package kr.re.etri.autoflow.service;

import com.fasterxml.jackson.databind.ObjectMapper;
import jakarta.annotation.PostConstruct;
import kr.re.etri.autoflow.payload.request.EdgePkgInfoRequest;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.ByteArrayResource;
import org.springframework.http.*;
import org.springframework.stereotype.Service;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestTemplate;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.multipart.MultipartFile;

import javax.net.ssl.*;
import java.io.IOException;
import java.net.URI;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.security.cert.X509Certificate;
import java.util.HashMap;
import java.util.Map;

@Service
public class ExternalAuthService {

    private RestTemplate restTemplate;

    @Value("${external.auth.signin-url}")
    private String signinUrl;

    @Value("${external.auth.edge-search-url}")
    private String edgeSearchUrl;

    @Value("${external.edge.add-url:https://cuuva.com:24443/api/datamanager/edge-pkg/add}")
    private String edgeAddUrl;

    @PostConstruct
    public void init() {
        this.restTemplate = createUnsafeRestTemplate();
    }

    /** SSL 무시용 RestTemplate 생성 */
    private RestTemplate createUnsafeRestTemplate() {
        try {
            TrustManager[] trustAllCerts = new TrustManager[]{
                    new X509TrustManager() {
                        public X509Certificate[] getAcceptedIssuers() { return new X509Certificate[0]; }
                        public void checkClientTrusted(X509Certificate[] certs, String authType) { }
                        public void checkServerTrusted(X509Certificate[] certs, String authType) { }
                    }
            };

            SSLContext sslContext = SSLContext.getInstance("TLS");
            sslContext.init(null, trustAllCerts, new java.security.SecureRandom());

            HttpsURLConnection.setDefaultSSLSocketFactory(sslContext.getSocketFactory());
            HttpsURLConnection.setDefaultHostnameVerifier((hostname, session) -> true);

            SimpleClientHttpRequestFactory requestFactory = new SimpleClientHttpRequestFactory();
            return new RestTemplate(requestFactory);

        } catch (Exception e) {
            throw new RuntimeException("Failed to create unsafe RestTemplate", e);
        }
    }

    /** Bearer 토큰 발급 */
    public Map<String, Object> getUserInfo(String id, String password) {
        // 요청 본문
        Map<String, String> body = Map.of("id", id, "password", password);

        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);

        HttpEntity<Map<String, String>> request = new HttpEntity<>(body, headers);

        ResponseEntity<Map> response = restTemplate.exchange(
                signinUrl, HttpMethod.POST, request, Map.class);

        if (response.getStatusCode() == HttpStatus.OK) {
            Map<String, Object> respBody = response.getBody();
            if (respBody != null && respBody.get("data") instanceof Map dataMap) {
                Map<String, Object> result = new HashMap<>();
                result.put("id", dataMap.get("id"));
                result.put("name", dataMap.get("name"));
                result.put("token", dataMap.get("token"));
                return result;
            }
        }

        throw new RuntimeException("Failed to get user info from external server");
    }

    /**
     * Edge 패키지 검색 API 호출
     */
    public Map<String, Object> getEdgePackageList(String id, String token) {
        try {
            // 1) 입력 검증: id에 URL/공격 문자열 포함 금지
            if (id == null || id.isBlank()) {
                throw new IllegalArgumentException("잘못된 사용자 ID입니다.");
            }
            if (id.contains("http://") || id.contains("https://")) {
                throw new IllegalArgumentException("ID에 URL을 포함할 수 없습니다.");
            }

            // 2) 안전하게 파라미터 인코딩 및 URL 구성 (base URL은 외부 입력에서 분리)
            String safeId = URLEncoder.encode(id, StandardCharsets.UTF_8);
            String url = String.format("%s?sw_group=-1&sw_type=-1&searchType=&searchText=&pageNum=1&pageSize=10&auth_id=%s&user_id=",
                    edgeSearchUrl, safeId);

            // 3) URI 생성 (edgeSearchUrl이 올바른 형식인지 확인)
            URI uri = URI.create(url);

            // 추가 안전권장(선택) : 실제 호출되는 호스트가 설정한 base URL의 호스트와 동일한지 확인
            // (내부망 차단을 원치 않으셨으므로 private IP 검사 코드는 제외)
            URI baseUri = URI.create(edgeSearchUrl);
            if (!uri.getHost().equalsIgnoreCase(baseUri.getHost())) {
                throw new SecurityException("요청 호스트가 허용된 서비스와 일치하지 않습니다.");
            }

            // 4) 요청 헤더 구성
            HttpHeaders headers = new HttpHeaders();
            headers.setBearerAuth(token);
            headers.setAccept(java.util.List.of(MediaType.APPLICATION_JSON));
            HttpEntity<Void> request = new HttpEntity<>(headers);

            // 5) 요청 수행
            ResponseEntity<Map> response = restTemplate.exchange(uri, HttpMethod.GET, request, Map.class);

            if (response.getStatusCode() == HttpStatus.OK && response.getBody() != null) {
                return response.getBody();
            } else {
                throw new RuntimeException("외부 Edge 패키지 조회 실패");
            }

        } catch (IllegalArgumentException iae) {
            // 입력 검증 실패는 호출자에게 명확히 알릴 수 있음
            throw iae;
        } catch (Exception e) {
            // 내부 상세 예외는 래핑하여 외부에 노출하지 않음
            throw new RuntimeException("외부 Edge API 호출 중 오류가 발생했습니다.");
        }
    }

    public Object uploadEdgePackage(String bearerToken, EdgePkgInfoRequest edgePkgInfoRequest, MultipartFile file) throws IOException {
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.MULTIPART_FORM_DATA);
        headers.set("Authorization", bearerToken.startsWith("Bearer ") ? bearerToken : "Bearer " + bearerToken);

        // Object를 JSON 문자열로 변환
        ObjectMapper objectMapper = new ObjectMapper();
        String edgePkgInfoJson = objectMapper.writeValueAsString(edgePkgInfoRequest);

        MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
        body.add("edgePkgInfoVO", edgePkgInfoJson);

        if (file != null && !file.isEmpty()) {
            body.add("file", new ByteArrayResource(file.getBytes()) {
                @Override
                public String getFilename() {
                    return file.getOriginalFilename();
                }
            });
        }

        HttpEntity<MultiValueMap<String, Object>> request = new HttpEntity<>(body, headers);

        ResponseEntity<Object> response = restTemplate.exchange(
                edgeAddUrl,
                HttpMethod.POST,
                request,
                Object.class
        );

        return response.getBody();
    }
}