import SwiftUI
import SwiftData

struct HomeView: View {
    var onTapArchive: () -> Void = {}

    @Query(sort: \Indicator.capturedAt, order: .reverse)
    private var indicators: [Indicator]

    @Query(sort: \Report.reportDate, order: .reverse)
    private var reports: [Report]

    @Query(sort: \DiaryEntry.createdAt, order: .reverse)
    private var diaries: [DiaryEntry]

    @Query(sort: \Symptom.startedAt, order: .reverse)
    private var symptoms: [Symptom]

    @MainActor
    private var recentEntries: [TimelineEntry] {
        let all =
            TimelineEntry.from(indicators: indicators) +
            reports.map(TimelineEntry.from(report:)) +
            diaries.map(TimelineEntry.from(diary:)) +
            symptoms.map(TimelineEntry.from(symptom:))
        return all.sorted { $0.date > $1.date }.prefix(6).map { $0 }
    }

    private var recentGrouped: [(section: DateSection, items: [TimelineEntry])] {
        TimelineGrouping.group(recentEntries)
    }

    var body: some View {
        ScrollView(showsIndicators: false) {
            VStack(alignment: .leading, spacing: 0) {
                greeting
                    .padding(.top, 4)
                    .padding(.bottom, 18)

                OngoingSymptomsCard()
                    .padding(.bottom, 18)

                recentSection
                    .padding(.bottom, 22)

                archiveSection
            }
            .padding(.horizontal, 20)
            .padding(.bottom, 20)
        }
        .background(Tj.Palette.sand.ignoresSafeArea())
    }

    private var greeting: some View {
        HStack(alignment: .top) {
            VStack(alignment: .leading, spacing: 4) {
                Text(todayLine)
                    .font(.system(size: 12))
                    .tracking(1)
                    .foregroundStyle(Tj.Palette.text3)
                Text(greetingWord)
                    .font(.tjTitle())
                    .foregroundStyle(Tj.Palette.text)
            }
            Spacer()
            TjLockChip()
                .padding(.top, 4)
        }
    }

    private var todayLine: String {
        let f = DateFormatter()
        f.locale = Locale(identifier: "zh_CN")
        f.dateFormat = "M 月 d 日 · EEE"
        return f.string(from: Date())
    }

    private var greetingWord: String {
        switch Calendar.current.component(.hour, from: Date()) {
        case 5..<12:  return "早安"
        case 12..<18: return "下午好"
        default:      return "晚上好"
        }
    }

    private var recentSection: some View {
        VStack(alignment: .leading, spacing: 10) {
            HStack(alignment: .lastTextBaseline) {
                Text("最近记录").font(.tjH2()).foregroundStyle(Tj.Palette.text)
                Spacer()
                Button(action: onTapArchive) {
                    Text("全部 ›")
                        .font(.system(size: 12))
                        .foregroundStyle(Tj.Palette.text3)
                }
                .buttonStyle(.plain)
            }

            if recentEntries.isEmpty {
                emptyRecent
            } else {
                VStack(alignment: .leading, spacing: 14) {
                    ForEach(recentGrouped, id: \.section) { group in
                        VStack(alignment: .leading, spacing: 8) {
                            Text(group.section.label)
                                .font(.system(size: 11, weight: .semibold))
                                .tracking(0.5)
                                .foregroundStyle(Tj.Palette.text3)
                            VStack(spacing: 10) {
                                ForEach(group.items) { entry in
                                    TimelineRow(entry: entry)
                                }
                            }
                        }
                    }
                }
            }
        }
    }

    private var emptyRecent: some View {
        HStack {
            Text("还没有任何记录,点底部 + 号开始第一条")
                .font(.system(size: 13))
                .foregroundStyle(Tj.Palette.text3)
            Spacer()
        }
        .padding(.vertical, 14)
        .padding(.horizontal, 16)
        .tjCard(bordered: true)
    }

    private var archiveSection: some View {
        VStack(alignment: .leading, spacing: 10) {
            Text("影像档案").font(.tjH2()).foregroundStyle(Tj.Palette.text)

            Button(action: onTapArchive) {
                HStack(spacing: 14) {
                    TjPlaceholder(label: "档案 · \(reports.count)")
                        .frame(width: 56, height: 56)
                    VStack(alignment: .leading, spacing: 2) {
                        Text("我的报告档案")
                            .font(.system(size: 14, weight: .semibold))
                            .foregroundStyle(Tj.Palette.text)
                        Text("\(reports.count) 份 · \(indicators.count) 项指标 · 端侧加密")
                            .font(.system(size: 11))
                            .foregroundStyle(Tj.Palette.text3)
                    }
                    Spacer()
                    Image(systemName: "chevron.right")
                        .font(.system(size: 14, weight: .medium))
                        .foregroundStyle(Tj.Palette.text3)
                }
                .padding(14)
                .tjCard(bordered: true)
            }
            .buttonStyle(.plain)
        }
    }
}

#Preview {
    HomeView()
}