package io.codef.api;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.HashMap;

import org.apache.commons.codec.binary.Base64;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;

/**
 * <pre>
 * io.codef.easycodef
 *   |_ EasyCodefConnector.java
 * </pre>
 * 
 * Desc : CODEF 엑세스 토큰 및 상품 조회를 위한 HTTP 요청 클래스
 * @Company : ©CODEF corp.
 * @Author  : notfound404@codef.io
 * @Date    : Jun 26, 2020 3:35:17 PM
 */
public class EasyCodefConnector {
	private static ObjectMapper mapper = new ObjectMapper();
	private static final int REPEAT_COUNT = 3;
	
	/**
	 * Desc : CODEF 상품 조회 요청
	 * @Company : ©CODEF corp.
	 * @Author  : notfound404@codef.io
	 * @Date    : Jun 26, 2020 3:35:26 PM
	 * @param urlPath
	 * @param serviceType
	 * @param bodyMap
	 * @param properties
	 * @return
	 * @throws InterruptedException
	 */
	@SuppressWarnings("unchecked")
	protected static EasyCodefResponse execute(String urlPath, int serviceType, HashMap<String, Object> bodyMap, EasyCodefProperties properties) throws InterruptedException {
		/**	#1.토큰 체크	*/
		String domain;
		String clientId;
		String clientSecret;

		if(serviceType == 0) {
			domain = EasyCodefConstant.API_DOMAIN;
			clientId = properties.getClientId();
			clientSecret = properties.getClientSecret();
		} else if(serviceType == 1) {
			domain = EasyCodefConstant.DEMO_DOMAIN;
			clientId = properties.getDemoClientId();
			clientSecret = properties.getDemoClientSecret();
		} else {
			domain = EasyCodefConstant.SANDBOX_DOMAIN;
			clientId = EasyCodefConstant.SANDBOX_CLIENT_ID;
			clientSecret = EasyCodefConstant.SANDBOX_CLIENT_SECRET;
		}
		
		String accessToken = getToken(clientId, clientSecret); // 토큰 반환
		
		/**	#2.요청 파라미터 인코딩	*/
		String bodyString;
		try {
			bodyString = mapper.writeValueAsString(bodyMap);
			bodyString = URLEncoder.encode(bodyString, "UTF-8");
		} catch (JsonProcessingException e) {
			EasyCodefResponse response = new EasyCodefResponse(EasyCodefMessageConstant.INVALID_JSON); 
			return response;
		} catch (UnsupportedEncodingException e) {
			EasyCodefResponse response = new EasyCodefResponse(EasyCodefMessageConstant.UNSUPPORTED_ENCODING); 
			return response;
		}
		
		/**	#3.상품 조회 요청	*/
		HashMap<String, Object> responseMap = requestProduct(domain + urlPath, accessToken, bodyString);
		if(EasyCodefConstant.INVALID_TOKEN.equals(responseMap.get("error")) || "CF-00401".equals(((HashMap<String, Object>)responseMap.get(EasyCodefConstant.RESULT)).get(EasyCodefConstant.CODE))){	// 액세스 토큰 유효기간 만료되었을 경우 토큰 재발급 후 상품 조회 요청 진행
			EasyCodefTokenMap.setToken(clientId, null);		// 토큰 정보 초기화
			accessToken = getToken(clientId, clientSecret); // 토큰 설정
			responseMap = requestProduct(domain + urlPath, accessToken, bodyString);
		} else if (EasyCodefConstant.ACCESS_DENIED.equals(responseMap.get("error")) || "CF-00403".equals(((HashMap<String, Object>)responseMap.get(EasyCodefConstant.RESULT)).get(EasyCodefConstant.CODE))) {	// 접근 권한이 없는 경우 - 오류코드 반환
			EasyCodefResponse response = new EasyCodefResponse(EasyCodefMessageConstant.UNAUTHORIZED, EasyCodefConstant.ACCESS_DENIED); 
			return response;
		}
		
		/**	#4.상품 조회 결과 반환	*/
		EasyCodefResponse response = new EasyCodefResponse(responseMap); 
		return response;
	}
	
	/**
	 * Desc : CODEF HTTP POST 요청
	 * @Company : ©CODEF corp.
	 * @Author  : notfound404@codef.io
	 * @Date    : Jun 26, 2020 3:35:34 PM
	 * @param urlPath
	 * @param token
	 * @param bodyString
	 * @return
	 */
	private static HashMap<String, Object> requestProduct(String urlPath, String token, String bodyString) {
		BufferedReader br = null;
		try {
			// HTTP 요청을 위한 URL 오브젝트 생성
			URL url = new URL(urlPath);
			HttpURLConnection con = (HttpURLConnection) url.openConnection();
			con.setDoOutput(true);
			con.setRequestMethod("POST");
			con.setRequestProperty("Accept", "application/json");

			if (token != null && !"".equals(token)) {
				con.setRequestProperty("Authorization", "Bearer " + token);		// 엑세스 토큰 헤더 설정
			}

			// 리퀘스트 바디 전송
			OutputStream os = con.getOutputStream();
			if (bodyString != null && !"".equals(bodyString)) {
				os.write(bodyString.getBytes());
			}
			os.flush();
			os.close();

			// 응답 코드 확인
			int responseCode = con.getResponseCode();
			if (responseCode == HttpURLConnection.HTTP_OK) {
				br = new BufferedReader(new InputStreamReader(con.getInputStream())); 
			} else if (responseCode == HttpURLConnection.HTTP_BAD_REQUEST) {
				EasyCodefResponse response = new EasyCodefResponse(EasyCodefMessageConstant.BAD_REQUEST, urlPath); 
				return response;
			} else if (responseCode == HttpURLConnection.HTTP_UNAUTHORIZED) {
				EasyCodefResponse response = new EasyCodefResponse(EasyCodefMessageConstant.UNAUTHORIZED, urlPath); 
				return response; 
			} else if (responseCode == HttpURLConnection.HTTP_FORBIDDEN) {
				EasyCodefResponse response = new EasyCodefResponse(EasyCodefMessageConstant.FORBIDDEN, urlPath); 
				return response; 
			} else if (responseCode == HttpURLConnection.HTTP_NOT_FOUND) {
				EasyCodefResponse response = new EasyCodefResponse(EasyCodefMessageConstant.NOT_FOUND, urlPath); 
				return response; 
			} else {
				EasyCodefResponse response = new EasyCodefResponse(EasyCodefMessageConstant.SERVER_ERROR, urlPath); 
				return response;
			}
			
			// 응답 바디 read
			String inputLine;
			StringBuffer responseStr = new StringBuffer();
			while ((inputLine = br.readLine()) != null) {
				responseStr.append(inputLine);
			}
			br.close();
			
			// 결과 반환
			return mapper.readValue(URLDecoder.decode(responseStr.toString(), "UTF-8"), new TypeReference<HashMap<String, Object>>(){});	
		} catch (Exception e) {
			EasyCodefResponse response = new EasyCodefResponse(EasyCodefMessageConstant.LIBRARY_SENDER_ERROR, e.getMessage()); 
			return response;
		} finally {
			if(br != null) {
				try {
					br.close();
				} catch (IOException e) {}
			}
		}
	}
	
	/**
	 * Desc : 엑세스 토큰 반환
	 * @Company : ©CODEF corp.
	 * @Author  : notfound404@codef.io
	 * @Date    : Jun 26, 2020 3:35:47 PM
	 * @param clientId
	 * @param clientSecret
	 * @return
	 * @throws InterruptedException
	 */
	private static String getToken(String clientId, String clientSecret) throws InterruptedException {
		int i = 0;
		String accessToken = EasyCodefTokenMap.getToken(clientId);
		if(accessToken == null || "".equals(accessToken) || !checkToken(accessToken)) { //만료 조건 추가
			while(i < REPEAT_COUNT) {	// 토큰 발급 요청은 최대 3회까지 재시도
				HashMap<String, Object> tokenMap = publishToken(clientId, clientSecret);	// 토큰 발급 요청
				if(tokenMap != null) {
					String newToken = (String)tokenMap.get("access_token");
					EasyCodefTokenMap.setToken(clientId, newToken);	// 토큰 저장
					accessToken = newToken;
				}
				
				if(accessToken != null || !"".equals(accessToken)) {
					break;	// 정상 발급시 반복문 종료
				}
				
				Thread.sleep(20);
				i++;
			}
		}
		
		return accessToken;
	}
	
	/**
	 * Desc : CODEF 엑세스 토큰 발급 요청
	 * @Company : ©CODEF corp.
	 * @Author  : notfound404@codef.io
	 * @Date    : Jun 26, 2020 3:36:01 PM
	 * @param clientId
	 * @param clientSecret
	 * @return
	 */
	protected static HashMap<String, Object> publishToken(String clientId, String clientSecret) {
		BufferedReader br = null;
		try {
			// HTTP 요청을 위한 URL 오브젝트 생성
			URL url = new URL(EasyCodefConstant.OAUTH_DOMAIN + EasyCodefConstant.GET_TOKEN);
			String params = "grant_type=client_credentials&scope=read";	// Oauth2.0 사용자 자격증명 방식(client_credentials) 토큰 요청 설정
			
			HttpURLConnection con = (HttpURLConnection) url.openConnection();
			con.setRequestMethod("POST");
			con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
			
			// 클라이언트아이디, 시크릿코드 Base64 인코딩
			String auth = clientId + ":" + clientSecret;
			byte[] authEncBytes = Base64.encodeBase64(auth.getBytes());
			String authStringEnc = new String(authEncBytes);
			String authHeader = "Basic " + authStringEnc;
			
			con.setRequestProperty("Authorization", authHeader);
			con.setDoInput(true);
			con.setDoOutput(true);
			
			// 리퀘스트 바디 전송
			OutputStream os = con.getOutputStream();
			os.write(params.getBytes());
			os.flush();
			os.close();
	
			// 응답 코드 확인
			int responseCode = con.getResponseCode();
			if (responseCode == HttpURLConnection.HTTP_OK) {	// 정상 응답
				br = new BufferedReader(new InputStreamReader(con.getInputStream()));
			} else {	 // 에러 발생
				return null;
			}
			
			// 응답 바디 read
			String inputLine;
			StringBuffer responseStr = new StringBuffer();
			while ((inputLine = br.readLine()) != null) {
				responseStr.append(inputLine);
			}
			br.close();
			
			HashMap<String, Object> tokenMap = mapper.readValue(URLDecoder.decode(responseStr.toString(), "UTF-8"), new TypeReference<HashMap<String, Object>>(){});
			return tokenMap;
		} catch (Exception e) {
			return null;
		} finally {
			if(br != null) {
				try {
					br.close();
				} catch (IOException e) { }
			}
		}
	}

	/**
	 * 토큰 유효기간 확인
	 * @param accessToken
	 * @return
	 */
	private static boolean checkToken(String accessToken) {
        HashMap<String, Object> tokenMap = null;
        try {
            tokenMap = EasyCodefUtil.getTokenMap(accessToken);
        } catch (IOException e) {
            // 확인 중 오류 발생 시
            return false;
        }
        // 토큰의 유효 기간 확인
        return EasyCodefUtil.checkValidity((int) (tokenMap.get("exp")));
    }
}