package com.redhat.thermostat.web.server;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.gson.Gson;
import com.redhat.thermostat.common.storage.Query;
import com.redhat.thermostat.common.storage.Storage;
import com.redhat.thermostat.web.common.Qualifier;
import com.redhat.thermostat.web.common.RESTQuery;
import com.redhat.thermostat.web.common.StorageWrapper;

@SuppressWarnings("serial")
public class RESTStorageEndPoint extends HttpServlet {

    private Storage storage;

    public void init() {
        storage = StorageWrapper.getStorage();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        String uri = req.getRequestURI();
        System.err.println("request uri: " + uri);
        int lastPartIdx = uri.lastIndexOf("/");
        String cmd = uri.substring(lastPartIdx + 1);
        if (cmd.equals("find-pojo")) {
            findPojo(req, resp);
        }
    }

    @SuppressWarnings({ "rawtypes", "unchecked" })
    private void findPojo(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        try {
            Reader in = req.getReader();
            Gson gson = new Gson();
            RESTQuery query = gson.fromJson(in, RESTQuery.class);
            Class resultClass = Class.forName(query.getResultClassName());
            Query targetQuery = storage.createQuery();
            targetQuery = targetQuery.from(query.getCategory());
            List<Qualifier<?>> qualifiers = query.getQualifiers();
            for (Qualifier q : qualifiers) {
                targetQuery = targetQuery.where(q.getKey(), q.getCriteria(), q.getValue());
            }
            Object result = storage.findPojo(targetQuery, resultClass);
            resp.setStatus(HttpServletResponse.SC_OK);
            resp.setContentType("application/json");
            gson.toJson(result, resp.getWriter());
            resp.flushBuffer();
        } catch (ClassNotFoundException e) {
            resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "result class not found");
        }
    }

}