import Foundation

/// 长期监测指标预设目录。`IndicatorRecordSheet` 顶部 grid 由 `MonitorMetric.allCases` 渲染。
///
/// 录入时按 metric 展开 1 或 2 个 Field;血压拆 2 条 Indicator(同 capturedAt + 各自 seriesKey),
/// 其他预设产 1 条。`effectiveRange(for:profile:)` 用 Profile 调整参考范围(目前只 1 条规则:
/// 老人收缩压上限 140→150)。
enum MonitorMetric: String, CaseIterable, Identifiable {
    case bloodPressure         // bp.systolic + bp.diastolic
    case fastingGlucose        // glucose.fasting
    case postprandialGlucose   // glucose.postprandial
    case temperature           // temperature
    case heartRate             // heart_rate
    case spo2                  // spo2

    // 注:身高 / 体重不在这里——它们是 UserProfile 的字段(单值,不存历史)。

    var id: String { rawValue }

    var displayName: String {
        switch self {
        case .bloodPressure:       return "血压"
        case .fastingGlucose:      return "空腹血糖"
        case .postprandialGlucose: return "餐后血糖"
        case .temperature:         return "体温"
        case .heartRate:           return "心率"
        case .spo2:                return "血氧"
        }
    }

    /// SF Symbol。grid 卡片图标。
    var icon: String {
        switch self {
        case .bloodPressure:       return "heart.fill"
        case .fastingGlucose:      return "drop.fill"
        case .postprandialGlucose: return "drop.circle.fill"
        case .temperature:         return "thermometer.medium"
        case .heartRate:           return "waveform.path.ecg"
        case .spo2:                return "lungs.fill"
        }
    }

    var fields: [Field] {
        switch self {
        case .bloodPressure:
            return [
                Field(seriesKey: "bp.systolic",
                      label: "收缩压",
                      unit: "mmHg",
                      placeholder: "120",
                      baseRange: 90...140),
                Field(seriesKey: "bp.diastolic",
                      label: "舒张压",
                      unit: "mmHg",
                      placeholder: "80",
                      baseRange: 60...90),
            ]
        case .fastingGlucose:
            return [Field(seriesKey: "glucose.fasting",
                          label: "空腹血糖",
                          unit: "mmol/L",
                          placeholder: "5.0",
                          baseRange: 3.9...6.1)]
        case .postprandialGlucose:
            return [Field(seriesKey: "glucose.postprandial",
                          label: "餐后 2h",
                          unit: "mmol/L",
                          placeholder: "6.5",
                          baseRange: 0...7.8)]
        case .temperature:
            return [Field(seriesKey: "temperature",
                          label: "体温",
                          unit: "°C",
                          placeholder: "36.5",
                          baseRange: 36.0...37.2)]
        case .heartRate:
            return [Field(seriesKey: "heart_rate",
                          label: "心率",
                          unit: "bpm",
                          placeholder: "72",
                          baseRange: 60...100)]
        case .spo2:
            return [Field(seriesKey: "spo2",
                          label: "血氧",
                          unit: "%",
                          placeholder: "98",
                          baseRange: 95...100)]
        }
    }
}

extension MonitorMetric {
    struct Field: Identifiable, Hashable {
        let seriesKey: String
        let label: String
        let unit: String
        let placeholder: String
        let baseRange: ClosedRange<Double>?

        var id: String { seriesKey }

        /// 给 IndicatorRecordSheet 显示在数值旁的「90-140 mmHg」字样。
        func rangeText(_ range: ClosedRange<Double>?) -> String {
            guard let r = range else { return "无参考范围" }
            let lower = format(r.lowerBound)
            let upper = format(r.upperBound)
            // 餐后血糖 baseRange 是 0...7.8,显示成「<7.8」
            if r.lowerBound == 0 { return "<\(upper) \(unit)" }
            return "\(lower)–\(upper) \(unit)"
        }

        private func format(_ v: Double) -> String {
            v.truncatingRemainder(dividingBy: 1) == 0
                ? String(format: "%.0f", v)
                : String(format: "%.1f", v)
        }
    }

    /// 给定 field 在 profile 下的有效参考范围。
    /// 目前只 1 条规则:age ≥ 65 时 bp.systolic 上限 140 → 150。
    /// profile 为 nil(未设资料)时返回 baseRange。
    func effectiveRange(for field: Field, profile: UserProfile?) -> ClosedRange<Double>? {
        if let age = profile?.age, age >= 65, field.seriesKey == "bp.systolic" {
            return 90...150
        }
        return field.baseRange
    }

    /// 算出 effectiveRange 后,判定 value 的 status。
    /// value 高于上限 → high;低于下限 → low;在内 → normal;无范围 → normal。
    static func status(value: Double, in range: ClosedRange<Double>?) -> IndicatorStatus {
        guard let r = range else { return .normal }
        if value > r.upperBound { return .high }
        if value < r.lowerBound { return .low }
        return .normal
    }

    /// 给 IndicatorRecordSheet 「按你的年龄(67)调整」提示用:
    /// 当 effectiveRange ≠ baseRange 时返回 true。
    func isRangePersonalized(for field: Field, profile: UserProfile?) -> Bool {
        guard let p = profile else { return false }
        let base = field.baseRange
        let eff = effectiveRange(for: field, profile: p)
        return base != eff
    }
}