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

import SwiftUI
import SwiftData

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

    @State 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
    @State private var showingDeleteConfirmation: Bool = false

    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")) {
                    List {
                        if let assignments = split.exercises, !assignments.isEmpty {
                            let sortedAssignments = assignments.sorted(by: { $0.order == $1.order ? $0.name < $1.name : $0.order < $1.order })
                            
                            ForEach(sortedAssignments) { item in
                                ListItem(
                                    title: item.name,
                                    subtitle: "\(item.sets) × \(item.reps) × \(item.weight) lbs  \(item.order)"
                                )
                                .swipeActions {
                                    Button {
                                        itemToDelete = item
                                    } label: {
                                        Label("Delete", systemImage: "trash")
                                    }
                                    .tint(.red)
                                    Button {
                                        itemToEdit = item
                                    } label: {
                                        Label("Edit", systemImage: "pencil")
                                    }
                                    .tint(.indigo)
                                }
                            }
                            .onMove(perform: { indices, destination in
                                var exerciseArray = Array(sortedAssignments)
                                exerciseArray.move(fromOffsets: indices, toOffset: destination)
                                for (index, exercise) in exerciseArray.enumerated() {
                                    exercise.order = index
                                }
                                if let modelContext = exerciseArray.first?.modelContext {
                                    do {
                                        try modelContext.save()
                                    } catch {
                                        print("Error saving after reordering: \(error)")
                                    }
                                }
                            })
                            
                            Button {
                                showingAddSheet = true
                            } label: {
                                ListItem(title: "Add Exercise")
                            }
                            
                        } else {
                            Text("No exercises added yet.")
                            Button(action: { showingAddSheet.toggle() }) {
                                ListItem(title: "Add Exercise")
                            }
                        }
                    }
                }
                
                Button ("Delete This Split", role: .destructive) {
                    showingDeleteConfirmation = true
                }
                .tint(.red)
            }
            .navigationTitle("\(split.name)")
        }
        .toolbar {
            ToolbarItem(placement: .primaryAction) {
                Button("Start This Split") {
                    let workout = Workout(start: Date(), end: Date(), split: split)
                    modelContext.insert(workout)
                    if let exercises = split.exercises {
                        for assignment in exercises {
                            let workoutLog = WorkoutLog(
                                workout: workout,
                                exerciseName: assignment.name,
                                date: Date(),
                                order: assignment.order,
                                sets: assignment.sets,
                                reps: assignment.reps,
                                weight: assignment.weight
                            )
                            modelContext.insert(workoutLog)
                        }
                    }
                    try? modelContext.save()
                    
                    // Set the created workout to trigger navigation
                    createdWorkout = workout
                }
            }
        }
        .navigationDestination(item: $createdWorkout, destination: { workout in
            WorkoutLogListView(workout: workout)
        })
        .sheet (isPresented: $showingAddSheet) {
            ExercisePickerView(onExerciseSelected: { exerciseNames in
                let splitId = split.persistentModelID
                print("exerciseNames: \(exerciseNames)")
                if exerciseNames.count == 1 {
                    itemToEdit = Exercise(
                        split: split,
                        exerciseName: exerciseNames.first ?? "Exercise.unnamed",
                        order: 0,
                        sets: 3,
                        reps: 10,
                        weight: 40
                    )
                } else {
                    for exerciseName in exerciseNames {
                        var duplicateExercise: [Exercise]? = nil
                        do {
                            duplicateExercise = try modelContext.fetch(FetchDescriptor<Exercise>(predicate: #Predicate{ exercise in
                                exerciseName == exercise.name && splitId == exercise.split?.persistentModelID
                            }))
                        } catch {
                            print("ERROR: failed to fetch \(exerciseName)")
                        }
                        
                        if let dup = duplicateExercise, dup.count > 0 {
                            print("Skipping duplicate \(exerciseName) found \(dup.count) duplicate(s)")
                        } else {
                            print("Creating \(exerciseName) for \(split.name)")
                            modelContext.insert(Exercise(
                                split: split,
                                exerciseName: exerciseName,
                                order: 0,
                                sets: 3,
                                reps: 10,
                                weight: 40
                            ))
                        }
                    }
                }
                try? modelContext.save()
            }, allowMultiSelect: true)
        }
        .sheet(item: $itemToEdit) { item in
            ExerciseAddEditView(model: item)
        }
        .confirmationDialog(
            "Delete Exercise?",
            isPresented: .constant(itemToDelete != nil),
            titleVisibility: .visible
        ) {
            Button("Delete", role: .destructive) {
                if let item = itemToDelete {
                    withAnimation {
                        modelContext.delete(item)
                        try? modelContext.save()
                        itemToDelete = nil
                    }
                }
            }
        }
        .confirmationDialog(
            "Delete This Split?",
            isPresented: $showingDeleteConfirmation,
            titleVisibility: .visible
        ) {
            Button("Delete", role: .destructive) {
                modelContext.delete(split)
                try? modelContext.save()
                dismiss()
            }
        }

    }
}