import SwiftUI
import SwiftData

/// 化验项 free-form 预设(用户当时手动加的辅助列表)。
/// 跟 MonitorMetric 不同——这些是「一次性化验单数值」,不进 Trends,无 seriesKey。
struct IndicatorPreset: Identifiable, Hashable {
    let name: String
    let unit: String
    let range: String
    var id: String { name }
}

private let labPresets: [IndicatorPreset] = [
    .init(name: "LDL-C",     unit: "mmol/L", range: "< 3.40"),
    .init(name: "HDL-C",     unit: "mmol/L", range: "> 1.04"),
    .init(name: "总胆固醇",   unit: "mmol/L", range: "< 5.18"),
    .init(name: "甘油三酯",   unit: "mmol/L", range: "< 1.70"),
    .init(name: "ALT",        unit: "U/L",    range: "9 - 50"),
    .init(name: "尿酸",       unit: "μmol/L", range: "208 - 428"),
    .init(name: "血红蛋白",   unit: "g/L",    range: "130 - 175"),
]

/// 指标录入 sheet,支持 3 种路径:
/// 1. **长期监测预设**(MonitorMetric)— 选预设后字段自动填,带 seriesKey,
///    保存进 Trends。血压拆 2 条 Indicator。
/// 2. **化验项快捷**(labPresets)— 跟 a 类似但只填 name/unit/range 辅助,
///    无 seriesKey,不进 Trends。
/// 3. **自由输入** — name/value/unit/range 全自己填,status 手动选。
struct IndicatorQuickSheet: View {
    @Environment(\.modelContext) private var ctx
    @Environment(\.dismiss) private var dismiss
    @Query private var profiles: [UserProfile]

    // 状态
    @State private var selectedMonitor: MonitorMetric?
    @State private var selectedLabPreset: IndicatorPreset?

    // 单字段(monitor 单字段、lab、自由)
    @State private var name: String = ""
    @State private var value: String = ""
    @State private var unit: String = ""
    @State private var range: String = ""
    @State private var manualStatus: IndicatorStatus = .normal
    @State private var capturedAt: Date = .now
    @State private var note: String = ""

    // 血压双字段
    @State private var systolic: String = ""
    @State private var diastolic: String = ""

    private var profile: UserProfile? { profiles.first }

    private var isBP: Bool { selectedMonitor == .bloodPressure }

    private var canSubmit: Bool {
        if isBP {
            return !systolic.trimmingCharacters(in: .whitespaces).isEmpty &&
                   !diastolic.trimmingCharacters(in: .whitespaces).isEmpty
        }
        return !name.trimmingCharacters(in: .whitespaces).isEmpty &&
               !value.trimmingCharacters(in: .whitespaces).isEmpty
    }

    var body: some View {
        VStack(spacing: 0) {
            handle
            header

            ScrollView(showsIndicators: false) {
                VStack(alignment: .leading, spacing: 20) {
                    monitorGridSection
                    labPresetSection
                    Divider().padding(.vertical, 4)

                    if isBP {
                        bpFieldSection
                    } else {
                        nameSection
                        valueRow
                        rangeSection
                        if selectedMonitor == nil {
                            // 自由输入或 lab preset 时 status 手动;monitor 单字段自动
                            statusSection
                        } else {
                            autoStatusHint
                        }
                    }

                    timeSection
                    noteSection
                }
                .padding(.horizontal, 20)
                .padding(.bottom, 20)
            }

            footer
        }
        .background(
            Tj.Palette.sand
                .clipShape(RoundedRectangle(cornerRadius: Tj.Radius.xl, style: .continuous))
                .ignoresSafeArea(edges: .bottom)
        )
        .presentationDetents([.large])
        .presentationDragIndicator(.hidden)
        .presentationBackground(Tj.Palette.sand)
        .presentationCornerRadius(Tj.Radius.xl)
    }

    // MARK: - Sections

    private var handle: some View {
        Capsule()
            .fill(Tj.Palette.line)
            .frame(width: 40, height: 4)
            .padding(.top, 10)
            .padding(.bottom, 14)
    }

    private var header: some View {
        HStack {
            Text("记录指标")
                .font(.tjH2())
                .foregroundStyle(Tj.Palette.text)
            Spacer()
            Text("本地处理 · 永不上传")
                .font(.system(size: 12))
                .foregroundStyle(Tj.Palette.text3)
        }
        .padding(.horizontal, 20)
        .padding(.bottom, 16)
    }

    private var monitorGridSection: some View {
        VStack(alignment: .leading, spacing: 8) {
            sectionLabel("长期监测(进趋势)")
            let columns = [GridItem(.flexible()), GridItem(.flexible())]
            LazyVGrid(columns: columns, spacing: 8) {
                ForEach(MonitorMetric.allCases) { m in
                    monitorTile(m)
                }
            }
        }
    }

    private func monitorTile(_ m: MonitorMetric) -> some View {
        let selected = selectedMonitor == m
        return Button {
            applyMonitor(m)
        } label: {
            HStack(spacing: 10) {
                Image(systemName: m.icon)
                    .font(.system(size: 18, weight: .medium))
                    .foregroundStyle(selected ? Tj.Palette.paper : Tj.Palette.ink)
                    .frame(width: 32, height: 32)
                    .background(Circle().fill(selected ? Tj.Palette.ink : Tj.Palette.amber.opacity(0.25)))

                Text(m.displayName)
                    .font(.system(size: 14, weight: selected ? .semibold : .medium))
                    .foregroundStyle(selected ? Tj.Palette.paper : Tj.Palette.text)
                Spacer()
            }
            .padding(.horizontal, 10)
            .padding(.vertical, 10)
            .background(
                RoundedRectangle(cornerRadius: Tj.Radius.sm, style: .continuous)
                    .fill(selected ? Tj.Palette.ink : Tj.Palette.paper)
            )
            .overlay(
                RoundedRectangle(cornerRadius: Tj.Radius.sm, style: .continuous)
                    .strokeBorder(Tj.Palette.line, lineWidth: selected ? 0 : 1)
            )
        }
        .buttonStyle(.plain)
    }

    private var labPresetSection: some View {
        VStack(alignment: .leading, spacing: 8) {
            sectionLabel("化验项快捷(不进趋势)")
            ScrollView(.horizontal, showsIndicators: false) {
                HStack(spacing: 8) {
                    ForEach(labPresets) { p in
                        chip(p.name, selected: selectedLabPreset == p) {
                            applyLab(p)
                        }
                    }
                }
            }
        }
    }

    private var bpFieldSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            HStack {
                sectionLabel("收缩 / 舒张")
                Spacer()
                bpRangeHint
            }
            HStack(spacing: 12) {
                bpField(label: "收缩压", value: $systolic, placeholder: "120")
                Text("/").font(.system(size: 22, weight: .light)).foregroundStyle(Tj.Palette.text3)
                bpField(label: "舒张压", value: $diastolic, placeholder: "80")
                Text("mmHg").foregroundStyle(Tj.Palette.text3)
            }
            bpStatusChips
        }
    }

    private func bpField(label: String, value: Binding<String>, placeholder: String) -> some View {
        VStack(alignment: .leading, spacing: 4) {
            Text(label).font(.system(size: 11)).foregroundStyle(Tj.Palette.text3)
            TextField(placeholder, text: value)
                .keyboardType(.decimalPad)
                .font(.system(size: 20, weight: .semibold, design: .monospaced))
                .multilineTextAlignment(.center)
                .padding(.vertical, 10)
                .frame(width: 90)
                .background(fieldBg)
                .overlay(fieldBorder)
        }
    }

    private var bpRangeHint: some View {
        let sysRange = MonitorMetric.bloodPressure.effectiveRange(
            for: MonitorMetric.bloodPressure.fields[0], profile: profile)
        let diasRange = MonitorMetric.bloodPressure.effectiveRange(
            for: MonitorMetric.bloodPressure.fields[1], profile: profile)
        let personalized = MonitorMetric.bloodPressure.isRangePersonalized(
            for: MonitorMetric.bloodPressure.fields[0], profile: profile)
        let rangeText = "\(formatRange(sysRange)) / \(formatRange(diasRange))"
        return HStack(spacing: 4) {
            Text(rangeText)
                .font(.system(size: 11, design: .monospaced))
                .foregroundStyle(Tj.Palette.text3)
            if personalized, let age = profile?.age {
                Text("· 按\(age)岁调整")
                    .font(.system(size: 10))
                    .foregroundStyle(Tj.Palette.amber)
            }
        }
    }

    private var bpStatusChips: some View {
        HStack(spacing: 8) {
            if let s = computedBPStatus(.systolic) {
                statusBadge("收缩 " + s.label, color: s.color)
            }
            if let s = computedBPStatus(.diastolic) {
                statusBadge("舒张 " + s.label, color: s.color)
            }
            Spacer()
        }
    }

    private var nameSection: some View {
        VStack(alignment: .leading, spacing: 8) {
            sectionLabel("指标名")
            TextField("例如:血红蛋白", text: $name)
                .textInputAutocapitalization(.never)
                .padding(.horizontal, 14)
                .padding(.vertical, 12)
                .background(fieldBg)
                .overlay(fieldBorder)
                .onChange(of: name) { _, _ in
                    if let p = selectedLabPreset, p.name != name {
                        selectedLabPreset = nil
                    }
                }
                .disabled(selectedMonitor != nil)
                .opacity(selectedMonitor != nil ? 0.6 : 1)
        }
    }

    private var valueRow: some View {
        HStack(alignment: .top, spacing: 12) {
            VStack(alignment: .leading, spacing: 8) {
                sectionLabel("数值")
                TextField(monitorFieldPlaceholder, text: $value)
                    .keyboardType(.decimalPad)
                    .font(.system(size: 18, weight: .semibold, design: .monospaced))
                    .padding(.horizontal, 14)
                    .padding(.vertical, 12)
                    .background(fieldBg)
                    .overlay(fieldBorder)
            }
            VStack(alignment: .leading, spacing: 8) {
                sectionLabel("单位")
                TextField("mmol/L", text: $unit)
                    .textInputAutocapitalization(.never)
                    .autocorrectionDisabled()
                    .padding(.horizontal, 14)
                    .padding(.vertical, 12)
                    .background(fieldBg)
                    .overlay(fieldBorder)
                    .disabled(selectedMonitor != nil)
                    .opacity(selectedMonitor != nil ? 0.6 : 1)
            }
            .frame(maxWidth: 130)
        }
    }

    private var rangeSection: some View {
        VStack(alignment: .leading, spacing: 8) {
            HStack {
                sectionLabel("参考范围")
                Spacer()
                if let m = selectedMonitor, m != .bloodPressure {
                    monitorRangeHint(m)
                }
            }
            TextField("例如:< 3.40 或 3.9 - 6.1", text: $range)
                .textInputAutocapitalization(.never)
                .autocorrectionDisabled()
                .padding(.horizontal, 14)
                .padding(.vertical, 12)
                .background(fieldBg)
                .overlay(fieldBorder)
                .disabled(selectedMonitor != nil)
                .opacity(selectedMonitor != nil ? 0.6 : 1)
        }
    }

    private func monitorRangeHint(_ m: MonitorMetric) -> some View {
        let personalized = m.isRangePersonalized(for: m.fields[0], profile: profile)
        return HStack(spacing: 4) {
            if personalized, let age = profile?.age {
                Text("按\(age)岁调整")
                    .font(.system(size: 10))
                    .foregroundStyle(Tj.Palette.amber)
            }
        }
    }

    private var statusSection: some View {
        VStack(alignment: .leading, spacing: 8) {
            sectionLabel("状态")
            HStack(spacing: 8) {
                statusChip(.normal, label: "正常", color: Tj.Palette.leaf)
                statusChip(.high,   label: "偏高 ↑", color: Tj.Palette.brick)
                statusChip(.low,    label: "偏低 ↓", color: Tj.Palette.amber)
            }
        }
    }

    private var autoStatusHint: some View {
        let auto = computedSingleStatus
        return HStack(spacing: 8) {
            sectionLabel("状态(按数值自动判)")
            if let s = auto {
                statusBadge(s.label, color: s.color)
            } else {
                Text("待输入")
                    .font(.system(size: 12))
                    .foregroundStyle(Tj.Palette.text3)
            }
        }
    }

    private var timeSection: some View {
        VStack(alignment: .leading, spacing: 8) {
            sectionLabel("测量时间")
            DatePicker("", selection: $capturedAt, in: ...Date.now)
                .datePickerStyle(.compact)
                .labelsHidden()
        }
    }

    private var noteSection: some View {
        VStack(alignment: .leading, spacing: 8) {
            sectionLabel("备注(可选)")
            TextField("例如:空腹采血", text: $note, axis: .vertical)
                .lineLimit(1...3)
                .padding(.horizontal, 14)
                .padding(.vertical, 12)
                .background(fieldBg)
                .overlay(fieldBorder)
        }
    }

    private var footer: some View {
        HStack(spacing: 12) {
            Button("取消") { dismiss() }
                .buttonStyle(TjGhostButton(height: 44, fontSize: 15, horizontalPadding: 18))
            Button("保存到记录") { submit() }
                .buttonStyle(TjPrimaryButton(height: 44, fontSize: 15, horizontalPadding: 18))
                .disabled(!canSubmit)
                .opacity(canSubmit ? 1 : 0.4)
        }
        .padding(.horizontal, 20)
        .padding(.vertical, 14)
        .background(
            Tj.Palette.sand
                .overlay(alignment: .top) {
                    Rectangle().fill(Tj.Palette.lineSoft).frame(height: 1)
                }
        )
    }

    // MARK: - helpers

    private var fieldBg: some View {
        RoundedRectangle(cornerRadius: Tj.Radius.sm, style: .continuous)
            .fill(Tj.Palette.paper)
    }

    private var fieldBorder: some View {
        RoundedRectangle(cornerRadius: Tj.Radius.sm, style: .continuous)
            .strokeBorder(Tj.Palette.line, lineWidth: 1)
    }

    private func sectionLabel(_ text: String) -> some View {
        Text(text)
            .font(.system(size: 12, weight: .semibold))
            .tracking(0.3)
            .foregroundStyle(Tj.Palette.text2)
    }

    private func chip(_ label: String, selected: Bool, action: @escaping () -> Void) -> some View {
        Button(action: action) {
            Text(label)
                .font(.system(size: 13, weight: selected ? .semibold : .regular))
                .foregroundStyle(selected ? Tj.Palette.paper : Tj.Palette.text)
                .padding(.horizontal, 14)
                .padding(.vertical, 8)
                .background(Capsule().fill(selected ? Tj.Palette.ink : Tj.Palette.paper))
                .overlay(Capsule().strokeBorder(Tj.Palette.line, lineWidth: selected ? 0 : 1))
        }
        .buttonStyle(.plain)
    }

    private func statusChip(_ value: IndicatorStatus, label: String, color: Color) -> some View {
        let selected = manualStatus == value
        return Button {
            manualStatus = value
        } label: {
            Text(label)
                .font(.system(size: 13, weight: selected ? .semibold : .regular))
                .foregroundStyle(selected ? Tj.Palette.paper : color)
                .padding(.horizontal, 14)
                .padding(.vertical, 8)
                .frame(maxWidth: .infinity)
                .background(Capsule().fill(selected ? color : Tj.Palette.paper))
                .overlay(Capsule().strokeBorder(color.opacity(selected ? 0 : 0.5), lineWidth: 1))
        }
        .buttonStyle(.plain)
    }

    private func statusBadge(_ label: String, color: Color) -> some View {
        Text(label)
            .font(.system(size: 11, weight: .semibold))
            .foregroundStyle(color)
            .padding(.horizontal, 10)
            .padding(.vertical, 4)
            .background(Capsule().fill(color.opacity(0.18)))
    }

    private var monitorFieldPlaceholder: String {
        selectedMonitor?.fields.first?.placeholder ?? "3.84"
    }

    private func formatRange(_ r: ClosedRange<Double>?) -> String {
        guard let r = r else { return "—" }
        let fmt = { (v: Double) in
            v.truncatingRemainder(dividingBy: 1) == 0
                ? String(format: "%.0f", v) : String(format: "%.1f", v)
        }
        return "\(fmt(r.lowerBound))–\(fmt(r.upperBound))"
    }

    // MARK: - apply preset

    private func applyMonitor(_ m: MonitorMetric) {
        if selectedMonitor == m {
            // 取消选择
            clearMonitor()
            return
        }
        selectedMonitor = m
        selectedLabPreset = nil

        if m == .bloodPressure {
            // 血压走 bp 字段,不动 name/value/unit
            name = m.displayName
            unit = "mmHg"
        } else {
            let f = m.fields[0]
            name = m.displayName
            value = ""
            unit = f.unit
            let r = m.effectiveRange(for: f, profile: profile)
            range = f.rangeText(r)
        }
    }

    private func clearMonitor() {
        selectedMonitor = nil
        name = ""; value = ""; unit = ""; range = ""
        systolic = ""; diastolic = ""
    }

    private func applyLab(_ p: IndicatorPreset) {
        selectedLabPreset = p
        selectedMonitor = nil
        systolic = ""; diastolic = ""
        name = p.name
        if unit.trimmingCharacters(in: .whitespaces).isEmpty { unit = p.unit }
        if range.trimmingCharacters(in: .whitespaces).isEmpty { range = p.range }
    }

    // MARK: - auto status

    private var computedSingleStatus: (label: String, color: Color)? {
        guard let m = selectedMonitor, m != .bloodPressure,
              let v = Double(value.trimmingCharacters(in: .whitespaces)) else { return nil }
        let f = m.fields[0]
        let r = m.effectiveRange(for: f, profile: profile)
        let s = MonitorMetric.status(value: v, in: r)
        return (s.label, s.color)
    }

    private enum BPSide { case systolic, diastolic }

    private func computedBPStatus(_ side: BPSide) -> (label: String, color: Color)? {
        let text = side == .systolic ? systolic : diastolic
        guard let v = Double(text.trimmingCharacters(in: .whitespaces)) else { return nil }
        let m = MonitorMetric.bloodPressure
        let f = m.fields[side == .systolic ? 0 : 1]
        let r = m.effectiveRange(for: f, profile: profile)
        let s = MonitorMetric.status(value: v, in: r)
        return (s.label, s.color)
    }

    // MARK: - submit

    private func submit() {
        guard canSubmit else { return }

        if isBP {
            saveBP()
        } else if let m = selectedMonitor {
            saveSingleMonitor(m)
        } else {
            saveFreeform()
        }
        dismiss()
    }

    private func saveBP() {
        let m = MonitorMetric.bloodPressure
        let sys = Double(systolic.trimmingCharacters(in: .whitespaces)) ?? 0
        let dia = Double(diastolic.trimmingCharacters(in: .whitespaces)) ?? 0
        let sysField = m.fields[0]
        let diaField = m.fields[1]
        let sysRange = m.effectiveRange(for: sysField, profile: profile)
        let diaRange = m.effectiveRange(for: diaField, profile: profile)
        let sysStatus = MonitorMetric.status(value: sys, in: sysRange)
        let diaStatus = MonitorMetric.status(value: dia, in: diaRange)

        let timestamp = capturedAt
        let systolicI = Indicator(
            name: sysField.label,
            value: systolic,
            unit: sysField.unit,
            range: sysField.rangeText(sysRange),
            status: sysStatus,
            note: note.isEmpty ? nil : note,
            capturedAt: timestamp,
            pinned: true,
            seriesKey: sysField.seriesKey
        )
        let diastolicI = Indicator(
            name: diaField.label,
            value: diastolic,
            unit: diaField.unit,
            range: diaField.rangeText(diaRange),
            status: diaStatus,
            note: nil,
            capturedAt: timestamp,
            pinned: true,
            seriesKey: diaField.seriesKey
        )
        ctx.insert(systolicI)
        ctx.insert(diastolicI)
        try? ctx.save()
    }

    private func saveSingleMonitor(_ m: MonitorMetric) {
        let f = m.fields[0]
        let v = Double(value.trimmingCharacters(in: .whitespaces)) ?? 0
        let r = m.effectiveRange(for: f, profile: profile)
        let status = MonitorMetric.status(value: v, in: r)
        let indicator = Indicator(
            name: m.displayName,
            value: value.trimmingCharacters(in: .whitespaces),
            unit: f.unit,
            range: f.rangeText(r),
            status: status,
            note: note.isEmpty ? nil : note,
            capturedAt: capturedAt,
            pinned: true,
            seriesKey: f.seriesKey
        )
        ctx.insert(indicator)
        try? ctx.save()

        // 身高顺手回写 Profile
        if m == .height, let cm = Int(value.trimmingCharacters(in: .whitespaces)),
           let p = profile {
            p.heightCM = cm
            p.updatedAt = .now
            try? ctx.save()
        }
    }

    private func saveFreeform() {
        let indicator = Indicator(
            name: name.trimmingCharacters(in: .whitespaces),
            value: value.trimmingCharacters(in: .whitespaces),
            unit: unit.trimmingCharacters(in: .whitespaces),
            range: range.trimmingCharacters(in: .whitespaces),
            status: manualStatus,
            note: note.trimmingCharacters(in: .whitespaces).isEmpty ? nil : note,
            capturedAt: capturedAt
        )
        ctx.insert(indicator)
        try? ctx.save()
    }
}

// MARK: - Status display helpers

private extension IndicatorStatus {
    var label: String {
        switch self {
        case .normal: return "正常"
        case .high:   return "偏高 ↑"
        case .low:    return "偏低 ↓"
        }
    }

    var color: Color {
        switch self {
        case .normal: return Tj.Palette.leaf
        case .high:   return Tj.Palette.brick
        case .low:    return Tj.Palette.amber
        }
    }
}

#Preview {
    IndicatorQuickSheet()
        .modelContainer(for: [Indicator.self, UserProfile.self], inMemory: true)
}