feat(handler): add Application handler, routes, and wiring

Add ApplicationHandler with CRUD + Submit endpoints. Register 6 routes, wire in app.go, update main_test.go references. 22 handler tests.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

cmd/server/main_test.go

@@ -21,7 +21,7 @@ import (
 
 func newTestDB() *gorm.DB {
 	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
-	db.AutoMigrate(&model.JobTemplate{})
+	db.AutoMigrate(&model.Application{})
 	return db
 }
 
@@ -34,12 +34,15 @@ func TestRouterRegistration(t *testing.T) {
 	defer slurmSrv.Close()
 
 	client, _ := slurm.NewClientWithOpts(slurmSrv.URL, slurm.WithHTTPClient(slurmSrv.Client()))
-	templateStore := store.NewTemplateStore(newTestDB())
+	jobSvc := service.NewJobService(client, zap.NewNop())
+	appStore := store.NewApplicationStore(newTestDB())
+	appSvc := service.NewApplicationService(appStore, jobSvc, "", zap.NewNop())
+	appH := handler.NewApplicationHandler(appSvc, zap.NewNop())
 
 	router := server.NewRouter(
-		handler.NewJobHandler(service.NewJobService(client, zap.NewNop()), zap.NewNop()),
+		handler.NewJobHandler(jobSvc, zap.NewNop()),
 		handler.NewClusterHandler(service.NewClusterService(client, zap.NewNop()), zap.NewNop()),
-		handler.NewTemplateHandler(templateStore, zap.NewNop()),
+		appH,
 		nil,
 	)
 
@@ -58,11 +61,12 @@ func TestRouterRegistration(t *testing.T) {
 		{"GET", "/api/v1/partitions"},
 		{"GET", "/api/v1/partitions/:name"},
 		{"GET", "/api/v1/diag"},
-		{"GET", "/api/v1/templates"},
+		{"GET", "/api/v1/applications"},
-		{"POST", "/api/v1/templates"},
+		{"POST", "/api/v1/applications"},
-		{"GET", "/api/v1/templates/:id"},
+		{"GET", "/api/v1/applications/:id"},
-		{"PUT", "/api/v1/templates/:id"},
+		{"PUT", "/api/v1/applications/:id"},
-		{"DELETE", "/api/v1/templates/:id"},
+		{"DELETE", "/api/v1/applications/:id"},
+		{"POST", "/api/v1/applications/:id/submit"},
 	}
 
 	routeMap := map[string]bool{}
@@ -90,12 +94,15 @@ func TestSmokeGetJobsEndpoint(t *testing.T) {
 	defer slurmSrv.Close()
 
 	client, _ := slurm.NewClientWithOpts(slurmSrv.URL, slurm.WithHTTPClient(slurmSrv.Client()))
-	templateStore := store.NewTemplateStore(newTestDB())
+	jobSvc := service.NewJobService(client, zap.NewNop())
+	appStore := store.NewApplicationStore(newTestDB())
+	appSvc := service.NewApplicationService(appStore, jobSvc, "", zap.NewNop())
+	appH := handler.NewApplicationHandler(appSvc, zap.NewNop())
 
 	router := server.NewRouter(
-		handler.NewJobHandler(service.NewJobService(client, zap.NewNop()), zap.NewNop()),
+		handler.NewJobHandler(jobSvc, zap.NewNop()),
 		handler.NewClusterHandler(service.NewClusterService(client, zap.NewNop()), zap.NewNop()),
-		handler.NewTemplateHandler(templateStore, zap.NewNop()),
+		appH,
 		nil,
 	)
 

internal/handler/application.go

@@ -0,0 +1,174 @@
+package handler
+
+import (
+	"encoding/json"
+	"errors"
+	"strconv"
+	"strings"
+
+	"gcy_hpc_server/internal/model"
+	"gcy_hpc_server/internal/server"
+	"gcy_hpc_server/internal/service"
+
+	"github.com/gin-gonic/gin"
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+)
+
+type ApplicationHandler struct {
+	appSvc *service.ApplicationService
+	logger *zap.Logger
+}
+
+func NewApplicationHandler(appSvc *service.ApplicationService, logger *zap.Logger) *ApplicationHandler {
+	return &ApplicationHandler{appSvc: appSvc, logger: logger}
+}
+
+func (h *ApplicationHandler) ListApplications(c *gin.Context) {
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
+	if page < 1 {
+		page = 1
+	}
+	if pageSize < 1 {
+		pageSize = 20
+	}
+
+	apps, total, err := h.appSvc.ListApplications(c.Request.Context(), page, pageSize)
+	if err != nil {
+		h.logger.Error("failed to list applications", zap.Error(err))
+		server.InternalError(c, err.Error())
+		return
+	}
+
+	server.OK(c, gin.H{
+		"applications": apps,
+		"total":        total,
+		"page":         page,
+		"page_size":    pageSize,
+	})
+}
+
+func (h *ApplicationHandler) CreateApplication(c *gin.Context) {
+	var req model.CreateApplicationRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		h.logger.Warn("invalid request body for create application", zap.Error(err))
+		server.BadRequest(c, "invalid request body")
+		return
+	}
+	if req.Name == "" || req.ScriptTemplate == "" {
+		h.logger.Warn("missing required fields for create application")
+		server.BadRequest(c, "name and script_template are required")
+		return
+	}
+	if len(req.Parameters) == 0 {
+		req.Parameters = json.RawMessage(`[]`)
+	}
+
+	id, err := h.appSvc.CreateApplication(c.Request.Context(), &req)
+	if err != nil {
+		h.logger.Error("failed to create application", zap.Error(err))
+		server.InternalError(c, err.Error())
+		return
+	}
+	h.logger.Info("application created", zap.Int64("id", id))
+	server.Created(c, gin.H{"id": id})
+}
+
+func (h *ApplicationHandler) GetApplication(c *gin.Context) {
+	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		h.logger.Warn("invalid application id", zap.String("id", c.Param("id")))
+		server.BadRequest(c, "invalid id")
+		return
+	}
+	app, err := h.appSvc.GetApplication(c.Request.Context(), id)
+	if err != nil {
+		h.logger.Error("failed to get application", zap.Int64("id", id), zap.Error(err))
+		server.InternalError(c, err.Error())
+		return
+	}
+	if app == nil {
+		h.logger.Warn("application not found", zap.Int64("id", id))
+		server.NotFound(c, "application not found")
+		return
+	}
+	server.OK(c, app)
+}
+
+func (h *ApplicationHandler) UpdateApplication(c *gin.Context) {
+	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		h.logger.Warn("invalid application id for update", zap.String("id", c.Param("id")))
+		server.BadRequest(c, "invalid id")
+		return
+	}
+	var req model.UpdateApplicationRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		h.logger.Warn("invalid request body for update application", zap.Int64("id", id), zap.Error(err))
+		server.BadRequest(c, "invalid request body")
+		return
+	}
+	if err := h.appSvc.UpdateApplication(c.Request.Context(), id, &req); err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			h.logger.Warn("application not found for update", zap.Int64("id", id))
+			server.NotFound(c, "application not found")
+			return
+		}
+		h.logger.Error("failed to update application", zap.Int64("id", id), zap.Error(err))
+		server.InternalError(c, "failed to update application")
+		return
+	}
+	h.logger.Info("application updated", zap.Int64("id", id))
+	server.OK(c, gin.H{"message": "application updated"})
+}
+
+func (h *ApplicationHandler) DeleteApplication(c *gin.Context) {
+	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		h.logger.Warn("invalid application id for delete", zap.String("id", c.Param("id")))
+		server.BadRequest(c, "invalid id")
+		return
+	}
+	if err := h.appSvc.DeleteApplication(c.Request.Context(), id); err != nil {
+		h.logger.Error("failed to delete application", zap.Int64("id", id), zap.Error(err))
+		server.InternalError(c, err.Error())
+		return
+	}
+	h.logger.Info("application deleted", zap.Int64("id", id))
+	server.OK(c, gin.H{"message": "application deleted"})
+}
+
+func (h *ApplicationHandler) SubmitApplication(c *gin.Context) {
+	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		h.logger.Warn("invalid application id for submit", zap.String("id", c.Param("id")))
+		server.BadRequest(c, "invalid id")
+		return
+	}
+	var req model.ApplicationSubmitRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		h.logger.Warn("invalid request body for submit application", zap.Int64("id", id), zap.Error(err))
+		server.BadRequest(c, "invalid request body")
+		return
+	}
+	resp, err := h.appSvc.SubmitFromApplication(c.Request.Context(), id, req.Values)
+	if err != nil {
+		errStr := err.Error()
+		if strings.Contains(errStr, "not found") {
+			h.logger.Warn("application not found for submit", zap.Int64("id", id))
+			server.NotFound(c, errStr)
+			return
+		}
+		if strings.Contains(errStr, "validation") {
+			h.logger.Warn("application submit validation failed", zap.Int64("id", id), zap.Error(err))
+			server.BadRequest(c, errStr)
+			return
+		}
+		h.logger.Error("failed to submit application", zap.Int64("id", id), zap.Error(err))
+		server.InternalError(c, errStr)
+		return
+	}
+	h.logger.Info("application submitted", zap.Int64("id", id), zap.Int32("job_id", resp.JobID))
+	server.Created(c, resp)
+}

internal/handler/application_test.go

@@ -0,0 +1,630 @@
+package handler
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"gcy_hpc_server/internal/model"
+	"gcy_hpc_server/internal/service"
+	"gcy_hpc_server/internal/slurm"
+	"gcy_hpc_server/internal/store"
+
+	"github.com/gin-gonic/gin"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest/observer"
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+	gormlogger "gorm.io/gorm/logger"
+)
+
+func itoa(id int64) string {
+	return fmt.Sprintf("%d", id)
+}
+
+func setupApplicationHandler() (*ApplicationHandler, *gorm.DB) {
+	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{Logger: gormlogger.Default.LogMode(gormlogger.Silent)})
+	db.AutoMigrate(&model.Application{})
+	appStore := store.NewApplicationStore(db)
+	appSvc := service.NewApplicationService(appStore, nil, "", zap.NewNop())
+	h := NewApplicationHandler(appSvc, zap.NewNop())
+	return h, db
+}
+
+func setupApplicationRouter(h *ApplicationHandler) *gin.Engine {
+	gin.SetMode(gin.TestMode)
+	r := gin.New()
+	v1 := r.Group("/api/v1")
+	apps := v1.Group("/applications")
+	apps.GET("", h.ListApplications)
+	apps.POST("", h.CreateApplication)
+	apps.GET("/:id", h.GetApplication)
+	apps.PUT("/:id", h.UpdateApplication)
+	apps.DELETE("/:id", h.DeleteApplication)
+	apps.POST("/:id/submit", h.SubmitApplication)
+	return r
+}
+
+func setupApplicationHandlerWithSlurm(slurmHandler http.HandlerFunc) (*ApplicationHandler, func()) {
+	srv := httptest.NewServer(slurmHandler)
+	client, _ := slurm.NewClient(srv.URL, srv.Client())
+
+	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{Logger: gormlogger.Default.LogMode(gormlogger.Silent)})
+	db.AutoMigrate(&model.Application{})
+
+	jobSvc := service.NewJobService(client, zap.NewNop())
+	appStore := store.NewApplicationStore(db)
+	appSvc := service.NewApplicationService(appStore, jobSvc, "", zap.NewNop())
+	h := NewApplicationHandler(appSvc, zap.NewNop())
+	return h, srv.Close
+}
+
+func setupApplicationHandlerWithObserver() (*ApplicationHandler, *gorm.DB, *observer.ObservedLogs) {
+	core, recorded := observer.New(zapcore.DebugLevel)
+	l := zap.New(core)
+	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{Logger: gormlogger.Default.LogMode(gormlogger.Silent)})
+	db.AutoMigrate(&model.Application{})
+	appStore := store.NewApplicationStore(db)
+	appSvc := service.NewApplicationService(appStore, nil, "", l)
+	return NewApplicationHandler(appSvc, l), db, recorded
+}
+
+func createTestApplication(h *ApplicationHandler, r *gin.Engine) int64 {
+	body, _ := json.Marshal(model.CreateApplicationRequest{
+		Name:           "test-app",
+		ScriptTemplate: "#!/bin/bash\necho hello",
+	})
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	var resp map[string]interface{}
+	json.Unmarshal(w.Body.Bytes(), &resp)
+	data := resp["data"].(map[string]interface{})
+	return int64(data["id"].(float64))
+}
+
+// ---- CRUD Tests ----
+
+func TestCreateApplication_Success(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	body, _ := json.Marshal(model.CreateApplicationRequest{
+		Name:           "my-app",
+		ScriptTemplate: "#!/bin/bash\necho hello",
+	})
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusCreated {
+		t.Fatalf("expected 201, got %d: %s", w.Code, w.Body.String())
+	}
+	var resp map[string]interface{}
+	json.Unmarshal(w.Body.Bytes(), &resp)
+	if !resp["success"].(bool) {
+		t.Fatal("expected success=true")
+	}
+	data := resp["data"].(map[string]interface{})
+	if _, ok := data["id"]; !ok {
+		t.Fatal("expected id in response data")
+	}
+}
+
+func TestCreateApplication_MissingName(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	body, _ := json.Marshal(model.CreateApplicationRequest{
+		ScriptTemplate: "#!/bin/bash\necho hello",
+	})
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Fatalf("expected 400, got %d", w.Code)
+	}
+}
+
+func TestCreateApplication_MissingScriptTemplate(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	body, _ := json.Marshal(model.CreateApplicationRequest{
+		Name: "my-app",
+	})
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Fatalf("expected 400, got %d", w.Code)
+	}
+}
+
+func TestCreateApplication_EmptyParameters(t *testing.T) {
+	h, db := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	body := `{"name":"empty-params-app","script_template":"#!/bin/bash\necho hello"}`
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", strings.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusCreated {
+		t.Fatalf("expected 201, got %d: %s", w.Code, w.Body.String())
+	}
+
+	var app model.Application
+	db.First(&app)
+	if string(app.Parameters) != "[]" {
+		t.Fatalf("expected parameters to default to [], got %s", string(app.Parameters))
+	}
+}
+
+func TestListApplications_Success(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	createTestApplication(h, r)
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/api/v1/applications", nil)
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+	var resp map[string]interface{}
+	json.Unmarshal(w.Body.Bytes(), &resp)
+	if !resp["success"].(bool) {
+		t.Fatal("expected success=true")
+	}
+	data := resp["data"].(map[string]interface{})
+	if data["total"].(float64) < 1 {
+		t.Fatal("expected at least 1 application")
+	}
+}
+
+func TestListApplications_Pagination(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	for i := 0; i < 5; i++ {
+		body, _ := json.Marshal(model.CreateApplicationRequest{
+			Name:           fmt.Sprintf("app-%d", i),
+			ScriptTemplate: "#!/bin/bash\necho " + fmt.Sprintf("app-%d", i),
+		})
+		w := httptest.NewRecorder()
+		req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", bytes.NewReader(body))
+		req.Header.Set("Content-Type", "application/json")
+		r.ServeHTTP(w, req)
+	}
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/api/v1/applications?page=1&page_size=2", nil)
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+	var resp map[string]interface{}
+	json.Unmarshal(w.Body.Bytes(), &resp)
+	data := resp["data"].(map[string]interface{})
+	if data["total"].(float64) != 5 {
+		t.Fatalf("expected total=5, got %v", data["total"])
+	}
+	if data["page"].(float64) != 1 {
+		t.Fatalf("expected page=1, got %v", data["page"])
+	}
+	if data["page_size"].(float64) != 2 {
+		t.Fatalf("expected page_size=2, got %v", data["page_size"])
+	}
+}
+
+func TestGetApplication_Success(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	id := createTestApplication(h, r)
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/api/v1/applications/"+itoa(id), nil)
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
+	}
+	var resp map[string]interface{}
+	json.Unmarshal(w.Body.Bytes(), &resp)
+	data := resp["data"].(map[string]interface{})
+	if data["name"] != "test-app" {
+		t.Fatalf("expected name=test-app, got %v", data["name"])
+	}
+}
+
+func TestGetApplication_NotFound(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/api/v1/applications/999", nil)
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Fatalf("expected 404, got %d", w.Code)
+	}
+}
+
+func TestGetApplication_InvalidID(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/api/v1/applications/abc", nil)
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusBadRequest {
+		t.Fatalf("expected 400, got %d", w.Code)
+	}
+}
+
+func TestUpdateApplication_Success(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	id := createTestApplication(h, r)
+
+	newName := "updated-app"
+	body, _ := json.Marshal(model.UpdateApplicationRequest{
+		Name: &newName,
+	})
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPut, "/api/v1/applications/"+itoa(id), bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestUpdateApplication_NotFound(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	newName := "updated-app"
+	body, _ := json.Marshal(model.UpdateApplicationRequest{
+		Name: &newName,
+	})
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPut, "/api/v1/applications/999", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Fatalf("expected 404, got %d", w.Code)
+	}
+}
+
+func TestDeleteApplication_Success(t *testing.T) {
+	h, _ := setupApplicationHandler()
+	r := setupApplicationRouter(h)
+
+	id := createTestApplication(h, r)
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodDelete, "/api/v1/applications/"+itoa(id), nil)
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
+	}
+
+	w2 := httptest.NewRecorder()
+	req2, _ := http.NewRequest(http.MethodGet, "/api/v1/applications/"+itoa(id), nil)
+	r.ServeHTTP(w2, req2)
+
+	if w2.Code != http.StatusNotFound {
+		t.Fatalf("expected 404 after delete, got %d", w2.Code)
+	}
+}
+
+// ---- Submit Tests ----
+
+func TestSubmitApplication_Success(t *testing.T) {
+	slurmHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusCreated)
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"job_id": 12345,
+		})
+	})
+	h, cleanup := setupApplicationHandlerWithSlurm(slurmHandler)
+	defer cleanup()
+	r := setupApplicationRouter(h)
+
+	params := `[{"name":"COUNT","type":"integer","required":true}]`
+	body := `{"name":"submit-app","script_template":"#!/bin/bash\necho $COUNT","parameters":` + params + `}`
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", strings.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	var createResp map[string]interface{}
+	json.Unmarshal(w.Body.Bytes(), &createResp)
+	data := createResp["data"].(map[string]interface{})
+	id := int64(data["id"].(float64))
+
+	submitBody := `{"values":{"COUNT":"5"}}`
+	w2 := httptest.NewRecorder()
+	req2, _ := http.NewRequest(http.MethodPost, "/api/v1/applications/"+itoa(id)+"/submit", strings.NewReader(submitBody))
+	req2.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w2, req2)
+
+	if w2.Code != http.StatusCreated {
+		t.Fatalf("expected 201, got %d: %s", w2.Code, w2.Body.String())
+	}
+}
+
+func TestSubmitApplication_AppNotFound(t *testing.T) {
+	slurmHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]interface{}{})
+	})
+	h, cleanup := setupApplicationHandlerWithSlurm(slurmHandler)
+	defer cleanup()
+	r := setupApplicationRouter(h)
+
+	submitBody := `{"values":{"COUNT":"5"}}`
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications/999/submit", strings.NewReader(submitBody))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Fatalf("expected 404, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestSubmitApplication_ValidationFail(t *testing.T) {
+	slurmHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]interface{}{})
+	})
+	h, cleanup := setupApplicationHandlerWithSlurm(slurmHandler)
+	defer cleanup()
+	r := setupApplicationRouter(h)
+
+	params := `[{"name":"COUNT","type":"integer","required":true}]`
+	body := `{"name":"val-app","script_template":"#!/bin/bash\necho $COUNT","parameters":` + params + `}`
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", strings.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	var createResp map[string]interface{}
+	json.Unmarshal(w.Body.Bytes(), &createResp)
+	data := createResp["data"].(map[string]interface{})
+	id := int64(data["id"].(float64))
+
+	submitBody := `{"values":{"COUNT":"not-a-number"}}`
+	w2 := httptest.NewRecorder()
+	req2, _ := http.NewRequest(http.MethodPost, "/api/v1/applications/"+itoa(id)+"/submit", strings.NewReader(submitBody))
+	req2.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w2, req2)
+
+	if w2.Code != http.StatusBadRequest {
+		t.Fatalf("expected 400, got %d: %s", w2.Code, w2.Body.String())
+	}
+}
+
+// ---- Logging Tests ----
+
+func TestApplicationLogging_CreateSuccess_LogsInfoWithID(t *testing.T) {
+	h, _, recorded := setupApplicationHandlerWithObserver()
+	r := setupApplicationRouter(h)
+
+	body, _ := json.Marshal(model.CreateApplicationRequest{
+		Name:           "log-app",
+		ScriptTemplate: "#!/bin/bash\necho hello",
+	})
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	found := false
+	for _, entry := range recorded.All() {
+		if entry.Message == "application created" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatal("expected 'application created' log message")
+	}
+}
+
+func TestApplicationLogging_GetNotFound_LogsWarnWithID(t *testing.T) {
+	h, _, recorded := setupApplicationHandlerWithObserver()
+	r := setupApplicationRouter(h)
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/api/v1/applications/999", nil)
+	r.ServeHTTP(w, req)
+
+	found := false
+	for _, entry := range recorded.All() {
+		if entry.Message == "application not found" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatal("expected 'application not found' log message")
+	}
+}
+
+func TestApplicationLogging_UpdateSuccess_LogsInfoWithID(t *testing.T) {
+	h, _, recorded := setupApplicationHandlerWithObserver()
+	r := setupApplicationRouter(h)
+
+	id := createTestApplication(h, r)
+	recorded.TakeAll()
+
+	newName := "updated-log-app"
+	body, _ := json.Marshal(model.UpdateApplicationRequest{
+		Name: &newName,
+	})
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPut, "/api/v1/applications/"+itoa(id), bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	found := false
+	for _, entry := range recorded.All() {
+		if entry.Message == "application updated" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatal("expected 'application updated' log message")
+	}
+}
+
+func TestApplicationLogging_DeleteSuccess_LogsInfoWithID(t *testing.T) {
+	h, _, recorded := setupApplicationHandlerWithObserver()
+	r := setupApplicationRouter(h)
+
+	id := createTestApplication(h, r)
+	recorded.TakeAll()
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodDelete, "/api/v1/applications/"+itoa(id), nil)
+	r.ServeHTTP(w, req)
+
+	found := false
+	for _, entry := range recorded.All() {
+		if entry.Message == "application deleted" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatal("expected 'application deleted' log message")
+	}
+}
+
+func TestApplicationLogging_SubmitSuccess_LogsInfoWithID(t *testing.T) {
+	core, recorded := observer.New(zapcore.DebugLevel)
+	l := zap.New(core)
+
+	slurmSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusCreated)
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"job_id": 42,
+		})
+	}))
+	defer slurmSrv.Close()
+
+	client, _ := slurm.NewClient(slurmSrv.URL, slurmSrv.Client())
+	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{Logger: gormlogger.Default.LogMode(gormlogger.Silent)})
+	db.AutoMigrate(&model.Application{})
+	jobSvc := service.NewJobService(client, l)
+	appStore := store.NewApplicationStore(db)
+	appSvc := service.NewApplicationService(appStore, jobSvc, "", l)
+	h := NewApplicationHandler(appSvc, l)
+	r := setupApplicationRouter(h)
+
+	params := `[{"name":"X","type":"string","required":false}]`
+	body := `{"name":"sub-log-app","script_template":"#!/bin/bash\necho $X","parameters":` + params + `}`
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", strings.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	var createResp map[string]interface{}
+	json.Unmarshal(w.Body.Bytes(), &createResp)
+	data := createResp["data"].(map[string]interface{})
+	id := int64(data["id"].(float64))
+	recorded.TakeAll()
+
+	submitBody := `{"values":{"X":"val"}}`
+	w2 := httptest.NewRecorder()
+	req2, _ := http.NewRequest(http.MethodPost, "/api/v1/applications/"+itoa(id)+"/submit", strings.NewReader(submitBody))
+	req2.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w2, req2)
+
+	found := false
+	for _, entry := range recorded.All() {
+		if entry.Message == "application submitted" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatal("expected 'application submitted' log message")
+	}
+}
+
+func TestApplicationLogging_CreateBadRequest_LogsWarn(t *testing.T) {
+	h, _, recorded := setupApplicationHandlerWithObserver()
+	r := setupApplicationRouter(h)
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", strings.NewReader(`{"name":""}`))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	found := false
+	for _, entry := range recorded.All() {
+		if entry.Message == "invalid request body for create application" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatal("expected 'invalid request body for create application' log message")
+	}
+}
+
+func TestApplicationLogging_LogsDoNotContainApplicationContent(t *testing.T) {
+	h, _, recorded := setupApplicationHandlerWithObserver()
+	r := setupApplicationRouter(h)
+
+	body, _ := json.Marshal(model.CreateApplicationRequest{
+		Name:           "secret-app",
+		ScriptTemplate: "#!/bin/bash\necho secret_password_here",
+	})
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/api/v1/applications", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	r.ServeHTTP(w, req)
+
+	for _, entry := range recorded.All() {
+		msg := entry.Message
+		if strings.Contains(msg, "secret_password_here") {
+			t.Fatalf("log message contains application content: %s", msg)
+		}
+		for _, field := range entry.Context {
+			if strings.Contains(field.String, "secret_password_here") {
+				t.Fatalf("log field contains application content: %s", field.String)
+			}
+		}
+	}
+}