import 'package:flutter_test/flutter_test.dart';

import 'package:mews/mews/atom.dart';
import 'package:mews/mews/parser.dart';

const defaultNamespaced = '''
<?xml version="1.0" encoding="utf-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <title>Signal Bars</title>
  <entry>
    <title>Collecting retro phones</title>
    <link rel="alternate" href="2026-10-08-retro.html" />
    <id>tag:example.com,2026:retro</id>
    <updated>2026-10-08T09:30:00Z</updated>
  </entry>
  <entry>
    <title>First post</title>
    <link href="2026-09-21-first.html" />
    <published>2026-09-21T12:00:00Z</published>
  </entry>
</feed>
''';

const prefixed = '''
<?xml version="1.0" encoding="utf-8"?>
<atom:feed xmlns:atom="http://www.w3.org/2005/Atom">
  <atom:entry>
    <atom:title>Reading the bars</atom:title>
    <atom:link rel="alternate" href="https://example.com/bars.html" />
    <atom:updated>2026-10-09T08:00:00Z</atom:updated>
  </atom:entry>
</atom:feed>
''';

void main() {
  test('reads entries from a feed in the default namespace', () {
    final entries = parseAtomEntries(
        source: defaultNamespaced, feedUrl: 'https://example.com/feed.xml');

    expect(entries, hasLength(2));
    // Newest first, like the dated links a page lists.
    expect(entries.first.title, 'Collecting retro phones');
    expect(entries.first.date, DateTime.utc(2026, 10, 8, 9, 30));
    // Relative links resolve against the feed's own address.
    expect(entries.first.url, 'https://example.com/2026-10-08-retro.html');
    // A link without a rel is the alternate one.
    expect(entries.last.url, 'https://example.com/2026-09-21-first.html');
    // published stands in when updated is absent.
    expect(entries.last.date, DateTime.utc(2026, 9, 21, 12));
  });

  test('reads a feed using an atom prefix', () {
    final entries =
        parseAtomEntries(source: prefixed, feedUrl: 'https://example.com/feed.xml');
    expect(entries.single.title, 'Reading the bars');
    expect(entries.single.url, 'https://example.com/bars.html');
  });

  test('falls back to the id when it is a web address', () {
    const source = '''
<feed xmlns="http://www.w3.org/2005/Atom">
  <entry>
    <title>No link here</title>
    <id>https://example.com/no-link.html</id>
    <updated>2026-10-08T09:30:00Z</updated>
  </entry>
</feed>
''';
    final entries =
        parseAtomEntries(source: source, feedUrl: 'https://example.com/feed.xml');
    expect(entries.single.url, 'https://example.com/no-link.html');
  });

  test('skips entries with nothing to identify or date them', () {
    const source = '''
<feed xmlns="http://www.w3.org/2005/Atom">
  <entry>
    <title>No date</title>
    <link rel="alternate" href="a.html" />
  </entry>
  <entry>
    <title>No address</title>
    <id>tag:example.com,2026:nope</id>
    <updated>2026-10-08T09:30:00Z</updated>
  </entry>
  <entry>
    <title>Unreadable date</title>
    <link rel="alternate" href="b.html" />
    <updated>last Tuesday</updated>
  </entry>
</feed>
''';
    expect(
        parseAtomEntries(source: source, feedUrl: 'https://example.com/feed.xml'),
        isEmpty);
  });

  test('a malformed feed is an error, not a guess', () {
    expect(
      () => parseAtomEntries(
          source: '<feed><entry><title>Half', feedUrl: 'https://example.com/feed.xml'),
      throwsA(isA<MewsParseException>()),
    );
  });

  test('an empty feed reads as no entries', () {
    expect(
        parseAtomEntries(
            source: '<feed xmlns="http://www.w3.org/2005/Atom"></feed>',
            feedUrl: 'https://example.com/feed.xml'),
        isEmpty);
  });
}