package io.gitlab.jfronny.inceptum.launcher.gson;

import io.gitlab.jfronny.gson.JsonParseException;
import io.gitlab.jfronny.gson.stream.JsonReader;
import io.gitlab.jfronny.gson.stream.JsonWriter;
import io.gitlab.jfronny.inceptum.launcher.system.source.*;

import java.io.IOException;
import java.util.LinkedHashSet;
import java.util.Set;

public class ModSourceAdapter {
    public static void write(ModSource src, JsonWriter writer) throws IOException {
        writer.beginObject();
        if (src instanceof ModrinthModSource mo) {
            writer.name("type").value("modrinth")
                    .name("id").value(mo.versionId);
        } else if (src instanceof DirectModSource di) {
            writer.name("type").value("direct")
                    .name("fileName").value(di.fileName)
                    .name("url").value(di.url)
                    .name("dependencies");
            writer.beginArray();
            for (ModSource dependency : di.dependencies) {
                write(dependency, writer);
            }
            writer.endArray();
        } else if (src instanceof CurseforgeModSource cu) {
            writer.name("type").value("curseforge");
            if (cu.shortName.matches("\\d+")) {
                writer.name("projectId").value(cu.projectId);
            } else {
                writer.name("project").value(cu.shortName);
            }
            writer.name("fileId").value(cu.fileId);
        } else throw new RuntimeException("ModSources with the type " + src.getClass() + " are not supported");
        writer.endObject();
    }

    public static ModSource read(JsonReader reader) throws IOException {
        String type = null;

        String mr$id = null;

        Integer cf$projectId = null;
        String cf$project = null;
        Integer cf$fileId = null;

        String direct$fileName = null;
        String direct$url = null;
        Set<ModSource> direct$dependencies = null;

        reader.beginObject();
        while (reader.hasNext()) {
            switch (reader.nextName()) {
                case "type" -> type = reader.nextString();
                case "id" -> mr$id = reader.nextString();
                case "projectId" -> cf$projectId = reader.nextInt();
                case "project" -> cf$project = reader.nextString();
                case "fileId" -> cf$fileId = reader.nextInt();
                case "fileName" -> direct$fileName = reader.nextString();
                case "url" -> direct$url = reader.nextString();
                case "dependencies" -> {
                    direct$dependencies = new LinkedHashSet<>();
                    reader.beginArray();
                    while (reader.hasNext()) direct$dependencies.add(read(reader));
                    reader.endArray();
                }
            }
        }
        reader.endObject();
        if (type == null) throw new JsonParseException("Expected ModSource to contain a type");
        return switch (type) {
            case "modrinth" -> {
                if (mr$id == null) throw new JsonParseException("Expected ModrinthModSource to contain a version ID");
                yield new ModrinthModSource(mr$id);
            }
            case "curseforge" -> {
                if (cf$fileId == null)
                    throw new JsonParseException("Expected a fileId in this curseforge project");
                if (cf$projectId != null) yield new CurseforgeModSource(cf$projectId, cf$fileId);
                else if (cf$project != null) yield new CurseforgeModSource(cf$project, cf$fileId);
                else throw new JsonParseException("Expected a projectId in this curseforge project");
            }
            case "direct" -> {
                if (direct$fileName == null) throw new JsonParseException("Expected direct download to have a fileName");
                if (direct$url == null) throw new JsonParseException("Expected direct download to have a url");
                if (direct$dependencies == null) yield new DirectModSource(direct$fileName, direct$url, Set.of());
                else {
                    yield new DirectModSource(direct$fileName, direct$url, direct$dependencies);
                }
            }
            default -> throw new JsonParseException("Unexpected ModSource type: " + type);
        };
    }
}