fix: drop history export and tolerate empty tdengine tables

modules/services/event-history-service/src/main/java/com/lingniu/ingest/eventhistory/EventHistoryController.java

@@ -1,7 +1,5 @@
 package com.lingniu.ingest.eventhistory;
 
-import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.ObjectMapper;
 import com.lingniu.ingest.api.ProtocolId;
 import com.lingniu.ingest.eventfilestore.EventFileQuery;
 import com.lingniu.ingest.eventfilestore.EventFileRecord;
@@ -14,8 +12,6 @@ import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -31,8 +27,6 @@ import java.util.Map;
 @RequestMapping("/api/event-history")
 public class EventHistoryController {
 
-    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
-
     private final EventFileStore store;
 
     public EventHistoryController(EventFileStore store) {
@@ -52,51 +46,6 @@ public class EventHistoryController {
                 .toList();
     }
 
-    @GetMapping(value = "/export.csv", produces = "text/csv;charset=UTF-8")
-    public String exportCsv(
-            @RequestParam ProtocolId protocol,
-            @RequestParam String dateFrom,
-            @RequestParam String dateTo,
-            @RequestParam(defaultValue = "ASC") EventFileQuery.Order order,
-            @RequestParam(defaultValue = "100000") int limit,
-            @RequestParam(required = false) String vin,
-            @RequestParam(required = false) String fields) throws IOException {
-        List<EventFileRecord> records = queryRecords(protocol, dateFrom, dateTo, order, limit, vin);
-        List<String> selectedFields = parseFields(fields);
-        StringBuilder csv = new StringBuilder(256 + records.size() * 128);
-        csv.append("event_id,protocol,event_type,vin,event_time,ingest_time,raw_archive_uri");
-        for (String field : selectedFields) {
-            csv.append(',').append(csv(field));
-        }
-        csv.append(",payload_json\n");
-        for (EventFileRecord record : records) {
-            Map<String, String> telemetryFields = selectedFields.isEmpty()
-                    ? Map.of()
-                    : telemetryFields(record.payloadJson());
-            csv.append(csv(record.eventId())).append(',')
-                    .append(csv(record.protocol().name())).append(',')
-                    .append(csv(record.eventType())).append(',')
-                    .append(csv(record.vin())).append(',')
-                    .append(csv(record.eventTime().toString())).append(',')
-                    .append(csv(record.ingestTime().toString())).append(',')
-                    .append(csv(record.rawArchiveUri()));
-            for (String field : selectedFields) {
-                csv.append(',').append(csv(fieldValue(record, telemetryFields, field)));
-            }
-            csv.append(',')
-                    .append(csv(record.payloadJson())).append('\n');
-        }
-        return csv.toString();
-    }
-
-    public String exportCsv(ProtocolId protocol,
-                            String dateFrom,
-                            String dateTo,
-                            EventFileQuery.Order order,
-                            int limit) throws IOException {
-        return exportCsv(protocol, dateFrom, dateTo, order, limit, null, null);
-    }
-
     private List<EventFileRecord> queryRecords(ProtocolId protocol,
                                                String dateFrom,
                                                String dateTo,
@@ -140,64 +89,4 @@ public class EventHistoryController {
                     record.payloadJson());
         }
     }
-
-    private static List<String> parseFields(String fields) {
-        if (fields == null || fields.isBlank()) {
-            return List.of();
-        }
-        List<String> out = new ArrayList<>();
-        for (String field : fields.split(",")) {
-            String normalized = field.trim();
-            if (!normalized.isBlank()) {
-                out.add(normalized);
-            }
-        }
-        return List.copyOf(out);
-    }
-
-    private static Map<String, String> telemetryFields(String payloadJson) throws IOException {
-        if (payloadJson == null || payloadJson.isBlank()) {
-            return Map.of();
-        }
-        JsonNode root = OBJECT_MAPPER.readTree(payloadJson);
-        JsonNode fields = root.path("fields");
-        if (!fields.isArray()) {
-            return Map.of();
-        }
-        // 通用导出只识别 telemetry snapshot 的扁平 fields；复杂 GB32960 block 字段用专用 CSV 接口。
-        Map<String, String> out = new LinkedHashMap<>();
-        for (JsonNode field : fields) {
-            String key = field.path("key").asText("");
-            if (!key.isBlank()) {
-                out.put(key, field.path("value").asText(""));
-            }
-        }
-        return out;
-    }
-
-    private static String fieldValue(EventFileRecord record,
-                                     Map<String, String> telemetryFields,
-                                     String field) {
-        if (field == null || field.isBlank()) {
-            return "";
-        }
-        if (field.startsWith("metadata.")) {
-            return record.metadata().get(field.substring("metadata.".length()));
-        }
-        return telemetryFields.get(field);
-    }
-
-    private static String csv(String value) {
-        if (value == null) {
-            return "";
-        }
-        boolean quote = value.indexOf(',') >= 0
-                || value.indexOf('"') >= 0
-                || value.indexOf('\n') >= 0
-                || value.indexOf('\r') >= 0;
-        if (!quote) {
-            return value;
-        }
-        return "\"" + value.replace("\"", "\"\"") + "\"";
-    }
 }