Untitled

//-------------------------------------------------------------------------

/**
 * The database implementation for this project.
 * This manages the commands for the DNA tree.
 *
 * @author CS3114/5040 Staff
 * @version Spring 2026
 *
 */
public class DNADB implements DNA {

    /**
     * Create a new DNADB object.
     */
    public DNADB() {
        // Tree will be added later
    }


    // ----------------------------------------------------------
    /**
     * Insert a DNA string into the database
     * @param sequence The sequence to insert
     * @return The outcomes message string
     */
    public String insert(String sequence) {

        String bad = validate(sequence);
        if (bad != null) {
            return bad;
        }

        // Milestone 1 minimal behavior
        return "Sequence |" + sequence + "| inserted";
    }


    // ----------------------------------------------------------
    /**
     * Remove a DNA string into the database
     * @param sequence The sequence to remove
     * @return The outcomes message string
     */
    public String remove(String sequence) {

        String bad = validate(sequence);
        if (bad != null) {
            return bad;
        }

        return "Sequence |" + sequence + "| does not exist";
    }


    // ----------------------------------------------------------
    /**
     * Print the tree
     * @return the print string
     */
    public String print() {
        return "tree dump:\r\nE";
    }


    // ----------------------------------------------------------
    /**
     * Print the lengths
     * @return the print string
     */
    public String printLengths() {
        return "tree dump with lengths:\r\nE";
    }


    // ----------------------------------------------------------
    /**
     * Print the stats
     * @return the print string
     */
    public String printStats() {
        return "tree dump with stats:\r\nE";
    }


    // ----------------------------------------------------------
    /**
     * Search for a given string
     * @param sequence The sequence to search for
     * @return the print string
     */
    public String search(String sequence) {

        String bad = validate(sequence);
        if (bad != null) {
            return bad;
        }

        return "No sequence found\r\n# of nodes visited: 1";
    }


    /**
     * Validates input for Milestone 1
     */
    private String validate(String sequence) {

        if (sequence == null) {
            return "Bad input: Sequence may not be null\r\n";
        }

        if (sequence.isEmpty()) {
            return "Bad input: Sequence may not be empty\r\n";
        }

        for (int i = 0; i < sequence.length(); i++) {
            char c = sequence.charAt(i);
            
           // if (c != 'A' && c != 'C' && c != 'G' && c != 'T' && c != '$')
           // this top if might be a problem later just to note
            if (c != 'A' && c != 'C' && c != 'G' && c != 'T') {
                return "Bad Input Sequence |" + sequence + "|\r\n";
            }
        }

        return null;
    }
}