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)
			}
		}
	}
}