//  HotkeyRecorder.swift
//  GreenshotMac
//
//  A small AppKit control that records the next key combination, wrapped for SwiftUI.

import AppKit
import SwiftUI
import Carbon.HIToolbox

final class HotkeyRecorderControl: NSButton {

    var onRecord: ((HotkeySpec) -> Void)?
    var spec: HotkeySpec = .none {
        didSet { refreshTitle() }
    }

    private var isRecording = false {
        didSet { refreshTitle() }
    }

    init() {
        super.init(frame: .zero)
        bezelStyle = .rounded
        setButtonType(.momentaryPushIn)
        target = self
        action = #selector(startRecording)
        refreshTitle()
    }

    required init?(coder: NSCoder) { fatalError("init(coder:) is not used") }

    private func refreshTitle() {
        title = isRecording ? "Press a key…" : HotkeyManager.description(of: spec)
    }

    @objc private func startRecording() {
        isRecording = true
        window?.makeFirstResponder(self)
    }

    override var acceptsFirstResponder: Bool { true }

    override func keyDown(with event: NSEvent) {
        guard isRecording else { return super.keyDown(with: event) }

        if event.keyCode == UInt16(kVK_Escape) {
            isRecording = false
            return
        }
        if event.keyCode == UInt16(kVK_Delete) {
            isRecording = false
            spec = .none
            onRecord?(.none)
            return
        }

        let modifiers = HotkeyManager.carbonModifiers(from: event.modifierFlags)
        guard modifiers != 0 else {
            NSSound.beep()   // a global hotkey without modifiers would swallow normal typing
            return
        }
        let recorded = HotkeySpec(keyCode: UInt32(event.keyCode), modifiers: modifiers)
        isRecording = false
        spec = recorded
        onRecord?(recorded)
    }

    override func resignFirstResponder() -> Bool {
        isRecording = false
        return super.resignFirstResponder()
    }
}

struct HotkeyRecorder: NSViewRepresentable {
    let action: HotkeyAction

    func makeNSView(context: Context) -> HotkeyRecorderControl {
        let control = HotkeyRecorderControl()
        control.spec = HotkeyBindings.shared.spec(for: action)
        control.onRecord = { spec in
            HotkeyBindings.shared.set(spec, for: action)
        }
        return control
    }

    func updateNSView(_ nsView: HotkeyRecorderControl, context: Context) {
        nsView.spec = HotkeyBindings.shared.spec(for: action)
    }
}