//
//  AppLayoutDirection.swift
//  App for Indeed
//

import Cocoa

/// Layout direction for the in-app language (Arabic and Hebrew are RTL).
enum AppLayoutDirection {
    static var isRightToLeft: Bool {
        currentAppLanguage().isRightToLeft
    }

    static var interface: NSUserInterfaceLayoutDirection {
        isRightToLeft ? .rightToLeft : .leftToRight
    }

    static var naturalTextAlignment: NSTextAlignment {
        isRightToLeft ? .right : .natural
    }

    static var naturalWritingDirection: NSWritingDirection {
        isRightToLeft ? .rightToLeft : .natural
    }

    static func naturalParagraphStyle(
        alignment: NSTextAlignment? = nil,
        lineBreakMode: NSLineBreakMode = .byWordWrapping
    ) -> NSParagraphStyle {
        let paragraph = NSMutableParagraphStyle()
        paragraph.alignment = alignment ?? naturalTextAlignment
        paragraph.baseWritingDirection = naturalWritingDirection
        paragraph.lineBreakMode = lineBreakMode
        return paragraph
    }

    static func apply(to view: NSView) {
        view.userInterfaceLayoutDirection = interface
    }

    static func applyRecursively(to root: NSView) {
        var stack: [NSView] = [root]
        while let view = stack.popLast() {
            view.userInterfaceLayoutDirection = interface
            stack.append(contentsOf: view.subviews)
        }
    }

    static func configureTextField(_ field: NSTextField) {
        field.alignment = naturalTextAlignment
        field.baseWritingDirection = naturalWritingDirection
        if let cell = field.cell as? NSTextFieldCell {
            cell.alignment = naturalTextAlignment
            cell.baseWritingDirection = naturalWritingDirection
        }
    }

    static func placeholderAttributes(
        font: NSFont,
        color: NSColor,
        lineBreakMode: NSLineBreakMode = .byTruncatingTail
    ) -> [NSAttributedString.Key: Any] {
        [
            .foregroundColor: color,
            .font: font,
            .paragraphStyle: naturalParagraphStyle(alignment: naturalTextAlignment, lineBreakMode: lineBreakMode)
        ]
    }

    static func attributedString(
        _ text: String,
        font: NSFont,
        color: NSColor,
        lineBreakMode: NSLineBreakMode = .byWordWrapping
    ) -> NSAttributedString {
        NSAttributedString(string: text, attributes: [
            .font: font,
            .foregroundColor: color,
            .paragraphStyle: naturalParagraphStyle(lineBreakMode: lineBreakMode)
        ])
    }

    static func refreshTextFields(in root: NSView) {
        var stack: [NSView] = [root]
        while let view = stack.popLast() {
            if let field = view as? NSTextField {
                configureTextField(field)
            }
            stack.append(contentsOf: view.subviews)
        }
    }

    @MainActor
    static func applyToAllWindows() {
        for window in NSApp.windows {
            guard let content = window.contentView else { continue }
            applyRecursively(to: content)
            refreshTextFields(in: content)
        }
    }
}

extension AppLanguage {
    var isRightToLeft: Bool {
        switch self {
        case .arabic, .hebrew:
            return true
        default:
            return false
        }
    }
}