),
    rename              = require('gulp-rename'),
    lessPluginCleanCSS  = require('less-plugin-clean-css'),
    mkdirp              = require('mkdirp'),
    del                 = require('del'),
    format              = require('string-format').extend(String.prototype),
    colors              = require('colors'),
    gulp                = require('gulp'),
    zui                 = require('./zui.json'),
    pkg                 = require('./package.json');

// Disable the 'possible EventEmitter memory leak detected' warning.
gulp.setMaxListeners(0);

// try load zui.custom.json and merge into zui.
try {
    var zuicustom  = require('./zui.custom.json');
    if(zuicustom) extend(true, zui, zuicustom);
} catch(e) {}

var today   = moment();
var typeSet = ['less', 'js', 'resource'],
    lib     = zui.lib,
    builds  = zui.builds,
    banner  = ('/*!\n' +
        ' * {title} - v{version} - {date}\n' +
        ' * {homepage}\n' +
        ' * GitHub: {repo} \n' +
        ' * Copyright (c) {year} {author}; Licensed {license}\n' +
        ' */\n\n').format({
            title: pkg.title || pkg.name,
            version: pkg.version,
            date: today.format('YYYY-MM-DD'),
            homepage: pkg.homepage,
            repo: pkg.repository.url,
            year: today.format('YYYY'),
            author: pkg.author,
            license: pkg.license
        }),
    statement = '/* Some code copy from Bootstrap v3.0.0 by @fat and @mdo. (Copyright 2013 Twitter, Inc. Licensed under http://www.apache.org/licenses/)*/\n\n';

function tryStatSync(path) {
    try {
        return fs.statSync(path);
    } catch(e) {
        return false;
    }
}

function isFileExist(path) {
    var stats = tryStatSync(path);
    return stats && stats.isFile();
}

function getItemList(list, items, ignoreDpds) {
    items = items || [];

    if (Array.isArray(list)) {
        list.forEach(function(name) {
            getItemList(name, items, ignoreDpds);
        });
    } else {
        var item = lib[list];
        if (item && items.indexOf(list) < 0) {
            if (!ignoreDpds && item.dpds) {
                getItemList(item.dpds, items, ignoreDpds);
            }
            if (item.src) items.push(list);
        }
    }

    return items;
}

function getBuildSource(build) {
    var list = [];

    var sources = {
        less: [],
        js: [],
        resource: []
    };

    if (!Array.isArray(list)) list = [list];

    if (build.basicDpds) list = getItemList(build.basicDpds, list);
    list = getItemList(build.includes, list, build.ignoreDpds);

    list.forEach(function(item) {
        var libItem = lib[item];
        if (libItem && libItem.src) {
            typeSet.forEach(function(type) {
                if (libItem.src[type]) {
                    libItem.src[type].forEach(function(file) {
                        if (sources[type].indexOf(file) < 0) {
                            sources[type].push(file);
                        }
                    });
                }
            });
        }
    });

    return sources;
}

function getSourceConfig(src) {
    var idx = src.lastIndexOf('//');
    if (idx > 0) {
        return {
            base: src.substr(0, idx + 1),
            src: src.replace(/\/\//g, '/')
        };
    }
    idx = src.lastIndexOf('/');
    return {
        base: src.substr(0, idx + 1),
        src: src
    }
}

function getBuildPath(build, type) {
    var path = build.dest;
    if (build.subdirectories) {
        path += '/' + type + '/';
    }
    if(path.indexOf('.') !== 0) {
        path = './' + path;
    }
    return path.replace(/\/\//g, '/').replace(/\/\//g, '/');
}

function getBuildDestFilename(build, type, suffix) {
    var file = getBuildPath(build, type);
    file += '/' + build.filename + '.' + (suffix || type);
    return file.replace(/\/\//g, '/');
}

function buildBundle(name, callback, type) {
    name  = name|| 'all';
    var build = builds[name];

    // clean files
    if(name === 'dist') {
        del.sync('./dist/**/*');
    } else if(name === 'doc') {
        del.sync([
            './docs/js/**/*',
            './docs/css/**/*',
            './docs/fonts/**/*']);
    }

    if(!build) {
        if(name === 'all') {
            console.log('========== BUILD ALL =========='.blue.bold);
            var buildList = Object.keys(builds);
            var taskList = [];
            buildList.forEach(function(nm) {
                build = builds[nm];
                if(build && !build.bundles) {
                    var taskName = 'build:' + nm;
                    gulp.task(taskName, function(cb) {
                        buildBundle(nm, cb, type)
                    });
                    taskList.push(taskName);
                }
            });
            if(taskList.length) runSequence(taskList, function() {
                console.log(('√  Build ' + 'ALL'.bold + ' success! ').green);
                callback && callback();
            });
            return;
        } else {
            var buildLib = lib[name];
            if (buildLib) {
                build = {
                    title: buildLib.name,
                    dest: 'dist/lib/' + name + '/',
                    filename: name,
                    includes: [name],
                    thirdpart: buildLib.thirdpart
                };
            } else {
                console.log(('Cannot found the build config: ' + name).red);
                return false;
            }
        }
    } else if (build.bundles) {
        console.log(('=== BUILD BUNDLES ' + name.toUpperCase() + ' (' + build.title + ') ===').blue.bold);
        var taskList = [];
        build.bundles.forEach(function(bundleName) {
            build = builds[bundleName];
            if(build) {
                var taskName = 'build:' + bundleName;

                gulp.task(taskName, function(cb) {
                    buildBundle(bundleName, cb, type);
                });

                taskList.push(taskName);
            }
        });

        if(taskList.length) runSequence(taskList, function() {
            console.log(('√  Build BUNDLES ' + name.toUpperCase().bold + ' (' + build.title + ') success! ').green);
            callback && callback();
        });
        return;
    }

    console.log(('--- build ' + name + ' ---').cyan.bold);
    
    var source        = getBuildSource(build),
        bannerContent = build.thirdpart ? 
            '' : banner + (build.bootstrapStatement ? statement : ''),
        taskList      = [],
        depTaskList   = [];

    if(source.js && source.js.length && (!type || type === 'js')) {
        console.log(('+  Ready to process ' + source.js.length + ' javascript files.').bold);
        source.js.forEach(function(f, idx) {
            if(f.indexOf('~/') === 0) {
                source.js[idx] = f = 'src/js/' + f.substr(2);
            }
            console.log(('   - ' + f).italic);
        });

        //ar taskName = 'build:' + name + ':js';
        gulp.task('build:' + name + ':js', function() {
            var destPath = getBuildPath(build, 'js');
            return gulp.src(source.js)
                .pipe(concat(build.filename + '.js'))
                .pipe(header(bannerContent))
                .pipe(gulp.dest(destPath))
                .pipe(uglify())
                .pipe(rename({suffix: '.min'}))
                .pipe(header(bannerContent))
                .pipe(gulp.dest(destPath));
        });
        taskList.push('build:' + name + ':js');
    }

    if(source.less && source.less.length && (!type || type === 'less')) {
        var lessFileContent = '// \n// ' + build.title + '\n// Build config: ' + name + '\n//\n// This file generated by ZUI builder automatically at ' + today.toString() + '.\n//\n\n';
        console.log(('+  Ready to process ' + source.less.length + ' less files.').bold);
        source.less.forEach(function(f, idx) {
            if(f.indexOf('~/') === 0) {
                source.less[idx] = f = 'src/less/' + f.substr(2);
            }

            if(isFileExist(f)) {
                lessFileContent += '@import "';
                lessFileContent += '../../' + f;
                lessFileContent += '";\n';
                console.log(('   - ' + f).italic);
            } else {
                lessFileContent += '// @import "';
                lessFileContent += '../../' + f;
                lessFileContent += '" // FILE NOT FOUND;\n';
                console.log(('   ! ' + f + ' [NOT FOUND]').red.italic);
            }
        });

        gulp.task('build:' + name + ':less', function() {
            var buildSourceFilePath = './build/less/' + build.filename + '.less';
            var destPath = getBuildPath(build, 'css');

            mkdirp.sync('./build/less/');
            fs.writeFileSync(buildSourceFilePath, lessFileContent);

            return gulp.src(buildSourceFilePath)
                .pipe(less())
                .pipe(autoprefixer({browsers: ['> 1%'], cascade: true}))
                .pipe(csscomb())
                .pipe(header(bannerContent))
                .pipe(rename(build.filename + '.css'))
                .pipe(gulp.dest(destPath))
                .pipe(cssmin())
                .pipe(rename({suffix: '.min'}))
                .pipe(header(bannerContent))
                .pipe(gulp.dest(destPath));
        });
        taskList.push('build:' + name + ':less');
    }

    if(source.resource && source.resource.length && (!type || type === 'resource')) {
        console.log(('+  Ready to process ' + source.resource.length + ' resource files.').bold);
        var destPath = getBuildPath(build, '');
        source.resource.forEach(function(f, idx) {
            if(f.indexOf('~/') === 0) {
                source.resource[idx] = f = 'src//' + f.substr(2);
            }
            console.log(('   - [' + idx + '] ' + f).italic);
            gulp.task('build:' + name + ':resource:' + idx, function() {
                var sourceConfig = getSourceConfig(f);
                return gulp.src(sourceConfig.src, {base: sourceConfig.base})
                    .pipe(gulp.dest(destPath));
            });
            taskList.push('build:' + name + ':resource:' + idx);
        });
    }

    if(taskList.length || depTaskList.length) {
        var completeCallback = function() {
            console.log(('√  Build ' + name.bold + ' success! ').green);
            callback && callback();
        };
        
        if(taskList.length) {
            if(depTaskList.length) {
                runSequence(depTaskList, taskList, completeCallback);
            } else {
                runSequence(taskList, completeCallback);
            }
        } else {
            runSequence(depTaskList, completeCallback);
        }
        
    } else {
        console.log(('No source files for build: ' + name).red);
        callback && callback();
    }
}

gulp.task('build', function(callback) {
    var name = process.argv[3] || 'dist';
    if(name && name[0] === '-') name = name.substr(1);
    var type = process.argv.length > 4 ? process.argv[4] : false;
    if(type && type[0] === '-') type = type.substr(1);
    console.log(('>>  Build ' + name.bold + ' BEGIN ').inverse);
    buildBundle(name, callback, type);
});

['dist', 'doc'].forEach(function(name) {
    gulp.task(name, function(callback) {
        console.log(('>>  Build ' + name.bold + ' BEGIN ').inverse);
        buildBundle(name, callback);
    });

    gulp.task('watch:' + name, function() {
        gulp.watch(["./src/less/**/*"], function(event) {
            buildBundle(name, function() {
                console.log((' √ WATCH ' + name.bold + ' COMPLETED!').yellow.inverse);
            }, 'less');
        });

        gulp.watch(["./src/js/**/*"], function(event) {
            buildBundle(name, function() {
                console.log((' √ WATCH ' + name.bold + ' COMPLETED!').yellow.inverse);
            }, 'js');
        });

        gulp.watch(["./src/fonts/**/*"], function(event) {
            buildBundle(name, function() {
                console.log((' √ WATCH ' + name.bold + ' COMPLETED!').yellow.inverse);
            }, 'resource');
        });
    });
});

gulp.task('default', function() {
    buildBundle('all');
});