library angular2.transformer;

import 'dart:async';

import 'package:barback/barback.dart';

import 'package:html5lib/dom.dart' as dom;

import 'package:html5lib/parser.dart' show parse;

import 'package:path/path.dart' as path;

import 'options.dart';

Future transformHtmlEntryPoint(

TransformerOptions options, Transform transform) {

// For now at least, [options.htmlEntryPoint], [options.entryPoint], and

// [options.newEntryPoint] need to be in the same folder.

// TODO(jakemac): support package urls with [options.entryPoint] or

// [options.newEntryPoint] in `lib`, and [options.htmlEntryPoint] in another

// directory.

var _expectedDir = path.split(options.htmlEntryPoint)[0];

if (!options.inSameTopLevelDir()) {

transform.logger.error(

'${options.htmlEntryPointParam}, ${options.entryPointParam}, and '

'${options.newEntryPointParam} (if supplied) all must be in the '

'same top level directory.');

}

// The relative path from [options.htmlEntryPoint] to [dartEntry]. You must

// ensure that neither of these is null before calling this function.

String _relativeDartEntryPath(String dartEntry) =>

path.relative(dartEntry, from: path.dirname(options.htmlEntryPoint));

// Checks if the src of this script tag is pointing at `options.entryPoint`.

bool _isEntryPointScript(dom.Element script) =>

path.normalize(script.attributes['src']) ==

_relativeDartEntryPath(options.entryPoint);

return transform.primaryInput.readAsString().then((String html) {

var found = false;

var doc = parse(html);

var scripts = doc.querySelectorAll('script[type="application/dart"]');

for (dom.Element script in scripts) {

if (!_isEntryPointScript(script)) continue;

script.attributes['src'] = _relativeDartEntryPath(options.newEntryPoint);

found = true;

}

if (!found) {

transform.logger.error('Unable to find script for ${options.entryPoint} '

'in ${options.htmlEntryPoint}.');

}

return transform.addOutput(

new Asset.fromString(transform.primaryInput.id, doc.outerHtml));

});

}