blight/blight-common/src/main/java/de/blight/common/model/CharacterIO.java

package de.blight.common.model;

import com.google.gson.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.*;
import java.util.stream.Stream;

/**
 * Lädt und speichert {@link GameCharacter}-Instanzen als JSON.
 * Dateiformat: <id>.character  im Verzeichnis  character/
 *
 * JSON-Struktur:
 * {
 *   "type": "MAIN_CHARACTER" | "NPC",
 *   "characterId": "hero",
 *   "name": "Der Held",
 *   "modelPath": "Models/hero.j3o",
 *   "animSetPath": "animations/sets/hero.j3o",
 *   ... (subclass fields via Gson)
 * }
 * Die Aktions-Zuweisung (IDLE → Clip-Name usw.) ist im AnimSet gespeichert
 * (animSetPath.replaceAll(".j3o", "") + ".animset.json").
 */
public final class CharacterIO {

    private static final Logger log = LoggerFactory.getLogger(CharacterIO.class);
    private static final String EXTENSION = ".character";
    private static final Gson GSON = new GsonBuilder().setPrettyPrinting().create();

    private CharacterIO() {}

    // ── Save ──────────────────────────────────────────────────────────────────

    public static void save(GameCharacter character, Path directory) throws IOException {
        String id = character.getCharacterId();
        if (id == null || id.isBlank()) throw new IllegalArgumentException("characterId must be set");
        Files.createDirectories(directory);

        JsonObject obj = (JsonObject) GSON.toJsonTree(character);
        obj.addProperty("type", character instanceof MainCharacter ? "MAIN_CHARACTER" : "NPC");
        Files.writeString(directory.resolve(id + EXTENSION),
                GSON.toJson(obj), StandardCharsets.UTF_8);
        log.debug("[CharacterIO] Gespeichert: {}", id);
    }

    // ── Load ──────────────────────────────────────────────────────────────────

    public static GameCharacter load(Path file) throws IOException {
        String json = Files.readString(file, StandardCharsets.UTF_8);
        JsonObject obj = JsonParser.parseString(json).getAsJsonObject();
        String type = obj.has("type") ? obj.get("type").getAsString() : "NPC";
        GameCharacter c = "MAIN_CHARACTER".equals(type)
                ? GSON.fromJson(obj, MainCharacter.class)
                : GSON.fromJson(obj, NPC.class);
        log.debug("[CharacterIO] Geladen: {}", file.getFileName());
        return c;
    }

    /** Lädt alle .character-Dateien aus dem angegebenen Verzeichnis. */
    public static List<GameCharacter> loadAll(Path directory) {
        if (!Files.isDirectory(directory)) return List.of();
        List<GameCharacter> result = new ArrayList<>();
        try (Stream<Path> walk = Files.list(directory)) {
            walk.filter(p -> p.toString().endsWith(EXTENSION))
                .sorted()
                .forEach(p -> {
                    try { result.add(load(p)); } catch (IOException e) {
                        log.warn("[CharacterIO] Fehler beim Laden von {}: {}", p, e.getMessage());
                    }
                });
        } catch (IOException e) {
            log.warn("[CharacterIO] Fehler beim Scannen von {}: {}", directory, e.getMessage());
        }
        return result;
    }

    /** Gibt true zurück wenn bereits eine MainCharacter-Datei im Verzeichnis existiert (außer der mit excludeId). */
    public static boolean mainCharacterExists(Path directory, String excludeId) {
        for (GameCharacter c : loadAll(directory)) {
            if (c instanceof MainCharacter
                    && !Objects.equals(c.getCharacterId(), excludeId)) return true;
        }
        return false;
    }
}