//
//  FontManager.swift
//  QuickLocation
//
//  Created by 八条 on 2026/8/5.
//

import UIKit

/// 项目自定义字体样式
enum AppFont {
    /// 荆南波波黑-Bold
    case boboBold
    /// 字魂扁黑体
    case ziHunBianHei
    /// 优设标题黑
    case youSheBiaoTiHei

    /// 候选字体名（按优先级；部分字体 PostScript 名异常，需多试）
    var candidateNames: [String] {
        switch self {
        case .boboBold:
            // TTF Full Name 为「荆南波波黑 Bold」，PostScript 名为异常的「-Bold」
            return ["荆南波波黑 Bold", "荆南波波黑-Bold", "JingNanBoBoHei-Bold"]
        case .ziHunBianHei:
            return ["zihunbiantaoti", "字魂扁黑体"]
        case .youSheBiaoTiHei:
            // PostScript / Full Name 均为 YouSheBiaoTiHei
            return ["YouSheBiaoTiHei", "优设标题黑"]
        }
    }

    var familyName: String? {
        switch self {
        case .boboBold: return "荆南波波黑"
        case .ziHunBianHei: return nil
        case .youSheBiaoTiHei: return "YouSheBiaoTiHei"
        }
    }

    var fileName: String {
        switch self {
        case .boboBold: return "荆南波波黑-Bold.ttf"
        case .ziHunBianHei: return "zihunbiantaoti-r.ttf"
        case .youSheBiaoTiHei: return "优设标题黑_猫啃网.ttf"
        }
    }

    var fallbackWeight: UIFont.Weight {
        switch self {
        case .boboBold: return .bold
        case .ziHunBianHei: return .medium
        case .youSheBiaoTiHei: return .bold
        }
    }
}

/// 统一字体管理：取字体 + 启动注册
enum FontManager {

    private static var resolvedNames: [AppFont: String] = [:]
    private static var didRegister = false

    /// 按样式与字号取字体，失败回退系统字体
    static func font(_ style: AppFont, size: CGFloat) -> UIFont {
        ensureRegistered()
        if let name = resolvedFontName(for: style),
           let custom = UIFont(name: name, size: size) {
            return custom
        }
        return .systemFont(ofSize: size, weight: style.fallbackWeight)
    }

    static func boboBold(_ size: CGFloat) -> UIFont {
        font(.boboBold, size: size)
    }

    static func ziHunBianHei(_ size: CGFloat) -> UIFont {
        font(.ziHunBianHei, size: size)
    }

    static func youSheBiaoTiHei(_ size: CGFloat) -> UIFont {
        font(.youSheBiaoTiHei, size: size)
    }

    /// 注册 Bundle 内自定义字体（可重复调用）
    static func registerCustomFonts() {
        for style in [AppFont.boboBold, .ziHunBianHei, .youSheBiaoTiHei] {
            if let registered = UIFont.loadFontName(style.fileName), !registered.isEmpty {
                // 忽略异常 PostScript（如 "-Bold"），优先用可实例化的名
                if !registered.hasPrefix("-"),
                   UIFont(name: registered, size: 12) != nil {
                    resolvedNames[style] = registered
                    continue
                }
            }
            if let name = resolveAvailableName(for: style) {
                resolvedNames[style] = name
            }
        }
        didRegister = true
    }

    private static func ensureRegistered() {
        guard !didRegister else { return }
        registerCustomFonts()
    }

    private static func resolvedFontName(for style: AppFont) -> String? {
        if let cached = resolvedNames[style] { return cached }
        if let name = resolveAvailableName(for: style) {
            resolvedNames[style] = name
            return name
        }
        return nil
    }

    private static func resolveAvailableName(for style: AppFont) -> String? {
        for name in style.candidateNames {
            if UIFont(name: name, size: 12) != nil {
                return name
            }
        }
        if let family = style.familyName {
            let names = UIFont.fontNames(forFamilyName: family)
            if let first = names.first {
                return first
            }
        }
        return nil
    }
}