//
// WorkoutDetailView.swift
// Workouts
//
// Created by rzen on 7/22/25 at 9:54 PM.
//
// Copyright 2025 Rouslan Zenetl. All Rights Reserved.
//

import SwiftUI
import SwiftData

struct WorkoutDetailView: View {
    let workout: Workout
    @Environment(\.modelContext) private var modelContext
    @Environment(\.dismiss) private var dismiss
    
    @State private var showingCompletedDialog = false
    @State private var selectedLog: WorkoutLog? = nil
    @State private var navigateToExercise = false
    
    var body: some View {
        VStack(alignment: .center, spacing: 8) {
            if let logs = workout.logs?.sorted(by: { $0.order < $1.order }), !logs.isEmpty {
                List {
                    ForEach(logs) { log in
                        Button {
                            handleExerciseTap(log)
                        } label: {
                            WorkoutLogCardView(log: log)
                        }
                        .listRowBackground(
                            RoundedRectangle(cornerRadius: 12)
                                .fill(Color.secondary.opacity(0.2))
                                .padding(
                                    EdgeInsets(
                                        top: 4,
                                        leading: 8,
                                        bottom: 4,
                                        trailing: 8
                                    )
                                )
                        )
                    }
                }
                .listStyle(.carousel)
            } else {
                Text("No exercises in this workout")
                    .font(.body)
                    .foregroundStyle(.secondary)
                    .padding()
                
                Spacer()
            }
        }
        .navigationDestination(isPresented: $navigateToExercise) {
            if let selectedLog = selectedLog {
                ExerciseProgressControlView(log: selectedLog)
            }
        }
        .alert("Exercise Completed", isPresented: $showingCompletedDialog) {
            Button("Cancel", role: .cancel) {
                // Do nothing, just dismiss
            }
            Button("Restart") {
                if let log = selectedLog {
                    restartExercise(log)
                }
            }
            Button("One More Set") {
                if let log = selectedLog {
                    addOneMoreSet(log)
                }
            }
        } message: {
            Text("This exercise is already completed. What would you like to do?")
        }
    }
    
    private func handleExerciseTap(_ log: WorkoutLog) {
        selectedLog = log
        
        switch log.status {
        case .notStarted:
            // Start from beginning
            log.currentStateIndex = 0
            try? modelContext.save()
            navigateToExercise = true
            
        case .inProgress:
            // If we're in a rest state, advance to the next set
            if let currentStateIndex = log.currentStateIndex, isRestState(currentStateIndex) {
                log.currentStateIndex = currentStateIndex + 1
                try? modelContext.save()
            }
            // Continue from current (possibly updated) position
            navigateToExercise = true
            
        case .completed:
            // Show dialog for completed exercise
            showingCompletedDialog = true
            
        default:
            // Default to not started behavior
            log.currentStateIndex = 0
            try? modelContext.save()
            navigateToExercise = true
        }
    }
    
    private func restartExercise(_ log: WorkoutLog) {
        log.status = .notStarted
        log.currentStateIndex = 0
        log.elapsedSeconds = 0
        try? modelContext.save()
        navigateToExercise = true
    }
    
    private func addOneMoreSet(_ log: WorkoutLog) {
        // Increment total sets
        log.sets += 1
        
        // Calculate the state index for the additional set
        // States: intro(0) → set1(1) → rest1(2) → ... → setN(2N-1) → done(2N)
        // For the additional set, we want to go to setN+1 which is at index 2N+1
        let additionalSetStateIndex = (log.sets * 2) - 1
        
        log.status = .inProgress
        log.currentStateIndex = additionalSetStateIndex
        log.elapsedSeconds = 0
        
        try? modelContext.save()
        navigateToExercise = true
    }
    
    private func isRestState(_ stateIndex: Int) -> Bool {
        // Rest states are at even indices > 0
        return stateIndex > 0 && stateIndex % 2 == 0
    }
}