import Cocoa

enum SidebarDestination: Int, CaseIterable {
    case home
    case scan
    case scanAndHome
    case settings
}

final class SidebarView: NSView {
    var onDestinationSelected: ((SidebarDestination) -> Void)?

    private var navItems: [SidebarNavItem] = []

    init() {
        super.init(frame: .zero)
        wantsLayer = true
        layer?.backgroundColor = AppTheme.sidebarBackground.cgColor
        translatesAutoresizingMaskIntoConstraints = false
        setup()
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) { nil }

    func select(_ destination: SidebarDestination) {
        for (index, item) in navItems.enumerated() {
            item.isSelected = index == destination.rawValue
        }
    }

    private func setup() {
        let logoContainer = NSView()
        logoContainer.translatesAutoresizingMaskIntoConstraints = false

        let logoIcon = NSImageView()
        logoIcon.translatesAutoresizingMaskIntoConstraints = false
        if let image = NSImage(systemSymbolName: "printer.fill", accessibilityDescription: "Smart Printer") {
            let config = NSImage.SymbolConfiguration(pointSize: 28, weight: .medium)
            logoIcon.image = image.withSymbolConfiguration(config)
        }
        logoIcon.contentTintColor = AppTheme.purple

        let appNameLabel = NSTextField(labelWithString: "Smart Printer")
        appNameLabel.font = AppTheme.semiboldFont(size: 15)
        appNameLabel.textColor = AppTheme.textPrimary
        appNameLabel.alignment = .center
        appNameLabel.translatesAutoresizingMaskIntoConstraints = false

        let navStack = NSStackView()
        navStack.orientation = .vertical
        navStack.spacing = 4
        navStack.alignment = .leading
        navStack.translatesAutoresizingMaskIntoConstraints = false

        let bottomNavStack = NSStackView()
        bottomNavStack.orientation = .vertical
        bottomNavStack.spacing = 4
        bottomNavStack.alignment = .leading
        bottomNavStack.translatesAutoresizingMaskIntoConstraints = false

        let homeItem = SidebarNavItem(title: "Home", symbolName: "house.fill", isSelected: true)
        let scanItem = SidebarNavItem(title: "Scan", symbolName: "viewfinder")
        let scanAndHomeItem = SidebarNavItem(title: "Premium", symbolName: "diamond.fill", accent: .premium)
        let settingsItem = SidebarNavItem(title: "Settings", symbolName: "gearshape")

        let mainNavItems = [homeItem, scanItem, scanAndHomeItem]
        navItems = mainNavItems + [settingsItem]

        for (index, item) in navItems.enumerated() {
            item.onClick = { [weak self] in
                guard let self, let destination = SidebarDestination(rawValue: index) else { return }
                self.select(destination)
                self.onDestinationSelected?(destination)
            }
        }

        for item in mainNavItems {
            navStack.addArrangedSubview(item)
        }
        bottomNavStack.addArrangedSubview(settingsItem)

        addSubview(logoContainer)
        logoContainer.addSubview(logoIcon)
        addSubview(appNameLabel)
        addSubview(navStack)
        addSubview(bottomNavStack)

        let divider = NSBox()
        divider.boxType = .separator
        divider.translatesAutoresizingMaskIntoConstraints = false
        addSubview(divider)

        NSLayoutConstraint.activate([
            widthAnchor.constraint(equalToConstant: AppTheme.sidebarWidth),

            logoContainer.topAnchor.constraint(equalTo: topAnchor, constant: 52),
            logoContainer.centerXAnchor.constraint(equalTo: centerXAnchor),
            logoContainer.widthAnchor.constraint(equalToConstant: 48),
            logoContainer.heightAnchor.constraint(equalToConstant: 48),

            logoIcon.centerXAnchor.constraint(equalTo: logoContainer.centerXAnchor),
            logoIcon.centerYAnchor.constraint(equalTo: logoContainer.centerYAnchor),
            logoIcon.widthAnchor.constraint(equalToConstant: 36),
            logoIcon.heightAnchor.constraint(equalToConstant: 36),

            appNameLabel.topAnchor.constraint(equalTo: logoContainer.bottomAnchor, constant: 8),
            appNameLabel.centerXAnchor.constraint(equalTo: centerXAnchor),

            navStack.topAnchor.constraint(equalTo: appNameLabel.bottomAnchor, constant: 32),
            navStack.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 12),
            navStack.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -12),

            bottomNavStack.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 12),
            bottomNavStack.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -12),
            bottomNavStack.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -24),

            homeItem.widthAnchor.constraint(equalTo: navStack.widthAnchor),
            scanItem.widthAnchor.constraint(equalTo: navStack.widthAnchor),
            scanAndHomeItem.widthAnchor.constraint(equalTo: navStack.widthAnchor),
            settingsItem.widthAnchor.constraint(equalTo: bottomNavStack.widthAnchor),

            divider.trailingAnchor.constraint(equalTo: trailingAnchor),
            divider.topAnchor.constraint(equalTo: topAnchor),
            divider.bottomAnchor.constraint(equalTo: bottomAnchor),
            divider.widthAnchor.constraint(equalToConstant: 1),
        ])
    }
}