import AppKit
import SwiftUI
import Combine

@MainActor
public class StatusBarController: NSObject, NSPopoverDelegate {
    private var statusItem: NSStatusItem
    private var popover: NSPopover
    private var store: UsageStore
    private var cancellables = Set<AnyCancellable>()
    private var contextMenu: NSMenu!
    private var hostingController: NSHostingController<PopoverContentView>?
    private var lastCloseTime: Date?

    public init(store: UsageStore) {
        self.store = store
        self.statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.variableLength)
        self.popover = NSPopover()
        super.init()

        setupPopover()
        setupContextMenu()
        setupStatusItem()
        bindStore()
    }

    private func setupPopover() {
        popover.behavior = .transient
        popover.animates = true
        popover.appearance = NSAppearance(named: .darkAqua)
        popover.delegate = self
    }

    public func popoverDidClose(_ notification: Notification) {
        lastCloseTime = Date()
        popover.contentViewController = nil
        hostingController = nil
    }

    private func setupContextMenu() {
        contextMenu = NSMenu()

        let refreshItem = NSMenuItem(title: "Refresh Now", action: #selector(menuRefresh), keyEquivalent: "r")
        refreshItem.target = self
        contextMenu.addItem(refreshItem)

        let openConfigItem = NSMenuItem(title: "Open config.json", action: #selector(menuOpenConfig), keyEquivalent: "c")
        openConfigItem.target = self
        contextMenu.addItem(openConfigItem)

        let openAuthItem = NSMenuItem(title: "Open auth.json", action: #selector(menuOpenAuth), keyEquivalent: "o")
        openAuthItem.target = self
        contextMenu.addItem(openAuthItem)

        contextMenu.addItem(NSMenuItem.separator())

        let quitItem = NSMenuItem(title: "Quit UsageTray", action: #selector(menuQuit), keyEquivalent: "q")
        quitItem.target = self
        contextMenu.addItem(quitItem)
    }

    private func setupStatusItem() {
        guard let button = statusItem.button else { return }

        let config = NSImage.SymbolConfiguration(pointSize: 13, weight: .medium)
        if let image = NSImage(systemSymbolName: "gauge.open.with.lines.needle.33percent", accessibilityDescription: "Usage")?.withSymbolConfiguration(config) {
            image.isTemplate = true
            button.image = image
        }

        if let font = NSFont(name: "Comic Mono", size: 12) {
            button.font = font
        }

        button.imagePosition = .imageLeading
        button.action = #selector(handleClick(_:))
        button.target = self
        button.sendAction(on: [.leftMouseUp, .rightMouseUp])
    }

    private func bindStore() {
        store.$harmonized
            .receive(on: DispatchQueue.main)
            .sink { [weak self] _ in
                guard let self = self else { return }
                self.statusItem.button?.title = self.store.statusItemTitle
            }
            .store(in: &cancellables)
    }

    @objc private func handleClick(_ sender: AnyObject?) {
        guard let button = statusItem.button else { return }
        let event = NSApp.currentEvent
        if event?.type == .rightMouseUp {
            contextMenu.popUp(positioning: nil, at: NSPoint(x: 0, y: button.bounds.height + 4), in: button)
        } else {
            togglePopover(sender)
        }
    }

    @objc public func togglePopover(_ sender: AnyObject?) {
        guard let button = statusItem.button else { return }

        if popover.isShown {
            popover.performClose(sender)
            return
        }

        if let lastClose = lastCloseTime, Date().timeIntervalSince(lastClose) < 0.25 {
            return
        }

        Task {
            await store.refresh(force: false)
        }
        let hc = NSHostingController(rootView: PopoverContentView(store: store))
        self.hostingController = hc
        popover.contentViewController = hc

        let v = hc.view
        v.layoutSubtreeIfNeeded()
        let fit = v.fittingSize
        popover.contentSize = NSSize(width: 360, height: max(320, fit.height))
        popover.show(relativeTo: button.bounds, of: button, preferredEdge: .minY)
        hc.view.window?.makeKey()
    }

    @objc private func menuRefresh() {
        Task {
            await store.refresh(force: true)
        }
    }

    @objc private func menuOpenConfig() {
        NSWorkspace.shared.open(AppConfig.configURL)
    }

    @objc private func menuOpenAuth() {
        NSWorkspace.shared.open(AuthStorage.authURL)
    }

    @objc private func menuQuit() {
        NSApplication.shared.terminate(nil)
    }
}