package mage.game.draft;

import mage.cards.Card;
import mage.cards.ExpansionSet;
import mage.game.draft.DraftOptions.TimingOption;
import mage.game.events.*;
import mage.game.events.TableEvent.EventType;
import mage.players.Player;
import mage.players.PlayerList;
import mage.util.ThreadUtils;
import mage.util.XmageThreadFactory;
import org.apache.log4j.Logger;

import java.util.*;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

/**
 * @author BetaSteward_at_googlemail.com, JayDi85
 */
public abstract class DraftImpl implements Draft {

    protected static final Logger logger = Logger.getLogger(DraftImpl.class);

    protected final UUID id;
    protected UUID tableId = null;
    protected final Map<UUID, DraftPlayer> players = new LinkedHashMap<>();
    protected final PlayerList table = new PlayerList();
    protected int numberBoosters;
    protected DraftCube draftCube;
    protected List<ExpansionSet> sets;
    protected List<String> setCodes;
    protected int boosterNum = 1; // starts with booster 1
    protected int cardNum = 1; // starts with card number 1, increases by +1 after each picking
    protected TimingOption timing;
    protected int boosterLoadingCounter; // number of times the boosters have been sent to players until all are confirmed to have received them
    protected final int BOOSTER_LOADING_INTERVAL_SECS = 2; // interval in seconds

    protected boolean abort = false;
    protected boolean started = false;

    protected transient TableEventSource tableEventSource = new TableEventSource();
    protected transient PlayerQueryEventSource playerQueryEventSource = new PlayerQueryEventSource();

    protected ScheduledFuture<?> boosterSendingWorker;
    protected ScheduledExecutorService boosterSendingExecutor = null;

    public DraftImpl(DraftOptions options, List<ExpansionSet> sets) {
        this.id = UUID.randomUUID();
        this.setCodes = options.getSetCodes();
        this.draftCube = options.getDraftCube();
        this.timing = options.getTiming();
        this.sets = sets;
        this.numberBoosters = options.getNumberBoosters();
    }

    @Override
    public UUID getId() {
        return id;
    }

    @Override
    public UUID getTableId() {
        return tableId;
    }

    @Override
    public void setTableId(UUID tableId) {
        this.tableId = tableId;
    }

    @Override
    public void addPlayer(Player player) {
        DraftPlayer draftPlayer = new DraftPlayer(player);
        players.put(player.getId(), draftPlayer);
        table.add(player.getId());
    }

    @Override
    public boolean replacePlayer(Player oldPlayer, Player newPlayer) {
        if (newPlayer != null) {
            DraftPlayer newDraftPlayer = new DraftPlayer(newPlayer);
            DraftPlayer oldDraftPlayer = players.get(oldPlayer.getId());
            Map<UUID, DraftPlayer> newPlayers = new LinkedHashMap<>();
            synchronized (players) {
                for (Map.Entry<UUID, DraftPlayer> entry : players.entrySet()) {
                    if (entry.getKey().equals(oldPlayer.getId())) {
                        newPlayers.put(newPlayer.getId(), newDraftPlayer);
                    } else {
                        newPlayers.put(entry.getKey(), entry.getValue());
                    }
                }
                players.clear();
                for (Map.Entry<UUID, DraftPlayer> entry : newPlayers.entrySet()) {
                    players.put(entry.getKey(), entry.getValue());
                }
            }
            synchronized (table) {
                UUID currentId = table.get();
                if (currentId.equals(oldPlayer.getId())) {
                    currentId = newPlayer.getId();
                }
                table.clear();
                for (UUID playerId : players.keySet()) {
                    table.add(playerId);
                }

                table.setCurrent(currentId);
            }

            // boosters send to all players by timeout, so don't need to send it manually here
            newDraftPlayer.setBoosterAndLoad(oldDraftPlayer.getBooster());
            if (oldDraftPlayer.isPicking()) {
                newDraftPlayer.setPickingAndSending();
            }
            boosterSendingStart(); // if it's AI then make pick from it

            return true;
        }
        return false;
    }

    @Override
    public Collection<DraftPlayer> getPlayers() {
        synchronized (players) {
            return new ArrayList<>(players.values());
        }
    }

    @Override
    public DraftPlayer getPlayer(UUID playerId) {
        return players.get(playerId);
    }

    @Override
    public DraftCube getDraftCube() {
        return draftCube;
    }

    /**
     * Number of boosters that each player gets in this draft
     *
     * @return
     */
    @Override
    public int getNumberBoosters() {
        return numberBoosters;
    }

    @Override
    public List<ExpansionSet> getSets() {
        return sets;
    }

    @Override
    public int getBoosterNum() {
        return boosterNum;
    }

    @Override
    public int getCardNum() {
        return cardNum;
    }

    @Override
    public void leave(UUID playerId) {
        //TODO: implement this
    }

    @Override
    public void autoPick(UUID playerId) {
        if (players.containsKey(playerId)) {
            List<Card> booster = players.get(playerId).getBooster();
            if (booster.size() > 0) {
                this.addPick(playerId, booster.get(booster.size() - 1).getId(), null);
            }
        }
    }

    protected void passBoosterToLeft() {
        synchronized (players) {
            UUID startId = table.get(0);
            UUID currentId = startId;
            UUID nextId = table.getNext(); // getNext return left player by default
            DraftPlayer current = players.get(currentId);
            DraftPlayer next = players.get(nextId);
            List<Card> currentBooster = current.booster;
            while (true) {
                List<Card> nextBooster = next.booster;
                next.setBoosterAndLoad(currentBooster);
                if (Objects.equals(nextId, startId)) {
                    break;
                }
                currentBooster = nextBooster;
                nextId = table.getNext();
                next = players.get(nextId);
            }
        }
    }

    protected void passBoosterToRight() {
        synchronized (players) {
            UUID startId = table.get(0);
            UUID currentId = startId;
            UUID prevId = table.getPrevious(); // getPrevious return right player by default
            DraftPlayer current = players.get(currentId);
            DraftPlayer prev = players.get(prevId);
            List<Card> currentBooster = current.booster;
            while (true) {
                List<Card> prevBooster = prev.booster;
                prev.setBoosterAndLoad(currentBooster);
                if (Objects.equals(prevId, startId)) {
                    break;
                }
                currentBooster = prevBooster;
                prevId = table.getPrevious();
                prev = players.get(prevId);
            }
        }
    }

    protected void openBooster() {
        synchronized (players) {
            if (boosterNum <= numberBoosters) {
                for (DraftPlayer player : players.values()) {
                    if (draftCube != null) {
                        player.setBoosterAndLoad(draftCube.createBooster());
                    } else {
                        player.setBoosterAndLoad(sets.get(boosterNum - 1).createBooster());
                    }
                }
            }
        }
    }

    protected boolean pickCards() {
        synchronized (players) {
            for (DraftPlayer player : players.values()) {
                if (player.getBooster().isEmpty()) {
                    return false;
                }
                player.setPickingAndSending();
            }
        }

        while (!donePicking()) {
            boosterSendingStart();
            picksWait();
        }

        cardNum++;
        return true;
    }

    public void boosterSendingStart() {
        if (this.boosterSendingExecutor == null) {
            this.boosterSendingExecutor = Executors.newSingleThreadScheduledExecutor(
                    new XmageThreadFactory(ThreadUtils.THREAD_PREFIX_TOURNEY_BOOSTERS_SEND + " " + this.getId())
            );
        }
        boosterLoadingCounter = 0;

        if (boosterSendingWorker == null) {
            boosterSendingWorker = boosterSendingExecutor.scheduleAtFixedRate(() -> {
                try {
                    if (isAbort() || sendBoostersToPlayers()) {
                        boosterSendingEnd();
                    } else {
                        boosterLoadingCounter++;
                    }
                } catch (Exception ex) {
                    logger.fatal("Fatal boosterLoadingHandle error in draft " + id + " pack " + boosterNum + " pick " + cardNum, ex);
                }
            }, 0, BOOSTER_LOADING_INTERVAL_SECS, TimeUnit.SECONDS);
        }
    }

    protected void boosterSendingEnd() {
        if (boosterSendingWorker != null) {
            boosterSendingWorker.cancel(true);
            boosterSendingWorker = null;
        }
    }

    protected boolean sendBoostersToPlayers() {
        boolean allBoostersLoaded = true;
        for (DraftPlayer player : getPlayers()) {
            if (player.isPicking() && !player.isBoosterLoaded()) {
                allBoostersLoaded = false;
                player.getPlayer().pickCard(player.getBooster(), player.getDeck(), this);
            }
        }
        return allBoostersLoaded;
    }

    protected boolean donePicking() {
        if (isAbort()) {
            return true;
        }

        synchronized (players) {
            return players.values()
                    .stream()
                    .noneMatch(DraftPlayer::isPicking);
        }
    }

    @Override
    public boolean allJoined() {
        synchronized (players) {
            return players.values().stream()
                    .allMatch(DraftPlayer::isJoined);
        }
    }

    @Override
    public void addTableEventListener(Listener<TableEvent> listener) {
        tableEventSource.addListener(listener);
    }

    @Override
    public void fireUpdatePlayersEvent() {
        tableEventSource.fireTableEvent(EventType.UPDATE, null, this);
    }

    @Override
    public void fireEndDraftEvent() {
        tableEventSource.fireTableEvent(EventType.END, null, this);
    }

    @Override
    public void addPlayerQueryEventListener(Listener<PlayerQueryEvent> listener) {
        playerQueryEventSource.addListener(listener);
    }

    @Override
    public void firePickCardEvent(UUID playerId) {
        DraftPlayer player = players.get(playerId);
        playerQueryEventSource.pickCard(playerId, "Pick card", player.getBooster(), getPickTimeout());
    }

    @Override
    public int getPickTimeout() {
        int cardNum = Math.min(15, this.cardNum);
        int time = timing.getPickTimeout(cardNum);
        // if the pack is re-sent to a player because they haven't been able to successfully load it, the pick time is reduced appropriately because of the elapsed time
        // the time is always at least 1 second unless it's set to 0, i.e. unlimited time
        if (time > 0) {
            time = Math.max(1, time - boosterLoadingCounter * BOOSTER_LOADING_INTERVAL_SECS);
        }
        return time;
    }

    public void picksCheckDone() {
        // notify main thread about changes, can be called from user's thread
        synchronized (this) {
            this.notifyAll();
        }
    }

    protected void picksWait() {
        // main thread waiting any picks or changes
        synchronized (this) {
            try {
                this.wait(10000); // checked every 10s to make sure the draft moves on
            } catch (InterruptedException ignore) {
            }
        }

        if (donePicking()) {
            boosterSendingEnd();
        }
    }

    @Override
    public boolean addPick(UUID playerId, UUID cardId, Set<UUID> hiddenCards) {
        DraftPlayer player = players.get(playerId);
        if (player.isPicking()) {
            for (Card card : player.booster) {
                if (card.getId().equals(cardId)) {
                    player.addPick(card, hiddenCards);
                    break;
                }
            }
            picksCheckDone();
        }
        return !player.isPicking();
    }

    @Override
    public void setBoosterLoaded(UUID playerId) {
        DraftPlayer player = players.get(playerId);
        player.setBoosterLoaded();
    }

    @Override
    public boolean isAbort() {
        return abort;
    }

    @Override
    public void setAbort(boolean abort) {
        this.abort = abort;
    }

    @Override
    public boolean isStarted() {
        return started;
    }

    @Override
    public void setStarted() {
        started = true;
    }

}