import Foundation
import WebSocketKit

private extension Int {
    
    mutating func advanceInTable() {
        self = (self + 1) % maximumPlayersPerTable
    }
}

final class Table {
    
    let id: TableId
    
    let name: TableName
    
    let isPublic: Bool
    
    var players: [Player] = []
    
    var phase: GamePhase = .waitingForPlayers
    
    var gameType: GameType? = nil
    
    var minimumPlayableGame: GameType.GameClass = .ruf
    
    /// Indicates if doubles are still allowed
    var canDoubleDuringGame = false
    
    /// Indicates if any player doubled during the current round, extending it to the next round
    var didDoubleInCurrentRound = false
    
    /// Indicates that all players acted after the first four cards
    var allPlayersFinishedDoubling: Bool {
        !players.contains { $0.didDoubleAfterFourCards == nil }
    }
    
    init(id: TableId, name: TableName, isPublic: Bool) {
        self.id = id
        self.name = name
        self.isPublic = isPublic
    }
    
    init(newTable name: TableName, isPublic: Bool) {
        self.id = .newToken()
        self.name = name
        self.isPublic = isPublic
    }
    
    func add(player: PlayerName) -> Bool {
        guard !isFull else {
            return false
        }
        let player = Player(name: player)
        players.append(player)
        if isFull {
            prepareTableForFirstGame()
        }
        sendUpdateToAllPlayers()
        return true
    }
    
    func contains(player: PlayerName) -> Bool {
        players.contains { $0.name == player }
    }
    
    func select(player: PlayerName) -> Player? {
        players.first { $0.name == player }
    }
    
    func player(leftOf index: Int) -> Player? {
        player(at: (index + 1) % 4)
    }
    
    func player(acrossOf index: Int) -> Player? {
        player(at: (index + 2) % 4)
    }
    
    func player(rightOf index: Int) -> Player? {
        player(at: (index + 3) % 4)
    }
    
    func player(at index: Int) -> Player? {
        guard index < players.count else {
            return nil
        }
        return players[index]
    }
    
    func remove(player: PlayerName) {
        guard contains(player: player) else {
            return
        }
        players = players.filter { $0.name != player }
        reset()
    }
    
    func connect(player name: PlayerName, using socket: WebSocket) -> Bool {
        guard let player = select(player: name) else {
            return false
        }
        player.connect(using: socket)
        sendUpdateToAllPlayers()
        return true
    }
    
    func disconnect(player name: PlayerName) {
        guard let player = select(player: name) else {
            return
        }
        guard player.disconnect() else {
            return
        }
        sendUpdateToAllPlayers()
        return
    }
    
    private func prepareTableForFirstGame() {
        self.phase = .waitingForPlayers
        self.gameType = nil
        self.minimumPlayableGame = .ruf // Not relevant in this phase
        self.canDoubleDuringGame = true // Not relevant in this phase
        self.didDoubleInCurrentRound = false // Not relevant in this phase
        let index = players.firstIndex { $0.playsFirstCard } ?? 0
        for i in 0..<maximumPlayersPerTable {
            players[i].prepareForFirstGame(isFirstPlayer: i == index)
        }
    }
    
    private func sendUpdateToAllPlayers() {
        players.enumerated().forEach { playerIndex, player in
            guard player.isConnected else {
                return
            }
            let info = TableInfo(self, forPlayerAt: playerIndex)
            player.send(info)
        }
    }
    
    // MARK: Player actions
    
    func perform(action: Player.Action, forPlayer player: PlayerName) -> PlayerActionResult {
        defer { sendUpdateToAllPlayers() }
        switch action {
        case .deal:
            return dealInitialCards()
        case .initialDoubleCost:
            return perform(double: true, forPlayer: player)
        case .noDoubleCost:
            return perform(double: false, forPlayer: player)
        case .offerWedding:
            fatalError()
        case .acceptWedding:
            fatalError()
        case .increaseOrMatchGame:
            fatalError()
        case .withdrawFromAuction:
            fatalError()
        case .doubleDuringGame:
            fatalError()
        }
    }
    
    private func dealInitialCards() -> PlayerActionResult {
        guard isFull else {
            return .tableNotFull
        }
        guard phase == .waitingForPlayers else {
            return .tableStateInvalid
        }
        
        phase = .collectingDoubles
        gameType = nil
        minimumPlayableGame = .ruf
        
        let cards = Dealer.dealFirstCards()
        for (index, player) in players.enumerated() {
            player.assignFirstCards(cards[index])
        }
        return .success
    }
    
    func perform(double: Bool, forPlayer name: PlayerName) -> PlayerActionResult {
        let player = select(player: player)!
        player.didDouble(double)
        if allPlayersFinishedDoubling {
            dealAdditionalCards()
        }
        return .success
    }
    
    private func dealAdditionalCards() {
        let cards = Dealer.dealRemainingCards(of: players.map { $0.rawCards })
        for (index, player) in players.enumerated() {
            player.assignRemainingCards(cards[index])
        }
        return .success
    }
    
    private func startAuction() {
        players.forEach { $0.startAuction() }
        minimumPlayableGame = .ruf
    }
    
    private func reset() {
        phase = .waitingForPlayers
        gameType = nil
        minimumPlayableGame = .ruf
    }
}

extension Table {
    
    var isFull: Bool {
        players.count == maximumPlayersPerTable
    }
    
    var publicInfo: PublicTableInfo {
        .init(id: id, name: name, players: playerNames)
    }
    
    var playerNames: [PlayerName] {
        players.map { $0.name }
    }
    
    func compileInfo(for player: PlayerName) -> TableInfo? {
        guard let index = players.firstIndex(where: { $0.name == player }) else {
            return nil
        }
        
        return TableInfo(self, forPlayerAt: index)
    }
}