//
//  GroceryListTabView.swift
//  Nextcloud Cookbook iOS Client
//
//  Created by Vincent Meilinger on 23.01.24.
//

import Foundation
import SwiftUI
import SwiftData

@Model class GroceryItem {
    var name: String
    var isChecked: Bool
    
    init(name: String, isChecked: Bool) {
        self.name = name
        self.isChecked = isChecked
    }
}

@Model class RecipeGroceries: Identifiable {
    var id: String
    var name: String
    @Relationship(deleteRule: .cascade) var items: [GroceryItem]
    var multiplier: Double
    
    init(id: String, name: String, items: [GroceryItem], multiplier: Double) {
        self.id = id
        self.name = name
        self.items = items
        self.multiplier = multiplier
    }
    
    init(id: String, name: String) {
        self.id = id
        self.name = name
        self.items = []
        self.multiplier = 1
    }
}

struct GroceryListTabView: View {
    @Environment(\.modelContext) var modelContext
    @Query var groceryList: [RecipeGroceries] = []
    @State var newGroceries: String = ""
    @FocusState private var isFocused: Bool
    
    var body: some View {
        NavigationStack {
            List {
                HStack(alignment: .top) {
                    TextEditor(text: $newGroceries)
                        .padding(4)
                        .overlay(RoundedRectangle(cornerRadius: 8)
                        .stroke(Color.secondary).opacity(0.5))
                        .focused($isFocused)
                    Button {
                        if !newGroceries.isEmpty {
                            let items = newGroceries
                                .split(separator: "\n")
                                .compactMap { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
                                .filter { !$0.isEmpty }
                            Task {
                                await addGroceryItems(items, toCategory: "Other", named: String(localized: "Other"))
                            }
                        }
                        newGroceries = ""
                        
                    } label: {
                        Text("Add")
                    }
                    .disabled(newGroceries.isEmpty)
                    .buttonStyle(.borderedProminent)
                }
                
                
                ForEach(groceryList, id: \.name) { category in
                    Section {
                        ForEach(category.items, id: \.self) { item in
                            GroceryListItemView(item: item)
                        }
                    } header: {
                        HStack {
                            Text(category.name)
                                .foregroundStyle(Color.nextcloudBlue)
                            Spacer()
                            Button {
                                modelContext.delete(category)
                            } label: {
                                Image(systemName: "trash")
                                    .foregroundStyle(Color.nextcloudBlue)
                            }
                        }
                    }
                }
                
                if groceryList.isEmpty {
                    Text("You're all set for cooking 🍓")
                        .font(.headline)
                    Text("Add groceries to this list by either using the button next to an ingredient list in a recipe, or by swiping right on individual ingredients of a recipe.")
                        .foregroundStyle(.secondary)
                    Text("To add grocieries manually, type them in the box below and press the button. To add multiple items at once, separate them by a new line.")
                        .foregroundStyle(.secondary)
                    Text("Your grocery list is stored locally and therefore not synchronized across your devices.")
                        .foregroundStyle(.secondary)
                }
            }
            
            .listStyle(.plain)
            .navigationTitle("Grocery List")
            .toolbar {
                Button {
                    do {
                        try modelContext.delete(model: RecipeGroceries.self)
                    } catch {
                        print("Failed to delete all GroceryCategory models.")
                    }
                } label: {
                    Text("Delete")
                        .foregroundStyle(Color.nextcloudBlue)
                }
            }
            
        }
    }
    
    private func addGroceryItems(_ itemNames: [String], toCategory categoryId: String, named name: String) async {
        do {
            // Find or create the target category
            let categoryPredicate = #Predicate<RecipeGroceries> { $0.id == categoryId }
            let fetchDescriptor = FetchDescriptor<RecipeGroceries>(predicate: categoryPredicate)
            
            var targetCategory: RecipeGroceries?
            if let existingCategory = try modelContext.fetch(fetchDescriptor).first {
                targetCategory = existingCategory
            } else {
                // Create the category if it doesn't exist
                let newCategory = RecipeGroceries(id: categoryId, name: name)
                modelContext.insert(newCategory)
                targetCategory = newCategory
            }
            
            guard let category = targetCategory else { return }
            
            // Add new GroceryItems to the category
            for itemName in itemNames {
                let newItem = GroceryItem(name: itemName, isChecked: false)
                category.items.append(newItem)
            }
            
            try modelContext.save()
        } catch {
            print("Error adding grocery items: \(error.localizedDescription)")
        }
    }
    
    private func deleteGroceryItems(at offsets: IndexSet, in category: RecipeGroceries) {
        for index in offsets {
            let itemToDelete = category.items[index]
            modelContext.delete(itemToDelete)
        }
    }
}



fileprivate struct GroceryListItemView: View {
    @Environment(\.modelContext) var modelContext
    @Bindable var item: GroceryItem

    var body: some View {
        HStack(alignment: .top) {
            if item.isChecked {
                Image(systemName: "checkmark.circle")
            } else {
                Image(systemName: "circle")
            }

            Text("\(item.name)")
                .multilineTextAlignment(.leading)
                .lineLimit(5)
        }
        .padding(5)
        .foregroundStyle(item.isChecked ? Color.secondary : Color.primary)
        .onTapGesture(perform: { item.isChecked.toggle() })
        .animation(.easeInOut, value: item.isChecked)
        .swipeActions(edge: .trailing, allowsFullSwipe: true) {
            Button(action: { modelContext.delete(item) }) {
                Label("Delete", systemImage: "trash")
            }
            .tint(.red)
        }
    }
}