//
// SplitAddEditView.swift
// Workouts
//
// Created by rzen on 7/18/25 at 9:42 AM.
//
// Copyright 2025 Rouslan Zenetl. All Rights Reserved.
//

import IndieSync
import SwiftUI
import SwiftData

struct SplitAddEditView: View {
    @Environment(SyncEngine.self) private var sync
    @Environment(\.modelContext) private var modelContext
    @Environment(\.dismiss) private var dismiss

    // Resolve the split by id, not a captured entity: a clone-on-edit swaps a seed's
    // identity mid-screen (the seed entity is deleted and a clone inserted), which
    // would dangle a stored `Split`. `currentSplitID` follows that swap. `splitID` is
    // nil in create mode.
    @State private var splitID: String?
    @Query private var splits: [Split]

    var onDelete: (() -> Void)?

    @State private var name: String = ""
    @State private var color: String = "indigo"
    @State private var systemImage: String = "dumbbell.fill"
    @State private var activityType: WorkoutActivityType = .traditionalStrength
    @State private var showingIconPicker: Bool = false
    @State private var showingDeleteConfirmation: Bool = false

    var isEditing: Bool { splitID != nil }

    init(split: Split?, onDelete: (() -> Void)? = nil) {
        _splitID = State(initialValue: split?.id)
        self.onDelete = onDelete
        if let split = split {
            _name = State(initialValue: split.name)
            _color = State(initialValue: split.color)
            _systemImage = State(initialValue: split.systemImage)
            _activityType = State(initialValue: split.activityTypeEnum)
        }
    }

    private var split: Split? {
        guard let splitID else { return nil }
        let id = sync.currentSplitID(for: splitID)
        return splits.first { $0.id == id }
    }

    var body: some View {
        NavigationStack {
            if isEditing && split == nil {
                // The id we held no longer maps to a live split (deleted on another
                // device, or a transient mid-clone frame). Show nothing and leave.
                ContentUnavailableView("Split Unavailable", systemImage: "dumbbell")
                    .task { dismiss() }
            } else {
                form(for: split)
            }
        }
    }

    @ViewBuilder
    private func form(for split: Split?) -> some View {
        Form {
            Section(header: Text("Name")) {
                TextField("Name", text: $name)
                    .bold()
            }

            Section(header: Text("Appearance")) {
                Picker("Color", selection: $color) {
                    ForEach(availableColors, id: \.self) { colorName in
                        HStack {
                            Circle()
                                .fill(Color.color(from: colorName))
                                .frame(width: 20, height: 20)
                            Text(colorName.capitalized)
                        }
                        .tag(colorName)
                    }
                }

                Button {
                    showingIconPicker = true
                } label: {
                    HStack {
                        Text("Icon")
                            .foregroundColor(.primary)
                        Spacer()
                        Image(systemName: systemImage)
                            .font(.title2)
                            .foregroundColor(.accentColor)
                    }
                }
            }

            Section {
                Picker("Activity Type", selection: $activityType) {
                    ForEach(WorkoutActivityType.allCases, id: \.self) { type in
                        Label(type.displayName, systemImage: type.systemImage).tag(type)
                    }
                }
            } header: {
                Text("Activity Type")
            } footer: {
                Text("Determines how this workout is categorized in Apple Health and how it credits your Activity rings.")
            }

            if let split = split {
                Section(header: Text("Exercises")) {
                    NavigationLink {
                        ExerciseListView(split: split)
                    } label: {
                        ListItem(
                            text: "Exercises",
                            count: split.exercisesArray.count
                        )
                    }
                }

                Section {
                    Button("Delete Split", role: .destructive) {
                        showingDeleteConfirmation = true
                    }
                }
            }
        }
        .navigationTitle(isEditing ? "Edit Split" : "New Split")
        .toolbar {
            ToolbarItem(placement: .navigationBarLeading) {
                Button("Cancel") {
                    dismiss()
                }
            }

            ToolbarItem(placement: .navigationBarTrailing) {
                Button("Save") {
                    save()
                    dismiss()
                }
                .disabled(name.isEmpty)
            }
        }
        .sheet(isPresented: $showingIconPicker) {
            SFSymbolPicker(selection: $systemImage)
        }
        .confirmationDialog(
            "Delete This Split?",
            isPresented: $showingDeleteConfirmation,
            titleVisibility: .visible
        ) {
            Button("Delete", role: .destructive) {
                if let split = split {
                    Task {
                        await sync.delete(split: split)
                    }
                    dismiss()
                    onDelete?()
                }
            }
        } message: {
            Text("This will permanently delete the split and all its exercises.")
        }
    }

    private func save() {
        if isEditing {
            // Update existing split. If the id no longer resolves (deleted remotely
            // mid-edit), there's nothing to save.
            guard let split = split else { return }
            var doc = SplitDocument(from: split)
            doc.name = name
            doc.color = color
            doc.systemImage = systemImage
            doc.activityType = activityType.rawValue
            doc.updatedAt = Date()
            Task { await sync.save(split: doc) }
        } else {
            // Create new split
            let existing = (try? modelContext.fetch(FetchDescriptor<Split>())) ?? []
            let doc = SplitDocument(
                schemaVersion: SplitDocument.currentSchemaVersion,
                id: ULID.make(),
                name: name,
                color: color,
                systemImage: systemImage,
                order: existing.count,
                createdAt: Date(),
                updatedAt: Date(),
                exercises: [],
                activityType: activityType.rawValue
            )
            Task { await sync.save(split: doc) }
        }
    }
}
