package com.thebrokenrail.scriptcraft.core.quickjs;

import com.thebrokenrail.scriptcraft.core.ScriptCraftCore;
import com.thebrokenrail.scriptcraft.core.ScriptCraftEntryPoint;
import net.fabricmc.loader.api.FabricLoader;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;

@SuppressWarnings("unused")
public class QuickJSModules {
    private static boolean isDirectory(String data, String path, Class<?> clazz) {
        String[] lines = data.split("\n");
        for (String line : lines) {
            InputStream stream = clazz.getResourceAsStream(path + File.separator + line);
            return stream != null;
        }
        return false;
    }

    public static String loadModule(String name) {
        List<ScriptCraftEntryPoint> mods = FabricLoader.getInstance().getEntrypoints(ScriptCraftCore.NAMESPACE, ScriptCraftEntryPoint.class);
        for (ScriptCraftEntryPoint mod : mods) {
            //noinspection CatchMayIgnoreException
            try {
                String path = File.separator + ScriptCraftCore.NAMESPACE + File.separator + name;
                InputStream stream = mod.getClass().getResourceAsStream(path);

                if (stream != null) {
                    StringBuilder textBuilder = new StringBuilder();
                    try (Reader reader = new BufferedReader(new InputStreamReader(stream))) {
                        int c;
                        while ((c = reader.read()) != -1) {
                            textBuilder.append((char) c);
                        }
                    }
                    stream.close();

                    return isDirectory(textBuilder.toString(), path, mod.getClass()) ? null : textBuilder.toString();
                }
            } catch (IOException e) {
            }
        }
        return null;
    }

    private static final String[] SUPPORTED_EXTENSIONS;
    static {
        final String[] supportedExtensions = new String[]{"", ".js", ".json", ".mjs"};
        SUPPORTED_EXTENSIONS = new String[supportedExtensions.length * 2];
        for (int i = 0; i < supportedExtensions.length; i++) {
            SUPPORTED_EXTENSIONS[i + supportedExtensions.length] = File.separator + "index" + supportedExtensions[i];
            SUPPORTED_EXTENSIONS[i] = supportedExtensions[i];
        }
    }

    public static String normalizeModule(String baseName, String name) {
        String normalizedPath;

        baseName = baseName.replaceAll("/", File.separator);
        name = name.replaceAll("/", File.separator);

        if (name.startsWith(".")) {
            Path parentPath = Paths.get(baseName).getParent();
            if (parentPath == null) {
                parentPath = Paths.get(File.separator);
            }
            normalizedPath = Paths.get(parentPath.toString(), name).normalize().toString();
            if (normalizedPath.charAt(0) == File.separatorChar) {
                normalizedPath = normalizedPath.substring(1);
            }
        } else {
            normalizedPath = name;
        }

        for (String extension : SUPPORTED_EXTENSIONS) {
            if (loadModule(normalizedPath + extension) != null) {
                return normalizedPath + extension;
            }
        }

        return normalizedPath;
    }
}