package work

import (
	"context"
	"errors"
	"fmt"
	"tercul/internal/app/authz"
	"tercul/internal/domain"
	"tercul/internal/domain/search"
	"tercul/internal/domain/work"
	platform_auth "tercul/internal/platform/auth"

	"gorm.io/gorm"
)

// WorkCommands contains the command handlers for the work aggregate.
type WorkCommands struct {
	repo         work.WorkRepository
	searchClient search.SearchClient
	authzSvc     *authz.Service
}

// NewWorkCommands creates a new WorkCommands handler.
func NewWorkCommands(repo work.WorkRepository, searchClient search.SearchClient, authzSvc *authz.Service) *WorkCommands {
	return &WorkCommands{
		repo:         repo,
		searchClient: searchClient,
		authzSvc:     authzSvc,
	}
}

// CreateWork creates a new work.
func (c *WorkCommands) CreateWork(ctx context.Context, work *work.Work) (*work.Work, error) {
	if work == nil {
		return nil, errors.New("work cannot be nil")
	}
	if work.Title == "" {
		return nil, errors.New("work title cannot be empty")
	}
	if work.Language == "" {
		return nil, errors.New("work language cannot be empty")
	}
	err := c.repo.Create(ctx, work)
	if err != nil {
		return nil, err
	}
	// Index the work in the search client
	err = c.searchClient.IndexWork(ctx, work, "")
	if err != nil {
		// Log the error but don't fail the operation
	}
	return work, nil
}

// UpdateWork updates an existing work after performing an authorization check.
func (c *WorkCommands) UpdateWork(ctx context.Context, work *work.Work) error {
	if work == nil {
		return fmt.Errorf("%w: work cannot be nil", domain.ErrValidation)
	}
	if work.ID == 0 {
		return fmt.Errorf("%w: work ID cannot be zero", domain.ErrValidation)
	}

	userID, ok := platform_auth.GetUserIDFromContext(ctx)
	if !ok {
		return domain.ErrUnauthorized
	}

	existingWork, err := c.repo.GetByID(ctx, work.ID)
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return fmt.Errorf("%w: work with id %d not found", domain.ErrNotFound, work.ID)
		}
		return fmt.Errorf("failed to get work for authorization: %w", err)
	}

	can, err := c.authzSvc.CanEditWork(ctx, userID, existingWork)
	if err != nil {
		return err
	}
	if !can {
		return domain.ErrForbidden
	}

	if work.Title == "" {
		return fmt.Errorf("%w: work title cannot be empty", domain.ErrValidation)
	}
	if work.Language == "" {
		return fmt.Errorf("%w: work language cannot be empty", domain.ErrValidation)
	}

	err = c.repo.Update(ctx, work)
	if err != nil {
		return err
	}
	// Index the work in the search client
	return c.searchClient.IndexWork(ctx, work, "")
}

// DeleteWork deletes a work by ID after performing an authorization check.
func (c *WorkCommands) DeleteWork(ctx context.Context, id uint) error {
	if id == 0 {
		return fmt.Errorf("%w: invalid work ID", domain.ErrValidation)
	}

	userID, ok := platform_auth.GetUserIDFromContext(ctx)
	if !ok {
		return domain.ErrUnauthorized
	}

	existingWork, err := c.repo.GetByID(ctx, id)
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return fmt.Errorf("%w: work with id %d not found", domain.ErrNotFound, id)
		}
		return fmt.Errorf("failed to get work for authorization: %w", err)
	}

	can, err := c.authzSvc.CanEditWork(ctx, userID, existingWork) // Re-using CanEditWork for deletion for now
	if err != nil {
		return err
	}
	if !can {
		return domain.ErrForbidden
	}

	return c.repo.Delete(ctx, id)
}

// AnalyzeWork performs linguistic analysis on a work.
func (c *WorkCommands) AnalyzeWork(ctx context.Context, workID uint) error {
	// TODO: implement this
	return nil
}