import Foundation
import SwiftUI
import Combine

@MainActor
final class DashboardViewModel: ViewModel {

	@Published private(set) var patient: PatientDTO?
	@Published private(set) var prescriptions: [PrescriptionWithSchedulesResponse] = []
	@Published private(set) var medications: [String: MedicationDTO] = [:]
	@Published private(set) var errorMessage: String?
	@Published private(set) var logoutErrorMessage: String?

	private let api: MedMapAPI = DIContainer.shared.resolve()

	var patientAge: Int? {
		guard let dateOfBirth = patient?.dateOfBirth else { return nil }
		let formatter = DateFormatter()
		formatter.locale = Locale(identifier: "en_US_POSIX")
		formatter.dateFormat = "yyyy-MM-dd"
		guard let birthDate = formatter.date(from: dateOfBirth) else { return nil }
		return Calendar.current.dateComponents([.year], from: birthDate, to: .now).year
	}

	var totalDosesToday: Int {
		medicationCards.reduce(0) { $0 + $1.doseTimes.count }
	}

	var medicationCards: [MedicationCard] {
		prescriptions.map { response in
			let times = response.schedules
				.flatMap(\.timesOfDay)
				.sorted()
			let medication = medications[response.medicationId]

			return MedicationCard(
				id: response.prescription.id,
				medicationId: response.medicationId,
				name: medication?.name ?? "Medicacao prescrita",
				tag: medication?.activeIngredient ?? medication?.dosageForm ?? "Ativo",
				photoBase64: medication?.medicationPhoto,
				doseTimes: times,
				nextDoseTime: times.first(where: { $0 >= currentTime }) ?? times.first
			)
		}
	}

	func loadDashboard() async {
		guard !isLoading else { return }

		isLoading = true
		errorMessage = nil
		defer { isLoading = false }

		do {
			async let myPatient = api.getMyPatientProfile()
			async let activePrescriptions = api.listMyActivePrescriptions()
			async let medicationsResponse = api.listMedications()

			let (patient, prescriptions, medicationsResponseValue) = try await (myPatient, activePrescriptions, medicationsResponse)
			self.patient = patient
			self.prescriptions = prescriptions
			medications = Dictionary(
				uniqueKeysWithValues: medicationsResponseValue.medications.map { ($0.medicationId, $0) }
			)
		} catch {
			errorMessage = "Nao foi possivel carregar a sua medicacao."
			fluxlog("Patient dashboard load failed: \(error.localizedDescription)")
		}
	}

	func logout() async {
		guard !isLoading else { return }

		isLoading = true
		logoutErrorMessage = nil
		defer { isLoading = false }

		do {
			try await api.logout()
			appStateManager.resetNavigation()
			appStateManager.navigateTo(state: .login)
		} catch {
			logoutErrorMessage = "Nao foi possivel terminar a sessao. Tente novamente."
			fluxlog("Patient logout failed: \(error.localizedDescription)")
		}
	}

	private var currentTime: String {
		let formatter = DateFormatter()
		formatter.locale = Locale(identifier: "en_US_POSIX")
		formatter.dateFormat = "HH:mm"
		return formatter.string(from: .now)
	}
}

struct MedicationCard: Identifiable {
	let id: String
	let medicationId: String
	let name: String
	let tag: String
	let photoBase64: String?
	let doseTimes: [String]
	let nextDoseTime: String?
}
//  Created by RSA on 28/08/2026.
//