import SwiftUI
import Kingfisher

struct ChannelDonationItemView: View {
    let item: GetChannelDonationListItem
    let previewLimit: Int?
    let isShowFullMessageOnTap: Bool

    @State private var isExpanded = false

    init(
        item: GetChannelDonationListItem,
        previewLimit: Int? = nil,
        isShowFullMessageOnTap: Bool = false
    ) {
        self.item = item
        self.previewLimit = previewLimit
        self.isShowFullMessageOnTap = isShowFullMessageOnTap
    }

    private var donationBackgroundColor: Color {
        if item.isSecret {
            return Color(hex: "59548f").opacity(0.8)
        }

        if item.can >= 10000 {
            return Color(hex: "c25264").opacity(0.8)
        }

        if item.can >= 5000 {
            return Color(hex: "d85e37").opacity(0.8)
        }

        if item.can >= 1000 {
            return Color(hex: "d38c38").opacity(0.8)
        }

        if item.can >= 500 {
            return Color(hex: "c25264").opacity(0.8)
        }

        if item.can >= 100 {
            return Color(hex: "4d6aa4").opacity(0.8)
        }

        if item.can >= 50 {
            return Color(hex: "2d7390").opacity(0.8)
        }

        return Color(hex: "548f7d").opacity(0.8)
    }

    var body: some View {
        VStack(alignment: .leading, spacing: 10) {
            HStack(spacing: 11) {
                KFImage(URL(string: item.profileUrl))
                    .cancelOnDisappear(true)
                    .downsampling(size: CGSize(width: 40, height: 40))
                    .resizable()
                    .scaledToFill()
                    .frame(width: 40, height: 40)
                    .clipShape(Circle())

                VStack(alignment: .leading, spacing: 2) {
                    Text(item.nickname)
                        .appFont(size: 18, weight: .bold)
                        .foregroundColor(.white)
                        .lineLimit(1)

                    Text(item.relativeTimeText())
                        .appFont(size: 14, weight: .regular)
                        .foregroundColor(Color(hex: "78909C"))
                }

                Spacer()
            }

            highlightedMessageText(displayMessage)
                .appFont(size: 16, weight: .regular)
                .lineLimit(isExpanded ? nil : 2)
                .multilineTextAlignment(.leading)
                .frame(maxWidth: .infinity, alignment: .leading)
        }
        .padding(16)
        .frame(maxWidth: .infinity, alignment: .leading)
        .background(donationBackgroundColor)
        .cornerRadius(16)
        .onTapGesture {
            guard isShowFullMessageOnTap else { return }
            guard isTruncated else { return }
            isExpanded = true
        }
    }
}

private extension ChannelDonationItemView {
    var normalizedMessage: String {
        item.message.trimmingCharacters(in: .whitespacesAndNewlines)
    }

    var displayMessage: String {
        guard !isExpanded else { return normalizedMessage }
        guard let previewLimit else { return normalizedMessage }

        if normalizedMessage.count > previewLimit {
            return String(normalizedMessage.prefix(previewLimit)) + "..."
        }

        return normalizedMessage
    }

    var isTruncated: Bool {
        guard let previewLimit else { return false }
        return normalizedMessage.count > previewLimit
    }

    func highlightedMessageText(_ message: String) -> Text {
        let plainCanToken = "\(item.can)캔"
        let commaCanToken = "\(item.can.comma())캔"

        let range = message.range(of: commaCanToken)
            ?? message.range(of: plainCanToken)

        guard let range else {
            return Text(message).foregroundColor(Color(hex: "CFD8DC"))
        }

        let prefixText = String(message[..<range.lowerBound])
        let canText = String(message[range])
        let suffixText = String(message[range.upperBound...])

        return Text(prefixText).foregroundColor(Color(hex: "CFD8DC"))
            + Text(canText).foregroundColor(Color(hex: "FDCA2F"))
            + Text(suffixText).foregroundColor(Color(hex: "CFD8DC"))
    }
}