SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// Multi-Phasic Applications: SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package cc.squirreljme.c;

import java.lang.ref.Reference;
import java.lang.ref.WeakReference;

/**
 * Represents a file name in C.
 *
 * @since 2023/06/04
 */
public final class CFileName
    implements Comparable<CFileName>
{
    /** The file name. */
    protected final String fileName;
    
    /** Basename cache. */
    private volatile Reference<CFileName> _baseName;
    
    /**
     * Initializes the C file name.
     * 
     * @param __fileName The C file name.
     * @throws NullPointerException On null arguments.
     * @since 2023/06/04
     */
    CFileName(String __fileName)
        throws NullPointerException
    {
        if (__fileName == null)
            throw new NullPointerException("NARG");
        
        /* {@squirreljme.error CW0a Identifier cannot be blank.} */
        if (__fileName.isEmpty())
            throw new IllegalArgumentException("CW0a");
        
        // Check identifier
        boolean hasDot = false;
        for (int i = 0, n = __fileName.length(); i < n; i++)
        {
            char c = __fileName.charAt(i);
            
            if (c == '.')
            {
                /* {@squirreljme.error CW31 Filename has multiple extensions.} */
                if (hasDot)
                    throw new IllegalArgumentException("CW31");
                    
                hasDot = true;
            }
            
            /* {@squirreljme.error CW01 Identifier cannot start with a number.
            (The identifier)} */
            else if (i == 0 && c >= '0' && c <= '9')
                throw new IllegalArgumentException("CW01 " + __fileName);
            
            /* {@squirreljme.error CW09 Identifier contains an invalid
            character. (The identifier)} */
            else if (!((c >= 'a' && c <= 'z') ||
                (c >= 'A' && c <= 'Z') ||
                (c >= '0' && c <= '9') ||
                c == '_' || c == '/'))
                throw new IllegalArgumentException("CW09 " + __fileName);
        }
        
        // Is fine
        this.fileName = __fileName;
    }
    
    /**
     * Returns the base name of this file.
     *
     * @return The base name.
     * @since 2023/10/15
     */
    public CFileName baseName()
    {
        Reference<CFileName> ref = this._baseName;
        CFileName rv;
        
        if (ref == null || (rv = ref.get()) == null)
        {
            String fileName = this.fileName;
            int lastSlash = fileName.lastIndexOf('/');
            
            // Only if there is a slash component may the basename be different
            if (lastSlash >= 0)
                rv = new CFileName(fileName.substring(lastSlash + 1));
            else
                rv = this;
            
            this._baseName = new WeakReference<>(rv);
        }
        
        return rv;
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/06/04
     */
    @Override
    public int compareTo(CFileName __b)
    {
        return this.fileName.compareTo(__b.fileName);
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/06/04
     */
    @Override
    public boolean equals(Object __o)
    {
        if (__o == this)
            return true;
        if (!(__o instanceof CFileName))
            return false;
        
        return this.fileName.equals(((CFileName)__o).fileName);
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/06/04
     */
    @Override
    public int hashCode()
    {
        return this.fileName.hashCode();
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/06/04
     */
    @Override
    public String toString()
    {
        return this.fileName;
    }
    
    /**
     * Initializes the C file name.
     * 
     * @param __fileName The C file name.
     * @throws NullPointerException On null arguments.
     * @since 2023/06/04
     */
    public static CFileName of(String __fileName)
        throws NullPointerException
    {
        return new CFileName(__fileName);
    }
}