import AppKit
import VoiceCatCore

final class ChannelEditSheet: NSViewController {

    var onComplete: ((ChannelEdit?) -> Void)?

    private let channels: [Channel]
    private var editing: ChannelEdit?

    private let nameField = NSTextField()
    private let topicField = NSTextField()
    private let parentPicker = NSPopUpButton()
    private let pwCheckbox = NSButton(checkboxWithTitle: "Password protected", target: nil, action: nil)
    private let pwField = NSSecureTextField()
    private let maxUsersField: NSTextField = {
        let f = NSTextField(); f.stringValue = "0"; return f
    }()
    private let sortOrderField: NSTextField = {
        let f = NSTextField(); f.stringValue = "0"; return f
    }()
    private let stereoCheckbox = NSButton(checkboxWithTitle: "Stereo", target: nil, action: nil)
    private let bitrateField: NSTextField = {
        let f = NSTextField(); f.stringValue = "64000"; return f
    }()
    private let fecCheckbox = NSButton(checkboxWithTitle: "FEC", target: nil, action: nil)
    private let dtxCheckbox = NSButton(checkboxWithTitle: "DTX", target: nil, action: nil)
    private let frameMsPicker = NSPopUpButton()

    init(channels: [Channel], editing: ChannelEdit?) {
        self.channels = channels
        self.editing = editing
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder: NSCoder) { fatalError() }

    override func loadView() {
        view = NSView(frame: NSRect(x: 0, y: 0, width: 440, height: 360))
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        buildUI()
        populateIfEditing()
    }

    private func buildUI() {
        let titleText = editing == nil ? "Create Channel" : "Edit Channel"
        let titleLabel = NSTextField(labelWithString: titleText)
        titleLabel.font = .boldSystemFont(ofSize: 13)

        nameField.placeholderString = "Channel name"
        nameField.setAccessibilityLabel("Channel name")
        topicField.placeholderString = "Topic (optional)"
        topicField.setAccessibilityLabel("Channel topic")

        parentPicker.addItem(withTitle: "(root)")
        parentPicker.menu?.items.last?.representedObject = nil as UInt32?
        for ch in channels.sorted(by: { $0.name < $1.name }) {
            let item = NSMenuItem(title: ch.name, action: nil, keyEquivalent: "")
            item.representedObject = ch.id
            parentPicker.menu?.addItem(item)
        }
        parentPicker.setAccessibilityLabel("Parent channel")

        pwCheckbox.target = self; pwCheckbox.action = #selector(pwToggled)
        pwField.placeholderString = "password (leave blank to keep existing)"
        pwField.setAccessibilityLabel("Channel password")
        pwField.isEnabled = false

        maxUsersField.setAccessibilityLabel("Max users (0 = unlimited)")
        sortOrderField.setAccessibilityLabel("Sort order")

        for ms in ["20", "40", "60"] { frameMsPicker.addItem(withTitle: "\(ms) ms") }
        frameMsPicker.setAccessibilityLabel("Opus frame duration")

        fecCheckbox.state = .on
        stereoCheckbox.setAccessibilityLabel("Stereo audio")
        bitrateField.setAccessibilityLabel("Bitrate in bits per second")
        fecCheckbox.setAccessibilityLabel("Forward error correction")
        dtxCheckbox.setAccessibilityLabel("Discontinuous transmission")

        let generalGrid = NSGridView(views: [
            [NSTextField(labelWithString: "Name:"), nameField],
            [NSTextField(labelWithString: "Topic:"), topicField],
            [NSTextField(labelWithString: "Parent:"), parentPicker],
            [pwCheckbox, pwField],
            [NSTextField(labelWithString: "Max users:"), maxUsersField],
            [NSTextField(labelWithString: "Sort order:"), sortOrderField],
        ])
        generalGrid.rowSpacing = 8; generalGrid.columnSpacing = 8
        generalGrid.column(at: 0).xPlacement = .trailing

        let audioGrid = NSGridView(views: [
            [NSTextField(labelWithString: "Bitrate:"), bitrateField],
            [NSTextField(labelWithString: "Frame:"), frameMsPicker],
            [stereoCheckbox, fecCheckbox],
            [dtxCheckbox, NSView()],
        ])
        audioGrid.rowSpacing = 8; audioGrid.columnSpacing = 8
        audioGrid.column(at: 0).xPlacement = .trailing

        let tabs = NSTabView()
        let generalTab = NSTabViewItem(identifier: "general")
        generalTab.label = "General"
        generalTab.view = generalGrid
        let audioTab = NSTabViewItem(identifier: "audio")
        audioTab.label = "Audio"
        audioTab.view = audioGrid
        tabs.addTabViewItem(generalTab)
        tabs.addTabViewItem(audioTab)

        let cancelButton = NSButton(title: "Cancel", target: self, action: #selector(cancelClicked))
        cancelButton.bezelStyle = .rounded
        let saveButton = NSButton(title: editing == nil ? "Create" : "Save",
                                  target: self, action: #selector(saveClicked))
        saveButton.bezelStyle = .rounded; saveButton.keyEquivalent = "\r"

        let buttonRow = NSStackView(views: [NSView(), cancelButton, saveButton])
        buttonRow.orientation = .horizontal; buttonRow.spacing = 8

        let stack = NSStackView(views: [titleLabel, tabs, buttonRow])
        stack.orientation = .vertical
        stack.spacing = 12
        stack.edgeInsets = NSEdgeInsets(top: 16, left: 16, bottom: 16, right: 16)
        stack.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(stack)
        NSLayoutConstraint.activate([
            stack.topAnchor.constraint(equalTo: view.topAnchor),
            stack.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            stack.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            stack.bottomAnchor.constraint(equalTo: view.bottomAnchor),
        ])
    }

    private func populateIfEditing() {
        guard let e = editing else { return }
        nameField.stringValue = e.name
        topicField.stringValue = e.topic
        if e.parentId != 0 {
            for item in parentPicker.itemArray where (item.representedObject as? UInt32) == e.parentId {
                parentPicker.select(item); break
            }
        }
        pwCheckbox.state = e.passwordProtected ? .on : .off
        pwField.isEnabled = e.passwordProtected
        maxUsersField.stringValue = "\(e.maxUsers)"
        sortOrderField.stringValue = "\(e.sortOrder)"
        stereoCheckbox.state = e.audio.stereo ? .on : .off
        bitrateField.stringValue = "\(e.audio.bitrateBps)"
        fecCheckbox.state = e.audio.fec ? .on : .off
        dtxCheckbox.state = e.audio.dtx ? .on : .off
        let frameStr = "\(e.audio.frameMs) ms"
        if let item = frameMsPicker.item(withTitle: frameStr) { frameMsPicker.select(item) }
    }

    @objc private func pwToggled() {
        pwField.isEnabled = pwCheckbox.state == .on
    }

    @objc private func saveClicked() {
        let name = nameField.stringValue.trimmingCharacters(in: .whitespaces)
        guard !name.isEmpty else { nameField.becomeFirstResponder(); return }

        let parentId = parentPicker.selectedItem?.representedObject as? UInt32 ?? 0
        let maxUsers = UInt32(maxUsersField.stringValue) ?? 0
        let sortOrder = UInt32(sortOrderField.stringValue) ?? 0
        let bitrate = UInt32(bitrateField.stringValue) ?? 64000
        let frameMsStr = frameMsPicker.titleOfSelectedItem?.replacingOccurrences(of: " ms", with: "") ?? "20"
        let frameMs = UInt32(frameMsStr) ?? 20

        let audio = AudioConfig(
            stereo: stereoCheckbox.state == .on,
            bitrateBps: bitrate,
            frameMs: frameMs,
            fec: fecCheckbox.state == .on,
            dtx: dtxCheckbox.state == .on
        )
        let pwProtected = pwCheckbox.state == .on
        let pw: String? = pwProtected ? (pwField.stringValue.isEmpty ? nil : pwField.stringValue) : nil

        let result = ChannelEdit(
            id: editing?.id ?? 0,
            parentId: parentId,
            name: name,
            topic: topicField.stringValue,
            passwordProtected: pwProtected,
            password: pw,
            maxUsers: maxUsers,
            sortOrder: sortOrder,
            audio: audio
        )
        dismiss(nil)
        onComplete?(result)
    }

    @objc private func cancelClicked() {
        dismiss(nil)
        onComplete?(nil)
    }
}