import { router } from 'expo-router';
import { StatusBar } from 'expo-status-bar';
import { useState } from 'react';
import { KeyboardAvoidingView, Platform, ScrollView, Text, TextInput, TouchableOpacity, View } from 'react-native';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import { getDB } from '../db';

export default function AddTransactionScreen() {
  const insets = useSafeAreaInsets();
  const [amount, setAmount] = useState('');
  const [category, setCategory] = useState('');
  const [description, setDescription] = useState('');
  const [type, setType] = useState<'income' | 'expense'>('expense');
  const [date, setDate] = useState(new Date().toISOString().split('T')[0]); // YYYY-MM-DD

  const handleSave = async () => {
    if (!amount || !category) {
      alert('Please fill in amount and category');
      return;
    }

    try {
      const db = getDB();
      await db.runAsync(
        'INSERT INTO transactions (amount, category, date, description, type) VALUES (?, ?, ?, ?, ?)',
        [parseFloat(amount), category, date, description, type]
      );
      router.back();
    } catch (error) {
      console.error(error);
      alert('Failed to save transaction');
    }
  };

  return (
    <View className="flex-1 bg-gray-100 dark:bg-gray-900">
      <StatusBar style={Platform.OS === 'ios' ? 'light' : 'auto'} />

      {/* Header */}
      <View className="bg-blue-600 pt-4 pb-6 px-6 rounded-b-3xl shadow-lg">
        <Text className="text-white text-2xl font-bold mt-8 text-center">New Transaction</Text>
      </View>

      <KeyboardAvoidingView
        behavior={Platform.OS === 'ios' ? 'padding' : 'height'}
        className="flex-1"
      >
        <ScrollView className="flex-1 px-6 pt-6">

          {/* Type Selector */}
          <View className="flex-row bg-white dark:bg-gray-800 rounded-xl p-1 mb-6 shadow-sm">
            <TouchableOpacity
              className={`flex-1 py-3 rounded-lg ${type === 'expense' ? 'bg-red-500' : 'bg-transparent'}`}
              onPress={() => setType('expense')}
            >
              <Text className={`text-center font-semibold ${type === 'expense' ? 'text-white' : 'text-gray-500'}`}>Expense</Text>
            </TouchableOpacity>
            <TouchableOpacity
              className={`flex-1 py-3 rounded-lg ${type === 'income' ? 'bg-green-500' : 'bg-transparent'}`}
              onPress={() => setType('income')}
            >
              <Text className={`text-center font-semibold ${type === 'income' ? 'text-white' : 'text-gray-500'}`}>Income</Text>
            </TouchableOpacity>
          </View>

          {/* Amount Input */}
          <View className="bg-white dark:bg-gray-800 rounded-2xl p-6 mb-4 shadow-sm">
            <Text className="text-gray-500 text-sm mb-2">Amount</Text>
            <View className="flex-row items-center">
              <Text className="text-3xl font-bold text-gray-900 dark:text-white mr-2">€</Text>
              <TextInput
                className="flex-1 text-4xl font-bold text-gray-900 dark:text-white"
                placeholder="0.00"
                keyboardType="numeric"
                value={amount}
                onChangeText={setAmount}
                placeholderTextColor="#9CA3AF"
              />
            </View>
          </View>

          {/* Details Form */}
          <View className="bg-white dark:bg-gray-800 rounded-2xl p-6 shadow-sm space-y-4">
            <View>
              <Text className="text-gray-500 text-sm mb-2">Category</Text>
              <ScrollView horizontal showsHorizontalScrollIndicator={false} className="flex-row space-x-2 mb-2">
                {['Food', 'Transport', 'Shopping', 'Entertainment', 'Bills', 'Health', 'Salary', 'Investment', 'Other'].map((cat) => (
                  <TouchableOpacity
                    key={cat}
                    onPress={() => setCategory(cat)}
                    className={`px-4 py-2 rounded-full border ${category === cat ? 'bg-blue-600 border-blue-600' : 'bg-gray-50 border-gray-200 dark:bg-gray-700 dark:border-gray-600'}`}
                  >
                    <Text className={`${category === cat ? 'text-white' : 'text-gray-900 dark:text-gray-300'}`}>{cat}</Text>
                  </TouchableOpacity>
                ))}
              </ScrollView>
              <TextInput
                className="w-full bg-gray-50 dark:bg-gray-700 p-4 rounded-xl text-gray-900 dark:text-white"
                placeholder="Or type custom category..."
                value={category}
                onChangeText={setCategory}
                placeholderTextColor="#9CA3AF"
              />
            </View>

            <View className="mt-4">
              <Text className="text-gray-500 text-sm mb-2">Date</Text>
              <TextInput
                className="w-full bg-gray-50 dark:bg-gray-700 p-4 rounded-xl text-gray-900 dark:text-white"
                placeholder="YYYY-MM-DD"
                value={date}
                onChangeText={setDate}
                placeholderTextColor="#9CA3AF"
              />
            </View>

            <View className="mt-4">
              <Text className="text-gray-500 text-sm mb-2">Description (Optional)</Text>
              <TextInput
                className="w-full bg-gray-50 dark:bg-gray-700 p-4 rounded-xl text-gray-900 dark:text-white"
                placeholder="Add a note..."
                value={description}
                onChangeText={setDescription}
                placeholderTextColor="#9CA3AF"
              />
            </View>
          </View>

        </ScrollView>

        {/* Save Button */}
        <View className="p-6 bg-white dark:bg-gray-900 border-t border-gray-100 dark:border-gray-800" style={{ paddingBottom: Math.max(insets.bottom, 24) }}>
          <TouchableOpacity
            className="w-full bg-blue-600 py-4 rounded-2xl shadow-lg active:bg-blue-700"
            onPress={handleSave}
          >
            <Text className="text-white text-center font-bold text-lg">Save Transaction</Text>
          </TouchableOpacity>
        </View>
      </KeyboardAvoidingView>
    </View>
  );
}