import SwiftUI

struct MainHomeRankingCard: View {
    let item: MainHomeCreatorRankingItem
    let showRankChange: Bool
    let columnsPerRow: Int
    let onTapCreator: (Int) -> Void

    init(
        item: MainHomeCreatorRankingItem,
        showRankChange: Bool,
        columnsPerRow: Int = 1,
        onTapCreator: @escaping (Int) -> Void = { _ in }
    ) {
        self.item = item
        self.showRankChange = showRankChange
        self.columnsPerRow = columnsPerRow
        self.onTapCreator = onTapCreator
    }

    var body: some View {
        Button {
            onTapCreator(item.creatorId)
        } label: {
            GeometryReader { proxy in
                let side = min(proxy.size.width, proxy.size.height)

                ZStack(alignment: .topLeading) {
                    profileImage(size: CGSize(width: side, height: side))

                    LinearGradient(
                        colors: [Color.black.opacity(0), Color.black.opacity(0.72)],
                        startPoint: .top,
                        endPoint: .bottom
                    )

                    rankColumn(side: side)
                        .padding(.leading, rankColumnLeadingPadding(side))
                        .padding(.top, rankColumnTopPadding(side))

                    VStack {
                        Spacer()

                        Text(item.nickname)
                            .appFont(size: nicknameFontSize(side), weight: .bold)
                            .foregroundColor(.white)
                            .lineLimit(1)
                            .truncationMode(.tail)
                            .frame(maxWidth: .infinity, alignment: .center)
                            .padding(.horizontal, nicknameHorizontalPadding(side))
                            .padding(.bottom, nicknameBottomPadding(side))
                    }
                }
                .clipShape(RoundedRectangle(cornerRadius: SodaSpacing.s14, style: .continuous))
            }
            .aspectRatio(1, contentMode: .fit)
        }
        .buttonStyle(.plain)
    }

    private func profileImage(size: CGSize) -> some View {
        DownsampledKFImage(url: URL(string: item.profileImageUrl ?? ""), size: size)
            .background(Color.gray800)
    }

    private func rankText(side: CGFloat) -> some View {
        Text("\(item.rank)")
            .appFont(size: rankFontSize(side), family: .pattaya)
            .foregroundStyle(
                LinearGradient(
                    colors: [.white, Color.gray200],
                    startPoint: .top,
                    endPoint: .bottom
                )
            )
            .shadow(color: Color.black.opacity(0.48), radius: 2)
    }

    private func rankColumn(side: CGFloat) -> some View {
        VStack(alignment: .center, spacing: rankColumnSpacing) {
            rankText(side: side)
                .frame(maxWidth: .infinity, alignment: .center)

            MainHomeRankChangeBadge(
                showRankChange: showRankChange,
                rankChange: item.rankChange,
                isNew: item.isNew
            )
            .frame(maxWidth: .infinity, alignment: .center)
        }
        .frame(width: rankColumnWidth(side), alignment: .center)
    }

    private var rankColumnSpacing: CGFloat {
        switch columnsPerRow {
        case 1:
            return -20
        case 2:
            return -10
        case 3:
            return -5
        default:
            return -20
        }
    }

    private func rankFontSize(_ side: CGFloat) -> CGFloat {
        max(32, side * 0.26)
    }

    private func nicknameFontSize(_ side: CGFloat) -> CGFloat {
        max(14, side * 0.085)
    }

    private func rankColumnWidth(_ side: CGFloat) -> CGFloat {
        max(49, side * 0.19)
    }

    private func rankColumnLeadingPadding(_ side: CGFloat) -> CGFloat {
        max(0, side * 0.035)
    }

    private func rankColumnTopPadding(_ side: CGFloat) -> CGFloat {
        max(-8, side * 0.02)
    }

    private func nicknameHorizontalPadding(_ side: CGFloat) -> CGFloat {
        max(SodaSpacing.s12, side * 0.11)
    }

    private func nicknameBottomPadding(_ side: CGFloat) -> CGFloat {
        max(SodaSpacing.s16, side * 0.09)
    }
}

struct MainHomeRankingCard_Previews: PreviewProvider {
    private static let previewImageUrl = "https://picsum.photos/500/500"

    static var previews: some View {
        VStack(spacing: SodaSpacing.s20) {
            MainHomeRankingCard(
                item: previewItem(rank: 1, rankChange: 5, isNew: false),
                showRankChange: true
            )
            .frame(width: 374)

            HStack(spacing: SodaSpacing.s8) {
                MainHomeRankingCard(
                    item: previewItem(rank: 2, rankChange: -3, isNew: false),
                    showRankChange: true,
                    columnsPerRow: 2
                )
                MainHomeRankingCard(
                    item: previewItem(rank: 3, rankChange: 0, isNew: false),
                    showRankChange: true,
                    columnsPerRow: 2
                )
            }

            HStack(spacing: SodaSpacing.s8) {
                MainHomeRankingCard(
                    item: previewItem(rank: 8, rankChange: nil, isNew: true),
                    showRankChange: true,
                    columnsPerRow: 3
                )
                MainHomeRankingCard(
                    item: previewItem(rank: 9, rankChange: 2, isNew: false),
                    showRankChange: false,
                    columnsPerRow: 3
                )
                MainHomeRankingCard(
                    item: previewItem(rank: 10, rankChange: nil, isNew: false),
                    showRankChange: true,
                    columnsPerRow: 3
                )
            }
        }
        .padding(SodaSpacing.s20)
        .background(Color.black)
        .previewLayout(.sizeThatFits)
    }

    private static func previewItem(rank: Int, rankChange: Int?, isNew: Bool) -> MainHomeCreatorRankingItem {
        MainHomeCreatorRankingItem(
            rank: rank,
            rankChange: rankChange,
            isNew: isNew,
            creatorId: rank,
            nickname: "크리에이터이름",
            profileImageUrl: previewImageUrl
        )
    }
}