//
// ExerciseAddEditView.swift
// Workouts
//
// Created by rzen on 7/15/25 at 7:12 AM.
//
// Copyright 2025 Rouslan Zenetl. All Rights Reserved.
//

import SwiftUI
import CoreData

struct ExerciseAddEditView: View {
    @Environment(\.managedObjectContext) private var viewContext
    @Environment(\.dismiss) private var dismiss
    @State private var showingExercisePicker = false

    @ObservedObject var exercise: Exercise

    @State private var originalWeight: Int32? = nil
    @State private var loadType: LoadType = .none

    @State private var minutes = 0
    @State private var seconds = 0

    @State private var weight_tens = 0
    @State private var weight = 0

    @State private var reps: Int = 0
    @State private var sets: Int = 0

    var body: some View {
        NavigationStack {
            Form {
                Section(header: Text("Exercise")) {
                    if exercise.name.isEmpty {
                        Button(action: {
                            showingExercisePicker = true
                        }) {
                            HStack {
                                Text("Select Exercise")
                                Spacer()
                                Image(systemName: "chevron.right")
                                    .foregroundColor(.gray)
                            }
                        }
                    } else {
                        ListItem(title: exercise.name)
                    }
                }

                Section(header: Text("Sets/Reps")) {
                    HStack(alignment: .bottom) {
                        VStack(alignment: .center) {
                            Text("Sets")
                            Picker("", selection: $sets) {
                                ForEach(0..<20) { s in
                                    Text("\(s)").tag(s)
                                }
                            }
                            .frame(height: 100)
                            .pickerStyle(.wheel)
                        }
                        VStack(alignment: .center) {
                            Text("Reps")
                            Picker("", selection: $reps) {
                                ForEach(0..<100) { r in
                                    Text("\(r)").tag(r)
                                }
                            }
                            .frame(height: 100)
                            .pickerStyle(.wheel)
                        }
                    }
                }

                Section(header: Text("Load Type"), footer: Text("For bodyweight exercises choose None. For resistance or weight training select Weight. For exercises that are time oriented (like plank or meditation) select Time.")) {
                    Picker("", selection: $loadType) {
                        ForEach(LoadType.allCases, id: \.self) { load in
                            Text(load.name)
                                .tag(load)
                        }
                    }
                    .pickerStyle(.segmented)
                }

                if loadType == .weight {
                    Section(header: Text("Weight")) {
                        HStack {
                            Picker("", selection: $weight_tens) {
                                ForEach(0..<100) { lbs in
                                    Text("\(lbs * 10)").tag(lbs * 10)
                                }
                            }
                            .frame(height: 100)
                            .pickerStyle(.wheel)

                            Picker("", selection: $weight) {
                                ForEach(0..<10) { lbs in
                                    Text("\(lbs)").tag(lbs)
                                }
                            }
                            .frame(height: 100)
                            .pickerStyle(.wheel)

                            Text("lbs")
                        }
                    }
                }

                if loadType == .duration {
                    Section(header: Text("Duration")) {
                        HStack {
                            Picker("Minutes", selection: $minutes) {
                                ForEach(0..<60) { minute in
                                    Text("\(minute) min").tag(minute)
                                }
                            }
                            .pickerStyle(.wheel)

                            Picker("Seconds", selection: $seconds) {
                                ForEach(0..<60) { second in
                                    Text("\(second) sec").tag(second)
                                }
                            }
                            .pickerStyle(.wheel)
                        }
                    }
                }

                Section(header: Text("Weight Increase")) {
                    HStack {
                        Text("Remind every \(exercise.weightReminderTimeIntervalWeeks) weeks")
                        Spacer()
                        Stepper("", value: Binding(
                            get: { Int(exercise.weightReminderTimeIntervalWeeks) },
                            set: { exercise.weightReminderTimeIntervalWeeks = Int32($0) }
                        ), in: 0...366)
                    }
                    if let lastUpdated = exercise.weightLastUpdated {
                        Text("Last weight change \(Date().humanTimeInterval(to: lastUpdated)) ago")
                    }
                }
            }
            .onAppear {
                originalWeight = exercise.weight
                weight_tens = Int(exercise.weight) / 10 * 10
                weight = Int(exercise.weight) % 10
                loadType = exercise.loadTypeEnum
                sets = Int(exercise.sets)
                reps = Int(exercise.reps)
                if let duration = exercise.duration {
                    minutes = Int(duration.timeIntervalSince1970) / 60
                    seconds = Int(duration.timeIntervalSince1970) % 60
                }
            }
            .sheet(isPresented: $showingExercisePicker) {
                ExercisePickerView { exerciseNames in
                    exercise.name = exerciseNames.first ?? "Unnamed"
                }
            }
            .navigationTitle(exercise.name.isEmpty ? "New Exercise" : exercise.name)
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Cancel") {
                        dismiss()
                    }
                }

                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Save") {
                        if let originalWeight = originalWeight, originalWeight != Int32(weight_tens + weight) {
                            exercise.weightLastUpdated = Date()
                        }
                        exercise.duration = Date(timeIntervalSince1970: Double(minutes * 60 + seconds))
                        exercise.weight = Int32(weight_tens + weight)
                        exercise.sets = Int32(sets)
                        exercise.reps = Int32(reps)
                        exercise.loadType = Int32(loadType.rawValue)
                        try? viewContext.save()
                        dismiss()
                    }
                }
            }
        }
    }
}