var fs = require('fs');

var path = require('path');

var tmpl = require('blueimp-tmpl').tmpl;

function HtmlWebpackPlugin(options) {

this.options = options || {};

}

HtmlWebpackPlugin.prototype.apply = function(compiler) {

var self = this;

compiler.plugin('emit', function(compiler, callback) {

var webpackStatsJson = compiler.getStats().toJson();

var templateParams = {};

templateParams.webpack = webpackStatsJson;

templateParams.htmlWebpackPlugin = {};

templateParams.htmlWebpackPlugin.assets = self.htmlWebpackPluginAssets(compiler, webpackStatsJson);

templateParams.htmlWebpackPlugin.options = self.options;

var outputFilename = self.options.filename || 'index.html';

if (self.options.templateContent && self.options.template) {

compiler.errors.push(new Error('HtmlWebpackPlugin: cannot specify both template and templateContent options'));

callback();

} else if (self.options.templateContent) {

self.emitHtml(compiler, self.options.templateContent, templateParams, outputFilename);

callback();

} else {

var templateFile = self.options.template;

if (!templateFile) {

templateFile = path.join(__dirname, 'default_index.html');

}

fs.readFile(templateFile, 'utf8', function(err, htmlTemplateContent) {

if (err) {

compiler.errors.push(new Error('HtmlWebpackPlugin: Unable to read HTML template "' + templateFile + '"'));

} else {

self.emitHtml(compiler, htmlTemplateContent, templateParams, outputFilename);

}

callback();

});

}

});

};

HtmlWebpackPlugin.prototype.emitHtml = function(compiler, htmlTemplateContent, templateParams, outputFilename) {

var html = tmpl(htmlTemplateContent, templateParams);

compiler.assets[outputFilename] = {

source: function() {

return html;

},

size: function() {

return html.length;

}

};

};

HtmlWebpackPlugin.prototype.htmlWebpackPluginAssets = function(compiler, webpackStatsJson) {

var assets = {};

for (var chunk in webpackStatsJson.assetsByChunkName) {

var chunkValue = webpackStatsJson.assetsByChunkName[chunk];

// Webpack outputs an array for each chunk when using sourcemaps

if (chunkValue instanceof Array) {

// Is the main bundle always the first element?

chunkValue = chunkValue[0];

}

if (compiler.options.output.publicPath) {

chunkValue = compiler.options.output.publicPath + chunkValue;

}

assets[chunk] = chunkValue;

}

return assets;

};

module.exports = HtmlWebpackPlugin;