import AppKit
import SwiftUI

// MARK: - Theme Tokens

extension AppTheme {
    static let hoverAnimation: Animation = .easeOut(duration: 0.15)
    static let hoverPressScale: CGFloat = 0.98
    static let hoverLiftScale: CGFloat = 1.012
}

// MARK: - Button Styles

struct AppPlainButtonStyle: ButtonStyle {
    @State private var isHovered = false

    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .scaleEffect(
                configuration.isPressed ? AppTheme.hoverPressScale : (isHovered ? AppTheme.hoverLiftScale : 1)
            )
            .brightness(configuration.isPressed ? -0.04 : (isHovered ? 0.05 : 0))
            .animation(AppTheme.hoverAnimation, value: isHovered)
            .animation(AppTheme.hoverAnimation, value: configuration.isPressed)
            .onHover { isHovered = $0 }
            .hoverCursor()
    }
}

struct AppSecondaryButtonStyle: ButtonStyle {
    @State private var isHovered = false

    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .foregroundStyle(AppTheme.textSecondary)
            .padding(.horizontal, 12)
            .padding(.vertical, 8)
            .background(secondaryBackground(isPressed: configuration.isPressed))
            .clipShape(RoundedRectangle(cornerRadius: 8))
            .overlay(
                RoundedRectangle(cornerRadius: 8)
                    .stroke(
                        isHovered || configuration.isPressed
                            ? AppTheme.hoverBorder
                            : AppTheme.cardBorder,
                        lineWidth: 1
                    )
            )
            .scaleEffect(configuration.isPressed ? AppTheme.hoverPressScale : (isHovered ? AppTheme.hoverLiftScale : 1))
            .animation(AppTheme.hoverAnimation, value: isHovered)
            .animation(AppTheme.hoverAnimation, value: configuration.isPressed)
            .onHover { isHovered = $0 }
            .hoverCursor()
    }

    private func secondaryBackground(isPressed: Bool) -> Color {
        if isPressed {
            return AppTheme.cardBackground.opacity(0.55)
        }
        if isHovered {
            return AppTheme.cardBackground.opacity(0.85)
        }
        return AppTheme.cardBackground
    }
}

struct AppPrimaryButtonStyle: ButtonStyle {
    @State private var isHovered = false

    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .brightness(configuration.isPressed ? -0.08 : (isHovered ? 0.08 : 0))
            .scaleEffect(configuration.isPressed ? AppTheme.hoverPressScale : (isHovered ? AppTheme.hoverLiftScale : 1))
            .animation(AppTheme.hoverAnimation, value: isHovered)
            .animation(AppTheme.hoverAnimation, value: configuration.isPressed)
            .onHover { isHovered = $0 }
            .hoverCursor()
    }
}

struct AppTextLinkButtonStyle: ButtonStyle {
    @State private var isHovered = false

    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .foregroundStyle(isHovered ? AppTheme.textPrimary : AppTheme.textSecondary)
            .underline(isHovered || configuration.isPressed)
            .animation(AppTheme.hoverAnimation, value: isHovered)
            .animation(AppTheme.hoverAnimation, value: configuration.isPressed)
            .onHover { isHovered = $0 }
            .hoverCursor()
    }
}

// MARK: - View Modifiers

private struct HoverCursorModifier: ViewModifier {
    @State private var isHovered = false

    func body(content: Content) -> some View {
        content
            .onHover { hovering in
                isHovered = hovering
                if hovering {
                    NSCursor.pointingHand.push()
                } else {
                    NSCursor.pop()
                }
            }
    }
}

private struct HoverOverlayModifier: ViewModifier {
    let cornerRadius: CGFloat
    var isEnabled: Bool = true
    @State private var isHovered = false

    func body(content: Content) -> some View {
        content
            .overlay {
                if isEnabled && isHovered {
                    RoundedRectangle(cornerRadius: cornerRadius)
                        .fill(AppTheme.hoverFill)
                        .allowsHitTesting(false)
                }
            }
            .animation(AppTheme.hoverAnimation, value: isHovered)
            .onHover { isHovered = $0 }
    }
}

private struct HoverCardModifier: ViewModifier {
    let cornerRadius: CGFloat
    var isSelected: Bool = false
    var isEnabled: Bool = true
    @State private var isHovered = false

    func body(content: Content) -> some View {
        content
            .overlay {
                if isEnabled && isHovered {
                    RoundedRectangle(cornerRadius: cornerRadius)
                        .fill(isSelected ? AppTheme.selectedRowFill : AppTheme.hoverFill)
                        .allowsHitTesting(false)
                }
            }
            .overlay {
                if isEnabled && isHovered {
                    RoundedRectangle(cornerRadius: cornerRadius)
                        .stroke(AppTheme.hoverBorder, lineWidth: 1)
                        .allowsHitTesting(false)
                }
            }
            .scaleEffect(isEnabled && isHovered ? AppTheme.hoverLiftScale : 1)
            .animation(AppTheme.hoverAnimation, value: isHovered)
            .onHover { isHovered = $0 }
    }
}

private struct SidebarRowHoverModifier: ViewModifier {
    let isSelected: Bool
    let showsCardBackground: Bool
    let selectedBorderColor: Color
    @State private var isHovered = false

    func body(content: Content) -> some View {
        content
            .background(sidebarRowBackground)
            .animation(AppTheme.hoverAnimation, value: isHovered)
            .onHover { isHovered = $0 }
    }

    @ViewBuilder
    private var sidebarRowBackground: some View {
        if showsCardBackground && isSelected {
            RoundedRectangle(cornerRadius: AppTheme.cornerRadiusSmall)
                .fill(AppTheme.quickAccessBackground)
                .overlay(
                    RoundedRectangle(cornerRadius: AppTheme.cornerRadiusSmall)
                        .stroke(selectedBorderColor, lineWidth: 1)
                )
        } else if isSelected {
            RoundedRectangle(cornerRadius: AppTheme.cornerRadiusSmall)
                .fill(AppTheme.selectedRowFill)
        } else if isHovered {
            RoundedRectangle(cornerRadius: AppTheme.cornerRadiusSmall)
                .fill(AppTheme.hoverFill)
        }
    }
}

// MARK: - View Extensions

extension View {
    func hoverCursor(_ enabled: Bool = true) -> some View {
        modifier(HoverCursorEnabledModifier(enabled: enabled))
    }

    func hoverOverlay(cornerRadius: CGFloat, isEnabled: Bool = true) -> some View {
        modifier(HoverOverlayModifier(cornerRadius: cornerRadius, isEnabled: isEnabled))
    }

    func hoverCard(cornerRadius: CGFloat, isSelected: Bool = false, isEnabled: Bool = true) -> some View {
        modifier(HoverCardModifier(cornerRadius: cornerRadius, isSelected: isSelected, isEnabled: isEnabled))
    }

    func sidebarRowHover(
        isSelected: Bool,
        showsCardBackground: Bool = false,
        selectedBorderColor: Color = .clear
    ) -> some View {
        modifier(
            SidebarRowHoverModifier(
                isSelected: isSelected,
                showsCardBackground: showsCardBackground,
                selectedBorderColor: selectedBorderColor
            )
        )
    }
}

private struct HoverCursorEnabledModifier: ViewModifier {
    let enabled: Bool

    func body(content: Content) -> some View {
        if enabled {
            content.modifier(HoverCursorModifier())
        } else {
            content
        }
    }
}