import Combine
import Foundation

final class GiftRecipientAddressViewModel: ObservableObject {
    @Published var recipientName: String = ""
    @Published var recipientPhoneNumber: String = ""
    @Published var recipientZipCode: String = ""
    @Published var recipientAddress: String = ""
    @Published var recipientAddressDetail: String = ""
    @Published var recipientTermsAgreed: Bool = false
    @Published var recipientPrivacyAgreed: Bool = false

    @Published private(set) var isSubmitting = false
    @Published var errorMessage = ""
    @Published var isShowPopup = false
    @Published var isShowSuccessToast = false
    let successMessage = "배송지 입력 완료"

    private let applicationNo: String
    private let onSubmitted: () -> Void
    private let repository = GiftRepository()
    private var mutationSubscription: AnyCancellable?
    @Published private(set) var hasSubmitted = false
    private var hasNotifiedSubmission = false

    init(applicationNo: String, onSubmitted: @escaping () -> Void) {
        self.applicationNo = applicationNo
        self.onSubmitted = onSubmitted
    }

    var canSubmit: Bool {
        !isSubmitting && !hasSubmitted && recipientTermsAgreed && recipientPrivacyAgreed
            && GiftContactInputRule.name.acceptsSubmission(recipientName)
            && GiftContactInputRule.phoneNumber.acceptsSubmission(recipientPhoneNumber)
            && [recipientZipCode, recipientAddress].allSatisfy {
                !$0.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
            }
    }

    func submit() {
        guard canSubmit else { return }

        isSubmitting = true
        errorMessage = ""
        isShowPopup = false

        let request = SubmitGiftRecipientAddressRequest(
            recipientName: recipientName.trimmingCharacters(in: .whitespacesAndNewlines),
            recipientPhoneNumber: recipientPhoneNumber.trimmingCharacters(in: .whitespacesAndNewlines),
            recipientZipCode: recipientZipCode.trimmingCharacters(in: .whitespacesAndNewlines),
            recipientAddress: recipientAddress.trimmingCharacters(in: .whitespacesAndNewlines),
            recipientAddressDetail: recipientAddressDetail.trimmingCharacters(in: .whitespacesAndNewlines),
            recipientTermsAgreed: recipientTermsAgreed,
            recipientPrivacyAgreed: recipientPrivacyAgreed
        )
        mutationSubscription = repository.submitRecipientAddress(applicationNo: applicationNo, request: request)
            .receive(on: DispatchQueue.main)
            .sink { [weak self] result in
                guard let self, !self.hasSubmitted else { return }
                if case .failure(let error) = result {
                    self.finishFailure(data: error.response?.data)
                }
            } receiveValue: { [weak self] response in
                guard let self, !self.hasSubmitted else { return }
                do {
                    let decoded = try JSONDecoder().decode(ApiResponseWithoutData.self, from: response.data)
                    guard decoded.success else {
                        self.finishFailure(data: response.data)
                        return
                    }
                    self.hasSubmitted = true
                    self.isSubmitting = false
                    self.isShowSuccessToast = true
                } catch {
                    self.finishFailure(data: response.data)
                }
            }
    }

    func successToastDidDismiss() {
        guard hasSubmitted, !isShowSuccessToast, !hasNotifiedSubmission else { return }

        hasNotifiedSubmission = true
        onSubmitted()
    }

    private func finishFailure(data: Data?) {
        struct ErrorResponse: Decodable {
            let message: String?
        }

        let decoded = data.flatMap { try? JSONDecoder().decode(ErrorResponse.self, from: $0) }
        let message = decoded?.message?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
        isSubmitting = false
        errorMessage = message.isEmpty ? I18n.Common.commonError : message
        isShowPopup = true
    }
}