package com.zy.acs.manager.common.interceptor;

import com.alibaba.fastjson.JSON;
import com.zy.acs.framework.common.Cools;
import com.zy.acs.framework.common.R;
import com.zy.acs.framework.common.SnowflakeIdWorker;
import com.zy.acs.manager.common.interceptor.IntegrationOpenApiInterceptor.IntegrationRequestContext;
import com.zy.acs.manager.common.utils.IpTools;
import com.zy.acs.manager.manager.entity.IntegrationRecord;
import com.zy.acs.manager.manager.enums.IntegrationDirectionType;
import com.zy.acs.manager.manager.enums.StatusType;
import com.zy.acs.manager.manager.service.IntegrationRecordService;
import lombok.extern.slf4j.Slf4j;
import org.jetbrains.annotations.NotNull;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.web.util.ContentCachingRequestWrapper;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.UUID;

@Slf4j
@ControllerAdvice
public class IntegrationRecordAdvice implements ResponseBodyAdvice<Object> {

    private static final String HEADER_APP_KEY = "appkey";
    private static final String HEADER_CALLER = "caller";

    @Autowired
    private IntegrationRecordService integrationRecordService;
    @Resource
    private SnowflakeIdWorker snowflakeIdWorker;

    @Override
    public boolean supports(@NotNull MethodParameter methodParameter,
                            @NotNull Class<? extends HttpMessageConverter<?>> aClass) {
        return true;
    }

    @Override
    public Object beforeBodyWrite(Object body,
                                  @NotNull MethodParameter methodParameter,
                                  @NotNull MediaType mediaType,
                                  @NotNull Class<? extends HttpMessageConverter<?>> aClass,
                                  @NotNull ServerHttpRequest serverHttpRequest,
                                  @NotNull ServerHttpResponse serverHttpResponse) {
        if (!(serverHttpRequest instanceof ServletServerHttpRequest)) {
            return body;
        }
        HttpServletRequest request = ((ServletServerHttpRequest) serverHttpRequest).getServletRequest();
        IntegrationRequestContext context = IntegrationOpenApiInterceptor.getContext(request);
        if (context == null) {
            return body;
        }
        IntegrationRecord record = null;
        try {
            record = buildRecord(body, request, context, null);
        } catch (Exception e) {
            log.error("Failed to build integration log for {}", context.getHandler(), e);
            record = buildRecord(null, request, context, e);
        } finally {
            if (record != null) {
                try {
                    integrationRecordService.syncRecord(record);
                } catch (Exception persistEx) {
                    log.error("Failed to persist integration log for {}", context.getHandler(), persistEx);
                }
            }
        }
        return body;
    }

    private IntegrationRecord buildRecord(Object responseBody,
                                          HttpServletRequest request,
                                          IntegrationRequestContext context,
                                          Exception failure) {
        Date now = new Date();
        RequestSnapshot payload = buildSnapshot(request);


        IntegrationRecord record = new IntegrationRecord();
        record.setUuid(nextUuid());
        record.setNamespace(context.getNamespaceType().name());
        record.setUrl(payload.getUri());
        record.setAppkey(request.getHeader(HEADER_APP_KEY));
        record.setCaller(resolveCaller(request));
        record.setDirection(IntegrationDirectionType.INBOUND.value);
        record.setTimestamp(String.valueOf(context.getStartAt()));
        record.setClientIp(IpTools.gainRealIp(request));
        record.setRequest(safeToJson(payload));
        record.setResponse(safeToJson(responseBody));
        applyResult(record, responseBody, failure);
        record.setCostMs(cost(context.getStartAt()));
        record.setStatus(StatusType.ENABLE.val);
        record.setCreateTime(now);
        record.setUpdateTime(now);
        record.setMemo(context.getHandler());
        return record;
    }

    private void applyResult(IntegrationRecord record, Object body, Exception failure) {
        if (failure != null) {
            record.setResult(0);
            record.setErr(failure.getMessage());
            return;
        }
        if (!(body instanceof R)) {
            record.setResult(null);
            record.setErr(null);
            return;
        }
        R response = (R) body;
        Integer code = parseInteger(response.get("code"));
        if (code == null) {
            record.setResult(null);
            record.setErr(null);
            return;
        }
        boolean success = code == 200;
        record.setResult(success ? 1 : 0);
        record.setErr(success ? null : safeToString(response.get("msg")));
    }

    private Integer parseInteger(Object codeObj) {
        if (codeObj == null) {
            return null;
        }
        if (codeObj instanceof Integer) {
            return (Integer) codeObj;
        }
        try {
            return Integer.parseInt(String.valueOf(codeObj));
        } catch (NumberFormatException e) {
            return null;
        }
    }

    private String safeToJson(Object value) {
        if (value == null) {
            return null;
        }
        try {
            return JSON.toJSONString(value);
        } catch (Exception e) {
            log.warn("Failed to serialize value for integration log: {}", value.getClass().getName(), e);
            return String.valueOf(value);
        }
    }

    private String resolveCaller(HttpServletRequest request) {
        String caller = request.getHeader(HEADER_CALLER);
        if (Cools.isEmpty(caller)) {
            caller = request.getHeader(HEADER_APP_KEY);
        }
        return caller;
    }

    private int cost(long startAt) {
        long duration = System.currentTimeMillis() - startAt;
        if (duration < 0) {
            return 0;
        }
        return (int) duration;
    }

    private String nextUuid() {
        if (snowflakeIdWorker != null) {
            return String.valueOf(snowflakeIdWorker.nextId()).substring(3);
        }
        return UUID.randomUUID().toString().replace("-", "");
    }

    private String safeToString(Object value) {
        return value == null ? null : String.valueOf(value);
    }
    private RequestSnapshot buildSnapshot(HttpServletRequest request) {
        Map<String, Object> params = flattenParameters(request.getParameterMap());
        String body = normalizeBody(readBody(request), request.getContentType());
        return new RequestSnapshot(
                request.getMethod(),
                request.getRequestURI(),
                request.getQueryString(),
                request.getContentType(),
                params.isEmpty() ? null : params,
                body
        );
    }

    private String normalizeBody(String body, String contentType) {
        if (Cools.isEmpty(body)) {
            return null;
        }
        boolean isJson = !Cools.isEmpty(contentType) && contentType.toLowerCase().contains("json");
        if (isJson) {
            try {
                Object parsed = JSON.parse(body);
                return JSON.toJSONString(parsed, false);
            } catch (Exception ignore) {
                // fall through to compacting whitespace
            }
        }
        return body.replaceAll("[\\n\\r\\t]", "").trim();
    }

    private Map<String, Object> flattenParameters(Map<String, String[]> rawParams) {
        Map<String, Object> flattened = new LinkedHashMap<>();
        if (rawParams == null) {
            return flattened;
        }
        rawParams.forEach((key, values) -> {
            if (values == null) {
                flattened.put(key, null);
            } else if (values.length == 1) {
                flattened.put(key, values[0]);
            } else {
                flattened.put(key, Arrays.asList(values));
            }
        });
        return flattened;
    }

    private String readBody(HttpServletRequest request) {
        HttpServletRequest target = unwrapCachingRequest(request);
        if (target instanceof ContentCachingRequestWrapper) {
            ContentCachingRequestWrapper wrapper = (ContentCachingRequestWrapper) target;
            byte[] buffer = wrapper.getContentAsByteArray();
            if (buffer.length > 0) {
                Charset charset = charset(wrapper.getCharacterEncoding());
                return new String(buffer, charset);
            }
        }
        return null;
    }

    private HttpServletRequest unwrapCachingRequest(HttpServletRequest request) {
        HttpServletRequest current = request;
        while (current instanceof HttpServletRequestWrapper) {
            if (current instanceof ContentCachingRequestWrapper) {
                return current;
            }
            current = (HttpServletRequest) ((HttpServletRequestWrapper) current).getRequest();
        }
        return request;
    }

    private Charset charset(String encoding) {
        if (Cools.isEmpty(encoding)) {
            return StandardCharsets.UTF_8;
        }
        try {
            return Charset.forName(encoding);
        } catch (Exception e) {
            return StandardCharsets.UTF_8;
        }
    }

    private static class RequestSnapshot {
        private final String method;
        private final String uri;
        private final String query;
        private final String contentType;
        private final Map<String, Object> parameters;
        private final String body;

        RequestSnapshot(String method, String uri, String query, String contentType,
                        Map<String, Object> parameters, String body) {
            this.method = method;
            this.uri = uri;
            this.query = query;
            this.contentType = contentType;
            this.parameters = parameters;
            this.body = body;
        }

        public String getUri() {
            return uri;
        }
    }
}