package handler

import (
	"baron-sso-backend/internal/domain"
	"baron-sso-backend/internal/service"
	"bytes"
	"encoding/json"
	"fmt"
	"net/http/httptest"
	"testing"

	"github.com/gofiber/fiber/v2"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/mock"
)

func TestUserHandler_BulkCreateUsers_UUIDSupport(t *testing.T) {
	app := fiber.New()
	mockKratos := new(MockKratosAdmin)
	mockOry := new(MockOryProvider)
	mockTenant := new(MockTenantServiceForUser)

	h := &UserHandler{
		KratosAdmin:   mockKratos,
		OryProvider:   mockOry,
		TenantService: mockTenant,
	}

	app.Post("/users/bulk", h.BulkCreateUsers)

	t.Run("Success - Provided UUID", func(t *testing.T) {
		testUuid := "550e8400-e29b-41d4-a716-446655440000"
		mockTenant.On("GetTenantBySlug", mock.Anything, "test-tenant").Return(&domain.Tenant{
			ID:   "t-1",
			Slug: "test-tenant",
		}, nil).Once()

		mockOry.On("GetPasswordPolicy").Return(&domain.PasswordPolicy{MinLength: 8}, nil)

		// 1. Search-first check: Simulate user NOT found by this UUID
		mockKratos.On("FindIdentityIDByIdentifier", mock.Anything, testUuid).Return("", nil).Once()

		// 2. Create identity
		mockOry.On("CreateUser", mock.MatchedBy(func(user *domain.BrokerUser) bool {
			return user.ID == testUuid && user.Email == "uuid@test.com"
		}), mock.Anything).Return(testUuid, nil).Once()

		payload := map[string]any{
			"users": []map[string]any{
				{
					"email":      "uuid@test.com",
					"name":       "UUID User",
					"tenantSlug": "test-tenant",
					"id":         testUuid,
				},
			},
		}
		body, _ := json.Marshal(payload)
		req := httptest.NewRequest("POST", "/users/bulk", bytes.NewReader(body))
		req.Header.Set("Content-Type", "application/json")

		resp, _ := app.Test(req)
		assert.Equal(t, 200, resp.StatusCode)

		var result struct {
			Results []bulkUserResult `json:"results"`
		}
		json.NewDecoder(resp.Body).Decode(&result)
		assert.Len(t, result.Results, 1)
		assert.True(t, result.Results[0].Success)
		assert.Equal(t, testUuid, result.Results[0].UserID)
	})

	t.Run("Success - Provided UUID Already Exists (Idempotency)", func(t *testing.T) {
		testUuid := "550e8400-e29b-41d4-a716-446655440005"
		mockTenant.On("GetTenantBySlug", mock.Anything, "test-tenant").Return(&domain.Tenant{
			ID:   "t-1",
			Slug: "test-tenant",
		}, nil).Once()

		mockOry.On("GetPasswordPolicy").Return(&domain.PasswordPolicy{MinLength: 8}, nil)

		// 1. Search-first check: Simulate user FOUND by this UUID
		mockKratos.On("FindIdentityIDByIdentifier", mock.Anything, testUuid).Return(testUuid, nil).Once()

		// 2. Fetch existing identity for field comparison
		mockKratos.On("GetIdentity", mock.Anything, testUuid).Return(&service.KratosIdentity{
			ID: testUuid,
			Traits: map[string]any{
				"email": "existing@test.com",
				"name":  "Old Name",
			},
		}, nil).Once()

		payload := map[string]any{
			"users": []map[string]any{
				{
					"email":      "existing@test.com",
					"name":       "Existing User",
					"tenantSlug": "test-tenant",
					"id":         testUuid,
				},
			},
		}
		body, _ := json.Marshal(payload)
		req := httptest.NewRequest("POST", "/users/bulk", bytes.NewReader(body))
		req.Header.Set("Content-Type", "application/json")

		resp, _ := app.Test(req)
		assert.Equal(t, 200, resp.StatusCode)

		var result struct {
			Results []bulkUserResult `json:"results"`
		}
		json.NewDecoder(resp.Body).Decode(&result)
		assert.Len(t, result.Results, 1)
		assert.True(t, result.Results[0].Success)
		assert.Equal(t, testUuid, result.Results[0].UserID)
		assert.Equal(t, "updated", result.Results[0].Status)
		// Should have "Name" in modified fields since we changed from "Old Name" to "Existing User"
		assert.Contains(t, result.Results[0].ModifiedFields, "Name")
	})

	t.Run("Fail - Duplicate UUID Conflict", func(t *testing.T) {
		testUuid := "550e8400-e29b-41d4-a716-446655440001"
		mockTenant.On("GetTenantBySlug", mock.Anything, "test-tenant").Return(&domain.Tenant{
			ID:   "t-1",
			Slug: "test-tenant",
		}, nil).Once()

		mockOry.On("GetPasswordPolicy").Return(&domain.PasswordPolicy{MinLength: 8}, nil)

		// 1. Search-first check: Simulate NOT found by this UUID (initial check)
		mockKratos.On("FindIdentityIDByIdentifier", mock.Anything, testUuid).Return("", nil).Once()

		// 2. Create identity: Simulate Ory returning a 409 conflict for the UUID
		conflictErr := fmt.Errorf("ory provider: identity already exists for uuid=%s", testUuid)
		mockOry.On("CreateUser", mock.MatchedBy(func(user *domain.BrokerUser) bool {
			return user.ID == testUuid
		}), mock.Anything).Return("", conflictErr).Once()

		// 3. Conflict double-check: Search by EMAIL to see if it's the same person
		// If NOT found by email, it means it's a different person using this UUID
		mockKratos.On("FindIdentityIDByIdentifier", mock.Anything, "conflict@test.com").Return("", nil).Once()

		payload := map[string]any{
			"users": []map[string]any{
				{
					"email":      "conflict@test.com",
					"name":       "Conflict User",
					"tenantSlug": "test-tenant",
					"uuid":       testUuid,
				},
			},
		}
		body, _ := json.Marshal(payload)
		req := httptest.NewRequest("POST", "/users/bulk", bytes.NewReader(body))
		req.Header.Set("Content-Type", "application/json")

		resp, _ := app.Test(req)
		assert.Equal(t, 200, resp.StatusCode)

		var result struct {
			Results []bulkUserResult `json:"results"`
		}
		json.NewDecoder(resp.Body).Decode(&result)
		assert.Len(t, result.Results, 1)
		assert.False(t, result.Results[0].Success)
		assert.Contains(t, result.Results[0].Message, "Conflict: UUID already exists")
	})

	t.Run("Fail - Invalid UUID Format", func(t *testing.T) {
		invalidUuid := "not-a-uuid"
		mockTenant.On("GetTenantBySlug", mock.Anything, "test-tenant").Return(&domain.Tenant{
			ID:   "t-1",
			Slug: "test-tenant",
		}, nil).Once()

		mockOry.On("GetPasswordPolicy").Return(&domain.PasswordPolicy{MinLength: 8}, nil)

		// 1. Search-first check (even for invalid format, it currently tries to search)
		mockKratos.On("FindIdentityIDByIdentifier", mock.Anything, invalidUuid).Return("", nil).Once()

		payload := map[string]any{
			"users": []map[string]any{
				{
					"email":      "invalid@test.com",
					"name":       "Invalid User",
					"tenantSlug": "test-tenant",
					"id":         invalidUuid,
				},
			},
		}
		body, _ := json.Marshal(payload)
		req := httptest.NewRequest("POST", "/users/bulk", bytes.NewReader(body))
		req.Header.Set("Content-Type", "application/json")

		resp, _ := app.Test(req)
		assert.Equal(t, 200, resp.StatusCode)

		var result struct {
			Results []bulkUserResult `json:"results"`
		}
		json.NewDecoder(resp.Body).Decode(&result)
		assert.Len(t, result.Results, 1)
		assert.False(t, result.Results[0].Success)
		assert.Contains(t, result.Results[0].Message, "invalid UUID format")
	})

	t.Run("Success - Import after Delete (Visibility Check)", func(t *testing.T) {
		// This test is to ensure that if a user is deleted and then re-imported with the same UUID,
		// the process succeeds and ideally would result in a visible user.
		// NOTE: In this unit test we mock the Repository, so we can't fully test DB behavior,
		// but we can verify the Handler logic flow.

		testUuid := "550e8400-e29b-41d4-a716-446655440007"
		mockTenant.On("GetTenantBySlug", mock.Anything, "test-tenant").Return(&domain.Tenant{
			ID:   "t-1",
			Slug: "test-tenant",
		}, nil).Once()

		mockOry.On("GetPasswordPolicy").Return(&domain.PasswordPolicy{MinLength: 8}, nil)

		// 1. Search-first: Simulate NOT found (it was deleted from Kratos)
		mockKratos.On("FindIdentityIDByIdentifier", mock.Anything, testUuid).Return("", nil).Once()

		// 2. Create identity: Succeeds and returns a NEW Kratos ID
		newKratosId := "new-kratos-id-after-delete"
		mockOry.On("CreateUser", mock.MatchedBy(func(user *domain.BrokerUser) bool {
			return user.ID == testUuid
		}), mock.Anything).Return(newKratosId, nil).Once()

		payload := map[string]any{
			"users": []map[string]any{
				{
					"email":      "reimport@test.com",
					"name":       "Re-import User",
					"tenantSlug": "test-tenant",
					"id":         testUuid,
				},
			},
		}
		body, _ := json.Marshal(payload)
		req := httptest.NewRequest("POST", "/users/bulk", bytes.NewReader(body))
		req.Header.Set("Content-Type", "application/json")

		resp, _ := app.Test(req)
		assert.Equal(t, 200, resp.StatusCode)

		var result struct {
			Results []bulkUserResult `json:"results"`
		}
		json.NewDecoder(resp.Body).Decode(&result)
		assert.True(t, result.Results[0].Success)
		assert.Equal(t, testUuid, result.Results[0].UserID)
	})
}