WASAPhoto/service/database/db-photos.go

package database

import (
	"fmt"
	"time"
)

// Post a new photo
func (db *appdbimpl) PostPhoto(uid string) (DBTransaction, int64, error) {
	tx, err := db.c.Begin()

	if err != nil {
		return nil, 0, err
	}

	res, err := tx.Exec(`INSERT INTO "photos" ("user", "date") VALUES (?, ?)`, uid, time.Now().Format(time.RFC3339))
	if err != nil {
		err_rb := tx.Rollback()
		// If rollback fails, we return the original error plus the rollback error
		if err_rb != nil {
			err = fmt.Errorf("Rollback error. Rollback cause: %w", err)
		}

		return nil, 0, err
	}
	id, err := res.LastInsertId()

	if err != nil {
		err_rb := tx.Rollback()
		// If rollback fails, we return the original error plus the rollback error
		if err_rb != nil {
			err = fmt.Errorf("Rollback error. Rollback cause: %w", err)
		}

		return nil, 0, err
	}

	return &dbtransaction{
		c: tx,
	}, id, nil
}

// Delete a photo, returns true if the photo was deleted and false if it did not exist
func (db *appdbimpl) DeletePhoto(uid string, photo int64) (bool, error) {
	res, err := db.c.Exec(`DELETE FROM "photos" WHERE "id" = ? AND "user" = ?`, photo, uid)
	if err != nil {
		return false, err
	}
	rows, err := res.RowsAffected()
	if err != nil {
		return false, err
	}
	return rows > 0, nil
}

// Check if a given photo owned by a given user exists
func (db *appdbimpl) photoExists(uid string, photo int64) (bool, error) {

	var cnt int64
	err := db.c.QueryRow(`SELECT COUNT(*) FROM "photos" WHERE "id" = ? AND "user" = ?`, photo, uid).Scan(&cnt)
	if err != nil {
		return false, err
	}
	return cnt > 0, nil
}

// Check if a given photo owned by a given user exists, and the requesting user is not banned by the author
func (db *appdbimpl) PhotoExists(uid string, photo int64, requesting_uid string) (bool, error) {

	var cnt int64
	err := db.c.QueryRow(`SELECT COUNT(*) FROM "photos"
							WHERE "id" = ?
							AND "user" = ?
							AND "user" NOT IN (
								SELECT "bans"."user" FROM "bans"
								WHERE "bans"."user" = "photos"."user"
								AND "bans"."ban" = ?
							)`, photo, uid, requesting_uid).Scan(&cnt)
	if err != nil {
		return false, err
	}
	return cnt > 0, nil
}