import SwiftUI

struct WatchMeasurementView: View {
  @EnvironmentObject private var model: WatchAppModel
  @Environment(\.dismiss) private var dismiss
  @State private var errorMessage: String?
  @State private var previewStartedAt: Date?
  @State private var previewCompleted = false

  var body: some View {
    WatchFigmaCanvas {
      Group {
        if previewCompleted {
          WatchMeasurementResultView()
        } else if case let .completed(summary) = model.measurement.state, !WatchDesignMode.enabled {
          WatchMeasurementResultView(summary: summary)
        } else {
          TimelineView(.periodic(from: .now, by: 1)) { context in
            let seconds = remainingSeconds(at: context.date)
            VStack(spacing: 0) {
              WatchEyebrow(title: "Analyse")
              Spacer(minLength: 10)
              WatchSignalRing(progress: 1 - Double(seconds) / 60)
              Text(watchTime(TimeInterval(seconds)))
                .font(WatchTheme.font(15, weight: .bold)).monospacedDigit()
                .padding(.top, 12)
              Text("Restez immobile")
                .font(WatchTheme.font(14)).foregroundStyle(WatchTheme.secondary.opacity(0.6))
                .padding(.top, 6)
              Spacer(minLength: 12)
              Button("Fermer") { close() }.buttonStyle(WatchPillStyle())
            }
            .onChange(of: seconds) { _, value in
              if WatchDesignMode.enabled && !WatchDesignMode.frozen && value == 0 { previewCompleted = true }
            }
          }
        }
      }.padding(.horizontal, 20).padding(.vertical, 12)
    }
    .task { await startMeasurement() }
    .alert(errorMessage ?? "", isPresented: Binding(get: { errorMessage != nil }, set: { if !$0 { errorMessage = nil } })) {
      Button("Fermer") { close() }
    }
    .onChange(of: model.measurement.state) { _, state in
      if !WatchDesignMode.enabled, case let .failed(message) = state { errorMessage = message }
    }
    .onDisappear {
      guard !WatchDesignMode.enabled else { return }
      switch model.measurement.state {
      case .waitingForFirstSample, .collecting: model.measurement.cancel()
      default: break
      }
    }
  }

  private func remainingSeconds(at date: Date) -> Int {
    if WatchDesignMode.enabled {
      guard !WatchDesignMode.frozen, let previewStartedAt else { return 60 }
      return max(0, 60 - Int(date.timeIntervalSince(previewStartedAt)))
    }
    switch model.measurement.state {
    case let .collecting(progress): return max(0, Int((60 * (1 - progress)).rounded(.up)))
    case .finishing: return 0
    default: return 60
    }
  }

  private func startMeasurement() async {
    if WatchDesignMode.enabled { previewStartedAt = Date(); return }
    do {
      model.measurement.resetAfterResult()
      try await model.measurement.requestAuthorization()
      guard !Task.isCancelled else { return }
      try await model.measurement.start()
    } catch { errorMessage = error.localizedDescription }
  }

  private func close() {
    if !WatchDesignMode.enabled { model.measurement.cancel(); model.measurement.resetAfterResult() }
    dismiss()
  }
}

struct WatchSignalRing: View {
  let progress: Double
  var body: some View {
    ZStack {
      Circle().stroke(Color(red: 25 / 255, green: 32 / 255, blue: 44 / 255).opacity(0.4), lineWidth: 6)
      Circle().stroke(WatchTheme.accent.opacity(0.8), lineWidth: 6)
      Circle().stroke(WatchTheme.accent.opacity(0.6), lineWidth: 2)
      Circle().fill(WatchTheme.accent.opacity(0.2)).frame(width: 40, height: 40)
        .overlay(Circle().stroke(WatchTheme.accent.opacity(0.3)))
        .shadow(color: WatchTheme.accent.opacity(0.3), radius: 8)
      Image("WatchHeart").resizable().scaledToFit().frame(width: 16.667, height: 15.292)
    }.frame(width: 72, height: 72).padding(3)
      .accessibilityLabel("Analyse").accessibilityValue("\(Int(progress * 100)) pour cent")
  }
}

struct WatchMeasurementResultView: View {
  @EnvironmentObject private var model: WatchAppModel
  @Environment(\.dismiss) private var dismiss
  var summary: WatchMeasurementSummaryV1? = nil

  var body: some View {
    VStack(spacing: 0) {
      WatchEyebrow(title: "RÉSULTAT")
      Spacer(minLength: 12)
      HStack(alignment: .firstTextBaseline, spacing: 0) {
        Text(WatchDesignMode.enabled ? "72" : "—")
          .font(WatchTheme.font(64, weight: .bold)).tracking(-3.2)
          .foregroundStyle(LinearGradient(colors: [WatchTheme.mint, WatchTheme.accent], startPoint: .topLeading, endPoint: .bottomTrailing))
        Text("%").font(WatchTheme.font(14, weight: .medium)).foregroundStyle(WatchTheme.mint.opacity(0.8))
      }.foregroundStyle(WatchTheme.accent).shadow(color: WatchTheme.accent.opacity(0.5), radius: 5)
      WatchBalanceAxis(position: WatchDesignMode.enabled ? 0.77 : nil).padding(.top, 14)
      Text(WatchDesignMode.enabled ? "Équilibre favorable" : "")
        .font(WatchTheme.font(10)).foregroundStyle(WatchTheme.secondary).padding(.top, 14)
      Spacer(minLength: 12)
      Button("Fermer") {
        if !WatchDesignMode.enabled { model.measurement.resetAfterResult() }
        dismiss()
      }.buttonStyle(WatchPillStyle())
    }
  }
}