//
//  CVResumeAppearance.swift
//  App for Indeed
//
//  Shared résumé colours for gallery thumbnails and filled CV preview/export.
//  Résumés always use a print-style light palette regardless of app light/dark mode.
//

import AppKit

@MainActor
enum CVResumeAppearance {

    struct Colors {
        let paper: NSColor
        let ink: NSColor
        let muted: NSColor
        let rule: NSColor
        let cardBackground: NSColor
        let sidebarTint: NSColor
        let accentRed: NSColor
        let accentBlue: NSColor
    }

    /// Print-style palette — always light, even when the app chrome is in dark mode.
    static func colors() -> Colors {
        Colors(
            paper: NSColor.white,
            ink: NSColor(srgbRed: 38 / 255, green: 50 / 255, blue: 71 / 255, alpha: 1),
            muted: NSColor(srgbRed: 110 / 255, green: 118 / 255, blue: 132 / 255, alpha: 1),
            rule: NSColor(srgbRed: 228 / 255, green: 232 / 255, blue: 240 / 255, alpha: 1),
            cardBackground: NSColor.white,
            sidebarTint: NSColor(srgbRed: 244 / 255, green: 246 / 255, blue: 250 / 255, alpha: 1),
            accentRed: NSColor(srgbRed: 207 / 255, green: 67 / 255, blue: 50 / 255, alpha: 1),
            accentBlue: AppDashboardTheme.brandBlue
        )
    }

    /// Slight paper tint by layout variant (gallery + filled CV use the same rule).
    static func paperBackground(variant: Int, base: NSColor) -> NSColor {
        switch variant % 5 {
        case 0: return base
        case 1: return NSColor(srgbRed: 0.995, green: 0.992, blue: 0.985, alpha: 1)
        case 2: return NSColor(srgbRed: 0.96, green: 0.99, blue: 1, alpha: 1)
        case 3: return NSColor(srgbRed: 0.99, green: 0.99, blue: 0.99, alpha: 1)
        default: return NSColor(srgbRed: 0.99, green: 0.98, blue: 0.995, alpha: 1)
        }
    }

    static func accentColor(for template: CVTemplate) -> NSColor {
        let palette = colors()
        switch template.accent {
        case .redUnderline, .redBar:
            return palette.accentRed
        case .blueBar:
            return template.themeColor
        case .none:
            return template.themeColor.blended(withFraction: 0.5, of: palette.ink) ?? template.themeColor
        }
    }

    static func sectionHeadingColor(for template: CVTemplate) -> NSColor {
        accentColor(for: template)
    }

    // MARK: - Document layout (RTL for Arabic / Hebrew)

    static var isRightToLeft: Bool {
        AppLayoutDirection.isRightToLeft
    }

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

    static var documentTextAlignment: NSTextAlignment {
        isRightToLeft ? .right : .left
    }

    static var documentWritingDirection: NSWritingDirection {
        isRightToLeft ? .rightToLeft : .leftToRight
    }

    static func resolvedDocumentAlignment(_ alignment: NSTextAlignment) -> NSTextAlignment {
        alignment == .left ? documentTextAlignment : alignment
    }

    static func applyDocumentLayout(to view: NSView) {
        view.userInterfaceLayoutDirection = documentInterfaceLayoutDirection
        for child in view.subviews {
            applyDocumentLayout(to: child)
        }
    }

    static func documentParagraphStyle(
        alignment: NSTextAlignment,
        lineBreakMode: NSLineBreakMode = .byWordWrapping
    ) -> NSParagraphStyle {
        let paragraph = NSMutableParagraphStyle()
        paragraph.alignment = resolvedDocumentAlignment(alignment)
        paragraph.baseWritingDirection = documentWritingDirection
        paragraph.lineBreakMode = lineBreakMode
        return paragraph
    }

    static func applyDocumentTextLayout(to field: NSTextField, alignment: NSTextAlignment? = nil) {
        let sourceAlignment = alignment ?? field.alignment
        let resolved = resolvedDocumentAlignment(sourceAlignment)
        field.alignment = resolved
        field.baseWritingDirection = documentWritingDirection
        let lineBreak: NSLineBreakMode = field.maximumNumberOfLines == 0 ? .byWordWrapping : .byTruncatingTail
        field.attributedStringValue = NSAttributedString(string: field.stringValue, attributes: [
            .font: field.font ?? .systemFont(ofSize: 12),
            .foregroundColor: field.textColor ?? .labelColor,
            .paragraphStyle: documentParagraphStyle(alignment: resolved, lineBreakMode: lineBreak)
        ])
    }
}