SpotiFLAC-Mobile/lib/utils/audio_quality_badge_policy.dart

import 'package:spotiflac_android/models/settings.dart';
import 'package:spotiflac_android/utils/audio_format_utils.dart';
import 'package:spotiflac_android/utils/string_utils.dart';

const highQualityBadgeBitrateThresholdKbps = 900;

final RegExp _bitDepthQualityPattern = RegExp(
  r'\b\d+\s*(?:-\s*)?bit\b',
  caseSensitive: false,
);

String normalizeLibraryQualityLabelMode(String? mode) {
  return switch (mode) {
    AppSettings.libraryQualityLabelBitDepthOnly =>
      AppSettings.libraryQualityLabelBitDepthOnly,
    AppSettings.libraryQualityLabelBitDepth =>
      AppSettings.libraryQualityLabelBitDepth,
    AppSettings.libraryQualityLabelBitDepthBitrate =>
      AppSettings.libraryQualityLabelBitDepthBitrate,
    _ => AppSettings.libraryQualityLabelBitrate,
  };
}

/// Builds a Library label from metadata already held in memory. Lossy formats
/// keep their bitrate label because bit depth is not a useful quality signal
/// for encoded MP3/AAC/Opus audio.
String? buildLibraryAudioQualityLabel({
  required String mode,
  String? format,
  int? bitrateKbps,
  int? bitDepth,
  int? sampleRate,
  String? storedQuality,
}) {
  final stored = normalizeOptionalString(storedQuality);
  final storedBitrate = _bitrateFromStoredQuality(stored);
  final storedBitDepth = _bitDepthFromStoredQuality(stored);
  final effectiveBitrate = bitrateKbps != null && bitrateKbps > 0
      ? bitrateKbps
      : storedBitrate;
  final effectiveBitDepth = bitDepth != null && bitDepth > 0
      ? bitDepth
      : storedBitDepth;
  final bitrateLabel = effectiveBitrate != null
      ? buildDisplayAudioQuality(bitrateKbps: effectiveBitrate, format: format)
      : null;
  final bitDepthLabel =
      bitDepth != null && bitDepth > 0 && sampleRate != null && sampleRate > 0
      ? buildDisplayAudioQuality(bitDepth: bitDepth, sampleRate: sampleRate)
      : null;
  final bitDepthOnlyLabel = effectiveBitDepth != null
      ? '$effectiveBitDepth-bit'
      : null;
  final normalizedMode = normalizeLibraryQualityLabelMode(mode);

  if (isLossyAudioFormat(format)) {
    return bitrateLabel;
  }

  return switch (normalizedMode) {
    AppSettings.libraryQualityLabelBitDepthOnly =>
      bitDepthOnlyLabel ?? bitrateLabel ?? stored,
    AppSettings.libraryQualityLabelBitDepth =>
      bitDepthLabel ?? bitrateLabel ?? stored,
    AppSettings.libraryQualityLabelBitDepthBitrate =>
      _buildBitDepthBitrateLabel(
            bitDepth: effectiveBitDepth,
            bitrateKbps: effectiveBitrate,
          ) ??
          bitrateLabel ??
          bitDepthLabel ??
          stored,
    // Do not display bit depth/sample rate while the user selected bitrate.
    // Legacy rows are backfilled separately; a stored measured bitrate remains
    // usable while that migration completes.
    _ => bitrateLabel,
  };
}

int? _bitrateFromStoredQuality(String? quality) {
  final match = RegExp(
    r'\b(\d+(?:\.\d+)?)\s*(k(?:bps)?|mbps)\b',
    caseSensitive: false,
  ).firstMatch(quality ?? '');
  final value = double.tryParse(match?.group(1) ?? '');
  if (value == null || value <= 0) return null;
  final unit = match?.group(2)?.toLowerCase();
  return unit == 'mbps' ? (value * 1000).round() : value.round();
}

int? _bitDepthFromStoredQuality(String? quality) {
  final match = RegExp(
    r'\b(\d{1,3})(?:\s*[- ]?\s*bit\b|(?=/))',
    caseSensitive: false,
  ).firstMatch(quality ?? '');
  final value = int.tryParse(match?.group(1) ?? '');
  return value != null && value > 0 ? value : null;
}

String? _buildBitDepthBitrateLabel({int? bitDepth, int? bitrateKbps}) {
  if (bitDepth == null ||
      bitDepth <= 0 ||
      bitrateKbps == null ||
      bitrateKbps <= 0) {
    return null;
  }
  return '$bitDepth-bit/${bitrateKbps}kbps';
}

/// Keeps detailed bit-depth labels intact in Library grid badges while
/// shortening bitrate-only labels that already include a codec name.
String formatLibraryGridAudioQualityLabel(String quality) {
  final normalized = quality.trim().toLowerCase();
  if (_bitDepthQualityPattern.hasMatch(normalized)) return quality;

  final bitrateTextMatch = RegExp(
    r'(\d+)\s*k(?:bps)?',
    caseSensitive: false,
  ).firstMatch(quality);
  if (bitrateTextMatch != null) {
    return '${bitrateTextMatch.group(1)}k';
  }

  final bitrateIdMatch = RegExp(r'_(\d+)$').firstMatch(normalized);
  if (bitrateIdMatch != null) {
    return '${bitrateIdMatch.group(1)}k';
  }

  return quality.split(' ').first;
}

bool isDetailedLibraryAudioQualityLabel(String quality) {
  final normalized = quality.trim().toLowerCase();
  return _bitDepthQualityPattern.hasMatch(normalized) &&
      normalized.contains('/');
}

/// Preserves the highlighted color used by legacy 24-bit Library badges while
/// also supporting newer labels that display a measured bitrate instead.
bool shouldHighlightAudioQualityBadge(String quality) {
  final normalized = quality.trim().toLowerCase();
  if (RegExp(r'\b24(?:\s*[- ]?\s*bit|/)').hasMatch(normalized)) {
    return true;
  }

  final kbpsMatch = RegExp(
    r'\b(\d+(?:\.\d+)?)\s*k(?:bps)?\b',
  ).firstMatch(normalized);
  final kbps = double.tryParse(kbpsMatch?.group(1) ?? '');
  if (kbps != null) {
    return kbps > highQualityBadgeBitrateThresholdKbps;
  }

  final mbpsMatch = RegExp(
    r'\b(\d+(?:\.\d+)?)\s*mbps\b',
  ).firstMatch(normalized);
  final mbps = double.tryParse(mbpsMatch?.group(1) ?? '');
  return mbps != null && mbps * 1000 > highQualityBadgeBitrateThresholdKbps;
}