func ApplyRule()

in webv2/api/rules.go [25:120]
93 lines of code
17 McCabe index (conditional complexity)

func ApplyRule(w http.ResponseWriter, r *http.Request) {
	reqBody, err := ioutil.ReadAll(r.Body)
	if err != nil {
		http.Error(w, fmt.Sprintf("Body Read Error : %v", err), http.StatusInternalServerError)
		return
	}
	var rule internal.Rule
	err = json.Unmarshal(reqBody, &rule)
	if err != nil {
		http.Error(w, fmt.Sprintf("Request Body parse error : %v", err), http.StatusBadRequest)
		return
	}

	sessionState := session.GetSessionState()
	sessionState.Conv.ConvLock.Lock()
	defer sessionState.Conv.ConvLock.Unlock()
	if rule.Type == constants.GlobalDataTypeChange {
		d, err := json.Marshal(rule.Data)
		if err != nil {
			http.Error(w, "Invalid rule data", http.StatusInternalServerError)
			return
		}
		typeMap := map[string]string{}
		err = json.Unmarshal(d, &typeMap)
		if err != nil {
			http.Error(w, "Invalid rule data", http.StatusInternalServerError)
			return
		}
		setGlobalDataType(typeMap)
	} else if rule.Type == constants.AddIndex {
		d, err := json.Marshal(rule.Data)
		if err != nil {
			http.Error(w, "Invalid rule data", http.StatusInternalServerError)
			return
		}
		newIdx := ddl.CreateIndex{}
		err = json.Unmarshal(d, &newIdx)
		if err != nil {
			http.Error(w, "Invalid rule data", http.StatusInternalServerError)
			return
		}
		addedIndex, err := addIndex(newIdx)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		rule.Data = addedIndex
	} else if rule.Type == constants.EditColumnMaxLength {
		d, err := json.Marshal(rule.Data)
		if err != nil {
			http.Error(w, "Invalid rule data", http.StatusInternalServerError)
			return
		}
		var colMaxLength types.ColMaxLength
		err = json.Unmarshal(d, &colMaxLength)
		if err != nil {
			http.Error(w, "Invalid rule data", http.StatusInternalServerError)
			return
		}
		setSpColMaxLength(colMaxLength, rule.AssociatedObjects)
	} else if rule.Type == constants.AddShardIdPrimaryKey {
		d, err := json.Marshal(rule.Data)
		if err != nil {
			http.Error(w, "Invalid rule data", http.StatusInternalServerError)
			return
		}
		var shardIdPrimaryKey types.ShardIdPrimaryKey
		err = json.Unmarshal(d, &shardIdPrimaryKey)
		if err != nil {
			http.Error(w, "Invalid rule data", http.StatusInternalServerError)
			return
		}
		tableName := checkInterleaving()
		if tableName != "" {
			http.Error(w, fmt.Sprintf("Rule cannot be added because some tables, eg: %v are interleaved. Please remove interleaving and try again.", tableName), http.StatusBadRequest)
			return
		}
		setShardIdColumnAsPrimaryKey(shardIdPrimaryKey.AddedAtTheStart)
		addShardIdColumnToForeignKeys(shardIdPrimaryKey.AddedAtTheStart)
	} else {
		http.Error(w, "Invalid rule type", http.StatusInternalServerError)
		return
	}

	ruleId := internal.GenerateRuleId()
	rule.Id = ruleId

	sessionState.Conv.Rules = append(sessionState.Conv.Rules, rule)
	session.UpdateSessionFile()
	convm := session.ConvWithMetadata{
		SessionMetadata: sessionState.SessionMetadata,
		Conv:            *sessionState.Conv,
	}
	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(convm)
}