package dev.bigduckie.staticdata;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;

import net.minecraft.util.Identifier;

/**
 * Represents one file retrieved from static_data
 */
public class StaticDataItem {
    private final Identifier id;
    private final Path path;
    private volatile String readCache = null;

    public StaticDataItem(Identifier id, Path path) {
        this.id = id;
        this.path = path;
    }

    public InputStream createInputStream() throws IOException {
        if (!Files.exists(path)) throw new FileNotFoundException(); //Should never happen
        return Files.newInputStream(path, StandardOpenOption.READ);
    }

    /**
     * Reads this data in as a UTF-8 String and returns it. Caches the data for later accesses.
     *
     * <p>This method is threadsafe.
     *
     * @return a String representing the contents of this static data item
     * @throws IOException
     */
    public String getAsString() throws IOException {
        if (readCache != null) return readCache; //DCL
        synchronized (this) {
            if (readCache != null) return readCache;

            if (!Files.exists(path)) throw new FileNotFoundException(); //Should never happen
            readCache = new String(Files.readAllBytes(path), StandardCharsets.UTF_8);
            return readCache;
        }
    }

    public Identifier getIdentifier() {
        return id;
    }
}