Memola/Memola/Canvas/Tool/Core/Tool.swift

//
//  Tool.swift
//  Memola
//
//  Created by Dscyre Scotti on 5/4/24.
//

import Combine
import SwiftUI
import CoreData
import Foundation

public class Tool: NSObject, ObservableObject {
    let object: ToolObject

    @Published var pens: [Pen] = []
    @Published var selectedPen: Pen?
    @Published var draggedPen: Pen?

    let scrollPublisher = PassthroughSubject<String, Never>()
    var markers: [Pen] {
        pens.filter { $0.strokeStyle == .marker }
    }

    init(object: ToolObject) {
        self.object = object
    }

    func load() {
        DispatchQueue.main.async { [weak self] in
            guard let self else { return }
            pens = object.pens.sortedArray(using: [NSSortDescriptor(key: "orderIndex", ascending: true)]).compactMap {
                guard let pen = $0 as? PenObject else { return nil }
                return Pen(object: pen)
            }
            if let selectedPen = pens.first(where: { $0.isSelected }) {
                selectPen(selectedPen)
                scrollPublisher.send(selectedPen.id)
            }
        }
    }

    func selectPen(_ pen: Pen) {
        if let selectedPen {
            unselectPen(selectedPen)
        }
        withAnimation {
            selectedPen = pen
        }
        selectedPen?.isSelected = true
        withPersistence(\.viewContext) { context in
            try context.saveIfNeeded()
        }
    }

    func unselectPen(_ pen: Pen) {
        pen.isSelected = false
        withAnimation {
            selectedPen = nil
        }
        withPersistence(\.viewContext) { context in
            try context.saveIfNeeded()
        }
    }

    func duplicatePen(_ pen: Pen, of originalPen: Pen) {
        guard let index = pens.firstIndex(where: { originalPen === $0 }) else { return }
        withAnimation {
            pens.insert(pen, at: index + 1)
        }
        selectPen(pen)
        withPersistence(\.viewContext) { [pens] context in
            for (index, pen) in pens.enumerated() {
                pen.object?.orderIndex = Int16(index)
            }
            try context.saveIfNeeded()
        }
    }

    func addPen(_ pen: Pen) {
        withAnimation {
            pens.append(pen)
        }
        selectPen(pen)
        if let _pen = pen.object {
            object.pens.add(_pen)
        }
        scrollPublisher.send(pen.id)
        withPersistence(\.viewContext) { context in
            try context.saveIfNeeded()
        }
    }

    func removePen(_ pen: Pen) {
        guard let index = pens.firstIndex(where: { $0 === pen }) else { return }
        let deletedPen = withAnimation {
            pens.remove(at: index)
        }
        unselectPen(deletedPen)
        if let _pen = deletedPen.object {
            _pen.tool = nil
            object.pens.remove(_pen)
            withPersistence(\.viewContext) { context in
                context.delete(_pen)
                try context.saveIfNeeded()
            }
        }
    }
}