import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:muzzle_velocity/markdown_editing.dart';

final _formatter = MarkdownInputFormatter();

TextEditingValue _value(String text, int start, [int? end]) => TextEditingValue(
      text: text,
      selection: TextSelection(baseOffset: start, extentOffset: end ?? start),
    );

/// Simulates typing [typed] over the current selection of [old].
TextEditingValue _type(TextEditingValue old, String typed) {
  final s = old.selection.start;
  final raw = _value(old.text.replaceRange(s, old.selection.end, typed),
      s + typed.length);
  return _formatter.formatEditUpdate(old, raw);
}

/// Text with `|` marking the caret.
TextEditingValue _caret(String marked) =>
    _value(marked.replaceFirst('|', ''), marked.indexOf('|'));

String _marked(TextEditingValue v) =>
    v.text.replaceRange(v.selection.start, v.selection.start, '|');

Map<String, String> _classes(String text) => {
      for (final s in highlightMarkdown(text))
        text.substring(s.start, s.end): s.className,
    };

void main() {
  group('wrap selection', () {
    test('asterisk wraps and keeps the word selected', () {
      final once = _type(_value('a word here', 2, 6), '*');
      expect(once.text, 'a *word* here');
      expect(once.selection, const TextSelection(baseOffset: 3, extentOffset: 7));
      expect(_type(once, '*').text, 'a **word** here');
    });

    test('bracket uses its closing pair', () {
      expect(_type(_value('see link', 4, 8), '[').text, 'see [link]');
    });

    test('a letter still replaces the selection', () {
      final result = _type(_value('a word', 2, 6), 'x');
      expect(result.text, 'a x');
    });
  });

  group('new line', () {
    test('keeps indentation', () {
      expect(_marked(_type(_caret('    code|'), '\n')), '    code\n    |');
    });

    test('continues bullets, numbers, tasks and quotes', () {
      expect(_marked(_type(_caret('- one|'), '\n')), '- one\n- |');
      expect(_marked(_type(_caret('  * one|'), '\n')), '  * one\n  * |');
      expect(_marked(_type(_caret('9. nine|'), '\n')), '9. nine\n10. |');
      expect(_marked(_type(_caret('1) a|'), '\n')), '1) a\n2) |');
      expect(_marked(_type(_caret('- [x] done|'), '\n')), '- [x] done\n- [ ] |');
      expect(_marked(_type(_caret('> quote|'), '\n')), '> quote\n> |');
    });

    test('splits an item when the caret is mid-line', () {
      expect(_marked(_type(_caret('- one|two'), '\n')), '- one\n- |two');
    });

    test('an empty item ends the list', () {
      expect(_marked(_type(_caret('- one\n- |'), '\n')), '- one\n|');
      expect(_marked(_type(_caret('1. a\n2. |'), '\n')), '1. a\n|');
    });

    test('inside a code fence only indentation carries over', () {
      expect(_marked(_type(_caret('```\n  - x|'), '\n')), '```\n  - x\n  |');
    });

    test('emphasis at line start is not a bullet', () {
      expect(_marked(_type(_caret('*bold* text|'), '\n')), '*bold* text\n|');
    });
  });

  group('indentLines', () {
    test('indents and outdents all selected lines', () {
      final value = _value('a\nb\nc', 0, 3);
      final indented = indentLines(value);
      expect(indented.text, '  a\n  b\nc');
      expect(indentLines(indented, outdent: true).text, 'a\nb\nc');
    });
  });

  group('highlightMarkdown', () {
    test('line and inline syntax', () {
      final classes = _classes(
          '## Title\n- [ ] task **bold** and *it* `code` ~~gone~~\n[text](url) #tag +proj @ctx');
      expect(classes['## Title'], 'header-h2');
      expect(classes['- [ ] '], 'task-list');
      expect(classes['**bold**'], 'bold');
      expect(classes['*it*'], 'italic');
      expect(classes['`code`'], 'code');
      expect(classes['~~gone~~'], 'strikethrough');
      expect(classes['[text]'], 'link-text');
      expect(classes['(url)'], 'link-url');
      expect(classes['#tag'], 'tag-hash');
      expect(classes['+proj'], 'tag-plus');
      expect(classes['@ctx'], 'tag-at');
    });

    test('fenced code spans lines without inline highlighting', () {
      final classes = _classes('```\n**not bold**\n```\n**bold**');
      expect(classes['**not bold**'], 'code');
      expect(classes['**bold**'], 'bold');
    });

    test('segments are sorted and do not overlap', () {
      final segments = highlightMarkdown('- a **b** #c\n> q\n---');
      for (var i = 1; i < segments.length; i++) {
        expect(segments[i].start, greaterThanOrEqualTo(segments[i - 1].end));
      }
    });
  });

  group('MarkdownController search', () {
    test('finds terms case-insensitively and follows edits', () {
      final controller =
          MarkdownController(text: 'Foo bar foo #tag', theme: const {});
      controller.search(['foo', '#tag']);
      expect(controller.matches.map((m) => m.start), [0, 8, 12]);

      controller.text = 'bar foo';
      expect(controller.matches.map((m) => m.start), [4]);
    });

    test('builds spans covering the whole text', () {
      final controller =
          MarkdownController(text: '# Hi **there**', theme: const {});
      controller.search(['there']);
      final span = controller.buildTextSpan(
          context: _FakeContext(), withComposing: false);
      expect(span.toPlainText(), '# Hi **there**');
    });
  });
}

class _FakeContext extends Fake implements BuildContext {}