// Copyright 2019 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/material.dart';

import '../model/commit.pb.dart';
import 'web_image.dart';

/// Shows the appropriate avatar for a [Commit]'s author.
///
/// Tries to use the author's image from GitHub, but failing that, uses a [CircleAvatar]
/// with the author's first name and a color arbitrarily but deterministically generated
/// from the avatar's name.
class CommitAuthorAvatar extends StatelessWidget {
  const CommitAuthorAvatar({
    super.key,
    this.commit,
  });

  final Commit? commit;

  @override
  Widget build(BuildContext context) {
    assert(commit!.author.isNotEmpty);
    final String authorName = commit!.author;
    final String authorInitial = authorName.substring(0, 1).toUpperCase();
    final int authorHash = authorName.hashCode;
    final ThemeData theme = Theme.of(context);

    final double hue = (360.0 * authorHash / (1 << 15)) % 360.0;
    final double themeValue = HSVColor.fromColor(theme.colorScheme.background).value;
    Color authorColor = HSVColor.fromAHSV(1.0, hue, 0.4, themeValue).toColor();
    if (theme.brightness == Brightness.dark) {
      authorColor = HSLColor.fromColor(authorColor).withLightness(.65).toColor();
    }

    /// Fallback widget that shows the initial of the commit author. In cases
    /// where GitHub is down or slow internet this will be seen.
    final Widget avatar = CircleAvatar(
      backgroundColor: authorColor,
      child: Text(
        authorInitial,
        style: TextStyle(color: authorColor.computeLuminance() > 0.25 ? Colors.black : Colors.white),
      ),
    );

    return WebImage(
      imageUrl: commit!.authorAvatarUrl,
      placeholder: avatar,
    );
  }
}