import java.util.Stack;
import java.util.stream.Collectors;

import com.google.gson.JsonArray;
import com.google.gson.JsonObject;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

public class JsonConverter extends NlpBaseListener {
	public JsonConverter() {
		mGsonInstance = new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create();
		mRoot = new JsonObject();
		mSection = new JsonArray();
		mSectionStack = new Stack<JsonArray>();
	}
	/* ========== JSON related stuff ========== */

	Gson mGsonInstance;

	public String buildJsonString() {
		return mGsonInstance.toJson(mRoot);
	}

	/* ========== Section layout related stuff ========== */

	JsonObject mRoot;
	JsonArray mSection;
	Stack<JsonArray> mSectionStack;

	private void pushSection() {
		mSectionStack.push(mSection);
		mSection = new JsonArray();
	}

	private void popSection() {
		mSection = mSectionStack.pop();
	}

	/* ========== Listener ========== */

	@Override
	public void enterDocument(NlpParser.DocumentContext ctx) {
		// insert language prop
		mRoot.addProperty("language", StringHelper.cutLanguageHead(ctx.LANG_HEADER().getText()));
	}

	@Override
	public void exitDocument(NlpParser.DocumentContext ctx) {
		// insert document prop
		mRoot.add("entries", mSection);
	}

	@Override
	public void enterSection(NlpParser.SectionContext ctx) {
		pushSection();
	}

	@Override
	public void exitSection(NlpParser.SectionContext ctx) {
		// create new object
		JsonObject objSection = new JsonObject();
		objSection.addProperty("section", StringHelper.cutSectionHead(ctx.SECTION_HEAD().getText()));
		objSection.add("entries", mSection);
		// pop and insert
		popSection();
		mSection.add(objSection);
	}

	@Override
	public void enterSubSection(NlpParser.SubSectionContext ctx) {
		pushSection();
	}

	@Override
	public void exitSubSection(NlpParser.SubSectionContext ctx) {
		// create new object
		JsonObject objSubSection = new JsonObject();
		objSubSection.addProperty("section", StringHelper.cutSectionHead(ctx.SUB_SECTION_HEAD().getText()));
		objSubSection.add("entries", mSection);
		// pop and insert
		popSection();
		mSection.add(objSubSection);
	}

	@Override
	public void enterEntryString(NlpParser.EntryStringContext ctx) {
		mSection.add(StringHelper.processString(ctx.ENTRY_STRING().getText()));
	}

	@Override
	public void enterEntryConcatedString(NlpParser.EntryConcatedStringContext ctx) {
		mSection.add(StringHelper.processConcatedString(
				ctx.ENTRY_STRING().stream().map(value -> value.getText()).collect(Collectors.toList())));
	}

	@Override
	public void enterEntryInteger(NlpParser.EntryIntegerContext ctx) {
		mSection.add(Integer.parseInt(ctx.ENTRY_INTEGER().getText()));
	}
}