Phase 3 Capstone · Two-Screen Recipe Book

package com.mastercoding.phase3

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.consumeWindowInsets
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.rememberScrollState
import androidx.compose.foundation.verticalScroll
import androidx.compose.material3.Button
import androidx.compose.material3.Card
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Scaffold
import androidx.compose.material3.Text
import androidx.compose.material3.TextButton
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import androidx.lifecycle.compose.collectAsStateWithLifecycle
import androidx.lifecycle.viewmodel.compose.viewModel
import androidx.navigation.compose.NavHost
import androidx.navigation.compose.composable
import androidx.navigation.compose.rememberNavController
import androidx.navigation.toRoute
import kotlinx.serialization.Serializable

@Serializable
object RecipeList

@Serializable
data class RecipeDetail(val recipeId: Int)

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContent {
            MaterialTheme {
                RecipeApp()
            }
        }
    }
}

@Composable
fun RecipeApp(recipeViewModel: RecipeViewModel = viewModel()) {
    val state by recipeViewModel.uiState.collectAsStateWithLifecycle()
    val navController = rememberNavController()
    Scaffold { innerPadding ->
        NavHost(
            navController = navController,
            startDestination = RecipeList,
            modifier = Modifier.fillMaxSize().padding(innerPadding).consumeWindowInsets(innerPadding)
        ) {
            composable<RecipeList> {
                RecipeListScreen(
                    favoriteIds = state.favoriteIds,
                    onOpenRecipe = { id -> navController.navigate(RecipeDetail(id)) }
                )
            }
            composable<RecipeDetail> { entry ->
                val route = entry.toRoute<RecipeDetail>()
                RecipeDetailScreen(
                    recipe = RecipeBook.find(route.recipeId),
                    isFavorite = route.recipeId in state.favoriteIds,
                    onToggleFavorite = { recipeViewModel.toggleFavorite(route.recipeId) },
                    onBack = { navController.popBackStack() }
                )
            }
        }
    }
}

@Composable
fun RecipeListScreen(favoriteIds: Set<Int>, onOpenRecipe: (Int) -> Unit) {
    Column(
        modifier = Modifier.fillMaxSize().verticalScroll(rememberScrollState()).padding(20.dp),
        verticalArrangement = Arrangement.spacedBy(16.dp)
    ) {
        Text("My Recipe Book", style = MaterialTheme.typography.headlineMedium)
        Text("Choose one of three quick recipes. Favorites stay while the app is open.")
        RecipeBook.recipes.forEach { recipe ->
            Card(onClick = { onOpenRecipe(recipe.id) }, modifier = Modifier.fillMaxWidth()) {
                Column(Modifier.padding(16.dp), verticalArrangement = Arrangement.spacedBy(8.dp)) {
                    Text(recipe.title, style = MaterialTheme.typography.titleLarge)
                    Text("${recipe.minutes} minutes")
                    if (recipe.id in favoriteIds) Text("Favorite")
                }
            }
        }
    }
}

@Composable
fun RecipeDetailScreen(
    recipe: Recipe?,
    isFavorite: Boolean,
    onToggleFavorite: () -> Unit,
    onBack: () -> Unit
) {
    Column(
        modifier = Modifier.fillMaxSize().verticalScroll(rememberScrollState()).padding(20.dp),
        verticalArrangement = Arrangement.spacedBy(12.dp)
    ) {
        TextButton(onClick = onBack) { Text("Back to recipes") }
        if (recipe == null) {
            Text("Recipe not found", style = MaterialTheme.typography.headlineMedium)
            Text("This recipe is unavailable. Go back and choose another recipe.")
        } else {
            Text(recipe.title, style = MaterialTheme.typography.headlineMedium)
            Text("Ready in ${recipe.minutes} minutes")
            Button(onClick = onToggleFavorite) {
                Text(if (isFavorite) "Remove favorite" else "Add favorite")
            }
            Text("Ingredients", style = MaterialTheme.typography.titleLarge)
            recipe.ingredients.forEach { Text("• $it") }
            Text("Steps", style = MaterialTheme.typography.titleLarge)
            recipe.instructions.forEachIndexed { index, instruction ->
                Text("${index + 1}. $instruction")
            }
        }
    }
}