import AppKit
import ConjureKit

@MainActor
final class ApplicationActionsController: NSViewController, NSSearchFieldDelegate, NSPopoverDelegate {
    private let popover = NSPopover()
    private let search = ActionsSearchField()
    private let action = NSButton(title: "Uninstall application", target: nil, action: nil)
    private let empty = NSTextField(labelWithString: "No matching actions")
    private let applicationLabel = NSTextField(labelWithString: "")
    var uninstall: (() -> Void)?
    var closed: (() -> Void)?
    var isShown: Bool { popover.isShown }

    init() {
        super.init(nibName: nil, bundle: nil)
        popover.contentViewController = self
        popover.behavior = .semitransient
        popover.delegate = self
    }

    required init?(coder: NSCoder) { fatalError("Conjure creates actions programmatically") }

    override func loadView() {
        let content = NSVisualEffectView()
        content.material = .popover
        content.state = .active
        content.appearance = NSAppearance(named: .darkAqua)
        view = content
        preferredContentSize = NSSize(width: 340, height: 150)
        applicationLabel.textColor = SunsetPalette.secondaryText
        applicationLabel.lineBreakMode = .byTruncatingTail
        applicationLabel.font = .systemFont(ofSize: 12, weight: .medium)
        action.isBordered = false
        action.alignment = .left
        action.font = .systemFont(ofSize: 16, weight: .medium)
        action.contentTintColor = .systemRed
        action.attributedTitle = NSAttributedString(string: action.title, attributes: [
            .foregroundColor: NSColor.systemRed, .font: NSFont.systemFont(ofSize: 16, weight: .medium)
        ])
        action.image = NSImage(systemSymbolName: "trash", accessibilityDescription: nil)
        action.imagePosition = .imageLeading
        action.target = self
        action.action = #selector(chooseAction)
        action.setAccessibilityLabel("Uninstall application")
        search.placeholderString = "Search actions…"
        search.delegate = self
        search.sendsSearchStringImmediately = true
        search.setAccessibilityLabel("Search application actions")
        search.closeActions = { [weak self] in self?.close() }
        empty.textColor = SunsetPalette.secondaryText
        empty.isHidden = true
        let stack = NSStackView(views: [applicationLabel, action, empty, search])
        stack.orientation = .vertical
        stack.alignment = .leading
        stack.spacing = 12
        stack.translatesAutoresizingMaskIntoConstraints = false
        content.addSubview(stack)
        NSLayoutConstraint.activate([
            stack.leadingAnchor.constraint(equalTo: content.leadingAnchor, constant: 16),
            stack.trailingAnchor.constraint(equalTo: content.trailingAnchor, constant: -16),
            stack.topAnchor.constraint(equalTo: content.topAnchor, constant: 14),
            search.widthAnchor.constraint(equalTo: stack.widthAnchor),
            action.widthAnchor.constraint(equalTo: stack.widthAnchor),
            applicationLabel.widthAnchor.constraint(equalTo: stack.widthAnchor)
        ])
    }

    func show(for application: Application, relativeTo anchor: NSView) {
        if isShown { close(); return }
        _ = view
        applicationLabel.stringValue = application.name
        search.stringValue = ""
        controlTextDidChange(Notification(name: NSControl.textDidChangeNotification))
        popover.show(relativeTo: anchor.bounds, of: anchor, preferredEdge: .maxY)
        view.window?.makeFirstResponder(search)
    }

    func close() { popover.performClose(nil) }

    func popoverDidClose(_ notification: Notification) { closed?() }

    func controlTextDidChange(_ notification: Notification) {
        let query = search.stringValue.trimmingCharacters(in: .whitespacesAndNewlines)
        let matches = query.isEmpty || action.title.range(of: query, options: [.caseInsensitive, .diacriticInsensitive]) != nil
        action.isHidden = !matches
        empty.isHidden = matches
    }

    func control(_ control: NSControl, textView: NSTextView, doCommandBy selector: Selector) -> Bool {
        switch selector {
        case #selector(NSResponder.insertNewline(_:)):
            if !action.isHidden { chooseAction() }
        case #selector(NSResponder.cancelOperation(_:)):
            close()
        case #selector(NSResponder.moveUp(_:)), #selector(NSResponder.moveDown(_:)):
            return true // There is currently one contextual action.
        default: return false
        }
        return true
    }

    @objc private func chooseAction() {
        close()
        uninstall?()
    }
}

@MainActor
private final class ActionsSearchField: NSSearchField {
    var closeActions: (() -> Void)?

    override func performKeyEquivalent(with event: NSEvent) -> Bool {
        if event.modifierFlags.intersection([.command, .control, .option, .shift]) == .command,
           event.charactersIgnoringModifiers?.lowercased() == "k" {
            closeActions?()
            return true
        }
        return super.performKeyEquivalent(with: event)
    }
}