package translation

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

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/trace"
)

// TranslationCommands contains the command handlers for the translation aggregate.
type TranslationCommands struct {
	repo     domain.TranslationRepository
	authzSvc *authz.Service
	tracer   trace.Tracer
}

// NewTranslationCommands creates a new TranslationCommands handler.
func NewTranslationCommands(repo domain.TranslationRepository, authzSvc *authz.Service) *TranslationCommands {
	return &TranslationCommands{
		repo:     repo,
		authzSvc: authzSvc,
		tracer:   otel.Tracer("translation.commands"),
	}
}

// CreateTranslationInput represents the input for creating a new translation.
type CreateTranslationInput struct {
	Title              string
	Content            string
	Description        string
	Language           string
	Status             domain.TranslationStatus
	TranslatableID     uint
	TranslatableType   string
	TranslatorID       *uint
	IsOriginalLanguage bool
}

// CreateTranslation creates a new translation.
func (c *TranslationCommands) CreateTranslation(ctx context.Context, input CreateTranslationInput) (*domain.Translation, error) {
	ctx, span := c.tracer.Start(ctx, "CreateTranslation")
	defer span.End()
	translation := &domain.Translation{
		Title:              input.Title,
		Content:            input.Content,
		Description:        input.Description,
		Language:           input.Language,
		Status:             input.Status,
		TranslatableID:     input.TranslatableID,
		TranslatableType:   input.TranslatableType,
		TranslatorID:       input.TranslatorID,
		IsOriginalLanguage: input.IsOriginalLanguage,
	}
	err := c.repo.Create(ctx, translation)
	if err != nil {
		return nil, err
	}
	return translation, nil
}

// UpdateTranslationInput represents the input for updating an existing translation.
type UpdateTranslationInput struct {
	ID          uint
	Title       string
	Content     string
	Description string
	Language    string
	Status      domain.TranslationStatus
}

// UpdateTranslation updates an existing translation.
func (c *TranslationCommands) UpdateTranslation(ctx context.Context, input UpdateTranslationInput) (*domain.Translation, error) {
	ctx, span := c.tracer.Start(ctx, "UpdateTranslation")
	defer span.End()
	userID, ok := platform_auth.GetUserIDFromContext(ctx)
	if !ok {
		return nil, domain.ErrUnauthorized
	}

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

	translation, err := c.repo.GetByID(ctx, input.ID)
	if err != nil {
		if errors.Is(err, domain.ErrEntityNotFound) {
			return nil, fmt.Errorf("%w: translation with id %d not found", domain.ErrEntityNotFound, input.ID)
		}
		return nil, err
	}

	translation.Title = input.Title
	translation.Content = input.Content
	translation.Description = input.Description
	translation.Language = input.Language
	translation.Status = input.Status
	err = c.repo.Update(ctx, translation)
	if err != nil {
		return nil, err
	}
	return translation, nil
}

// DeleteTranslation deletes a translation by ID.
func (c *TranslationCommands) DeleteTranslation(ctx context.Context, id uint) error {
	ctx, span := c.tracer.Start(ctx, "DeleteTranslation")
	defer span.End()
	can, err := c.authzSvc.CanDeleteTranslation(ctx)
	if err != nil {
		return err
	}
	if !can {
		return domain.ErrForbidden
	}

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