import UIKit
import Runestone

// MARK: - Xcode Default Dark Theme

final class PadXcodeTheme: Theme {

    let fontSize: CGFloat
    init(fontSize: CGFloat = 14) { self.fontSize = fontSize }

    // MARK: Required visual properties

    var font: UIFont {
        UIFont.monospacedSystemFont(ofSize: fontSize, weight: .regular)
    }

    var textColor: UIColor {
        UIColor(r: 212, g: 212, b: 212)
    }

    var backgroundColor: UIColor {
        UIColor(r: 30, g: 30, b: 30)
    }

    var userInterfaceStyle: UIUserInterfaceStyle {
        .dark
    }

    var gutterBackgroundColor: UIColor {
        UIColor(r: 37, g: 37, b: 38)
    }

    var gutterHairlineColor: UIColor {
        UIColor(r: 60, g: 60, b: 60)
    }

    var lineNumberColor: UIColor {
        UIColor(r: 110, g: 118, b: 129)
    }

    var lineNumberFont: UIFont {
        UIFont.monospacedSystemFont(ofSize: 12, weight: .regular)
    }

    var selectedLineBackgroundColor: UIColor {
        UIColor(r: 42, g: 45, b: 46)
    }

    var selectedLinesLineNumberColor: UIColor {
        UIColor(r: 200, g: 200, b: 200)
    }

    var selectedLinesGutterBackgroundColor: UIColor {
        UIColor(r: 42, g: 45, b: 46)
    }

    var markedTextBackgroundColor: UIColor {
        UIColor(r: 38, g: 79, b: 120, alpha: 0.4)
    }

    var markedTextBackgroundCornerRadius: CGFloat {
        2
    }

    var invisibleCharactersColor: UIColor {
        UIColor(r: 64, g: 64, b: 64)
    }

    var pageGuideHairlineColor: UIColor {
        UIColor(r: 64, g: 64, b: 64)
    }

    var pageGuideBackgroundColor: UIColor {
        UIColor(r: 26, g: 26, b: 26)
    }

    // MARK: Syntax token colours (required by Theme protocol)

    func textColor(for highlightName: String) -> UIColor? {
        switch highlightName {
        case "keyword", "keyword.control", "keyword.operator",
             "keyword.other", "keyword.declaration", "storage.type",
             "storage.modifier":
            return UIColor(r: 255, g: 122, b: 178)   // pink

        case "type", "type.builtin", "entity.name.type",
             "entity.name.type.class", "entity.name.type.struct",
             "entity.name.type.enum", "entity.name.type.protocol":
            return UIColor(r: 218, g: 186, b: 255)   // lavender

        case "type.parameter":
            return UIColor(r: 107, g: 223, b: 255)   // light blue

        case "function", "entity.name.function",
             "meta.function-call", "function.method", "function.builtin":
            return UIColor(r: 103, g: 183, b: 251)   // blue

        case "property", "variable.other.property":
            return UIColor(r: 114, g: 185, b: 213)   // teal

        case "variable.builtin":
            return UIColor(r: 255, g: 122, b: 178)   // pink (self, super)

        case "constant", "constant.builtin":
            return UIColor(r: 217, g: 201, b: 124)   // gold bold

        case "constant.numeric", "number":
            return UIColor(r: 217, g: 201, b: 124)   // gold

        case "string", "string.special":
            return UIColor(r: 255, g: 129, b: 112)   // salmon

        case "string.escape":
            return UIColor(r: 255, g: 129, b: 112)   // salmon

        case "comment", "comment.line", "comment.block",
             "comment.block.documentation":
            return UIColor(r: 127, g: 140, b: 152)   // grey

        case "attribute":
            return UIColor(r: 191, g: 134, b: 200)   // purple

        case "operator", "punctuation.operator",
             "punctuation.bracket", "punctuation.delimiter":
            return UIColor(r: 212, g: 212, b: 212)   // default text

        default:
            return nil
        }
    }
}

// MARK: - Xcode Default Light Theme

final class PadXcodeLightTheme: Theme {

    let fontSize: CGFloat
    init(fontSize: CGFloat = 14) { self.fontSize = fontSize }

    // MARK: Required visual properties

    var font: UIFont {
        UIFont.monospacedSystemFont(ofSize: fontSize, weight: .regular)
    }

    var textColor: UIColor {
        UIColor(r: 0, g: 0, b: 0)
    }

    var backgroundColor: UIColor {
        UIColor(r: 255, g: 255, b: 255)
    }

    var userInterfaceStyle: UIUserInterfaceStyle {
        .light
    }

    var gutterBackgroundColor: UIColor {
        UIColor(r: 242, g: 242, b: 242)
    }

    var gutterHairlineColor: UIColor {
        UIColor(r: 216, g: 216, b: 216)
    }

    var lineNumberColor: UIColor {
        UIColor(r: 160, g: 160, b: 160)
    }

    var lineNumberFont: UIFont {
        UIFont.monospacedSystemFont(ofSize: 12, weight: .regular)
    }

    var selectedLineBackgroundColor: UIColor {
        UIColor(r: 236, g: 245, b: 255)
    }

    var selectedLinesLineNumberColor: UIColor {
        UIColor(r: 58, g: 58, b: 58)
    }

    var selectedLinesGutterBackgroundColor: UIColor {
        UIColor(r: 232, g: 240, b: 250)
    }

    var markedTextBackgroundColor: UIColor {
        UIColor(r: 181, g: 208, b: 247, alpha: 0.4)
    }

    var markedTextBackgroundCornerRadius: CGFloat {
        2
    }

    var invisibleCharactersColor: UIColor {
        UIColor(r: 204, g: 204, b: 204)
    }

    var pageGuideHairlineColor: UIColor {
        UIColor(r: 221, g: 221, b: 221)
    }

    var pageGuideBackgroundColor: UIColor {
        UIColor(r: 249, g: 249, b: 249)
    }

    // MARK: Syntax token colours (required by Theme protocol)

    func textColor(for highlightName: String) -> UIColor? {
        switch highlightName {
        case "keyword", "keyword.control", "keyword.operator",
             "keyword.other", "keyword.declaration", "storage.type",
             "storage.modifier":
            return UIColor(r: 173, g: 61, b: 164)    // purple

        case "type", "type.builtin", "entity.name.type",
             "entity.name.type.class", "entity.name.type.struct",
             "entity.name.type.enum", "entity.name.type.protocol":
            return UIColor(r: 112, g: 61, b: 170)    // dark purple

        case "type.parameter":
            return UIColor(r: 4, g: 124, b: 176)     // blue

        case "function", "entity.name.function",
             "meta.function-call", "function.method", "function.builtin":
            return UIColor(r: 57, g: 0, b: 160)      // indigo

        case "property", "variable.other.property":
            return UIColor(r: 4, g: 124, b: 176)     // blue

        case "variable.builtin":
            return UIColor(r: 173, g: 61, b: 164)    // purple (self, super)

        case "constant", "constant.builtin":
            return UIColor(r: 39, g: 42, b: 216)     // blue bold

        case "constant.numeric", "number":
            return UIColor(r: 39, g: 42, b: 216)     // blue

        case "string", "string.special":
            return UIColor(r: 196, g: 26, b: 22)     // red

        case "string.escape":
            return UIColor(r: 196, g: 26, b: 22)     // red

        case "comment", "comment.line", "comment.block",
             "comment.block.documentation":
            return UIColor(r: 93, g: 108, b: 121)    // grey

        case "attribute":
            return UIColor(r: 108, g: 54, b: 169)    // purple

        case "operator", "punctuation.operator",
             "punctuation.bracket", "punctuation.delimiter":
            return nil                               // inherits default textColor

        default:
            return nil
        }
    }
}

// MARK: - UIColor RGB convenience (private to this file)

private extension UIColor {
    convenience init(r: CGFloat, g: CGFloat, b: CGFloat, alpha: CGFloat = 1.0) {
        self.init(red: r / 255.0, green: g / 255.0, blue: b / 255.0, alpha: alpha)
    }
}