//
//  EmojiMemoryGameView.swift
//  Memorize
//
//  Created by ching on 2023/2/12.
//

import SwiftUI

struct EmojiMemoryGameView: View {
    @ObservedObject var game: EmojiMemoryGame
    @Namespace private var dealingNamespace

    var body: some View {
        ZStack(alignment: .bottom) {
            VStack {
                gameBody
                HStack {
                    restart
                    Spacer()
                    shuffle
                }
                .padding(.horizontal)
            }
            .padding()
            deckBody
        }
    }

    @State private var dealt = Set<Int>()

    private func deal(_ card: EmojiMemoryGame.Card) {
        dealt.insert(card.id)
    }

    private func isUndealt(_ card: EmojiMemoryGame.Card) -> Bool {
        !dealt.contains(card.id)
    }

    private func dealAnimation(for card: EmojiMemoryGame.Card) -> Animation {
        var delay = 0.0
        if let index = game.cards.firstIndex(where: { $0.id == card.id }) {
            delay = Double(index) * (const.DrawingConstants.totalDealDuration / Double(game.cards.count))
        }

        return Animation.easeInOut(duration: const.DrawingConstants.dealDuration).delay(delay)
    }

    private func zIndex(of card: EmojiMemoryGame.Card) -> Double {
        -Double(game.cards.firstIndex(where: { $0.id == card.id }) ?? 0)
    }

    var gameBody: some View {
        AspectVGrid(items: game.cards, aspectRatio: const.DrawingConstants.gridAspectRatio) {
            card in
            if isUndealt(card) || (card.isMatched && !card.isFaceUp) {
                Color.clear
            } else {
                CardView(card: card)
                    .matchedGeometryEffect(id: card.id, in: dealingNamespace)
                    .padding(const.DrawingConstants.gridPadding)
                    .zIndex(zIndex(of: card))
                    .transition(AnyTransition.asymmetric(insertion: .identity, removal: .scale))
                    .onTapGesture {
                        withAnimation {
                            game.choose(card)
                        }
                    }
            }
        }
        .foregroundColor(const.DrawingConstants.cardColor)
    }

    var deckBody: some View {
        ZStack {
            ForEach(game.cards.filter(isUndealt)) {
                card in CardView(card: card)
                    .matchedGeometryEffect(id: card.id, in: dealingNamespace)
                    .transition(AnyTransition.asymmetric(insertion: .opacity, removal: .identity))
                    .zIndex(zIndex(of: card))
            }
        }
        .frame(width: const.DrawingConstants.undealtWidth, height: const.DrawingConstants.undealtHeight)
        .foregroundColor(const.DrawingConstants.cardColor)
        .onTapGesture {
            for card in game.cards {
                withAnimation(dealAnimation(for: card)) {
                    deal(card)
                }
            }
        }
    }

    var shuffle: some View {
        Button("Shuffle") {
            withAnimation {
                game.shuffle()
            }
        }
    }

    var restart: some View {
        Button("Restart") {
            withAnimation {
                dealt = []
                game.restart()
            }
        }
    }
}

struct CardView: View {
    let card: EmojiMemoryGame.Card

    @State private var animatedBonusRemaining: Double = 0

    var body: some View {
        GeometryReader { geometry in
            ZStack {
                Group {
                    if card.isConsumingBonusTime {
                        Pie(startAngle: Angle(degrees: 270),
                            endAngle: Angle(degrees: (1 - animatedBonusRemaining) * 360 - 90))
                            .onAppear {
                                animatedBonusRemaining = card.bonusRemaining
                                withAnimation(.linear(duration: card.bonusTimeRemaining)) {
                                    animatedBonusRemaining = 0
                                }
                            }
                    } else {
                        Pie(startAngle: Angle(degrees: 0 - 90),
                            endAngle: Angle(degrees: (1 - card.bonusRemaining) * 360 - 90))
                    }
                }
                .padding(const.DrawingConstants.piePadding)
                .opacity(const.DrawingConstants.pieOpacity)
                Text(card.content)
                    .rotationEffect(Angle.degrees(card.isMatched ? 360 : 0))
                    .animation(Animation.easeInOut)
                    .font(Font.system(size: const.DrawingConstants.fontSize))
                    .scaleEffect(scale(thatFits: geometry.size))
            }.cadify(isFaceUp: card.isFaceUp)
        }
    }

    private func scale(thatFits size: CGSize) -> CGFloat {
        min(size.width, size.height) / const.DrawingConstants.fontSize * const.DrawingConstants.fontScale
    }

    private func font(in size: CGSize) -> Font {
        Font.system(size: min(size.width, size.height) * const.DrawingConstants.fontScale)
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        let game = EmojiMemoryGame()
        game.choose(game.cards.first!)
        return EmojiMemoryGameView(game: game)
//            .preferredColorScheme(.dark)
//        EmojiMemoryGameView(game: game)
            .preferredColorScheme(.light)
    }
}