import UIKit

public struct RDEPUBReaderTheme: Equatable {

    public var contentBackgroundColor: UIColor

    public var contentTextColor: UIColor

    public var toolBackgroundColor: UIColor

    public var toolControlTextColor: UIColor

    public var toolControlBorderUnselectColor: UIColor

    public var toolLineColor: UIColor

    public init(
        contentBackgroundColor: UIColor,
        contentTextColor: UIColor,
        toolBackgroundColor: UIColor,
        toolControlTextColor: UIColor,
        toolControlBorderUnselectColor: UIColor,
        toolLineColor: UIColor
    ) {
        self.contentBackgroundColor = contentBackgroundColor
        self.contentTextColor = contentTextColor
        self.toolBackgroundColor = toolBackgroundColor
        self.toolControlTextColor = toolControlTextColor
        self.toolControlBorderUnselectColor = toolControlBorderUnselectColor
        self.toolLineColor = toolLineColor
    }

    public static let light = preset(contentBackground: .white, text: .black)

    public static let dark = preset(contentBackground: .black, text: .white)

    public static let yellow = preset(
        contentBackground: UIColor(red: 0.89, green: 0.87, blue: 0.79, alpha: 1),
        text: .black
    )

    public static let green = preset(
        contentBackground: UIColor(red: 0.87, green: 0.91, blue: 0.82, alpha: 1),
        text: .black
    )

    public static let pink = preset(
        contentBackground: UIColor(red: 1, green: 0.89, blue: 0.91, alpha: 1),
        text: .black
    )

    public static let blue = preset(
        contentBackground: UIColor(red: 0.8, green: 0.84, blue: 0.89, alpha: 1),
        text: .black
    )

    /// 工具条/弹出页统一用比正文背景稍深的底色（暗色主题稍亮），拉开层次对比。
    private static func preset(contentBackground: UIColor, text: UIColor) -> RDEPUBReaderTheme {
        RDEPUBReaderTheme(
            contentBackgroundColor: contentBackground,
            contentTextColor: text,
            toolBackgroundColor: contentBackground.rd_chromeShade,
            toolControlTextColor: text,
            toolControlBorderUnselectColor: UIColor.lightGray.withAlphaComponent(0.5),
            toolLineColor: UIColor.lightGray.withAlphaComponent(0.5)
        )
    }
}

extension RDEPUBReaderTheme {

    /// Background color for the full-screen image viewer.
    /// Always near-black regardless of theme, since the image is the focus.
    var imageViewerBackgroundColor: UIColor {
        UIColor(white: 0.0, alpha: 0.95)
    }

    var themeBackgroundColorCSS: String {
        contentBackgroundColor.rd_cssString
    }

    var themeTextColorCSS: String {
        contentTextColor.rd_cssString
    }
}