package middleware

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"github.com/gin-gonic/gin"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"

	"github.com/dhao2001/mygo/internal/auth"
	"github.com/dhao2001/mygo/internal/model"
	"github.com/dhao2001/mygo/internal/repository"
)

func setupTestRouter(secret []byte) *gin.Engine {
	gin.SetMode(gin.TestMode)
	r := gin.New()
	r.Use(AuthRequired(secret))
	r.GET("/protected", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{"user_id": MustGetUserID(c)})
	})
	return r
}

func TestAuthRequiredNoHeader(t *testing.T) {
	r := setupTestRouter([]byte("test-secret"))

	req := httptest.NewRequest(http.MethodGet, "/protected", nil)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Errorf("status = %d, want %d", rec.Code, http.StatusUnauthorized)
	}
}

func TestAuthRequiredInvalidFormat(t *testing.T) {
	r := setupTestRouter([]byte("test-secret"))

	req := httptest.NewRequest(http.MethodGet, "/protected", nil)
	req.Header.Set("Authorization", "invalid")
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Errorf("status = %d, want %d", rec.Code, http.StatusUnauthorized)
	}
}

func TestAuthRequiredNotBearer(t *testing.T) {
	r := setupTestRouter([]byte("test-secret"))

	req := httptest.NewRequest(http.MethodGet, "/protected", nil)
	req.Header.Set("Authorization", "Basic dXNlcjpwYXNz")
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Errorf("status = %d, want %d", rec.Code, http.StatusUnauthorized)
	}
}

func TestAuthRequiredExpiredToken(t *testing.T) {
	secret := []byte("test-secret")
	token, err := auth.GenerateAccessToken("user-1", secret, -1*time.Minute)
	if err != nil {
		t.Fatalf("GenerateAccessToken = %v", err)
	}

	r := setupTestRouter(secret)
	req := httptest.NewRequest(http.MethodGet, "/protected", nil)
	req.Header.Set("Authorization", "Bearer "+token)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Errorf("status = %d, want %d", rec.Code, http.StatusUnauthorized)
	}
}

func TestAuthRequiredValidToken(t *testing.T) {
	secret := []byte("test-secret")
	token, err := auth.GenerateAccessToken("user-1", secret, 15*time.Minute)
	if err != nil {
		t.Fatalf("GenerateAccessToken = %v", err)
	}

	r := setupTestRouter(secret)
	req := httptest.NewRequest(http.MethodGet, "/protected", nil)
	req.Header.Set("Authorization", "Bearer "+token)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Errorf("status = %d, want %d", rec.Code, http.StatusOK)
	}
}

func TestAuthRequiredRefreshTokenRejected(t *testing.T) {
	secret := []byte("test-secret")
	token, err := auth.GenerateRefreshToken("user-1", secret, 7*24*time.Hour)
	if err != nil {
		t.Fatalf("GenerateRefreshToken = %v", err)
	}

	r := setupTestRouter(secret)
	req := httptest.NewRequest(http.MethodGet, "/protected", nil)
	req.Header.Set("Authorization", "Bearer "+token)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Errorf("status = %d, want %d (refresh token should be rejected)", rec.Code, http.StatusUnauthorized)
	}
}

func TestGetUserID(t *testing.T) {
	secret := []byte("test-secret")
	token, err := auth.GenerateAccessToken("alice-42", secret, 15*time.Minute)
	if err != nil {
		t.Fatalf("GenerateAccessToken = %v", err)
	}

	r := setupTestRouter(secret)
	req := httptest.NewRequest(http.MethodGet, "/protected", nil)
	req.Header.Set("Authorization", "Bearer "+token)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d", rec.Code)
	}

	body := rec.Body.String()
	if !strings.Contains(body, "alice-42") {
		t.Errorf("response body %q does not contain user id", body)
	}
}

func TestMustGetUserID(t *testing.T) {
	secret := []byte("test-secret")
	token, err := auth.GenerateAccessToken("bob-99", secret, 15*time.Minute)
	if err != nil {
		t.Fatalf("GenerateAccessToken = %v", err)
	}

	r := setupTestRouter(secret)
	req := httptest.NewRequest(http.MethodGet, "/protected", nil)
	req.Header.Set("Authorization", "Bearer "+token)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d", rec.Code)
	}

	body := rec.Body.String()
	if !strings.Contains(body, "bob-99") {
		t.Errorf("response body %q does not contain user id", body)
	}
}

func TestMustGetUserIDPanics(t *testing.T) {
	gin.SetMode(gin.TestMode)
	r := gin.New()
	r.GET("/naked", func(c *gin.Context) {
		MustGetUserID(c) // should panic — no AuthRequired middleware applied
	})

	req := httptest.NewRequest(http.MethodGet, "/naked", nil)
	rec := httptest.NewRecorder()

	defer func() {
		if r := recover(); r == nil {
			t.Error("expected panic, got none")
		}
	}()
	r.ServeHTTP(rec, req)
}

func TestAuthRequiredWrongSecret(t *testing.T) {
	secret := []byte("test-secret")
	token, err := auth.GenerateAccessToken("user-1", secret, 15*time.Minute)
	if err != nil {
		t.Fatalf("GenerateAccessToken = %v", err)
	}

	// Use a different secret for the middleware
	r := setupTestRouter([]byte("different-secret"))
	req := httptest.NewRequest(http.MethodGet, "/protected", nil)
	req.Header.Set("Authorization", "Bearer "+token)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Errorf("status = %d, want %d", rec.Code, http.StatusUnauthorized)
	}
}

// --- AdminRequired tests ---

// errorBody extracts the error.message field from a JSON response body.
type errorBody struct {
	Error struct {
		Message string `json:"message"`
	} `json:"error"`
}

func setupAdminTestDB(t *testing.T) repository.UserRepository {
	t.Helper()

	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	if err != nil {
		t.Fatalf("open db: %v", err)
	}
	if err := db.AutoMigrate(&model.User{}); err != nil {
		t.Fatalf("migrate: %v", err)
	}

	return repository.NewUserRepository(db)
}

// injectUserIDMiddleware simulates AuthRequired by injecting a user_id into the context.
func injectUserIDMiddleware(userID string) gin.HandlerFunc {
	return func(c *gin.Context) {
		c.Set(userIDKey, userID)
		c.Next()
	}
}

func TestAdminRequired_AdminPasses(t *testing.T) {
	repo := setupAdminTestDB(t)
	ctx := context.Background()

	user := &model.User{
		ID:       "admin-1",
		Username: "admin",
		Email:    "admin@example.com",
		IsAdmin:  true,
		Status:   model.StatusActive,
	}
	if err := repo.Create(ctx, user); err != nil {
		t.Fatalf("Create = %v", err)
	}

	gin.SetMode(gin.TestMode)
	r := gin.New()
	r.Use(injectUserIDMiddleware("admin-1"))
	r.Use(AdminRequired(repo))
	r.GET("/admin", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{"status": "ok"})
	})

	req := httptest.NewRequest(http.MethodGet, "/admin", nil)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Errorf("status = %d, want %d", rec.Code, http.StatusOK)
	}
}

func TestAdminRequired_NonAdminForbidden(t *testing.T) {
	repo := setupAdminTestDB(t)
	ctx := context.Background()

	user := &model.User{
		ID:       "user-1",
		Username: "regular",
		Email:    "regular@example.com",
		IsAdmin:  false,
		Status:   model.StatusActive,
	}
	if err := repo.Create(ctx, user); err != nil {
		t.Fatalf("Create = %v", err)
	}

	gin.SetMode(gin.TestMode)
	r := gin.New()
	r.Use(injectUserIDMiddleware("user-1"))
	r.Use(AdminRequired(repo))
	r.GET("/admin", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{"status": "ok"})
	})

	req := httptest.NewRequest(http.MethodGet, "/admin", nil)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusForbidden {
		t.Errorf("status = %d, want %d", rec.Code, http.StatusForbidden)
	}

	var body errorBody
	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
		t.Fatalf("unmarshal: %v", err)
	}
	if body.Error.Message != "admin access required" {
		t.Errorf("message = %q, want %q", body.Error.Message, "admin access required")
	}
}

func TestAdminRequired_SoftDeletedAdmin(t *testing.T) {
	repo := setupAdminTestDB(t)
	ctx := context.Background()

	user := &model.User{
		ID:       "admin-2",
		Username: "deleted_admin",
		Email:    "deleted_admin@example.com",
		IsAdmin:  true,
		Status:   model.StatusActive,
	}
	if err := repo.Create(ctx, user); err != nil {
		t.Fatalf("Create = %v", err)
	}

	// Soft-delete the admin user
	if err := repo.Delete(ctx, "admin-2"); err != nil {
		t.Fatalf("Delete = %v", err)
	}

	gin.SetMode(gin.TestMode)
	r := gin.New()
	r.Use(injectUserIDMiddleware("admin-2"))
	r.Use(AdminRequired(repo))
	r.GET("/admin", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{"status": "ok"})
	})

	req := httptest.NewRequest(http.MethodGet, "/admin", nil)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Errorf("status = %d, want %d", rec.Code, http.StatusUnauthorized)
	}
}

func TestAdminRequired_NoUserID(t *testing.T) {
	repo := setupAdminTestDB(t)

	gin.SetMode(gin.TestMode)
	r := gin.New()
	r.Use(AdminRequired(repo))
	r.GET("/admin", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{"status": "ok"})
	})

	req := httptest.NewRequest(http.MethodGet, "/admin", nil)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Errorf("status = %d, want %d", rec.Code, http.StatusUnauthorized)
	}
}