package net.knarcraft.placeholdersigns.handler;

import net.knarcraft.placeholdersigns.PlaceholderSigns;
import net.knarcraft.placeholdersigns.container.PlaceholderSign;
import org.bukkit.Bukkit;
import org.bukkit.Chunk;
import org.bukkit.Location;
import org.bukkit.World;
import org.bukkit.block.sign.Side;
import org.bukkit.configuration.ConfigurationSection;
import org.bukkit.configuration.file.YamlConfiguration;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import java.util.logging.Level;

/**
 * A handler for keeping track of placeholder signs
 */
public class PlaceholderSignHandler {

    private static final File signsFile = new File(PlaceholderSigns.getInstance().getDataFolder(), "signs.yml");

    private Set<PlaceholderSign> placeholderSigns;
    private Map<Location, PlaceholderSign> locationLookup;
    private Map<Chunk, Set<PlaceholderSign>> signsInChunk;

    /**
     * Gets a placeholder sign from the given location
     *
     * @param location <p>The location of the sign</p>
     * @return <p>The sign at the location, or null if no such sign exists</p>
     */
    @Nullable
    public PlaceholderSign getFromLocation(@NotNull Location location) {
        return locationLookup.get(location);
    }

    /**
     * Registers a new placeholder sign
     *
     * @param sign <p>The sign to register</p>
     */
    public void registerSign(@NotNull PlaceholderSign sign) {
        this.placeholderSigns.add(sign);
        this.locationLookup.put(sign.getLocation(), sign);

        Chunk chunk = sign.getLocation().getChunk();
        this.signsInChunk.putIfAbsent(chunk, new HashSet<>());
        this.signsInChunk.get(chunk).add(sign);
    }

    /**
     * Un-registers a placeholder sign
     *
     * @param sign <p>The sign to un-register</p>
     */
    public void unregisterSign(@NotNull PlaceholderSign sign) {
        this.locationLookup.remove(sign.getLocation());
        this.placeholderSigns.remove(sign);
        this.signsInChunk.get(sign.getLocation().getChunk()).remove(sign);
        PlaceholderSigns.getInstance().getUpdateQueueHandler().unQueueSign(sign);
    }

    /**
     * Gets all placeholder signs in the given chunk
     *
     * @param chunk <p>The chunk to check</p>
     * @return <p>All placeholder signs in the chunk</p>
     */
    @NotNull
    public Set<PlaceholderSign> getFromChunk(@NotNull Chunk chunk) {
        if (this.signsInChunk.containsKey(chunk)) {
            return this.signsInChunk.get(chunk);
        } else {
            return new HashSet<>();
        }
    }

    /**
     * Loads all placeholder signs from disk
     */
    public void load() {
        this.placeholderSigns = new HashSet<>();
        this.locationLookup = new HashMap<>();
        this.signsInChunk = new HashMap<>();

        YamlConfiguration configuration = YamlConfiguration.loadConfiguration(signsFile);
        ConfigurationSection signSection = configuration.getConfigurationSection("signs");
        if (signSection == null) {
            PlaceholderSigns.getInstance().getLogger().log(Level.INFO, "PlaceholderSigns found no signs to load");
            return;
        }

        for (String key : signSection.getKeys(false)) {
            String[] locationInfo = key.split(",");
            World world = Bukkit.getWorld(UUID.fromString(locationInfo[0]));
            double x = Integer.parseInt(locationInfo[1]);
            double y = Integer.parseInt(locationInfo[2]);
            double z = Integer.parseInt(locationInfo[3]);
            Location signLocation = new Location(world, x, y, z);

            Map<Side, Map<Integer, String>> allPlaceholders = new HashMap<>();
            Map<Integer, String> frontPlaceholders = new HashMap<>();
            Map<Integer, String> backPlaceholders = new HashMap<>();

            loadPlaceholders(signSection, key + ".placeholders.front.", frontPlaceholders);
            loadPlaceholders(signSection, key + ".placeholders.back.", backPlaceholders);

            allPlaceholders.put(Side.FRONT, frontPlaceholders);
            allPlaceholders.put(Side.BACK, backPlaceholders);

            String updateDelayKey = key + ".updateDelay";
            int updateDelay = -1;
            if (signSection.contains(updateDelayKey)) {
                updateDelay = signSection.getInt(updateDelayKey, -1);
            }
            if (updateDelay < 1) {
                updateDelay = PlaceholderSigns.getInstance().getSignUpdateDelay();
            }

            registerSign(new PlaceholderSign(signLocation, allPlaceholders, updateDelay));
        }
    }

    /**
     * Loads placeholders from one side of a sign
     *
     * @param signSection      <p>The configuration section to read</p>
     * @param configurationKey <p>The configuration key pointing to the placeholders</p>
     * @param placeholderMap   <p>The map to add read placeholders to</p>
     */
    private void loadPlaceholders(@NotNull ConfigurationSection signSection, @NotNull String configurationKey,
                                  @NotNull Map<Integer, String> placeholderMap) {
        for (int i = 0; i < 4; i++) {
            String placeholderKey = configurationKey + i;
            if (!signSection.contains(placeholderKey)) {
                continue;
            }

            String placeholder = signSection.getString(placeholderKey);
            placeholderMap.put(i, placeholder);
        }
    }

    /**
     * Saves all current placeholder signs
     */
    public void save() {
        try {
            YamlConfiguration configuration = new YamlConfiguration();
            ConfigurationSection signsSection = configuration.createSection("signs");
            for (PlaceholderSign sign : placeholderSigns) {
                saveSign(signsSection, sign);
            }
            configuration.save(signsFile);
        } catch (IOException exception) {
            PlaceholderSigns.getInstance().getLogger().log(Level.SEVERE, "Unable to save placeholder signs!");
        }
    }

    /**
     * Saves a sign to the given configuration section
     *
     * @param section <p>The configuration section to save to</p>
     * @param sign    <p>The sign to save</p>
     */
    private void saveSign(@NotNull ConfigurationSection section, @NotNull PlaceholderSign sign) {
        Location location = sign.getLocation();
        if (location.getWorld() == null) {
            return;
        }

        String key = location.getWorld().getUID() + "," + location.getBlockX() + "," + location.getBlockY() +
                "," + location.getBlockZ();
        String frontKey = key + ".placeholders.front";
        String backKey = key + ".placeholders.back";

        Map<Integer, String> frontPlaceholders = sign.getPlaceholders().get(Side.FRONT);
        if (frontPlaceholders != null) {
            for (Map.Entry<Integer, String> entry : frontPlaceholders.entrySet()) {
                section.set(frontKey + "." + entry.getKey(), entry.getValue());
            }
        }

        Map<Integer, String> backPlaceholders = sign.getPlaceholders().get(Side.BACK);
        if (backPlaceholders != null) {
            for (Map.Entry<Integer, String> entry : backPlaceholders.entrySet()) {
                section.set(backKey + "." + entry.getKey(), entry.getValue());
            }
        }

        section.set(key + ".updateDelay", sign.getUpdateDelay());
    }

}