package work

import (
	"context"
	"errors"
	"testing"
	"tercul/internal/platform/config"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/suite"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
	"tercul/internal/app/authz"
	"tercul/internal/data/sql"
	"tercul/internal/domain"
	platform_auth "tercul/internal/platform/auth"
)

type WorkCommandsSuite struct {
	suite.Suite
	repo         *mockWorkRepository
	searchClient *mockSearchClient
	authzSvc     *authz.Service
	analyticsSvc *mockAnalyticsService
	commands     *WorkCommands
}

func (s *WorkCommandsSuite) SetupTest() {
	s.repo = &mockWorkRepository{}
	s.searchClient = &mockSearchClient{}
	s.authzSvc = authz.NewService(s.repo, nil)
	s.analyticsSvc = &mockAnalyticsService{}
	s.commands = NewWorkCommands(s.repo, s.searchClient, s.authzSvc, s.analyticsSvc)
}

func TestWorkCommandsSuite(t *testing.T) {
	suite.Run(t, new(WorkCommandsSuite))
}

func (s *WorkCommandsSuite) TestCreateWork_Success() {
	work := &domain.Work{Title: "Test Work", TranslatableModel: domain.TranslatableModel{Language: "en"}}
	_, err := s.commands.CreateWork(context.Background(), work)
	assert.NoError(s.T(), err)
}

func (s *WorkCommandsSuite) TestCreateWork_Nil() {
	_, err := s.commands.CreateWork(context.Background(), nil)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestCreateWork_EmptyTitle() {
	work := &domain.Work{TranslatableModel: domain.TranslatableModel{Language: "en"}}
	_, err := s.commands.CreateWork(context.Background(), work)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestCreateWork_EmptyLanguage() {
	work := &domain.Work{Title: "Test Work"}
	_, err := s.commands.CreateWork(context.Background(), work)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestCreateWork_RepoError() {
	work := &domain.Work{Title: "Test Work", TranslatableModel: domain.TranslatableModel{Language: "en"}}
	s.repo.createFunc = func(ctx context.Context, w *domain.Work) error {
		return errors.New("db error")
	}
	_, err := s.commands.CreateWork(context.Background(), work)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestUpdateWork_Success() {
	ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 1, Role: string(domain.UserRoleAdmin)})
	work := &domain.Work{Title: "Test Work", TranslatableModel: domain.TranslatableModel{Language: "en"}}
	work.ID = 1

	s.repo.getByIDFunc = func(ctx context.Context, id uint) (*domain.Work, error) {
		return work, nil
	}
	s.repo.isAuthorFunc = func(ctx context.Context, workID uint, authorID uint) (bool, error) {
		return true, nil
	}

	err := s.commands.UpdateWork(ctx, work)
	assert.NoError(s.T(), err)
}

func (s *WorkCommandsSuite) TestUpdateWork_Nil() {
	err := s.commands.UpdateWork(context.Background(), nil)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestUpdateWork_ZeroID() {
	work := &domain.Work{Title: "Test Work", TranslatableModel: domain.TranslatableModel{Language: "en"}}
	err := s.commands.UpdateWork(context.Background(), work)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestUpdateWork_EmptyTitle() {
	work := &domain.Work{TranslatableModel: domain.TranslatableModel{Language: "en"}}
	work.ID = 1
	err := s.commands.UpdateWork(context.Background(), work)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestUpdateWork_EmptyLanguage() {
	work := &domain.Work{Title: "Test Work"}
	work.ID = 1
	err := s.commands.UpdateWork(context.Background(), work)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestUpdateWork_RepoError() {
	ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 1, Role: string(domain.UserRoleAdmin)})
	work := &domain.Work{Title: "Test Work", TranslatableModel: domain.TranslatableModel{Language: "en"}}
	work.ID = 1
	s.repo.updateFunc = func(ctx context.Context, w *domain.Work) error {
		return errors.New("db error")
	}
	err := s.commands.UpdateWork(ctx, work)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestUpdateWork_Forbidden() {
	ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 2, Role: string(domain.UserRoleReader)}) // Not an admin
	work := &domain.Work{Title: "Test Work", TranslatableModel: domain.TranslatableModel{Language: "en"}}
	work.ID = 1

	s.repo.isAuthorFunc = func(ctx context.Context, workID uint, authorID uint) (bool, error) {
		return false, nil // User is not an author
	}

	err := s.commands.UpdateWork(ctx, work)
	assert.Error(s.T(), err)
	assert.True(s.T(), errors.Is(err, domain.ErrForbidden))
}

func (s *WorkCommandsSuite) TestUpdateWork_Unauthorized() {
	work := &domain.Work{Title: "Test Work", TranslatableModel: domain.TranslatableModel{Language: "en"}}
	work.ID = 1
	err := s.commands.UpdateWork(context.Background(), work) // No user in context
	assert.Error(s.T(), err)
	assert.True(s.T(), errors.Is(err, domain.ErrUnauthorized))
}

func (s *WorkCommandsSuite) TestDeleteWork_Success() {
	ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 1, Role: string(domain.UserRoleAdmin)})
	work := &domain.Work{Title: "Test Work", TranslatableModel: domain.TranslatableModel{Language: "en"}}
	work.ID = 1

	s.repo.getByIDFunc = func(ctx context.Context, id uint) (*domain.Work, error) {
		return work, nil
	}
	s.repo.isAuthorFunc = func(ctx context.Context, workID uint, authorID uint) (bool, error) {
		return true, nil
	}

	err := s.commands.DeleteWork(ctx, 1)
	assert.NoError(s.T(), err)
}

func (s *WorkCommandsSuite) TestDeleteWork_ZeroID() {
	err := s.commands.DeleteWork(context.Background(), 0)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestDeleteWork_RepoError() {
	ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 1, Role: string(domain.UserRoleAdmin)})
	s.repo.deleteFunc = func(ctx context.Context, id uint) error {
		return errors.New("db error")
	}
	err := s.commands.DeleteWork(ctx, 1)
	assert.Error(s.T(), err)
}

func (s *WorkCommandsSuite) TestDeleteWork_Forbidden() {
	ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 2, Role: string(domain.UserRoleReader)}) // Not an admin
	err := s.commands.DeleteWork(ctx, 1)
	assert.Error(s.T(), err)
	assert.True(s.T(), errors.Is(err, domain.ErrForbidden))
}

func (s *WorkCommandsSuite) TestDeleteWork_Unauthorized() {
	err := s.commands.DeleteWork(context.Background(), 1) // No user in context
	assert.Error(s.T(), err)
	assert.True(s.T(), errors.Is(err, domain.ErrUnauthorized))
}

func (s *WorkCommandsSuite) TestAnalyzeWork_Success() {
	work := &domain.Work{
		TranslatableModel: domain.TranslatableModel{BaseModel: domain.BaseModel{ID: 1}},
		Translations: []*domain.Translation{
			{BaseModel: domain.BaseModel{ID: 101}},
			{BaseModel: domain.BaseModel{ID: 102}},
		},
	}
	s.repo.getWithTranslationsFunc = func(ctx context.Context, id uint) (*domain.Work, error) {
		return work, nil
	}

	var readingTime, complexity, sentiment, tReadingTime, tSentiment int
	s.analyticsSvc.updateWorkReadingTimeFunc = func(ctx context.Context, workID uint) error {
		readingTime++
		return nil
	}
	s.analyticsSvc.updateWorkComplexityFunc = func(ctx context.Context, workID uint) error {
		complexity++
		return nil
	}
	s.analyticsSvc.updateWorkSentimentFunc = func(ctx context.Context, workID uint) error {
		sentiment++
		return nil
	}
	s.analyticsSvc.updateTranslationReadingTimeFunc = func(ctx context.Context, translationID uint) error {
		tReadingTime++
		return nil
	}
	s.analyticsSvc.updateTranslationSentimentFunc = func(ctx context.Context, translationID uint) error {
		tSentiment++
		return nil
	}

	err := s.commands.AnalyzeWork(context.Background(), 1)
	assert.NoError(s.T(), err)

	assert.Equal(s.T(), 1, readingTime, "UpdateWorkReadingTime should be called once")
	assert.Equal(s.T(), 1, complexity, "UpdateWorkComplexity should be called once")
	assert.Equal(s.T(), 1, sentiment, "UpdateWorkSentiment should be called once")
	assert.Equal(s.T(), 2, tReadingTime, "UpdateTranslationReadingTime should be called for each translation")
	assert.Equal(s.T(), 2, tSentiment, "UpdateTranslationSentiment should be called for each translation")
}

func TestMergeWork_Integration(t *testing.T) {
	// Setup in-memory SQLite DB
	db, err := gorm.Open(sqlite.Open("file::memory:?cache=shared"), &gorm.Config{})
	assert.NoError(t, err)

	// Run migrations for all relevant tables
	err = db.AutoMigrate(
		&domain.Work{},
		&domain.Translation{},
		&domain.Author{},
		&domain.Tag{},
		&domain.Category{},
		&domain.Copyright{},
		&domain.Monetization{},
		&domain.WorkStats{},
		&domain.WorkAuthor{},
	)
	assert.NoError(t, err)

	// Create real repositories and services pointing to the test DB
	cfg, err := config.LoadConfig()
	assert.NoError(t, err)
	workRepo := sql.NewWorkRepository(db, cfg)
	authzSvc := authz.NewService(workRepo, nil) // Using real repo for authz checks
	searchClient := &mockSearchClient{}         // Mock search client is fine
	analyticsSvc := &mockAnalyticsService{}
	commands := NewWorkCommands(workRepo, searchClient, authzSvc, analyticsSvc)

	// Provide a realistic implementation for the GetOrCreateWorkStats mock
	analyticsSvc.getOrCreateWorkStatsFunc = func(ctx context.Context, workID uint) (*domain.WorkStats, error) {
		var stats domain.WorkStats
		if err := db.Where(domain.WorkStats{WorkID: workID}).FirstOrCreate(&stats).Error; err != nil {
			return nil, err
		}
		return &stats, nil
	}

	// --- Seed Data ---
	t.Run("Success", func(t *testing.T) {
		author1 := &domain.Author{Name: "Author One"}
		db.Create(author1)
		author2 := &domain.Author{Name: "Author Two"}
		db.Create(author2)

		tag1 := &domain.Tag{Name: "Tag One"}
		db.Create(tag1)
		tag2 := &domain.Tag{Name: "Tag Two"}
		db.Create(tag2)

		sourceWork := &domain.Work{
			TranslatableModel: domain.TranslatableModel{Language: "en"},
			Title:             "Source Work",
			Authors:           []*domain.Author{author1},
			Tags:              []*domain.Tag{tag1},
		}
		db.Create(sourceWork)
		db.Create(&domain.Translation{Title: "Source English", Language: "en", TranslatableID: sourceWork.ID, TranslatableType: "works"})
		db.Create(&domain.Translation{Title: "Source French", Language: "fr", TranslatableID: sourceWork.ID, TranslatableType: "works"})
		db.Create(&domain.WorkStats{WorkID: sourceWork.ID, Views: 10, Likes: 5})

		targetWork := &domain.Work{
			TranslatableModel: domain.TranslatableModel{Language: "en"},
			Title:             "Target Work",
			Authors:           []*domain.Author{author2},
			Tags:              []*domain.Tag{tag2},
		}
		db.Create(targetWork)
		db.Create(&domain.Translation{Title: "Target English", Language: "en", TranslatableID: targetWork.ID, TranslatableType: "works"})
		db.Create(&domain.WorkStats{WorkID: targetWork.ID, Views: 20, Likes: 10})

		// --- Execute Merge ---
		ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 1, Role: string(domain.UserRoleAdmin)})
		err = commands.MergeWork(ctx, sourceWork.ID, targetWork.ID)
		assert.NoError(t, err)

		// --- Assertions ---
		// 1. Source work should be deleted
		var deletedWork domain.Work
		err = db.First(&deletedWork, sourceWork.ID).Error
		assert.Error(t, err)
		assert.True(t, errors.Is(err, gorm.ErrRecordNotFound))

		// 2. Target work should have merged data
		var finalTargetWork domain.Work
		db.Preload("Translations").Preload("Authors").Preload("Tags").First(&finalTargetWork, targetWork.ID)

		assert.Len(t, finalTargetWork.Translations, 2, "Should have two translations after merge")
		foundEn := false
		foundFr := false
		for _, tr := range finalTargetWork.Translations {
			if tr.Language == "en" {
				foundEn = true
				assert.Equal(t, "Target English", tr.Title, "Should keep target's English translation")
			}
			if tr.Language == "fr" {
				foundFr = true
				assert.Equal(t, "Source French", tr.Title, "Should merge source's French translation")
			}
		}
		assert.True(t, foundEn, "English translation should be present")
		assert.True(t, foundFr, "French translation should be present")

		assert.Len(t, finalTargetWork.Authors, 2, "Authors should be merged")
		assert.Len(t, finalTargetWork.Tags, 2, "Tags should be merged")

		// 3. Stats should be merged
		var finalStats domain.WorkStats
		db.Where("work_id = ?", targetWork.ID).First(&finalStats)
		assert.Equal(t, int64(30), finalStats.Views, "Views should be summed")
		assert.Equal(t, int64(15), finalStats.Likes, "Likes should be summed")

		// 4. Source stats should be deleted
		var deletedStats domain.WorkStats
		err = db.First(&deletedStats, "work_id = ?", sourceWork.ID).Error
		assert.Error(t, err, "Source stats should be deleted")
		assert.True(t, errors.Is(err, gorm.ErrRecordNotFound))
	})

	t.Run("Success with no target stats", func(t *testing.T) {
		sourceWork := &domain.Work{Title: "Source with Stats"}
		db.Create(sourceWork)
		db.Create(&domain.WorkStats{WorkID: sourceWork.ID, Views: 15, Likes: 7})

		targetWork := &domain.Work{Title: "Target without Stats"}
		db.Create(targetWork)

		ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 1, Role: string(domain.UserRoleAdmin)})
		err := commands.MergeWork(ctx, sourceWork.ID, targetWork.ID)
		assert.NoError(t, err)

		var finalStats domain.WorkStats
		db.Where("work_id = ?", targetWork.ID).First(&finalStats)
		assert.Equal(t, int64(15), finalStats.Views)
		assert.Equal(t, int64(7), finalStats.Likes)
	})

	t.Run("Forbidden for non-admin", func(t *testing.T) {
		sourceWork := &domain.Work{Title: "Forbidden Source"}
		db.Create(sourceWork)
		targetWork := &domain.Work{Title: "Forbidden Target"}
		db.Create(targetWork)

		ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 2, Role: string(domain.UserRoleReader)})
		err := commands.MergeWork(ctx, sourceWork.ID, targetWork.ID)

		assert.Error(t, err)
		assert.True(t, errors.Is(err, domain.ErrForbidden))
	})

	t.Run("Source work not found", func(t *testing.T) {
		targetWork := &domain.Work{Title: "Existing Target"}
		db.Create(targetWork)
		ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 1, Role: string(domain.UserRoleAdmin)})

		err := commands.MergeWork(ctx, 99999, targetWork.ID)

		assert.Error(t, err)
		assert.Contains(t, err.Error(), "entity not found")
	})

	t.Run("Target work not found", func(t *testing.T) {
		sourceWork := &domain.Work{Title: "Existing Source"}
		db.Create(sourceWork)
		ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 1, Role: string(domain.UserRoleAdmin)})

		err := commands.MergeWork(ctx, sourceWork.ID, 99999)

		assert.Error(t, err)
		assert.Contains(t, err.Error(), "entity not found")
	})

	t.Run("Cannot merge work into itself", func(t *testing.T) {
		work := &domain.Work{Title: "Self Merge Work"}
		db.Create(work)
		ctx := context.WithValue(context.Background(), platform_auth.ClaimsContextKey, &platform_auth.Claims{UserID: 1, Role: string(domain.UserRoleAdmin)})

		err := commands.MergeWork(ctx, work.ID, work.ID)

		assert.Error(t, err)
		assert.Contains(t, err.Error(), "source and target work IDs cannot be the same")
	})
}