import Foundation

enum GiftDateFormatter {
    static func yyyyMMdd(fromUTC text: String?) -> String? {
        format(text, format: "yyyy.MM.dd")
    }

    static func mmDD(fromUTC text: String?) -> String? {
        format(text, format: "MM.dd")
    }

    private static func format(_ text: String?, format: String) -> String? {
        guard let text, let date = DateParser.parse(text) else { return nil }

        let formatter = DateFormatter()
        formatter.locale = Locale(identifier: "en_US_POSIX")
        formatter.timeZone = .autoupdatingCurrent
        formatter.dateFormat = format
        return formatter.string(from: date)
    }
}

enum GiftDisplayPolicy {
    static func listCard(from item: GiftListItemResponse) -> GiftListCardDisplayModel? {
        guard let direction = GiftDirection(rawValue: item.direction),
              let status = GiftStatus(rawValue: item.status) else {
            return nil
        }

        return GiftListCardDisplayModel(
            applicationNo: item.applicationNo,
            direction: direction,
            status: status,
            counterpartNickname: item.counterpartNickname,
            counterpartProfileImageUrl: item.counterpartProfileImageUrl,
            categoryName: item.categoryName,
            sizeName: item.sizeName,
            createdDateText: GiftDateFormatter.yyyyMMdd(fromUTC: item.createdAt),
            statusDisplay: listStatus(direction: direction, status: status, statusName: item.statusName)
        )
    }

    static func sentDetail(from detail: GiftDetailResponse) -> SentGiftDetailDisplayModel? {
        guard let status = status(from: detail, expectedDirection: .sent) else { return nil }

        return SentGiftDetailDisplayModel(
            status: status,
            statusName: detail.statusName,
            undeliverableReason: detail.delivery.undeliverableReason,
            recipientCreatorNickname: detail.giftInfo.recipientCreatorNickname,
            sizeName: detail.giftInfo.sizeName,
            categoryName: detail.giftInfo.categoryName,
            applicationNo: detail.applicationNo,
            paidCan: detail.giftInfo.paidCan,
            tracking: detail.giftInfo.tracking,
            shippingRequestedDateText: GiftDateFormatter.yyyyMMdd(fromUTC: detail.giftInfo.shippingRequestedAt),
            applicationDateText: GiftDateFormatter.yyyyMMdd(
                fromUTC: detail.statusTimeline.first { $0.status == GiftStatus.received.rawValue }?.occurredAt
            ),
            canceledDateText: GiftDateFormatter.yyyyMMdd(fromUTC: detail.delivery.canceledAt),
            senderInfo: detail.senderInfo.map(GiftAddressDisplayModel.init),
            mailbox: detail.mailbox.map(GiftAddressDisplayModel.init),
            trackingRequired: detail.trackingRequired,
            progress: progress(from: detail.statusTimeline)
        )
    }

    static func receivedDetail(from detail: GiftDetailResponse) -> ReceivedGiftDetailDisplayModel? {
        guard let status = status(from: detail, expectedDirection: .received) else { return nil }

        return ReceivedGiftDetailDisplayModel(
            status: status,
            statusName: detail.statusName,
            undeliverableReason: detail.delivery.undeliverableReason,
            senderNickname: detail.giftInfo.senderNickname,
            sizeName: detail.giftInfo.sizeName,
            categoryName: detail.giftInfo.categoryName,
            shippingRequestedDateText: GiftDateFormatter.yyyyMMdd(fromUTC: detail.giftInfo.shippingRequestedAt),
            recipientAddressRequired: status == .undeliverable ? false : detail.recipientAddressRequired,
            recipientAddress: status == .undeliverable ? nil : detail.recipientAddress.map(GiftAddressDisplayModel.init),
            progress: progress(from: detail.statusTimeline)
        )
    }

    static func sizeDescription(for sizeCode: String) -> String? {
        guard let size = GiftSize(rawValue: sizeCode) else { return nil }

        switch size {
        case .small:
            return "세 변의 합 100cm 이하 · 5kg 이하"
        case .medium:
            return "세 변의 합 120cm 이하 · 15kg 이하"
        case .large:
            return "세 변의 합 160cm 이하 · 20kg 이하"
        }
    }

    private static func listStatus(
        direction: GiftDirection,
        status: GiftStatus,
        statusName: String
    ) -> GiftListStatusDisplayModel {
        switch (direction, status) {
        case (.sent, .received):
            return GiftListStatusDisplayModel(title: "운송장 등록 필요", subtitle: nil)
        case (.sent, .trackingRegistered):
            return GiftListStatusDisplayModel(title: "발송 확인", subtitle: nil)
        case (.sent, .arrivedAtMailbox):
            return GiftListStatusDisplayModel(title: "사서함 도착", subtitle: nil)
        case (.sent, .inspectionCompleted):
            return GiftListStatusDisplayModel(title: "선물 검수 완료", subtitle: nil)
        case (.sent, .delivered):
            return GiftListStatusDisplayModel(title: "전달 완료", subtitle: nil)
        case (.sent, .undeliverable):
            return GiftListStatusDisplayModel(title: "전달 불가", subtitle: nil)
        case (.sent, .canceled):
            return GiftListStatusDisplayModel(title: "신청 취소", subtitle: nil)
        case (.received, .trackingRegistered):
            return GiftListStatusDisplayModel(title: "배송지 입력 필요", subtitle: "전달 예정")
        case (.received, .arrivedAtMailbox):
            return GiftListStatusDisplayModel(title: "선물 검수", subtitle: "선물 확인 중")
        case (.received, .inspectionCompleted):
            return GiftListStatusDisplayModel(title: "선물 검수 완료", subtitle: "배송 중")
        case (.received, .delivered):
            return GiftListStatusDisplayModel(title: "전달 완료", subtitle: nil)
        case (.received, .undeliverable):
            return GiftListStatusDisplayModel(title: "전달 불가", subtitle: nil)
        default:
            return GiftListStatusDisplayModel(title: statusName, subtitle: nil)
        }
    }

    private static func status(
        from detail: GiftDetailResponse,
        expectedDirection: GiftDirection
    ) -> GiftStatus? {
        guard GiftDirection(rawValue: detail.direction) == expectedDirection else { return nil }
        return GiftStatus(rawValue: detail.status)
    }

    private static func progress(from timeline: [GiftStatusTimelineResponse]) -> [GiftProgressDisplayModel] {
        GiftProgressStep.allCases.map { step in
            let occurredAt = timeline.first { $0.status == step.rawValue }?.occurredAt
            return GiftProgressDisplayModel(
                step: step,
                occurredDateText: GiftDateFormatter.mmDD(fromUTC: occurredAt)
            )
        }
    }
}

private extension GiftAddressDisplayModel {
    init(_ senderInfo: GiftSenderInfoResponse) {
        self.init(name: senderInfo.name, phoneNumber: senderInfo.phoneNumber, address: senderInfo.address)
    }

    init(_ recipientAddress: GiftRecipientAddressResponse) {
        self.init(name: recipientAddress.name, phoneNumber: recipientAddress.phoneNumber, address: recipientAddress.address)
    }

    init(_ mailbox: GiftMailboxResponse) {
        self.init(name: mailbox.name, phoneNumber: mailbox.phoneNumber, address: mailbox.address)
    }
}