From fbd2a6425b7210852d62e2410baecb2caaa0f54d Mon Sep 17 00:00:00 2001
From: Idriss Neumann <idriss.neumann@comwork.io>
Date: Thu, 14 Dec 2023 10:04:22 +0100
Subject: [PATCH] Issue #4: search the timestamp on the backend side

---
 pkg/quickwit/quickwit.go | 74 ++++++++++++++++++++++++++++++++++++++--
 src/datasource.ts        |  2 +-
 2 files changed, 73 insertions(+), 3 deletions(-)

diff --git a/pkg/quickwit/quickwit.go b/pkg/quickwit/quickwit.go
index 026651f..941139d 100644
--- a/pkg/quickwit/quickwit.go
+++ b/pkg/quickwit/quickwit.go
@@ -25,6 +25,69 @@ type QuickwitDatasource struct {
 	dsInfo es.DatasourceInfo
 }
 
+type QuickwitMapping struct {
+	IndexConfig struct {
+		DocMapping struct {
+			TimestampField string `json:"timestamp_field"`
+			FieldMappings  []struct {
+				Name         string   `json:"name"`
+				InputFormats []string `json:"input_formats"`
+			} `json:"field_mappings"`
+		} `json:"doc_mapping"`
+	} `json:"index_config"`
+}
+
+func getTimestampFieldInfos(index string, qwUrl string, cli *http.Client) (string, string, error) {
+	mappingEndpointUrl := qwUrl + "/indexes/" + index
+	qwlog.Info("Calling quickwit endpoint: " + mappingEndpointUrl)
+	r, err := cli.Get(mappingEndpointUrl)
+	if err != nil {
+		errMsg := fmt.Sprintf("Error when calling url = %s: err = %s", mappingEndpointUrl, err.Error())
+		qwlog.Error(errMsg)
+		return "", "", err
+	}
+
+	statusCode := r.StatusCode
+	if statusCode < 200 || statusCode >= 400 {
+		errMsg := fmt.Sprintf("Error when calling url = %s: statusCode = %d", mappingEndpointUrl, statusCode)
+		qwlog.Error(errMsg)
+		return "", "", fmt.Errorf(errMsg)
+	}
+
+	defer r.Body.Close()
+	body, err := io.ReadAll(r.Body)
+	if err != nil {
+		errMsg := fmt.Sprintf("Error when calling url = %s: err = %s", mappingEndpointUrl, err.Error())
+		qwlog.Error(errMsg)
+		return "", "", err
+	}
+
+	var payload QuickwitMapping
+	err = json.Unmarshal(body, &payload)
+	if err != nil {
+		errMsg := fmt.Sprintf("Unmarshalling body error: %s", string(body))
+		qwlog.Error(errMsg)
+		return "", "", fmt.Errorf(errMsg)
+	}
+
+	timestampFieldName := payload.IndexConfig.DocMapping.TimestampField
+	timestampFieldFormat := "undef"
+	for _, field := range payload.IndexConfig.DocMapping.FieldMappings {
+		if field.Name == timestampFieldName && len(field.InputFormats) > 0 {
+			timestampFieldFormat = field.InputFormats[0]
+			break
+		}
+	}
+
+	if timestampFieldFormat == "undef" {
+		errMsg := fmt.Sprintf("No format found for field: %s", string(timestampFieldName))
+		return timestampFieldName, "", fmt.Errorf(errMsg)
+	}
+
+	qwlog.Info(fmt.Sprintf("Found timestampFieldName = %s, timestampFieldFormat = %s", timestampFieldName, timestampFieldFormat))
+	return timestampFieldName, timestampFieldFormat, nil
+}
+
 // Creates a Quickwit datasource.
 func NewQuickwitDatasource(settings backend.DataSourceInstanceSettings) (instancemgmt.Instance, error) {
 	qwlog.Debug("Initializing new data source instance")
@@ -49,8 +112,8 @@ func NewQuickwitDatasource(settings backend.DataSourceInstanceSettings) (instanc
 		return nil, err
 	}
 
-	timeField, _ := jsonData["timeField"].(string)
-	timeOutputFormat, _ := jsonData["timeOutputFormat"].(string)
+	timeField, toerr := jsonData["timeField"].(string)
+	timeOutputFormat, toferr := jsonData["timeOutputFormat"].(string)
 
 	logLevelField, ok := jsonData["logLevelField"].(string)
 	if !ok {
@@ -84,6 +147,13 @@ func NewQuickwitDatasource(settings backend.DataSourceInstanceSettings) (instanc
 		maxConcurrentShardRequests = 256
 	}
 
+	if !toerr || !toferr {
+		timeField, timeOutputFormat, err = getTimestampFieldInfos(index, settings.URL, httpCli)
+		if nil != err {
+			return nil, err
+		}
+	}
+
 	configuredFields := es.ConfiguredFields{
 		TimeField:        timeField,
 		TimeOutputFormat: timeOutputFormat,
diff --git a/src/datasource.ts b/src/datasource.ts
index 236baa6..feac6a8 100644
--- a/src/datasource.ts
+++ b/src/datasource.ts
@@ -80,8 +80,8 @@ export class QuickwitDataSource
     from(this.getResource('indexes/' + this.index)).pipe(
       map((indexMetadata) => {
         let fields = getAllFields(indexMetadata.index_config.doc_mapping.field_mappings);
-        let timestampField = fields.find((field) => field.json_path === this.timeField);
         let timestampFieldName = indexMetadata.index_config.doc_mapping.timestamp_field
+        let timestampField = fields.find((field) => field.json_path === timestampFieldName);
         let timestampFormat = timestampField ? timestampField.field_mapping.output_format || '' : ''
         return { 'field': timestampFieldName, 'format': timestampFormat }
       })