import 'package:flutter/material.dart';

// ── Color tokens ──
const bgPrimary = Color(0xFF1a1a2e);
const bgCard = Color(0xFF16213e);
const bgInput = Color(0xFF111111);
const bgPayPeriod = Color(0xFF1b2745);
const accentGreen = Color(0xFF4ecca3);
const accentAmber = Color(0xFFe8b86d);
const accentRed = Color(0xFFe74c3c);
const accentBlue = Color(0xFF5b9bd5);
const textPrimary = Color(0xFFe0e0e0);
const textMuted = Color(0xFF888888);
const textDim = Color(0xFF6a6a6a);
const borderColor = Color(0xFF333333);
const dividerColor = Color(0xFF2a2a4a);

// ── Typography ──
const monoFont = 'Consolas';
const bodySize = 13.0;
const labelSize = 12.0;
const smallLabelSize = 11.0;

// ── Spacing ──
const rowHeight = 34.0;
const cardPadding = 12.0;
const cardGap = 12.0;

// ── Priority enum ──
enum BillPriority { green, yellow, red }

// ── Payout position enum ──
enum PayoutPosition { priority, notable }

// ── Payment rule enums ──
enum MathSource {
  totalIncome,       // 0: sum of paycheck amounts
  ledgerRemaining,   // 1: balance after non-rule deductions
  netBalance,        // 2: ledger remaining - eating out - misc
  netMinusBuffer;    // 3: net balance - buffer

  String get label => switch (this) {
    totalIncome => 'Total Income',
    ledgerRemaining => 'Ledger Remaining',
    netBalance => 'Net Balance',
    netMinusBuffer => 'Net − Buffer',
  };
}

enum RuleType {
  minimum,          // 0: fixed minimum amount
  math,             // 1: multiplier * source + addition
  remainingBalance; // 2: pay outstanding balance

  String get label => switch (this) {
    minimum => 'Minimum',
    math => 'Math',
    remainingBalance => 'Remaining Bal',
  };
}

// ── Reusable text styles ──
const monoStyle = TextStyle(fontSize: bodySize, fontFamily: monoFont, color: textPrimary);
const labelStyle = TextStyle(fontSize: smallLabelSize, color: textDim, letterSpacing: 0.5);
const mutedStyle = TextStyle(fontSize: labelSize, color: textMuted);

ThemeData buildAppTheme() {
  return ThemeData.dark().copyWith(
    scaffoldBackgroundColor: bgPrimary,
    colorScheme: const ColorScheme.dark(
      primary: accentGreen,
      surface: bgCard,
      error: accentRed,
    ),
  );
}

// ── Formatting helpers ──
String formatCents(int cents) {
  final negative = cents < 0;
  final abs = cents.abs();
  final dollars = abs ~/ 100;
  final remainder = abs % 100;
  final formatted = '\$${_addCommas(dollars)}.${remainder.toString().padLeft(2, '0')}';
  return negative ? '-$formatted' : formatted;
}

String formatCharge(int cents) {
  if (cents == 0) return '\$0.00';
  final prefix = cents > 0 ? '+' : '';
  return '$prefix${formatCents(cents)}';
}

String _addCommas(int n) {
  final s = n.toString();
  final buf = StringBuffer();
  for (var i = 0; i < s.length; i++) {
    if (i > 0 && (s.length - i) % 3 == 0) buf.write(',');
    buf.write(s[i]);
  }
  return buf.toString();
}