package sqlite

import (
	"context"
	"database/sql"
	"fmt"
	"messenger/internal/models"
)

type AttachmentRepository struct {
	db *DB
}

func NewAttachmentRepository(db *DB) *AttachmentRepository {
	return &AttachmentRepository{db: db}
}

func (r *AttachmentRepository) Create(ctx context.Context, attachment *models.Attachment) error {
	query := `
		INSERT INTO attachments (message_id, file_name, file_size, storage_path, mime_type, uploaded_at)
		VALUES (?, ?, ?, ?, ?, ?)
		RETURNING id
	`
	
	err := r.db.QueryRowContext(ctx, query,
		attachment.MessageID, attachment.FileName, attachment.FileSize,
		attachment.StoragePath, attachment.MimeType, attachment.UploadedAt,
	).Scan(&attachment.ID)
	
	if err != nil {
		return fmt.Errorf("failed to create attachment: %w", err)
	}
	
	return nil
}

func (r *AttachmentRepository) FindByID(ctx context.Context, id int64) (*models.Attachment, error) {
	query := `
		SELECT id, message_id, file_name, file_size, storage_path, mime_type, uploaded_at
		FROM attachments
		WHERE id = ?
	`
	
	var attachment models.Attachment
	var messageID sql.NullInt64
	
	err := r.db.QueryRowContext(ctx, query, id).Scan(
		&attachment.ID, &messageID, &attachment.FileName, &attachment.FileSize,
		&attachment.StoragePath, &attachment.MimeType, &attachment.UploadedAt,
	)
	
	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, fmt.Errorf("failed to find attachment by id: %w", err)
	}
	
	if messageID.Valid {
		attachment.MessageID = &messageID.Int64
	}
	
	return &attachment, nil
}

func (r *AttachmentRepository) UpdateMessageID(ctx context.Context, attachmentID, messageID int64) error {
	query := `UPDATE attachments SET message_id = ? WHERE id = ?`
	
	result, err := r.db.ExecContext(ctx, query, messageID, attachmentID)
	if err != nil {
		return fmt.Errorf("failed to update attachment message_id: %w", err)
	}
	
	rows, err := result.RowsAffected()
	if err != nil {
		return err
	}
	
	if rows == 0 {
		return fmt.Errorf("attachment not found: %d", attachmentID)
	}
	
	return nil
}

func (r *AttachmentRepository) Delete(ctx context.Context, attachmentID int64) error {
	query := `DELETE FROM attachments WHERE id = ?`
	
	result, err := r.db.ExecContext(ctx, query, attachmentID)
	if err != nil {
		return fmt.Errorf("failed to delete attachment: %w", err)
	}
	
	rows, err := result.RowsAffected()
	if err != nil {
		return err
	}
	
	if rows == 0 {
		return fmt.Errorf("attachment not found: %d", attachmentID)
	}
	
	return nil
}

func (r *AttachmentRepository) GetByMessageID(ctx context.Context, messageID int64) (*models.Attachment, error) {
	query := `
		SELECT id, message_id, file_name, file_size, storage_path, mime_type, uploaded_at
		FROM attachments
		WHERE message_id = ?
	`
	
	var attachment models.Attachment
	var msgID sql.NullInt64
	
	err := r.db.QueryRowContext(ctx, query, messageID).Scan(
		&attachment.ID, &msgID, &attachment.FileName, &attachment.FileSize,
		&attachment.StoragePath, &attachment.MimeType, &attachment.UploadedAt,
	)
	
	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, fmt.Errorf("failed to get attachment by message_id: %w", err)
	}
	
	if msgID.Valid {
		attachment.MessageID = &msgID.Int64
	}
	
	return &attachment, nil
}