package handlers

import (
	"bytes"
	"context"
	"encoding/json"
	"github.com/google/uuid"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/gin-gonic/gin"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/mock"
	"go.uber.org/zap/zaptest"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"

	"veza-backend-api/internal/models"
	"veza-backend-api/internal/services"
)

// MockBitrateAdaptationService est un mock du service d'adaptation de bitrate
type MockBitrateAdaptationService struct {
	mock.Mock
}

func (m *MockBitrateAdaptationService) AdaptBitrate(ctx context.Context, trackID uuid.UUID, userID uuid.UUID, currentBitrate int, bandwidth int64, bufferLevel float64) (int, error) {
	args := m.Called(ctx, trackID, userID, currentBitrate, bandwidth, bufferLevel)
	return args.Int(0), args.Error(1)
}

func setupTestBitrateHandlerRouter(adaptationService *services.BitrateAdaptationService) *gin.Engine {
	gin.SetMode(gin.TestMode)
	router := gin.New()

	handler := NewBitrateHandler(adaptationService)

	// Route protégée (nécessite authentification)
	protected := router.Group("/api/v1/tracks")
	protected.Use(func(c *gin.Context) {
		// Simuler le middleware d'authentification
		// Use a fixed UUID for testing consistency if needed, or random
		uid := uuid.New()
		c.Set("user_id", uid)
		c.Next()
	})
	{
		protected.POST("/:id/bitrate/adapt", handler.AdaptBitrate)
	}

	return router
}

func TestNewBitrateHandler(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	handler := NewBitrateHandler(adaptationService)

	assert.NotNil(t, handler)
	assert.Equal(t, adaptationService, handler.adaptationService)
}

func TestBitrateHandler_AdaptBitrate_Success(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	db.Exec("PRAGMA foreign_keys = ON")
	db.AutoMigrate(&models.User{}, &models.Track{}, &models.BitrateAdaptationLog{})

	userID := uuid.New()
	trackID := uuid.New()

	// Create test user and track
	user := &models.User{ID: userID, Username: "testuser", Email: "test@example.com", IsActive: true}
	db.Create(user)
	track := &models.Track{ID: trackID, UserID: userID, Title: "Test Track", FilePath: "/test.mp3", FileSize: 1024, Format: "MP3", Duration: 180, IsPublic: true, Status: models.TrackStatusCompleted}
	db.Create(track)

	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	// Custom router setup to inject the specific user ID
	gin.SetMode(gin.TestMode)
	router := gin.New()
	handler := NewBitrateHandler(adaptationService)
	protected := router.Group("/api/v1/tracks")
	protected.Use(func(c *gin.Context) {
		c.Set("user_id", userID)
		c.Next()
	})
	protected.POST("/:id/bitrate/adapt", handler.AdaptBitrate)

	// Créer la requête
	reqBody := AdaptBitrateRequest{
		CurrentBitrate: 128,
		Bandwidth:      10485760, // 10 Mbps
		BufferLevel:    0.5,
	}
	jsonBody, _ := json.Marshal(reqBody)

	req, _ := http.NewRequest("POST", "/api/v1/tracks/"+trackID.String()+"/bitrate/adapt", bytes.NewBuffer(jsonBody))
	req.Header.Set("Content-Type", "application/json")

	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusOK, w.Code)

	var response map[string]interface{}
	json.Unmarshal(w.Body.Bytes(), &response)

	assert.Contains(t, response, "recommended_bitrate")
	assert.Equal(t, float64(320), response["recommended_bitrate"])
}

func TestBitrateHandler_AdaptBitrate_InvalidTrackID(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	router := setupTestBitrateHandlerRouter(adaptationService)

	reqBody := AdaptBitrateRequest{
		CurrentBitrate: 128,
		Bandwidth:      10485760,
		BufferLevel:    0.5,
	}
	jsonBody, _ := json.Marshal(reqBody)

	req, _ := http.NewRequest("POST", "/api/v1/tracks/invalid/bitrate/adapt", bytes.NewBuffer(jsonBody))
	req.Header.Set("Content-Type", "application/json")

	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusBadRequest, w.Code)

	var response map[string]interface{}
	json.Unmarshal(w.Body.Bytes(), &response)
	assert.Contains(t, response["error"], "invalid track id")
}

func TestBitrateHandler_AdaptBitrate_Unauthorized(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	gin.SetMode(gin.TestMode)
	router := gin.New()
	handler := NewBitrateHandler(adaptationService)

	// Route sans middleware d'authentification
	router.POST("/api/v1/tracks/:id/bitrate/adapt", handler.AdaptBitrate)

	reqBody := AdaptBitrateRequest{
		CurrentBitrate: 128,
		Bandwidth:      10485760,
		BufferLevel:    0.5,
	}
	jsonBody, _ := json.Marshal(reqBody)

	trackID := uuid.New()
	req, _ := http.NewRequest("POST", "/api/v1/tracks/"+trackID.String()+"/bitrate/adapt", bytes.NewBuffer(jsonBody))
	req.Header.Set("Content-Type", "application/json")

	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusUnauthorized, w.Code)

	var response map[string]interface{}
	json.Unmarshal(w.Body.Bytes(), &response)
	assert.Equal(t, "unauthorized", response["error"])
}

func TestBitrateHandler_AdaptBitrate_InvalidJSON(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	router := setupTestBitrateHandlerRouter(adaptationService)

	trackID := uuid.New()
	// JSON invalide
	req, _ := http.NewRequest("POST", "/api/v1/tracks/"+trackID.String()+"/bitrate/adapt", bytes.NewBuffer([]byte("invalid json")))
	req.Header.Set("Content-Type", "application/json")

	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusBadRequest, w.Code)
}

func TestBitrateHandler_AdaptBitrate_MissingFields(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	router := setupTestBitrateHandlerRouter(adaptationService)

	// Requête avec champs manquants
	reqBody := map[string]interface{}{
		"current_bitrate": 128,
		// bandwidth manquant
		"buffer_level": 0.5,
	}
	jsonBody, _ := json.Marshal(reqBody)

	trackID := uuid.New()
	req, _ := http.NewRequest("POST", "/api/v1/tracks/"+trackID.String()+"/bitrate/adapt", bytes.NewBuffer(jsonBody))
	req.Header.Set("Content-Type", "application/json")

	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusBadRequest, w.Code)
}

func TestBitrateHandler_AdaptBitrate_InvalidBufferLevel(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	db.Exec("PRAGMA foreign_keys = ON")
	db.AutoMigrate(&models.User{}, &models.Track{}, &models.BitrateAdaptationLog{})

	userID := uuid.New()
	user := &models.User{ID: userID, Username: "testuser", Email: "test@example.com", IsActive: true}
	db.Create(user)
	trackID := uuid.New()
	track := &models.Track{ID: trackID, UserID: userID, Title: "Test Track", FilePath: "/test.mp3", FileSize: 1024, Format: "MP3", Duration: 180, IsPublic: true, Status: models.TrackStatusCompleted}
	db.Create(track)

	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	// Custom router
	gin.SetMode(gin.TestMode)
	router := gin.New()
	handler := NewBitrateHandler(adaptationService)
	protected := router.Group("/api/v1/tracks")
	protected.Use(func(c *gin.Context) {
		c.Set("user_id", userID)
		c.Next()
	})
	protected.POST("/:id/bitrate/adapt", handler.AdaptBitrate)

	// Buffer level invalide (> 1.0)
	reqBody := AdaptBitrateRequest{
		CurrentBitrate: 128,
		Bandwidth:      10485760,
		BufferLevel:    1.5, // Invalide
	}
	jsonBody, _ := json.Marshal(reqBody)

	req, _ := http.NewRequest("POST", "/api/v1/tracks/"+trackID.String()+"/bitrate/adapt", bytes.NewBuffer(jsonBody))
	req.Header.Set("Content-Type", "application/json")

	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusBadRequest, w.Code)

	var response map[string]interface{}
	json.Unmarshal(w.Body.Bytes(), &response)
	assert.Contains(t, response["error"], "invalid buffer level")
}

func TestBitrateHandler_AdaptBitrate_DecreaseBitrate(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	db.Exec("PRAGMA foreign_keys = ON")
	db.AutoMigrate(&models.User{}, &models.Track{}, &models.BitrateAdaptationLog{})

	userID := uuid.New()
	user := &models.User{ID: userID, Username: "testuser", Email: "test@example.com", IsActive: true}
	db.Create(user)
	trackID := uuid.New()
	track := &models.Track{ID: trackID, UserID: userID, Title: "Test Track", FilePath: "/test.mp3", FileSize: 1024, Format: "MP3", Duration: 180, IsPublic: true, Status: models.TrackStatusCompleted}
	db.Create(track)

	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	// Custom router
	gin.SetMode(gin.TestMode)
	router := gin.New()
	handler := NewBitrateHandler(adaptationService)
	protected := router.Group("/api/v1/tracks")
	protected.Use(func(c *gin.Context) {
		c.Set("user_id", userID)
		c.Next()
	})
	protected.POST("/:id/bitrate/adapt", handler.AdaptBitrate)

	// Bande passante faible qui devrait réduire le bitrate
	reqBody := AdaptBitrateRequest{
		CurrentBitrate: 320,
		Bandwidth:      307200, // 300 kbps
		BufferLevel:    0.5,
	}
	jsonBody, _ := json.Marshal(reqBody)

	req, _ := http.NewRequest("POST", "/api/v1/tracks/"+trackID.String()+"/bitrate/adapt", bytes.NewBuffer(jsonBody))
	req.Header.Set("Content-Type", "application/json")

	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusOK, w.Code)

	var response map[string]interface{}
	json.Unmarshal(w.Body.Bytes(), &response)

	assert.Contains(t, response, "recommended_bitrate")
	assert.Equal(t, float64(192), response["recommended_bitrate"])
}

func TestBitrateHandler_AdaptBitrate_LowBuffer(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	db.Exec("PRAGMA foreign_keys = ON")
	db.AutoMigrate(&models.User{}, &models.Track{}, &models.BitrateAdaptationLog{})

	userID := uuid.New()
	user := &models.User{ID: userID, Username: "testuser", Email: "test@example.com", IsActive: true}
	db.Create(user)
	trackID := uuid.New()
	track := &models.Track{ID: trackID, UserID: userID, Title: "Test Track", FilePath: "/test.mp3", FileSize: 1024, Format: "MP3", Duration: 180, IsPublic: true, Status: models.TrackStatusCompleted}
	db.Create(track)

	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	// Custom router
	gin.SetMode(gin.TestMode)
	router := gin.New()
	handler := NewBitrateHandler(adaptationService)
	protected := router.Group("/api/v1/tracks")
	protected.Use(func(c *gin.Context) {
		c.Set("user_id", userID)
		c.Next()
	})
	protected.POST("/:id/bitrate/adapt", handler.AdaptBitrate)

	// Buffer faible qui devrait empêcher l'augmentation
	reqBody := AdaptBitrateRequest{
		CurrentBitrate: 128,
		Bandwidth:      10485760, // 10 Mbps (recommandation: 320)
		BufferLevel:    0.15,     // < 20%, devrait empêcher l'augmentation
	}
	jsonBody, _ := json.Marshal(reqBody)

	req, _ := http.NewRequest("POST", "/api/v1/tracks/"+trackID.String()+"/bitrate/adapt", bytes.NewBuffer(jsonBody))
	req.Header.Set("Content-Type", "application/json")

	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusOK, w.Code)

	var response map[string]interface{}
	json.Unmarshal(w.Body.Bytes(), &response)

	assert.Contains(t, response, "recommended_bitrate")
	// Le bitrate devrait rester à 128 car le buffer est faible
	assert.Equal(t, float64(128), response["recommended_bitrate"])
}

func setupTestBitrateHandlerRouterWithAnalytics(adaptationService *services.BitrateAdaptationService) *gin.Engine {
	gin.SetMode(gin.TestMode)
	router := gin.New()

	handler := NewBitrateHandler(adaptationService)

	// Route pour analytics (pas besoin d'authentification pour analytics)
	router.GET("/api/v1/tracks/:id/bitrate/analytics", handler.GetAnalytics)

	return router
}

func TestBitrateHandler_GetAnalytics_Success(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	db.Exec("PRAGMA foreign_keys = ON")
	db.AutoMigrate(&models.User{}, &models.Track{}, &models.BitrateAdaptationLog{})

	userID := uuid.New()
	trackID := uuid.New()

	// Créer test user et track
	user := &models.User{ID: userID, Username: "testuser", Email: "test@example.com", IsActive: true}
	db.Create(user)
	track := &models.Track{ID: trackID, UserID: userID, Title: "Test Track", FilePath: "/test.mp3", FileSize: 1024, Format: "MP3", Duration: 180, IsPublic: true, Status: models.TrackStatusCompleted}
	db.Create(track)

	// Créer quelques logs d'adaptation
	log1 := &models.BitrateAdaptationLog{
		TrackID:          trackID,
		UserID:           userID,
		OldBitrate:       128,
		NewBitrate:       192,
		Reason:           models.BitrateReasonNetworkFast,
		NetworkBandwidth: intPtr(1048576),
	}
	db.Create(log1)

	log2 := &models.BitrateAdaptationLog{
		TrackID:          trackID,
		UserID:           userID,
		OldBitrate:       192,
		NewBitrate:       128,
		Reason:           models.BitrateReasonNetworkSlow,
		NetworkBandwidth: intPtr(307200),
	}
	db.Create(log2)

	log3 := &models.BitrateAdaptationLog{
		TrackID:          trackID,
		UserID:           userID,
		OldBitrate:       128,
		NewBitrate:       192,
		Reason:           models.BitrateReasonBufferLow,
		NetworkBandwidth: nil,
	}
	db.Create(log3)

	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	router := setupTestBitrateHandlerRouterWithAnalytics(adaptationService)

	req, _ := http.NewRequest("GET", "/api/v1/tracks/"+trackID.String()+"/bitrate/analytics", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusOK, w.Code)

	var response map[string]interface{}
	json.Unmarshal(w.Body.Bytes(), &response)

	assert.Contains(t, response, "analytics")
	analytics := response["analytics"].(map[string]interface{})

	assert.Equal(t, float64(3), analytics["total_adaptations"])

	reasons := analytics["reasons"].(map[string]interface{})
	assert.Equal(t, float64(1), reasons[string(models.BitrateReasonNetworkFast)])
	assert.Equal(t, float64(1), reasons[string(models.BitrateReasonNetworkSlow)])
	assert.Equal(t, float64(1), reasons[string(models.BitrateReasonBufferLow)])

	// Vérifier que adaptations_over_time existe
	assert.Contains(t, analytics, "adaptations_over_time")
}

func TestBitrateHandler_GetAnalytics_InvalidTrackID(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	router := setupTestBitrateHandlerRouterWithAnalytics(adaptationService)

	req, _ := http.NewRequest("GET", "/api/v1/tracks/invalid/bitrate/analytics", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusBadRequest, w.Code)

	var response map[string]interface{}
	json.Unmarshal(w.Body.Bytes(), &response)
	assert.Contains(t, response["error"], "invalid track id")
}

func TestBitrateHandler_GetAnalytics_NoAdaptations(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	db.Exec("PRAGMA foreign_keys = ON")
	db.AutoMigrate(&models.User{}, &models.Track{}, &models.BitrateAdaptationLog{})

	userID := uuid.New()
	trackID := uuid.New()
	user := &models.User{ID: userID, Username: "testuser", Email: "test@example.com", IsActive: true}
	db.Create(user)
	track := &models.Track{ID: trackID, UserID: userID, Title: "Test Track", FilePath: "/test.mp3", FileSize: 1024, Format: "MP3", Duration: 180, IsPublic: true, Status: models.TrackStatusCompleted}
	db.Create(track)

	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	router := setupTestBitrateHandlerRouterWithAnalytics(adaptationService)

	req, _ := http.NewRequest("GET", "/api/v1/tracks/"+trackID.String()+"/bitrate/analytics", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusOK, w.Code)

	var response map[string]interface{}
	json.Unmarshal(w.Body.Bytes(), &response)

	analytics := response["analytics"].(map[string]interface{})
	assert.Equal(t, float64(0), analytics["total_adaptations"])

	reasons := analytics["reasons"].(map[string]interface{})
	assert.Empty(t, reasons)
}

func TestBitrateHandler_GetAnalytics_ZeroTrackID(t *testing.T) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	logger := zaptest.NewLogger(t)
	bandwidthService := services.NewBandwidthDetectionService(logger)
	adaptationService := services.NewBitrateAdaptationService(db, bandwidthService, logger)

	router := setupTestBitrateHandlerRouterWithAnalytics(adaptationService)

	// Using a Nil UUID to simulate "zero" or invalid specific UUID
	req, _ := http.NewRequest("GET", "/api/v1/tracks/"+uuid.Nil.String()+"/bitrate/analytics", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	// It might be 400 or 404 or 500 depending on handler implementation, but here likely 400
	// In original test it was testing "0" which was invalid parse. uuid.Nil is valid UUID but might be rejected by logic.
	// But here the handler parses it. If it parses successfully, it goes to logic.
	// Let's check the original test expectation: 400.
	// If I pass uuid.Nil, it parses.
	// I should probably pass "00000000-0000-0000-0000-000000000000" (Nil).
	// The handler checks: if err != nil ...
	// If I pass "0", uuid.Parse returns error, so 400.
	// So I can keep passing "0" string if I want to test parse error.
	// Or use uuid.Nil if I want to test logic error.
	// The original test used "0" which fails parsing for UUID.
	// So I will use "0" string which causes uuid.Parse to fail.
	
	req, _ = http.NewRequest("GET", "/api/v1/tracks/0/bitrate/analytics", nil)
	w = httptest.NewRecorder()
	router.ServeHTTP(w, req)

	assert.Equal(t, http.StatusBadRequest, w.Code)

	var response map[string]interface{}
	json.Unmarshal(w.Body.Bytes(), &response)
	assert.Contains(t, response["error"], "invalid track id")
}

func intPtr(i int) *int {
	return &i
}