import 'package:flutter/material.dart';

/// Neutral palette. The accent colour comes from [AppSettings] through the
/// theme, so widgets read `Theme.of(context).colorScheme.primary` for it.
abstract final class OsColors {
  static const background = Color(0xFF0A0C10);
  static const surface = Color(0xFF13161C);
  static const surfaceHigh = Color(0xFF1C2028);
  static const good = Color(0xFF34C77B);
  static const warn = Color(0xFFFFB020);
  static const bad = Color(0xFFFF4D5E);
  static const text = Color(0xFFF2F4F8);
  static const textDim = Color(0xFF8A93A5);
  static const track = Color(0xFF20252E);

  static Color batteryColor(int? level) {
    if (level == null) return track;
    if (level <= 15) return bad;
    if (level <= 30) return warn;
    return good;
  }
}

ThemeData buildOsTheme(Color accent) {
  final onAccent = accent.computeLuminance() > 0.5 ? OsColors.background : Colors.white;
  final base = ThemeData(
    brightness: Brightness.dark,
    useMaterial3: true,
    colorScheme: ColorScheme.dark(
      primary: accent,
      onPrimary: onAccent,
      secondary: accent,
      onSecondary: onAccent,
      surface: OsColors.background,
      onSurface: OsColors.text,
      surfaceContainerHighest: OsColors.surfaceHigh,
      error: OsColors.bad,
    ),
    scaffoldBackgroundColor: OsColors.background,
  );
  return base.copyWith(
    appBarTheme: const AppBarTheme(
      backgroundColor: OsColors.background,
      foregroundColor: OsColors.text,
      elevation: 0,
      centerTitle: false,
    ),
    cardTheme: const CardThemeData(
      color: OsColors.surface,
      elevation: 0,
      margin: EdgeInsets.zero,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(20))),
    ),
    filledButtonTheme: FilledButtonThemeData(
      style: FilledButton.styleFrom(
        minimumSize: const Size(0, 52),
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
        textStyle: const TextStyle(fontWeight: FontWeight.w700, fontSize: 16),
      ),
    ),
    segmentedButtonTheme: SegmentedButtonThemeData(
      style: SegmentedButton.styleFrom(
        selectedBackgroundColor: accent,
        selectedForegroundColor: onAccent,
        side: const BorderSide(color: OsColors.surfaceHigh),
      ),
    ),
    switchTheme: SwitchThemeData(
      thumbColor: WidgetStateProperty.resolveWith(
          (s) => s.contains(WidgetState.selected) ? onAccent : OsColors.textDim),
      trackColor: WidgetStateProperty.resolveWith(
          (s) => s.contains(WidgetState.selected) ? accent : OsColors.surfaceHigh),
    ),
    inputDecorationTheme: InputDecorationTheme(
      filled: true,
      fillColor: OsColors.surfaceHigh,
      border: OutlineInputBorder(
        borderRadius: BorderRadius.circular(16),
        borderSide: BorderSide.none,
      ),
    ),
    snackBarTheme: const SnackBarThemeData(behavior: SnackBarBehavior.floating),
    progressIndicatorTheme: ProgressIndicatorThemeData(color: accent),
    textTheme: base.textTheme.apply(bodyColor: OsColors.text, displayColor: OsColors.text),
  );
}