import Foundation
import SwiftData
import SwiftUI

@Model
final class Split {
    var name: String = ""
    var intro: String = ""
    
    @Relationship(deleteRule: .cascade, inverse: \SplitExerciseAssignment.split)
    var exercises: [SplitExerciseAssignment]? = []
    
    @Relationship(deleteRule: .nullify, inverse: \Workout.split)
    var workouts: [Workout]? = []
    
    init(name: String, intro: String) {
        self.name = name
        self.intro = intro
    }
    
    static let unnamed = "Unnamed Split"
}

// MARK: - EditableEntity Conformance

extension Split: EditableEntity {
    var count: Int? {
        return self.exercises?.count
    }

    static func createNew() -> Split {
        return Split(name: "", intro: "")
    }
    
    static var navigationTitle: String {
        return "Splits"
    }
    
    @ViewBuilder
    static func formView(for model: Split) -> some View {
        EntityAddEditView(model: model) { $model in
            SplitFormView(model: $model)
        }
    }
}

// MARK: - Private Form View

fileprivate struct SplitFormView: View {
    @Binding var model: Split
    
    @State private var showingAddSheet: Bool = false
    @State private var itemToEdit: SplitExerciseAssignment? = nil
    @State private var itemToDelete: SplitExerciseAssignment? = nil
    
    var body: some View {
        Section(header: Text("Name")) {
            TextField("Name", text: $model.name)
                .bold()
        }
        
        Section(header: Text("Description")) {
            TextEditor(text: $model.intro)
                .frame(minHeight: 100)
        }
        
        Section(header: Text("Exercises")) {
            NavigationLink {
                NavigationStack {
                    Form {
                        List {
                            if let assignments = model.exercises, !assignments.isEmpty {
                                let sortedAssignments = assignments.sorted(by: { $0.order == $1.order ? $0.exercise?.name ?? Exercise.unnamed < $1.exercise?.name ?? Exercise.unnamed : $0.order < $1.order })
                                ForEach(sortedAssignments) { item in
                                    ListItem(
                                        title: item.exercise?.name ?? Exercise.unnamed,
                                        text: item.setup.isEmpty ? nil : item.setup,
                                        subtitle: "\(item.sets) × \(item.reps) × \(item.weight) lbs"
                                    )
                                    .swipeActions {
                                        Button(role: .destructive) {
                                            itemToDelete = item
                                        } label: {
                                            Label("Delete", systemImage: "trash")
                                        }
                                        Button {
                                            itemToEdit = item
                                        } label: {
                                            Label("Edit", systemImage: "pencil")
                                        }
                                        .tint(.indigo)
                                    }
                                }
                            } else {
                                Text("No exercises added yet.")
                            }
                        }
                    }
                    .navigationTitle("Exercises")
                }
                .toolbar {
                    ToolbarItem(placement: .navigationBarTrailing) {
                        Button(action: { showingAddSheet.toggle() }) {
                            Image(systemName: "plus")
                        }
                    }
                }
                .sheet (isPresented: $showingAddSheet) {
                    ExercisePickerView { exercise in
                        itemToEdit = SplitExerciseAssignment(
                            order: 0,
                            sets: exercise.sets,
                            reps: exercise.reps,
                            weight: exercise.weight,
                            split: model,
                            exercise: exercise
                        )
                    }
                }
                .sheet(item: $itemToEdit) { item in
                    SplitExerciseAssignmentAddEditView(model: item)
                }
                .confirmationDialog(
                    "Delete Exercise?",
                    isPresented: .constant(itemToDelete != nil),
                    titleVisibility: .visible
                ) {
                    Button("Delete", role: .destructive) {
                        if let item = itemToDelete {
                            withAnimation {
                                model.exercises?.removeAll { $0.id == item.id }
                                itemToDelete = nil
                            }
                        }
                    }
                }

            } label: {
                ListItem(
                    text: "Exercises",
                    count: model.exercises?.count ?? 0
                )
            }
        }
    }
}