package com.esotericsoftware.filesystem;

import com.esotericsoftware.scar.*;

import java.io.*;

public final class FilePath {
    private final File mSomeParentDir;
    private final String mFileSubPath;
    private final File mCanonicalPath;

    private FilePath( File pSomeParentDir, String pFileSubPath, File pCanonicalPath ) {
        mSomeParentDir = pSomeParentDir;
        mFileSubPath = pFileSubPath;
        mCanonicalPath = pCanonicalPath;
    }

    public FilePath( File pSomeParentDir, String pFileSubPath ) {
        this( pSomeParentDir, pFileSubPath, Utils.canonical( new File( pSomeParentDir, pFileSubPath ) ) );
    }

    public static FilePath canonical( File pSomeParentDir, String pFileSubPath ) {
        return new FilePath( pSomeParentDir, pFileSubPath, new File( pSomeParentDir, pFileSubPath ) );
    }

    private static FilePath innerAlreadyCanonical( File pFilePath ) {
        return new FilePath( pFilePath.getParentFile(), pFilePath.getName(), pFilePath );
    }

    public static FilePath canonicalize( File pFilePath ) {
        return innerAlreadyCanonical( Utils.canonical( pFilePath ) );
    }

    public File getSomeParentDir() {
        return mSomeParentDir;
    }

    public String getFileSubPath() {
        return mFileSubPath;
    }

    public String canonical() {
        return mCanonicalPath.getPath();
    }

    public File file() {
        return mCanonicalPath;
    }

    public String relativeFromDir( File pCanonicalJarDir ) {
        File zCommonDirPath = Utils.findCommonDirPathFromCanonicalDirPaths( pCanonicalJarDir, mCanonicalPath.getParentFile() );
        if ( zCommonDirPath == null ) {
            throw new IllegalStateException( "Unable to create Relative path from '" + pCanonicalJarDir + "' to: " + this );
        }
        String zJarDir = normalize( pCanonicalJarDir, zCommonDirPath );
        String zFilePath = normalize( mCanonicalPath, zCommonDirPath );
        while ( zJarDir.length() != 0 ) {
            zFilePath = "../" + zFilePath;
            int zAt = zJarDir.lastIndexOf( "/" );
            if ( zAt == -1 ) {
                zJarDir = "";
            } else {
                zJarDir = zJarDir.substring( 0, zAt );
            }
        }
        return zFilePath;
    }

    private String normalize( File pPath, File pCommonDirPath ) {
        String zPath = pPath.getPath().substring( pCommonDirPath.getPath().length() ).replace( '\\', '/' );
        return zPath.startsWith( "/" ) ? zPath.substring( 1 ) : zPath;
    }

    public boolean equals( FilePath them ) {
        return this == them || ((them != null) && this.canonical().equals( them.canonical() ));
    }

    @Override
    public boolean equals( Object obj ) {
        return (this == obj) || ((obj instanceof FilePath) && equals( (FilePath) obj ));
    }

    @Override
    public int hashCode() {
        return canonical().hashCode();
    }

    @Override
    public String toString() {
        return canonical();
    }
}