package de.lucas.litematica.placement;

import de.lucas.litematica.schematic.SchematicFiles;
import de.lucas.litematica.schematic.SchematicManager;
import net.minecraft.ChatFormatting;
import net.minecraft.client.Minecraft;
import net.minecraft.core.BlockPos;
import net.minecraft.network.chat.Component;
import net.minecraft.resources.ResourceLocation;
import org.jetbrains.annotations.Nullable;

import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.UUID;

/**
 * All placements of the current world/server. Main thread only. Placements are persisted per world and restored
 * on the next login, see {@link PlacementStorage}.
 */
public final class PlacementManager {
    private static final PlacementManager INSTANCE = new PlacementManager();
    private static final int SAVE_DELAY_TICKS = 40;

    private final List<SchematicPlacement> placements = new ArrayList<>();
    @Nullable
    private UUID selected;
    @Nullable
    private String worldKey;
    private int saveCountdown = -1;

    public static PlacementManager get() {
        return INSTANCE;
    }

    public List<SchematicPlacement> all() {
        return Collections.unmodifiableList(this.placements);
    }

    /** Placements in the player's current dimension. */
    public List<SchematicPlacement> inCurrentDimension() {
        Minecraft mc = Minecraft.getInstance();
        if (mc.level == null) {
            return List.of();
        }
        ResourceLocation dim = mc.level.dimension().location();
        return this.placements.stream().filter(p -> p.dimension().equals(dim)).toList();
    }

    @Nullable
    public SchematicPlacement selected() {
        for (SchematicPlacement p : this.placements) {
            if (p.id().equals(this.selected)) {
                return p;
            }
        }
        return null;
    }

    public void select(@Nullable SchematicPlacement placement) {
        this.selected = placement == null ? null : placement.id();
        this.markDirty();
    }

    /** Selects the next placement in the current dimension, wrapping around. */
    public void selectNext() {
        List<SchematicPlacement> list = this.inCurrentDimension();
        if (list.isEmpty()) {
            return;
        }
        int index = list.indexOf(this.selected());
        this.select(list.get((index + 1) % list.size()));
    }

    /** Places a schematic file with its minimum corner at {@code origin}. The file is loaded in the background. */
    public SchematicPlacement place(Path file, BlockPos origin) {
        Minecraft mc = Minecraft.getInstance();
        ResourceLocation dim = mc.level != null ? mc.level.dimension().location() : ResourceLocation.withDefaultNamespace("overworld");
        SchematicPlacement placement = new SchematicPlacement(UUID.randomUUID(), SchematicFiles.relativeName(file), dim,
                SchematicFiles.baseName(file), origin.immutable(), origin.immutable(), PlacementTransform.IDENTITY, true);
        this.placements.add(placement);
        this.selected = placement.id();
        this.loadSchematic(placement, true);
        this.markDirty();
        return placement;
    }

    public void remove(SchematicPlacement placement) {
        this.placements.remove(placement);
        if (placement.id().equals(this.selected)) {
            this.selected = this.placements.isEmpty() ? null : this.placements.getLast().id();
        }
        this.markDirty();
    }

    public void move(SchematicPlacement placement, int dx, int dy, int dz) {
        this.setOrigin(placement, placement.origin().offset(dx, dy, dz));
    }

    public void setOrigin(SchematicPlacement placement, BlockPos origin) {
        placement.setOrigin(origin);
        this.markDirty();
    }

    public void resetOrigin(SchematicPlacement placement) {
        this.setOrigin(placement, placement.originalOrigin());
    }

    /** Makes the current position the one {@link #resetOrigin} returns to. */
    public void storeOriginAsOriginal(SchematicPlacement placement) {
        placement.setOriginalOrigin(placement.origin());
        this.markDirty();
    }

    public void setTransform(SchematicPlacement placement, PlacementTransform transform) {
        placement.setTransform(transform);
        this.markDirty();
    }

    public void setEnabled(SchematicPlacement placement, boolean enabled) {
        placement.setEnabled(enabled);
        this.markDirty();
    }

    public void rename(SchematicPlacement placement, String name) {
        if (!name.isBlank()) {
            placement.setName(name.trim());
            this.markDirty();
        }
    }

    /** Reloads all placements that use the given file, e.g. after it was replaced on disk. */
    public void reloadFile(Path file) {
        String relative = SchematicFiles.relativeName(file);
        SchematicManager.get().invalidate(file);
        for (SchematicPlacement p : this.placements) {
            if (p.schematicFile().equals(relative)) {
                this.loadSchematic(p, false);
            }
        }
    }

    public void tick() {
        if (this.saveCountdown >= 0 && --this.saveCountdown < 0) {
            this.save();
        }
    }

    public void onLogin() {
        this.placements.clear();
        this.worldKey = PlacementStorage.currentWorldKey();
        PlacementStorage.Loaded loaded = PlacementStorage.load(this.worldKey);
        this.placements.addAll(loaded.placements());
        this.selected = loaded.selected();
        for (SchematicPlacement p : this.placements) {
            this.loadSchematic(p, false);
        }
    }

    public void onLogout() {
        this.save();
        this.placements.clear();
        this.selected = null;
        this.worldKey = null;
    }

    private void markDirty() {
        this.saveCountdown = SAVE_DELAY_TICKS;
    }

    private void save() {
        this.saveCountdown = -1;
        if (this.worldKey != null) {
            PlacementStorage.save(this.worldKey, this.placements, this.selected);
        }
    }

    private void loadSchematic(SchematicPlacement placement, boolean announce) {
        Minecraft mc = Minecraft.getInstance();
        Path file = SchematicFiles.resolve(placement.schematicFile());
        SchematicManager.get().load(file).whenComplete((schematic, error) -> mc.execute(() -> {
            if (!this.placements.contains(placement)) {
                return;
            }
            if (error != null) {
                String message = SchematicManager.errorMessage(error);
                placement.setSchematic(null, message);
                notify(Component.translatable("neolitematica.message.load_failed", placement.schematicFile(), message).withStyle(ChatFormatting.RED));
            } else {
                placement.setSchematic(schematic, null);
                if (announce) {
                    notify(Component.translatable("neolitematica.message.placed", placement.name(),
                            placement.origin().getX(), placement.origin().getY(), placement.origin().getZ()));
                }
            }
        }));
    }

    private static void notify(Component message) {
        Minecraft mc = Minecraft.getInstance();
        if (mc.player != null) {
            mc.player.displayClientMessage(message, false);
        }
    }
}