//
// SplitDetailView.swift
// Workouts
//
// Created by rzen on 7/25/25 at 3:27 PM.
//
// Copyright 2025 Rouslan Zenetl. All Rights Reserved.
//

import SwiftUI
import CoreData

struct SplitDetailView: View {
    @Environment(\.managedObjectContext) private var viewContext
    @Environment(\.dismiss) private var dismiss

    @ObservedObject var split: Split

    @State private var showingExerciseAddSheet: Bool = false
    @State private var showingSplitEditSheet: Bool = false
    @State private var itemToEdit: Exercise? = nil
    @State private var itemToDelete: Exercise? = nil

    var body: some View {
        NavigationStack {
            Form {
                Section(header: Text("What is a Split?")) {
                    Text("A \"split\" is simply how you divide (or \"split up\") your weekly training across different days. Instead of working every muscle group every session, you assign certain muscle groups, movement patterns, or training emphases to specific days.")
                        .font(.caption)
                }

                Section(header: Text("Exercises")) {
                    let sortedExercises = split.exercisesArray

                    if !sortedExercises.isEmpty {
                        ForEach(sortedExercises, id: \.objectID) { item in
                            ListItem(
                                title: item.name,
                                subtitle: "\(item.sets) × \(item.reps) × \(item.weight) lbs"
                            )
                            .swipeActions {
                                Button {
                                    itemToDelete = item
                                } label: {
                                    Label("Delete", systemImage: "trash")
                                }
                                .tint(.red)
                                Button {
                                    itemToEdit = item
                                } label: {
                                    Label("Edit", systemImage: "pencil")
                                }
                                .tint(.indigo)
                            }
                        }
                        .onMove(perform: moveExercises)

                        Button {
                            showingExerciseAddSheet = true
                        } label: {
                            ListItem(systemName: "plus.circle", title: "Add Exercise")
                        }
                    } else {
                        Text("No exercises added yet.")
                        Button(action: { showingExerciseAddSheet.toggle() }) {
                            ListItem(title: "Add Exercise")
                        }
                    }
                }
            }
            .navigationTitle("\(split.name)")
        }
        .toolbar {
            ToolbarItem(placement: .primaryAction) {
                Button {
                    showingSplitEditSheet = true
                } label: {
                    Image(systemName: "pencil")
                }
            }
        }
        .sheet(isPresented: $showingExerciseAddSheet) {
            ExercisePickerView(onExerciseSelected: { exerciseNames in
                addExercises(names: exerciseNames)
            }, allowMultiSelect: true)
        }
        .sheet(isPresented: $showingSplitEditSheet) {
            SplitAddEditView(split: split) {
                dismiss()
            }
        }
        .sheet(item: $itemToEdit) { item in
            ExerciseAddEditView(exercise: item)
        }
        .confirmationDialog(
            "Delete Exercise?",
            isPresented: .constant(itemToDelete != nil),
            titleVisibility: .visible
        ) {
            Button("Delete", role: .destructive) {
                if let item = itemToDelete {
                    withAnimation {
                        viewContext.delete(item)
                        try? viewContext.save()
                        itemToDelete = nil
                    }
                }
            }
            Button("Cancel", role: .cancel) {
                itemToDelete = nil
            }
        }
    }

    private func moveExercises(from source: IndexSet, to destination: Int) {
        var exercises = split.exercisesArray
        exercises.move(fromOffsets: source, toOffset: destination)
        for (index, exercise) in exercises.enumerated() {
            exercise.order = Int32(index)
        }
        try? viewContext.save()
    }

    private func addExercises(names: [String]) {
        if names.count == 1 {
            let exercise = Exercise(context: viewContext)
            exercise.name = names.first ?? "Unnamed"
            exercise.order = Int32(split.exercisesArray.count)
            exercise.sets = 3
            exercise.reps = 10
            exercise.weight = 40
            exercise.loadType = Int32(LoadType.weight.rawValue)
            exercise.split = split
            try? viewContext.save()
            itemToEdit = exercise
        } else {
            let existingNames = Set(split.exercisesArray.map { $0.name })
            for name in names where !existingNames.contains(name) {
                let exercise = Exercise(context: viewContext)
                exercise.name = name
                exercise.order = Int32(split.exercisesArray.count)
                exercise.sets = 3
                exercise.reps = 10
                exercise.weight = 40
                exercise.loadType = Int32(LoadType.weight.rawValue)
                exercise.split = split
            }
            try? viewContext.save()
        }
    }
}