app/src/main/java/com/example/tiptime/MainActivity.kt

@@ -1,82 +1,298 @@
+package com.example.tiptime
+
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
 import androidx.annotation.DrawableRes
 import androidx.annotation.StringRes
-import androidx.compose.foundation.Image
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.layout.width
-import androidx.compose.foundation.text.KeyboardActions
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.text.KeyboardOptions
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.OutlinedTextField
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.semantics.error
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.input.ImeAction
 import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import com.example.tiptime.ui.theme.TipTimeTheme
+
+class MainActivity : ComponentActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        enableEdgeToEdge()
+        super.onCreate(savedInstanceState)
+        setContent {
+            TipTimeTheme {
+                Surface(
+                    modifier = Modifier.fillMaxSize(),
+                    color = MaterialTheme.colorScheme.background
+                ) {
+                    NavigationController()
+                }
+            }
+        }
+    }
+}
+
+// Enum dan NavigationController tetap sama
+private sealed class Screen {
+    object Start : Screen()
+    object Main : Screen()
+}
 
-// --- Composable InputWithImage DIPERBARUI dengan Batas Karakter ---
 @Composable
-fun InputWithImage(
-    @DrawableRes imageRes: Int,
-    @StringRes label: Int,
-    value: String,
-    onValueChanged: (String) -> Unit,
-    isError: Boolean,
-    errorMessage: String,
-    imeAction: ImeAction,
-    maxLength: Int, // Parameter baru untuk batas maksimal karakter
-    keyboardActions: KeyboardActions = KeyboardActions.Default,
-    modifier: Modifier = Modifier
-) {
-    Row(
-        modifier = modifier.fillMaxWidth(),
-        verticalAlignment = Alignment.CenterVertically
-    ) {
-        Image(
-            painter = painterResource(id = imageRes),
-            contentDescription = stringResource(label),
-            modifier = Modifier.size(64.dp),
-            contentScale = ContentScale.Fit
-        )
-        Spacer(modifier = Modifier.width(16.dp))
+private fun NavigationController() {
+    var currentScreen by remember { mutableStateOf<Screen>(Screen.Start) }
 
-        Column(modifier = Modifier.weight(1f)) {
-            OutlinedTextField(
-                value = value,
-                onValueChange = {
-                    // LOGIKA BARU UNTUK MEMBATASI INPUT
-                    if (it.length <= maxLength) {
-                        onValueChanged(it)
-                    }
-                },
-                label = { Text(stringResource(label)) },
-                keyboardOptions = KeyboardOptions(
-                    keyboardType = KeyboardType.Number,
-                    imeAction = imeAction
-                ),
-                singleLine = true,
-                modifier = Modifier.fillMaxWidth(),
-                isError = isError,
-                keyboardActions = keyboardActions
-            )
-            if (isError) {
+    when (currentScreen) {
+        is Screen.Start -> {
+            StartScreen(onNavigateToMain = { currentScreen = Screen.Main })
+        }
+        is Screen.Main -> {
+            BMICalculatorScreen()
+        }
+    }
+}
+
+
+// --- INI ADALAH TAMPILAN BARU YANG LEBIH MENARIK ---
+@Composable
+fun BMICalculatorScreen() {
+    var heightInput by remember { mutableStateOf("") }
+    var weightInput by remember { mutableStateOf("") }
+    var useMetric by remember { mutableStateOf(true) }
+
+    val height = heightInput.toDoubleOrNull() ?: 0.0
+    val weight = weightInput.toDoubleOrNull() ?: 0.0
+
+    val bmiValue = calculateBMI(height, weight, useMetric)
+    val bmiCategory = bmiCategory(bmiValue)
+    val bmiCategoryColor = getBmiCategoryColor(bmiCategory)
+
+    Column(
+        modifier = Modifier
+            .fillMaxSize()
+            .verticalScroll(rememberScrollState())
+            .safeDrawingPadding()
+            .padding(16.dp),
+        horizontalAlignment = Alignment.CenterHorizontally
+    ) {
+        Text(
+            text = stringResource(R.string.bmi_calculator),
+            style = MaterialTheme.typography.headlineMedium,
+            fontWeight = FontWeight.Bold,
+            modifier = Modifier.padding(vertical = 16.dp)
+        )
+
+        // --- KARTU HASIL BMI ---
+        Card(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(vertical = 16.dp),
+            elevation = CardDefaults.cardElevation(defaultElevation = 8.dp),
+            colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surfaceVariant)
+        ) {
+            Column(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(24.dp),
+                horizontalAlignment = Alignment.CenterHorizontally,
+                verticalArrangement = Arrangement.Center
+            ) {
                 Text(
-                    text = errorMessage,
-                    color = MaterialTheme.colorScheme.error,
-                    style = MaterialTheme.typography.bodySmall,
-                    modifier = Modifier.padding(start = 16.dp, top = 4.dp)
+                    text = stringResource(id = R.string.your_bmi_is),
+                    style = MaterialTheme.typography.titleMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+                Text(
+                    text = "%.1f".format(bmiValue),
+                    fontSize = 52.sp,
+                    fontWeight = FontWeight.Bold,
+                    color = bmiCategoryColor
+                )
+                Spacer(modifier = Modifier.height(8.dp))
+                Text(
+                    text = bmiCategory,
+                    fontSize = 20.sp,
+                    fontWeight = FontWeight.SemiBold,
+                    color = bmiCategoryColor
+                )
+                Spacer(modifier = Modifier.height(16.dp))
+                BmiIndicatorBar(category = bmiCategory)
+            }
+        }
+
+        // --- KARTU INPUT DATA ---
+        Card(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(top = 16.dp),
+            elevation = CardDefaults.cardElevation(defaultElevation = 4.dp)
+        ) {
+            Column(
+                modifier = Modifier.padding(24.dp),
+                horizontalAlignment = Alignment.CenterHorizontally
+            ) {
+                UnitSwitchRow(
+                    isMetric = useMetric,
+                    onUnitChanged = { useMetric = it }
+                )
+                Spacer(modifier = Modifier.height(24.dp))
+
+                val heightLabel = if (useMetric) R.string.height_cm else R.string.height_in
+                EditNumberField(
+                    label = heightLabel,
+                    leadingIcon = R.drawable.ic_height,
+                    value = heightInput,
+                    onValueChanged = { heightInput = it },
+                    imeAction = ImeAction.Next
+                )
+
+                Spacer(modifier = Modifier.height(16.dp))
+
+                val weightLabel = if (useMetric) R.string.weight_kg else R.string.weight_lbs
+                EditNumberField(
+                    label = weightLabel,
+                    leadingIcon = R.drawable.ic_weight,
+                    value = weightInput,
+                    onValueChanged = { weightInput = it },
+                    imeAction = ImeAction.Done
                 )
             }
         }
     }
 }
+
+@Composable
+fun BmiIndicatorBar(category: String) {
+    val categories = listOf("Underweight", "Normal", "Overweight", "Obese")
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .clip(CircleShape)
+            .background(MaterialTheme.colorScheme.surface)
+            .padding(2.dp)
+    ) {
+        categories.forEach { cat ->
+            Box(
+                modifier = Modifier
+                    .weight(1f)
+                    .height(12.dp)
+                    .background(
+                        if (cat == category) getBmiCategoryColor(cat) else Color.LightGray.copy(alpha = 0.5f)
+                    )
+            ) {
+                if (cat == category) {
+                    Text(
+                        text = cat,
+                        color = Color.White,
+                        fontSize = 8.sp, // Ukuran font sangat kecil
+                        textAlign = TextAlign.Center,
+                        modifier = Modifier.align(Alignment.Center)
+                    )
+                }
+            }
+        }
+    }
+}
+
+@Composable
+fun EditNumberField(
+    @StringRes label: Int,
+    @DrawableRes leadingIcon: Int,
+    value: String,
+    onValueChanged: (String) -> Unit,
+    imeAction: ImeAction
+) {
+    OutlinedTextField(
+        value = value,
+        onValueChange = onValueChanged,
+        label = { Text(stringResource(label)) },
+        leadingIcon = { Icon(painter = painterResource(id = leadingIcon), contentDescription = null) },
+        keyboardOptions = KeyboardOptions(
+            keyboardType = KeyboardType.Number,
+            imeAction = imeAction
+        ),
+        singleLine = true,
+        modifier = Modifier.fillMaxWidth()
+    )
+}
+
+@Composable
+fun UnitSwitchRow(isMetric: Boolean, onUnitChanged: (Boolean) -> Unit) {
+    Row(
+        modifier = Modifier.fillMaxWidth(),
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.SpaceBetween
+    ) {
+        Text(text = stringResource(R.string.unit_system))
+        Row(verticalAlignment = Alignment.CenterVertically) {
+            Text("Imperial", style = MaterialTheme.typography.bodyMedium)
+            Switch(
+                checked = isMetric,
+                onCheckedChange = onUnitChanged,
+                modifier = Modifier.padding(horizontal = 8.dp)
+            )
+            Text("Metric", style = MaterialTheme.typography.bodyMedium)
+        }
+    }
+}
+
+// --- FUNGSI LOGIKA (HELPER) ---
+
+private fun calculateBMI(height: Double, weight: Double, isMetric: Boolean): Double {
+    if (height <= 0 || weight <= 0) return 0.0
+
+    return if (isMetric) {
+        val heightInMeters = height / 100
+        weight / (heightInMeters * heightInMeters)
+    } else {
+        703 * weight / (height * height)
+    }
+}
+
+private fun bmiCategory(bmi: Double): String {
+    return when {
+        bmi == 0.0 -> "..."
+        bmi < 18.5 -> "Underweight"
+        bmi < 25.0 -> "Normal"
+        bmi < 30.0 -> "Overweight"
+        else -> "Obese"
+    }
+}
+
+@Composable
+private fun getBmiCategoryColor(category: String): Color {
+    return when (category) {
+        "Underweight" -> Color(0xFF8AB4F8) // Biru
+        "Normal" -> Color(0xFF5BB974)      // Hijau
+        "Overweight" -> Color(0xFFFDD663)  // Kuning
+        "Obese" -> Color(0xFFE57373)       // Merah
+        else -> MaterialTheme.colorScheme.onSurface
+    }
+}
+
+// --- PREVIEW ---
+
+@Preview(showBackground = true, name = "New BMI Calculator")
+@Composable
+fun BMICalculatorScreenPreview() {
+    TipTimeTheme {
+        BMICalculatorScreen()
+    }
+}