import SwiftUI

struct DashboardView: View {

	@StateObject private var viewModel = DashboardViewModel()

	var body: some View {
		ZStack {
			Color.appSecondary.ignoresSafeArea()

			VStack(alignment: .leading, spacing: 20) {
				topBar
				patientHeader
				reminderBanner

				if viewModel.isLoading && viewModel.medicationCards.isEmpty {
					ProgressView()
						.frame(maxWidth: .infinity)
						.padding(.top, 40)
				} else if let errorMessage = viewModel.errorMessage {
					errorState(errorMessage)
				} else if viewModel.medicationCards.isEmpty {
					Text("Nao ha medicacao ativa para mostrar.")
						.font(.jakartaRegular16)
						.foregroundStyle(Color.appTextPrimary.opacity(0.65))
						.padding(.horizontal, 20)
				} else {
					medicationCarousel
				}

				Spacer(minLength: 0)
			}
			.padding(.top, 12)
		}
		.navigationBarHidden(true)
		.task {
			await viewModel.loadDashboard()
		}
		.refreshable {
			await viewModel.loadDashboard()
		}
	}

	// MARK: - Top bar

	private var topBar: some View {
		HStack {
			Circle()
				.fill(Color.appBackground)
				.frame(width: 40, height: 40)
				.overlay {
					Image(systemName: "person.fill")
						.foregroundStyle(.white)
				}

			Spacer()

			HStack(spacing: 6) {
				Image(systemName: "dot.radiowaves.left.and.right")
					.foregroundStyle(Color.appTextPrimary.opacity(0.55))
				Circle()
					.fill(.green)
					.frame(width: 8, height: 8)
			}
		}
		.padding(.horizontal, 20)
	}

	// MARK: - Patient header

	private var patientHeader: some View {
		VStack(spacing: 6) {
			ZStack {
				Circle()
					.stroke(Color.green, lineWidth: 3)
					.frame(width: 92, height: 92)

				patientAvatar
					.frame(width: 78, height: 78)
					.clipShape(Circle())
			}

			Text(viewModel.patient?.name ?? "Doente")
				.font(.jakartaBold18)
				.foregroundStyle(Color.appAccent)

			if let age = viewModel.patientAge {
				Text("\(age) Anos")
					.font(.jakartaRegular14)
					.foregroundStyle(Color.appTextPrimary.opacity(0.55))
			}

			Text("🙂")
				.font(.system(size: 20))
				.padding(.top, 2)
		}
		.frame(maxWidth: .infinity)
	}

	@ViewBuilder
	private var patientAvatar: some View {
		if let photo = viewModel.patient?.photo, let image = decodedImage(from: photo) {
			image.resizable().scaledToFill()
		} else {
			Color.appBorder
				.overlay {
					Image(systemName: "person.fill")
						.foregroundStyle(Color.appTextPrimary.opacity(0.4))
				}
		}
	}

	// MARK: - Reminder banner

	private var reminderBanner: some View {
		VStack(spacing: 4) {
			Text("Não se esqueça!")
				.font(.jakartaBold16)
				.foregroundStyle(Color.appAccent)

			Group {
				Text("Tem ") +
				Text("\(viewModel.totalDosesToday) Comprimidos")
					.fontWeight(.bold) +
				Text(" para tomar hoje.")
			}
			.font(.jakartaRegular14)
			.foregroundStyle(Color.appAccent)
		}
		.frame(maxWidth: .infinity)
		.multilineTextAlignment(.center)
	}

	// MARK: - Medication carousel

	private var medicationCarousel: some View {
		ScrollView(.horizontal, showsIndicators: false) {
			HStack(spacing: 16) {
				ForEach(viewModel.medicationCards) { card in
					MedicationCardView(card: card)
						.frame(width: 260)
				}
			}
			.padding(.horizontal, 20)
			.padding(.bottom, 20)
		}
	}

	private func errorState(_ message: String) -> some View {
		VStack(alignment: .leading, spacing: 12) {
			Text(message)
				.font(.jakartaRegular16)
				.foregroundStyle(.red)
			Button("Tentar novamente") {
				Task { await viewModel.loadDashboard() }
			}
			.font(.jakartaBold16)
			.foregroundStyle(Color.appBackground)
		}
		.padding(.horizontal, 20)
	}

	private func decodedImage(from base64String: String) -> Image? {
		guard let data = Data(base64Encoded: base64String), let uiImage = UIImage(data: data) else {
			return nil
		}
		return Image(uiImage: uiImage)
	}
}

private struct MedicationCardView: View {

	let card: MedicationCard

	var body: some View {
		VStack(spacing: 14) {
			medicationImage
				.frame(height: 140)
				.frame(maxWidth: .infinity)
				.background(Color.appSecondary)
				.clipShape(RoundedRectangle(cornerRadius: 12))
				.overlay(alignment: .topTrailing) {
					Image(systemName: "info.circle.fill")
						.foregroundStyle(Color.appBackground)
						.padding(8)
						.background(.white)
						.clipShape(Circle())
						.padding(8)
				}

			Text(card.name)
				.font(.jakartaBold16)
				.foregroundStyle(Color.appAccent)
				.multilineTextAlignment(.center)

			Text(card.tag)
				.font(.jakartaMedium14)
				.foregroundStyle(.white)
				.padding(.horizontal, 14)
				.padding(.vertical, 6)
				.background(Color.appBackground)
				.clipShape(Capsule())

			if let nextDoseTime = card.nextDoseTime {
				Group {
					Text("Próxima toma às ") +
					Text("\(nextDoseTime)h").fontWeight(.bold)
				}
				.font(.jakartaRegular14)
				.foregroundStyle(Color.appBackground)
			}

			Divider()

			doseTimesGrid
		}
		.padding(16)
		.background(.white)
		.clipShape(RoundedRectangle(cornerRadius: 16))
		.shadow(color: .black.opacity(0.06), radius: 8, y: 4)
	}

	@ViewBuilder
	private var medicationImage: some View {
		if let photoBase64 = card.photoBase64,
		   let data = Data(base64Encoded: photoBase64),
		   let uiImage = UIImage(data: data) {
			Image(uiImage: uiImage)
				.resizable()
				.scaledToFill()
				.clipped()
		} else {
			Image(systemName: "pills.fill")
				.font(.system(size: 40))
				.foregroundStyle(Color.appBackground.opacity(0.5))
		}
	}

	private var doseTimesGrid: some View {
		LazyVGrid(columns: [GridItem(.flexible()), GridItem(.flexible())], spacing: 10) {
			ForEach(card.doseTimes, id: \.self) { time in
				HStack(spacing: 6) {
					Image(systemName: time == card.nextDoseTime ? "bell.fill" : "clock")
						.font(.system(size: 13))
					Text("\(time)")
						.font(time == card.nextDoseTime ? .jakartaBold14 : .jakartaRegular14)
				}
				.foregroundStyle(
					time == card.nextDoseTime
						? Color.appBackground
						: Color.appTextPrimary.opacity(0.4)
				)
			}
		}
	}
}

#Preview {
	DashboardView()
}