import Foundation
import SwiftData

@Model
final class UserProfile {
    // —— 核心 5 项 ——
    var birthYear: Int?           // 1990。隐私考虑只存年,不存月日
    var biologicalSexRaw: String  // "" / "male" / "female"
    var heightCM: Int?
    var weightKG: Double?         // 体重支持小数(68.5)
    var bloodTypeRaw: String      // "" / "A" / "B" / "AB" / "O"

    // —— 健康背景 ——
    var allergies: [String]
    var chronicConditions: [String]
    var familyHistory: [String]

    // —— 当前用药 ——
    var currentMedications: [String]

    var updatedAt: Date

    init(birthYear: Int? = nil,
         biologicalSexRaw: String = "",
         heightCM: Int? = nil,
         weightKG: Double? = nil,
         bloodTypeRaw: String = "",
         allergies: [String] = [],
         chronicConditions: [String] = [],
         familyHistory: [String] = [],
         currentMedications: [String] = [],
         updatedAt: Date = .now) {
        self.birthYear = birthYear
        self.biologicalSexRaw = biologicalSexRaw
        self.heightCM = heightCM
        self.weightKG = weightKG
        self.bloodTypeRaw = bloodTypeRaw
        self.allergies = allergies
        self.chronicConditions = chronicConditions
        self.familyHistory = familyHistory
        self.currentMedications = currentMedications
        self.updatedAt = updatedAt
    }
}

extension UserProfile {
    enum Sex: String, CaseIterable {
        case male, female
        case undisclosed = ""

        var label: String {
            switch self {
            case .male:        return "男"
            case .female:      return "女"
            case .undisclosed: return "不愿透露"
            }
        }
    }

    var sex: Sex {
        get { Sex(rawValue: biologicalSexRaw) ?? .undisclosed }
        set { biologicalSexRaw = newValue.rawValue }
    }

    /// 当前年龄。无 birthYear 时返回 nil。基于当前日历年简单相减,不算月日。
    var age: Int? {
        guard let y = birthYear else { return nil }
        return Calendar.current.component(.year, from: .now) - y
    }

    /// 给 ProfileCard 一行预览:"38岁 · 男 · 175cm · 68kg · A型"
    var summaryLine: String {
        var parts: [String] = []
        if let age { parts.append("\(age)岁") }
        if sex != .undisclosed { parts.append(sex.label) }
        if let h = heightCM { parts.append("\(h)cm") }
        if let w = weightKG {
            let s = w.truncatingRemainder(dividingBy: 1) == 0
                ? String(format: "%.0fkg", w)
                : String(format: "%.1fkg", w)
            parts.append(s)
        }
        if !bloodTypeRaw.isEmpty { parts.append("\(bloodTypeRaw)型") }
        return parts.joined(separator: " · ")
    }

    /// 资料是否完整到值得显示 summaryLine(否则提示"完善资料")
    var hasAnyBasics: Bool {
        birthYear != nil ||
        sex != .undisclosed ||
        heightCM != nil ||
        weightKG != nil ||
        !bloodTypeRaw.isEmpty
    }

    /// BMI(kg/m²),需要同时有身高 + 体重才能算
    var bmi: Double? {
        guard let h = heightCM, h > 0, let w = weightKG else { return nil }
        let m = Double(h) / 100.0
        return w / (m * m)
    }
}

/// 单例存取:全 App 只允许一份 UserProfile。第一次取自动创建。
enum UserProfileStore {
    @MainActor
    static func loadOrCreate(in ctx: ModelContext) -> UserProfile {
        let descriptor = FetchDescriptor<UserProfile>()
        if let existing = try? ctx.fetch(descriptor).first {
            return existing
        }
        let new = UserProfile()
        ctx.insert(new)
        try? ctx.save()
        return new
    }
}