//
// ExerciseListView.swift
// Workouts
//
// Created by rzen on 7/18/25 at 8:38 AM.
//
// Copyright 2025 Rouslan Zenetl. All Rights Reserved.
//

import SwiftUI
import CoreData

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

    @ObservedObject var split: Split

    @State private var showingAddSheet: Bool = false
    @State private var itemToEdit: Exercise? = nil
    @State private var itemToDelete: Exercise? = nil
    @State private var createdWorkout: Workout? = nil

    var body: some View {
        NavigationStack {
            Form {
                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 {
                        showingAddSheet = true
                    } label: {
                        ListItem(title: "Add Exercise")
                    }
                } else {
                    Text("No exercises added yet.")
                    Button(action: { showingAddSheet.toggle() }) {
                        ListItem(title: "Add Exercise")
                    }
                }
            }
            .navigationTitle("\(split.name)")
        }
        .toolbar {
            ToolbarItem(placement: .primaryAction) {
                Button("Start This Split") {
                    startWorkout()
                }
            }
        }
        .navigationDestination(item: $createdWorkout) { workout in
            WorkoutLogListView(workout: workout)
        }
        .sheet(isPresented: $showingAddSheet) {
            ExercisePickerView(onExerciseSelected: { exerciseNames in
                addExercises(names: exerciseNames)
            }, allowMultiSelect: true)
        }
        .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 startWorkout() {
        let workout = Workout(context: viewContext)
        workout.start = Date()
        workout.end = Date()
        workout.status = .notStarted
        workout.split = split

        for exercise in split.exercisesArray {
            let workoutLog = WorkoutLog(context: viewContext)
            workoutLog.exerciseName = exercise.name
            workoutLog.date = Date()
            workoutLog.order = exercise.order
            workoutLog.sets = exercise.sets
            workoutLog.reps = exercise.reps
            workoutLog.weight = exercise.weight
            workoutLog.status = .notStarted
            workoutLog.workout = workout
        }

        try? viewContext.save()
        createdWorkout = workout
    }

    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()
        }
    }
}