//
// WorkoutLogsView.swift
// Workouts
//
// Created by rzen on 7/13/25 at 6:52 PM.
//
// Copyright 2025 Rouslan Zenetl. All Rights Reserved.
//

import SwiftUI
import CoreData

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

    @FetchRequest(
        sortDescriptors: [NSSortDescriptor(keyPath: \Workout.start, ascending: false)],
        animation: .default
    )
    private var workouts: FetchedResults<Workout>

    @State private var showingSplitPicker = false
    @State private var itemToDelete: Workout? = nil

    var body: some View {
        NavigationStack {
            List {
                ForEach(workouts, id: \.objectID) { workout in
                    NavigationLink(destination: WorkoutLogListView(workout: workout)) {
                        CalendarListItem(
                            date: workout.start,
                            title: workout.split?.name ?? Split.unnamed,
                            subtitle: getSubtitle(for: workout),
                            subtitle2: workout.statusName
                        )
                    }
                    .swipeActions(edge: .trailing, allowsFullSwipe: false) {
                        Button {
                            itemToDelete = workout
                        } label: {
                            Label("Delete", systemImage: "trash")
                        }
                        .tint(.red)
                    }
                }
            }
            .overlay {
                if workouts.isEmpty {
                    ContentUnavailableView(
                        "No Workouts Yet",
                        systemImage: "list.bullet.clipboard",
                        description: Text("Start a new workout from one of your splits.")
                    )
                }
            }
            .navigationTitle("Workout Logs")
            .toolbar {
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Start New") {
                        showingSplitPicker.toggle()
                    }
                }
            }
            .sheet(isPresented: $showingSplitPicker) {
                SplitPickerSheet()
            }
            .confirmationDialog(
                "Delete Workout?",
                isPresented: Binding<Bool>(
                    get: { itemToDelete != nil },
                    set: { if !$0 { 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 getSubtitle(for workout: Workout) -> String {
        if workout.status == .completed, let endDate = workout.end {
            return workout.start.humanTimeInterval(to: endDate)
        } else {
            return workout.start.formattedDate()
        }
    }
}

// MARK: - Split Picker Sheet

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

    @FetchRequest(
        sortDescriptors: [
            NSSortDescriptor(keyPath: \Split.order, ascending: true),
            NSSortDescriptor(keyPath: \Split.name, ascending: true)
        ],
        animation: .default
    )
    private var splits: FetchedResults<Split>

    var body: some View {
        NavigationStack {
            List {
                ForEach(splits, id: \.objectID) { split in
                    Button {
                        startWorkout(with: split)
                    } label: {
                        HStack {
                            Image(systemName: split.systemImage)
                                .foregroundColor(Color.color(from: split.color))
                            Text(split.name)
                            Spacer()
                            Text("\(split.exercisesArray.count) exercises")
                                .font(.caption)
                                .foregroundColor(.secondary)
                        }
                    }
                }
            }
            .navigationTitle("Select a Split")
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Cancel") {
                        dismiss()
                    }
                }
            }
        }
    }

    private func startWorkout(with split: Split) {
        let workout = Workout(context: viewContext)
        workout.start = 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()
        dismiss()
    }
}

#Preview {
    WorkoutLogsView()
        .environment(\.managedObjectContext, PersistenceController.preview.viewContext)
}