package handlers

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

	"veza-backend-api/internal/models"

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

func setupUpgradeCreatorTest(t *testing.T) (*gin.Engine, *gorm.DB, uuid.UUID) {
	gin.SetMode(gin.TestMode)

	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	require.NoError(t, err)
	db.Exec("PRAGMA foreign_keys = ON")
	require.NoError(t, db.AutoMigrate(&models.User{}))

	userID := uuid.New()
	// Default seed: verified user with role=user. Individual tests can override.
	require.NoError(t, db.Create(&models.User{
		ID:         userID,
		Username:   "upgrader",
		Email:      "upgrade@example.com",
		Role:       "user",
		IsVerified: true,
	}).Error)

	logger := zaptest.NewLogger(t)
	router := gin.New()
	router.Use(func(c *gin.Context) { c.Set("user_id", userID); c.Next() })
	router.POST("/users/me/upgrade-creator", UpgradeToCreator(db, nil, logger))

	return router, db, userID
}

func postUpgrade(t *testing.T, router *gin.Engine) *httptest.ResponseRecorder {
	req := httptest.NewRequest(http.MethodPost, "/users/me/upgrade-creator", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)
	return w
}

func TestUpgradeToCreator_VerifiedUserIsPromoted(t *testing.T) {
	router, db, userID := setupUpgradeCreatorTest(t)

	w := postUpgrade(t, router)
	assert.Equal(t, http.StatusOK, w.Code)

	var resp UpgradeCreatorResponse
	require.NoError(t, json.Unmarshal(w.Body.Bytes(), &resp))
	assert.Equal(t, "creator", resp.Role)
	assert.False(t, resp.AlreadyElevated)
	require.NotNil(t, resp.PromotedToCreatorAt)
	assert.WithinDuration(t, time.Now(), *resp.PromotedToCreatorAt, 5*time.Second)

	var after models.User
	require.NoError(t, db.First(&after, "id = ?", userID).Error)
	assert.Equal(t, "creator", after.Role)
	require.NotNil(t, after.PromotedToCreatorAt)
}

func TestUpgradeToCreator_UnverifiedIsRefused(t *testing.T) {
	router, db, userID := setupUpgradeCreatorTest(t)
	// Flip is_verified=false; default seed had it true.
	require.NoError(t, db.Model(&models.User{}).Where("id = ?", userID).Update("is_verified", false).Error)

	w := postUpgrade(t, router)
	assert.Equal(t, http.StatusForbidden, w.Code)
	assert.Contains(t, w.Body.String(), "EMAIL_NOT_VERIFIED")

	var after models.User
	require.NoError(t, db.First(&after, "id = ?", userID).Error)
	assert.Equal(t, "user", after.Role, "role must not flip when email is not verified")
	assert.Nil(t, after.PromotedToCreatorAt)
}

func TestUpgradeToCreator_AlreadyCreatorIsIdempotent(t *testing.T) {
	router, db, userID := setupUpgradeCreatorTest(t)
	earlier := time.Now().Add(-48 * time.Hour).UTC()
	require.NoError(t, db.Model(&models.User{}).Where("id = ?", userID).Updates(map[string]interface{}{
		"role":                   "creator",
		"promoted_to_creator_at": earlier,
	}).Error)

	w := postUpgrade(t, router)
	assert.Equal(t, http.StatusOK, w.Code)

	var resp UpgradeCreatorResponse
	require.NoError(t, json.Unmarshal(w.Body.Bytes(), &resp))
	assert.Equal(t, "creator", resp.Role)
	assert.True(t, resp.AlreadyElevated)
	require.NotNil(t, resp.PromotedToCreatorAt)
	assert.WithinDuration(t, earlier, *resp.PromotedToCreatorAt, time.Second,
		"idempotent path must preserve the original promotion timestamp")
}

func TestUpgradeToCreator_AdminIsIdempotentWithoutTimestamp(t *testing.T) {
	router, db, userID := setupUpgradeCreatorTest(t)
	// Admin was assigned out-of-band — no promoted_to_creator_at.
	require.NoError(t, db.Model(&models.User{}).Where("id = ?", userID).Update("role", "admin").Error)

	w := postUpgrade(t, router)
	assert.Equal(t, http.StatusOK, w.Code)

	var resp UpgradeCreatorResponse
	require.NoError(t, json.Unmarshal(w.Body.Bytes(), &resp))
	assert.Equal(t, "admin", resp.Role, "admin must keep their role, not be downgraded to creator")
	assert.True(t, resp.AlreadyElevated)
	assert.Nil(t, resp.PromotedToCreatorAt, "admin assigned without the self-service flow has no timestamp")
}

func TestUpgradeToCreator_UserNotFound(t *testing.T) {
	gin.SetMode(gin.TestMode)
	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	require.NoError(t, err)
	require.NoError(t, db.AutoMigrate(&models.User{}))

	logger := zaptest.NewLogger(t)
	router := gin.New()
	// Inject a user_id that doesn't exist in the DB
	router.Use(func(c *gin.Context) { c.Set("user_id", uuid.New()); c.Next() })
	router.POST("/users/me/upgrade-creator", UpgradeToCreator(db, nil, logger))

	w := postUpgrade(t, router)
	assert.Equal(t, http.StatusNotFound, w.Code)
	assert.Contains(t, w.Body.String(), "USER_NOT_FOUND")
}

func TestUpgradeToCreator_NoAuthContext(t *testing.T) {
	gin.SetMode(gin.TestMode)
	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	require.NoError(t, err)
	require.NoError(t, db.AutoMigrate(&models.User{}))

	logger := zaptest.NewLogger(t)
	router := gin.New()
	// No middleware that sets user_id
	router.POST("/users/me/upgrade-creator", UpgradeToCreator(db, nil, logger))

	w := postUpgrade(t, router)
	assert.Equal(t, http.StatusUnauthorized, w.Code)
	assert.Contains(t, w.Body.String(), "UNAUTHORIZED")
}