Adds an endpoint '/running' (#61)

* Adds an endpoint '/running' that returns either an empty JSON object if no model has been loaded so far, or the last model loaded (model key) and it's current state (state key). Possible state values are: stopped, starting, ready and stopping.

* Improves the `/running` endpoint by allowing multiple entries under the `running` key within the JSON response.
Refactors the `/running` method name (listRunningProcessesHandler).
Removes the unlisted filter implementation.

* Adds tests for:
- no model loaded
- one model loaded
- multiple models loaded

* Adds simple comments.

* Simplified code structure as per 250313 comments on PR #65.

---------

Co-authored-by: FGDumitru|B <xelotx@gmail.com>

proxy/proxymanager.go

@@ -108,6 +108,8 @@ func New(config *Config) *ProxyManager {
 
 	pm.ginEngine.GET("/unload", pm.unloadAllModelsHandler)
 
+	pm.ginEngine.GET("/running", pm.listRunningProcessesHandler)
+
 	pm.ginEngine.GET("/", func(c *gin.Context) {
 		// Set the Content-Type header to text/html
 		c.Header("Content-Type", "text/html")
@@ -387,6 +389,28 @@ func (pm *ProxyManager) unloadAllModelsHandler(c *gin.Context) {
 	c.String(http.StatusOK, "OK")
 }
 
+func (pm *ProxyManager) listRunningProcessesHandler(context *gin.Context) {
+	context.Header("Content-Type", "application/json")
+	runningProcesses := make([]gin.H, 0) // Default to an empty response.
+
+	for _, process := range pm.currentProcesses {
+
+		// Append the process ID and State (multiple entries if profiles are being used).
+		runningProcesses = append(runningProcesses, gin.H{
+			"model": process.ID,
+			"state": process.state,
+		})
+
+	}
+
+	// Put the results under the `running` key.
+	response := gin.H{
+		"running": runningProcesses,
+	}
+
+	context.JSON(http.StatusOK, response) // Always return 200 OK
+}
+
 func ProcessKeyName(groupName, modelName string) string {
 	return groupName + PROFILE_SPLIT_CHAR + modelName
 }