feat: create TransactionForm component

- Add useState hooks for form inputs
- Add type selector (income/expense)
- Add TextInput components
- Add category selector with ScrollView
- Add TouchableOpacity for buttons

components/TransactionForm.tsx

@@ -0,0 +1,224 @@
+import React, { useState } from 'react';
+import {
+  View,
+  Text,
+  TextInput,
+  TouchableOpacity,
+  StyleSheet,
+  ScrollView,
+} from 'react-native';
+import { COLORS, FONTS } from '../constants/theme';
+import { Transaction } from '../types';
+import { generateId, getCurrentDate } from '../utils/helpers';
+
+interface TransactionFormProps {
+  onAdd: (transaction: Transaction) => void;
+}
+
+const CATEGORIES = [
+  'makanan', 'transport', 'belanja', 'hiburan', 'kesehatan',
+  'pendidikan', 'investasi', 'gaji', 'lainnya'
+];
+
+export const TransactionForm: React.FC<TransactionFormProps> = ({ onAdd }) => {
+  const [amount, setAmount] = useState('');
+  const [description, setDescription] = useState('');
+  const [type, setType] = useState<'income' | 'expense'>('expense');
+  const [category, setCategory] = useState('lainnya');
+
+  const handleSubmit = () => {
+    if (!amount || !description) return;
+    
+    const transaction: Transaction = {
+      id: generateId(),
+      amount: parseInt(amount, 10),
+      description,
+      type,
+      category,
+      date: getCurrentDate(),
+    };
+    
+    onAdd(transaction);
+    setAmount('');
+    setDescription('');
+  };
+
+  return (
+    <View style={styles.container}>
+      <Text style={styles.title}>Tambah Transaksi</Text>
+      
+      <View style={styles.typeContainer}>
+        <TouchableOpacity
+          style={[
+            styles.typeButton,
+            type === 'expense' && styles.typeButtonActiveExpense,
+          ]}
+          onPress={() => setType('expense')}
+        >
+          <Text
+            style={[
+              styles.typeText,
+              type === 'expense' && styles.typeTextActive,
+            ]}
+          >
+            Pengeluaran
+          </Text>
+        </TouchableOpacity>
+        <TouchableOpacity
+          style={[
+            styles.typeButton,
+            type === 'income' && styles.typeButtonActiveIncome,
+          ]}
+          onPress={() => setType('income')}
+        >
+          <Text
+            style={[
+              styles.typeText,
+              type === 'income' && styles.typeTextActive,
+            ]}
+          >
+            Pemasukan
+          </Text>
+        </TouchableOpacity>
+      </View>
+
+      <TextInput
+        style={styles.input}
+        placeholder="Jumlah (Rp)"
+        value={amount}
+        onChangeText={setAmount}
+        keyboardType="numeric"
+        placeholderTextColor={COLORS.textSecondary}
+      />
+
+      <TextInput
+        style={styles.input}
+        placeholder="Deskripsi"
+        value={description}
+        onChangeText={setDescription}
+        placeholderTextColor={COLORS.textSecondary}
+      />
+
+      <Text style={styles.categoryLabel}>Kategori</Text>
+      <ScrollView horizontal showsHorizontalScrollIndicator={false}>
+        <View style={styles.categoryContainer}>
+          {CATEGORIES.map((cat) => (
+            <TouchableOpacity
+              key={cat}
+              style={[
+                styles.categoryButton,
+                category === cat && styles.categoryButtonActive,
+              ]}
+              onPress={() => setCategory(cat)}
+            >
+              <Text
+                style={[
+                  styles.categoryText,
+                  category === cat && styles.categoryTextActive,
+                ]}
+              >
+                {cat}
+              </Text>
+            </TouchableOpacity>
+          ))}
+        </View>
+      </ScrollView>
+
+      <TouchableOpacity style={styles.submitButton} onPress={handleSubmit}>
+        <Text style={styles.submitText}>Simpan</Text>
+      </TouchableOpacity>
+    </View>
+  );
+};
+
+const styles = StyleSheet.create({
+  container: {
+    backgroundColor: COLORS.card,
+    margin: 16,
+    marginTop: 0,
+    padding: 16,
+    borderRadius: 12,
+    shadowColor: '#000',
+    shadowOffset: { width: 0, height: 2 },
+    shadowOpacity: 0.1,
+    shadowRadius: 4,
+    elevation: 3,
+  },
+  title: {
+    fontSize: FONTS.regular,
+    fontWeight: 'bold',
+    color: COLORS.text,
+    marginBottom: 16,
+  },
+  typeContainer: {
+    flexDirection: 'row',
+    marginBottom: 16,
+    gap: 8,
+  },
+  typeButton: {
+    flex: 1,
+    padding: 12,
+    borderRadius: 8,
+    alignItems: 'center',
+    backgroundColor: COLORS.background,
+  },
+  typeButtonActiveExpense: {
+    backgroundColor: COLORS.expense,
+  },
+  typeButtonActiveIncome: {
+    backgroundColor: COLORS.income,
+  },
+  typeText: {
+    fontSize: FONTS.regular,
+    color: COLORS.textSecondary,
+  },
+  typeTextActive: {
+    color: COLORS.card,
+    fontWeight: '600',
+  },
+  input: {
+    backgroundColor: COLORS.background,
+    borderRadius: 8,
+    padding: 12,
+    marginBottom: 12,
+    fontSize: FONTS.regular,
+    color: COLORS.text,
+  },
+  categoryLabel: {
+    fontSize: FONTS.small,
+    color: COLORS.textSecondary,
+    marginBottom: 8,
+  },
+  categoryContainer: {
+    flexDirection: 'row',
+    gap: 8,
+    marginBottom: 16,
+  },
+  categoryButton: {
+    paddingHorizontal: 12,
+    paddingVertical: 8,
+    borderRadius: 16,
+    backgroundColor: COLORS.background,
+  },
+  categoryButtonActive: {
+    backgroundColor: COLORS.primary,
+  },
+  categoryText: {
+    fontSize: FONTS.small,
+    color: COLORS.textSecondary,
+  },
+  categoryTextActive: {
+    color: COLORS.card,
+  },
+  submitButton: {
+    backgroundColor: COLORS.primary,
+    padding: 14,
+    borderRadius: 8,
+    alignItems: 'center',
+  },
+  submitText: {
+    color: COLORS.card,
+    fontSize: FONTS.regular,
+    fontWeight: '600',
+  },
+});