import AppKit
import ApplicationServices

/// Bridge to macOS Accessibility APIs for window activation and title retrieval.
enum AccessibilityBridge {
    /// Check if we have Accessibility permission.
    static var hasPermission: Bool {
        AXIsProcessTrusted()
    }

    /// Prompt the user to grant Accessibility permission if not already granted.
    static func requestPermissionIfNeeded() {
        let options = [kAXTrustedCheckOptionPrompt.takeUnretainedValue(): true] as CFDictionary
        AXIsProcessTrustedWithOptions(options)
    }

    /// Activate the window with the given window ID and PID.
    static func activateWindow(pid: pid_t, windowID: CGWindowID) -> Bool {
        guard let app = NSRunningApplication(processIdentifier: pid) else { return false }

        // Activate the application
        app.activate()

        // Use Accessibility to raise the specific window
        let appElement = AXUIElementCreateApplication(pid)
        var windowsRef: CFTypeRef?
        let result = AXUIElementCopyAttributeValue(appElement, kAXWindowsAttribute as CFString, &windowsRef)
        guard result == .success, let axWindows = windowsRef as? [AXUIElement] else {
            return true // App activated but couldn't raise specific window
        }

        for axWindow in axWindows {
            if let cgWindowID = axWindowID(for: axWindow), cgWindowID == windowID {
                AXUIElementPerformAction(axWindow, kAXRaiseAction as CFString)
                return true
            }
        }

        return true
    }

    /// Get the title of a window via Accessibility (fallback when CGWindowList doesn't have it).
    static func windowTitle(pid: pid_t, windowID: CGWindowID) -> String? {
        let appElement = AXUIElementCreateApplication(pid)
        var windowsRef: CFTypeRef?
        let result = AXUIElementCopyAttributeValue(appElement, kAXWindowsAttribute as CFString, &windowsRef)
        guard result == .success, let axWindows = windowsRef as? [AXUIElement] else {
            return nil
        }

        for axWindow in axWindows {
            if let cgWinID = axWindowID(for: axWindow), cgWinID == windowID {
                var titleRef: CFTypeRef?
                let titleResult = AXUIElementCopyAttributeValue(axWindow, kAXTitleAttribute as CFString, &titleRef)
                if titleResult == .success, let title = titleRef as? String {
                    return title
                }
            }
        }
        return nil
    }

    /// Move a window to a new position using AXUIElement.
    /// The point should be in Quartz coordinates (top-left origin).
    static func moveWindow(pid: pid_t, windowID: CGWindowID, to point: CGPoint) -> Bool {
        let appElement = AXUIElementCreateApplication(pid)
        var windowsRef: CFTypeRef?
        let result = AXUIElementCopyAttributeValue(appElement, kAXWindowsAttribute as CFString, &windowsRef)
        guard result == .success, let axWindows = windowsRef as? [AXUIElement] else {
            return false
        }

        for axWindow in axWindows {
            if let cgWinID = axWindowID(for: axWindow), cgWinID == windowID {
                var position = point
                guard let axValue = AXValueCreate(.cgPoint, &position) else { return false }
                let setResult = AXUIElementSetAttributeValue(axWindow, kAXPositionAttribute as CFString, axValue)
                return setResult == .success
            }
        }
        return false
    }

    // MARK: - Private

    /// Map an AXUIElement to a CGWindowID using the private _AXUIElementGetWindow API.
    private static func axWindowID(for element: AXUIElement) -> CGWindowID? {
        var windowID: CGWindowID = 0
        let result = _AXUIElementGetWindow(element, &windowID)
        return result == .success ? windowID : nil
    }
}

// Private API declaration — widely used by AltTab, Rectangle, yabai, etc.
@_silgen_name("_AXUIElementGetWindow")
func _AXUIElementGetWindow(_ element: AXUIElement, _ windowID: UnsafeMutablePointer<CGWindowID>) -> AXError