import Cocoa

class MainWindowController: NSWindowController {
    var tabManager = TabManager()
    var tabBar: NSStackView!
    var contentView: NSView!
    var historyPanel: HistorySearchPanel!
    var snippetPanel: SnippetPanel!
    var aiPanel: AIGeneratorPanel!
    var settingsWindow: SettingsWindowController!
    
    convenience init() {
        let window = NSWindow(
            contentRect: NSRect(x: 0, y: 0, width: 1000, height: 700),
            styleMask: [.titled, .closable, .miniaturizable, .resizable],
            backing: .buffered,
            defer: false
        )
        window.titlebarAppearsTransparent = false
        window.titleVisibility = .visible
        window.center()
        window.title = "Enhanced Terminal"
        window.isReleasedWhenClosed = false
        
        self.init(window: window)
        setupUI()
        setupPanels()
        setupNotifications()
        
        // Restore previous session or create new tab
        restoreSession()
        
        // Force window to show
        window.makeKeyAndOrderFront(nil)
        window.orderFrontRegardless()
        
        // Debug: Print tab bar info
        NSLog("Tab bar frame: \(tabBar.frame)")
        NSLog("Tab bar subviews: \(tabBar.arrangedSubviews.count)")
        NSLog("Window content view: \(window.contentView?.frame ?? .zero)")
    }
    
    private func restoreSession() {
        let savedSessions = tabManager.loadSession()
        
        if savedSessions.isEmpty {
            // No saved session, create default tab
            addNewTab()
        } else {
            // Restore saved tabs
            for sessionData in savedSessions {
                let session = tabManager.addTab(title: sessionData.title)
                session.title = sessionData.title // Override the auto-generated title
                session.setupTextView(frame: contentView.bounds)
                session.startShell()
            }
            
            // Restore current tab index
            let savedIndex = tabManager.getSavedCurrentIndex()
            updateTabBar()
            switchToTab(index: min(savedIndex, tabManager.tabs.count - 1))
        }
    }
    
    private func setupUI() {
        guard let window = window else { return }
        
        let mainContainer = NSView(frame: window.contentView!.bounds)
        mainContainer.autoresizingMask = [.width, .height]
        
        // Tab bar - positioned below the title bar
        let tabBarHeight: CGFloat = 28
        let topMargin: CGFloat = 10  // Space below title bar
        tabBar = NSStackView(frame: NSRect(x: 0, y: mainContainer.bounds.height - tabBarHeight - topMargin, width: mainContainer.bounds.width, height: tabBarHeight))
        tabBar.orientation = .horizontal
        tabBar.distribution = .fill
        tabBar.alignment = .centerY
        tabBar.spacing = 5
        tabBar.autoresizingMask = [.width, .minYMargin]
        tabBar.wantsLayer = true
        tabBar.layer?.backgroundColor = NSColor(white: 0.15, alpha: 1.0).cgColor  // Dark gray background
        tabBar.edgeInsets = NSEdgeInsets(top: 2, left: 10, bottom: 2, right: 10)
        
        NSLog("Creating tab bar at: \(tabBar.frame)")
        
        // Content view below tab bar
        contentView = NSView(frame: NSRect(x: 0, y: 0, width: mainContainer.bounds.width, height: mainContainer.bounds.height - tabBarHeight - topMargin))
        contentView.autoresizingMask = [.width, .height]
        contentView.wantsLayer = true
        contentView.layer?.backgroundColor = NSColor.black.cgColor
        
        NSLog("Creating content view at: \(contentView.frame)")
        
        mainContainer.addSubview(contentView)
        mainContainer.addSubview(tabBar)
        
        window.contentView = mainContainer
        
        NSLog("Main container bounds: \(mainContainer.bounds)")
        
        setupMenuBar()
    }
    
    private func setupPanels() {
        historyPanel = HistorySearchPanel()
        snippetPanel = SnippetPanel()
        aiPanel = AIGeneratorPanel()
        settingsWindow = SettingsWindowController()
    }
    
    private func setupNotifications() {
        NotificationCenter.default.addObserver(self, selector: #selector(themeChanged), name: NSNotification.Name("ThemeChanged"), object: nil)
    }
    
    @objc private func themeChanged() {
        tabManager.tabs.forEach { $0.applyTheme() }
    }
    
    private func setupMenuBar() {
        let mainMenu = NSMenu()
        
        // App menu
        let appMenuItem = NSMenuItem()
        mainMenu.addItem(appMenuItem)
        let appMenu = NSMenu()
        appMenuItem.submenu = appMenu
        
        appMenu.addItem(NSMenuItem(title: "About Enhanced Terminal", action: #selector(showAbout), keyEquivalent: ""))
        appMenu.addItem(NSMenuItem.separator())
        appMenu.addItem(NSMenuItem(title: "Settings...", action: #selector(openSettings), keyEquivalent: ","))
        appMenu.addItem(NSMenuItem.separator())
        appMenu.addItem(NSMenuItem(title: "Quit", action: #selector(NSApplication.terminate(_:)), keyEquivalent: "q"))
        
        // File menu
        let fileMenuItem = NSMenuItem(title: "File", action: nil, keyEquivalent: "")
        mainMenu.addItem(fileMenuItem)
        let fileMenu = NSMenu(title: "File")
        fileMenuItem.submenu = fileMenu
        
        fileMenu.addItem(NSMenuItem(title: "New Tab", action: #selector(addNewTab), keyEquivalent: "t"))
        fileMenu.addItem(NSMenuItem(title: "Close Tab", action: #selector(closeCurrentTab), keyEquivalent: "w"))
        fileMenu.addItem(NSMenuItem.separator())
        fileMenu.addItem(NSMenuItem(title: "Clear Screen", action: #selector(clearScreen), keyEquivalent: "k"))
        fileMenu.addItem(NSMenuItem(title: "Clear Scrollback", action: #selector(clearScrollback), keyEquivalent: "K"))
        
        // Edit menu
        let editMenuItem = NSMenuItem(title: "Edit", action: nil, keyEquivalent: "")
        mainMenu.addItem(editMenuItem)
        let editMenu = NSMenu(title: "Edit")
        editMenuItem.submenu = editMenu
        
        editMenu.addItem(NSMenuItem(title: "Copy", action: #selector(NSText.copy(_:)), keyEquivalent: "c"))
        editMenu.addItem(NSMenuItem(title: "Paste", action: #selector(NSText.paste(_:)), keyEquivalent: "v"))
        editMenu.addItem(NSMenuItem(title: "Select All", action: #selector(NSText.selectAll(_:)), keyEquivalent: "a"))
        editMenu.addItem(NSMenuItem.separator())
        editMenu.addItem(NSMenuItem(title: "Find...", action: #selector(showFindPanel), keyEquivalent: "f"))
        editMenu.addItem(NSMenuItem.separator())
        
        let searchHistoryItem = NSMenuItem(title: "Search History", action: #selector(searchHistory), keyEquivalent: "r")
        searchHistoryItem.keyEquivalentModifierMask = [.command]
        editMenu.addItem(searchHistoryItem)
        
        // View menu
        let viewMenuItem = NSMenuItem(title: "View", action: nil, keyEquivalent: "")
        mainMenu.addItem(viewMenuItem)
        let viewMenu = NSMenu(title: "View")
        viewMenuItem.submenu = viewMenu
        
        viewMenu.addItem(NSMenuItem(title: "Toggle Fullscreen", action: #selector(NSWindow.toggleFullScreen(_:)), keyEquivalent: "f"))
        viewMenu.addItem(NSMenuItem.separator())
        viewMenu.addItem(NSMenuItem(title: "Increase Font Size", action: #selector(increaseFontSize), keyEquivalent: "+"))
        viewMenu.addItem(NSMenuItem(title: "Decrease Font Size", action: #selector(decreaseFontSize), keyEquivalent: "-"))
        viewMenu.addItem(NSMenuItem(title: "Reset Font Size", action: #selector(resetFontSize), keyEquivalent: "0"))
        
        // Tools menu
        let toolsMenuItem = NSMenuItem(title: "Tools", action: nil, keyEquivalent: "")
        mainMenu.addItem(toolsMenuItem)
        let toolsMenu = NSMenu(title: "Tools")
        toolsMenuItem.submenu = toolsMenu
        
        toolsMenu.addItem(NSMenuItem(title: "AI Command Generator", action: #selector(showAIGenerator), keyEquivalent: "k"))
        toolsMenu.addItem(NSMenuItem(title: "Command Snippets", action: #selector(showSnippets), keyEquivalent: "p"))
        toolsMenu.addItem(NSMenuItem.separator())
        toolsMenu.addItem(NSMenuItem(title: "Clear History", action: #selector(clearHistory), keyEquivalent: ""))
        
        // Window menu
        let windowMenuItem = NSMenuItem(title: "Window", action: nil, keyEquivalent: "")
        mainMenu.addItem(windowMenuItem)
        let windowMenu = NSMenu(title: "Window")
        windowMenuItem.submenu = windowMenu
        
        windowMenu.addItem(NSMenuItem(title: "Minimize", action: #selector(NSWindow.miniaturize(_:)), keyEquivalent: "m"))
        windowMenu.addItem(NSMenuItem(title: "Zoom", action: #selector(NSWindow.zoom(_:)), keyEquivalent: ""))
        
        NSApp.mainMenu = mainMenu
    }
    
    @objc func addNewTab() {
        let session = tabManager.addTab()
        session.setupTextView(frame: contentView.bounds)
        session.startShell()
        
        updateTabBar()
        switchToTab(index: tabManager.tabs.count - 1)
    }
    
    @objc func closeCurrentTab() {
        guard tabManager.tabs.count > 1 else {
            // If it's the last tab, quit the app
            NSApp.terminate(nil)
            return
        }
        
        let alert = NSAlert()
        alert.messageText = "Close Tab?"
        alert.informativeText = "Are you sure you want to close this terminal session?"
        alert.addButton(withTitle: "Close")
        alert.addButton(withTitle: "Cancel")
        alert.alertStyle = .warning
        
        if alert.runModal() == .alertFirstButtonReturn {
            tabManager.removeTab(at: tabManager.currentIndex)
            updateTabBar()
            switchToTab(index: min(tabManager.currentIndex, tabManager.tabs.count - 1))
        }
    }
    
    private func updateTabBar() {
        // Remove all existing views
        tabBar.arrangedSubviews.forEach { $0.removeFromSuperview() }
        
        // Add tab buttons
        for (index, session) in tabManager.tabs.enumerated() {
            // Create container for tab button and close button
            let tabContainer = NSView()
            tabContainer.wantsLayer = true
            tabContainer.translatesAutoresizingMaskIntoConstraints = false
            
            // Tab button
            let tabButton = NSButton()
            tabButton.title = session.title
            tabButton.bezelStyle = .rounded
            tabButton.tag = index
            tabButton.target = self
            tabButton.action = #selector(tabClicked(_:))
            tabButton.font = NSFont.systemFont(ofSize: 11)
            tabButton.translatesAutoresizingMaskIntoConstraints = false
            
            // Add double-click for rename
            let doubleClickGesture = NSClickGestureRecognizer(target: self, action: #selector(tabDoubleClicked(_:)))
            doubleClickGesture.numberOfClicksRequired = 2
            tabButton.addGestureRecognizer(doubleClickGesture)
            
            // Highlight current tab
            if index == tabManager.currentIndex {
                tabButton.contentTintColor = .systemBlue
                tabButton.isBordered = true
            } else {
                tabButton.contentTintColor = .systemGray
                tabButton.isBordered = false
            }
            
            // Close button (X)
            let closeButton = NSButton()
            closeButton.title = "×"
            closeButton.bezelStyle = .rounded
            closeButton.tag = index
            closeButton.target = self
            closeButton.action = #selector(closeTabAtIndex(_:))
            closeButton.font = NSFont.systemFont(ofSize: 13, weight: .bold)
            closeButton.translatesAutoresizingMaskIntoConstraints = false
            
            tabContainer.addSubview(tabButton)
            tabContainer.addSubview(closeButton)
            
            // Layout constraints
            NSLayoutConstraint.activate([
                tabButton.leadingAnchor.constraint(equalTo: tabContainer.leadingAnchor),
                tabButton.centerYAnchor.constraint(equalTo: tabContainer.centerYAnchor),
                tabButton.widthAnchor.constraint(equalToConstant: 60),
                tabButton.heightAnchor.constraint(equalToConstant: 20),
                
                closeButton.leadingAnchor.constraint(equalTo: tabButton.trailingAnchor, constant: 2),
                closeButton.centerYAnchor.constraint(equalTo: tabContainer.centerYAnchor),
                closeButton.widthAnchor.constraint(equalToConstant: 18),
                closeButton.heightAnchor.constraint(equalToConstant: 20),
                closeButton.trailingAnchor.constraint(equalTo: tabContainer.trailingAnchor),
                
                tabContainer.heightAnchor.constraint(equalToConstant: 20)
            ])
            
            // Prevent container from stretching
            tabContainer.setContentHuggingPriority(.init(1000), for: .horizontal)
            tabContainer.setContentCompressionResistancePriority(.init(1000), for: .horizontal)
            
            tabBar.addArrangedSubview(tabContainer)
        }
        
        // Add new tab button
        let newTabButton = NSButton()
        newTabButton.title = "+"
        newTabButton.bezelStyle = .rounded
        newTabButton.target = self
        newTabButton.action = #selector(addNewTab)
        newTabButton.font = NSFont.systemFont(ofSize: 13)
        newTabButton.translatesAutoresizingMaskIntoConstraints = false
        newTabButton.setContentHuggingPriority(.init(1000), for: .horizontal)
        
        NSLayoutConstraint.activate([
            newTabButton.widthAnchor.constraint(equalToConstant: 22),
            newTabButton.heightAnchor.constraint(equalToConstant: 20)
        ])
        
        tabBar.addArrangedSubview(newTabButton)
        
        // Add spacer at the end to push everything to the left
        let spacer = NSView()
        spacer.setContentHuggingPriority(.init(1), for: .horizontal)
        tabBar.addArrangedSubview(spacer)
        
        // Force layout update
        tabBar.needsLayout = true
        tabBar.layoutSubtreeIfNeeded()
    }
    
    @objc func closeTabAtIndex(_ sender: NSButton) {
        let index = sender.tag
        
        // Don't close if it's the last tab
        guard tabManager.tabs.count > 1 else {
            NSApp.terminate(nil)
            return
        }
        
        // Confirm if there's content
        let alert = NSAlert()
        alert.messageText = "Close Tab?"
        alert.informativeText = "Are you sure you want to close this tab?"
        alert.addButton(withTitle: "Close")
        alert.addButton(withTitle: "Cancel")
        alert.alertStyle = .warning
        
        if alert.runModal() == .alertFirstButtonReturn {
            tabManager.removeTab(at: index)
            
            // Switch to previous tab or first tab
            let newIndex = min(index, tabManager.tabs.count - 1)
            switchToTab(index: newIndex)
        }
    }
    
    @objc func tabClicked(_ sender: NSButton) {
        switchToTab(index: sender.tag)
    }
    
    @objc func tabDoubleClicked(_ sender: NSClickGestureRecognizer) {
        guard let button = sender.view as? NSButton else { return }
        let index = button.tag
        
        let alert = NSAlert()
        alert.messageText = "Rename Tab"
        alert.informativeText = "Enter a new name for this tab:"
        
        let textField = NSTextField(frame: NSRect(x: 0, y: 0, width: 200, height: 24))
        textField.stringValue = tabManager.tabs[index].title
        textField.placeholderString = "Tab name"
        
        alert.accessoryView = textField
        alert.addButton(withTitle: "Rename")
        alert.addButton(withTitle: "Cancel")
        
        alert.window.initialFirstResponder = textField
        
        if alert.runModal() == .alertFirstButtonReturn {
            let newName = textField.stringValue.trimmingCharacters(in: .whitespacesAndNewlines)
            if !newName.isEmpty {
                tabManager.tabs[index].title = newName
                updateTabBar()
                tabManager.saveSession()
            }
        }
    }
    
    private func switchToTab(index: Int) {
        guard index < tabManager.tabs.count else { return }
        
        // Remove current view from content view (but don't destroy it)
        contentView.subviews.forEach { $0.removeFromSuperview() }
        
        // Select the new tab
        tabManager.selectTab(at: index)
        tabManager.saveSession()
        
        // Add the selected tab's scroll view to content view
        if let session = tabManager.getCurrentSession() {
            session.scrollView.frame = contentView.bounds
            session.scrollView.autoresizingMask = [.width, .height]
            contentView.addSubview(session.scrollView)
            
            // Make the text view first responder
            window?.makeFirstResponder(session.textView)
        }
        
        updateTabBar()
    }
    
    @objc func searchHistory() {
        guard let window = window else { return }
        historyPanel.show(relativeTo: window) { [weak self] command in
            if let command = command, let session = self?.tabManager.getCurrentSession() {
                session.insertCommand(command)
            }
        }
    }
    
    @objc func showSnippets() {
        guard let window = window else { return }
        snippetPanel.show(relativeTo: window) { [weak self] snippet in
            if let snippet = snippet, let session = self?.tabManager.getCurrentSession() {
                session.insertCommand(snippet.command)
            }
        }
    }
    
    @objc func showAIGenerator() {
        guard AIManager.shared.isAvailable() else {
            let alert = NSAlert()
            alert.messageText = "AI Not Configured"
            alert.informativeText = "Please configure an AI provider in Settings (Cmd+,) first.\n\nYou can use:\n• OpenAI (requires API key)\n• Ollama (free, local)"
            alert.alertStyle = .informational
            alert.addButton(withTitle: "Open Settings")
            alert.addButton(withTitle: "Cancel")
            
            if alert.runModal() == .alertFirstButtonReturn {
                openSettings()
            }
            return
        }
        
        guard let window = window else { return }
        aiPanel.show(relativeTo: window) { [weak self] command in
            if let command = command, let session = self?.tabManager.getCurrentSession() {
                session.insertCommand(command)
            }
        }
    }
    
    @objc func openSettings() {
        settingsWindow.showWindow(nil)
    }
    
    @objc func clearScreen() {
        if let session = tabManager.getCurrentSession() {
            session.textView.string = ""
            session.showPrompt()
        }
    }
    
    @objc func clearScrollback() {
        if let session = tabManager.getCurrentSession() {
            let alert = NSAlert()
            alert.messageText = "Clear Scrollback?"
            alert.informativeText = "This will clear all terminal output history."
            alert.addButton(withTitle: "Clear")
            alert.addButton(withTitle: "Cancel")
            alert.alertStyle = .warning
            
            if alert.runModal() == .alertFirstButtonReturn {
                session.textView.string = ""
                session.showPrompt()
            }
        }
    }
    
    @objc func showFindPanel() {
        if let session = tabManager.getCurrentSession() {
            session.textView.performTextFinderAction(nil)
        }
    }
    
    @objc func clearHistory() {
        let alert = NSAlert()
        alert.messageText = "Clear Command History?"
        alert.informativeText = "This will permanently delete all command history."
        alert.addButton(withTitle: "Clear")
        alert.addButton(withTitle: "Cancel")
        alert.alertStyle = .warning
        
        if alert.runModal() == .alertFirstButtonReturn {
            HistoryManager.shared.clearHistory()
        }
    }
    
    @objc func increaseFontSize() {
        TerminalSettings.shared.fontSize += 1
        tabManager.tabs.forEach { $0.applyTheme() }
    }
    
    @objc func decreaseFontSize() {
        TerminalSettings.shared.fontSize = max(8, TerminalSettings.shared.fontSize - 1)
        tabManager.tabs.forEach { $0.applyTheme() }
    }
    
    @objc func resetFontSize() {
        TerminalSettings.shared.fontSize = 14
        tabManager.tabs.forEach { $0.applyTheme() }
    }
    
    @objc func showAbout() {
        let alert = NSAlert()
        alert.messageText = "Enhanced Terminal v3.0"
        alert.informativeText = """
        A feature-rich macOS terminal emulator
        
        Features:
        • Multiple tabs
        • Command history search (Cmd+R)
        • Auto-suggestions
        • AI command generation
        • Command snippets
        • Multiple themes
        • Customizable settings
        
        Built with Swift and Cocoa
        """
        alert.alertStyle = .informational
        alert.addButton(withTitle: "OK")
        alert.runModal()
    }
    
    deinit {
        NotificationCenter.default.removeObserver(self)
    }
}