package eu.dnetlib.uoaauthorizationlibrary.utils;

import com.google.gson.Gson;
import eu.dnetlib.uoaauthorizationlibrary.configuration.SecurityConfig;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.net.HttpURLConnection;
import java.net.URL;

@Component
public class AuthorizationUtils {
    private final Logger log = Logger.getLogger(this.getClass());
    private SecurityConfig securityConfig;

    @Autowired
    AuthorizationUtils(SecurityConfig securityConfig) {
        this.securityConfig = securityConfig;
    }

    public String getToken(HttpServletRequest request) {
        return this.getCookie(request, "AccessToken");
    }

    public boolean checkCookies(HttpServletRequest request) {
        boolean valid = true;
        String cookieValue = this.getCookie(request, "AccessToken");
        if (cookieValue == null || cookieValue.isEmpty()) {
            log.info("no cookie available ");
            valid = false;
        }
        return valid;
    }

    private String getCookie(HttpServletRequest request, String cookieName) {
        if (request.getCookies() == null) {
            return null;
        }
        for (Cookie c : request.getCookies()) {
            if (c.getName().equals(cookieName)) {
                return c.getValue();
            }

        }
        return null;
    }

    public UserInfo getUserInfo(String accessToken) {
        String url = securityConfig.getUserInfoUrl() + accessToken;
        try {
            URL obj = new URL(url);
            HttpURLConnection con = (HttpURLConnection) obj.openConnection();
            if (con.getResponseCode() != 200) {
                log.debug("User info response code is: " + con.getResponseCode());
                return null;
            }
            BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
            StringBuilder response = new StringBuilder();
            String inputLine;
            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine).append("\n");
            }
            in.close();
            return json2UserInfo(response.toString());
        } catch (Exception e) {
            log.error("An error occured while trying to fetch user info ", e);
            return null;
        }
    }

    private UserInfo json2UserInfo(String json) {
        if (json == null) {
            return null;
        }
        BufferedReader br = new BufferedReader(new StringReader(json));
        //convert the json string back to object
        Gson gson = new Gson();
        UserInfo userInfo = null;
        try {
            userInfo = gson.fromJson(br, UserInfo.class);
        } catch (Exception e) {
            log.debug("Error in parsing json response. Given json is : " + json, e);
            return null;
        }
        try {
            if (userInfo != null && userInfo.getEdu_person_entitlements() != null) {
                for (int i = 0; i < userInfo.getEdu_person_entitlements().size(); i++) {
                    String role = userInfo.getEdu_person_entitlements().get(i);
                    role = role.split(":")[role.split(":").length - 1];
                    role = role.replace("+", " ");
                    userInfo.getEdu_person_entitlements().set(i, role);
                }
            }
        } catch (Exception e) {
            log.debug("Error in parsing  Edu_person_entitlements : ", e);
            return null;
        }
        return userInfo;
    }

    public boolean isAuthorized(String token) {
        UserInfo userInfo = getUserInfo(token);
        if (userInfo != null) {
            return true;
        } else {
            log.debug(" User has no Valid UserInfo");
            return false;
        }

    }
}