<?php

//    Copyright 2017 Daniel Robert Bradley. All rights reserved.
//    Available under the GPL Version 3 License
//
//    Quasi extracts source code  from quasi-literate programming documentation files.
//    This incarnation of Quasi is implemented in PHP and is intended for extracting CSS statements
//    out of quasi-literate programming files.
//
//    In contrast to the command-line version of Quasi, this version does not write files to disk
//    but rather creates a string for each file, which is then returned in an associative array
//    to the caller. Also, the names of the files to be processed are passed as an array.
//
//    For example:
//
//    $files[] = "0-Frontmater.txt";
//    $files[] = "1-Overview.txt";
//    $files[] = "2-Body.txt";
//
//    $output = Quasi( $files )
//
//    foreach ( $output as $path => $string )
//    {
//        echo $string
//    }

define( "QUASI_DEBUG", FALSE );

function Quasi( $files, $suffix = "" )
{
    $output = array();

    foreach ( $files as $filepath )
    {
        Process( $output, $filepath, $suffix );
    }

    return $output;
}

function Process( &$output, $filepath, $suffix )
{
    $content = file_get_contents( $filepath );
    $lines   = explode( "\n", $content );
    $inside  = false;
    $file    = "";
    $linenum = 0;

    foreach ( $lines as $line )
    {
        $linenum++;

        if ( 0 < strlen( $line ) && ("~" == $line[0]) )
        {
            $inside = ! $inside;

            if ( ! $inside )
            {
                $file = "";
            }
            else
            {
                $provisional = substr( $line, 1, -1 );

                if ( QuasiEndsWith( $provisional, $suffix ) )
                {
                    $file = $provisional;

                    if ( ! array_key_exists( $file, $output ) ) $output[$file] = "";

                    $output[$file] .= "\n" . "/* Generated from $filepath:$linenum using Quasi.php */" . "\n\n";
                }
            }
        }
        else
        if ( $inside && ("" != $file) )
        {
            $output[$file] .= $line . "\n";
        }
    }
}

//
//  Helper functions
//

function QuasiFilesMatching( $suffix )
{
    $files = array();
    $list = scandir( "." );

    foreach ( $list as $index => $file )
    {
        if ( QuasiEndsWith( $file, $suffix ) )
        {
            $files[] = $file;
        }
    }
    return $files;
}

function QuasiEndsWith( $file, $suffix )
{
    $length = strlen($suffix);

    return $length === 0 || (substr($file, -$length) === $suffix);
}

function QuasiCreateVariablesDictionary( $filename )
{
    $dict                = array();
    $variables_file_path = dirname( __FILE__ ) . "/" . $filename;

    if ( file_exists( $variables_file_path ) )
    {
        $contents = file_get_contents( $variables_file_path );

        $lines = explode( "\n", $contents );

        foreach ( $lines as $line )
        {
            $trimmed = trim( $line );

            if ( 0 === strpos( $trimmed, '--' ) )
            {
                if ( defined( "QUASI_DEBUG" ) && QUASI_DEBUG ) error_log( $trimmed );
                $bits = explode( ":", $trimmed );
                if ( defined( "QUASI_DEBUG" ) && QUASI_DEBUG ) error_log( var_export( $bits, true ) );

                if ( 1 < count( $bits ) )
                {
                    $name  = trim( $bits[0] );
                    $value = trim( $bits[1] );
                    $value = trim( str_replace( ';', '', $value ) );

                    $key   = "var($name)";

                    if ( defined( "QUASI_DEBUG" ) && QUASI_DEBUG ) error_log( "dict[$key] = $value" );

                    $dict[$key] = $value . " /* $name */";
                }
            }
        }
    }
    return $dict;
}

function QuasiRetrieveCSS( $filename )
{
    $contents      = FALSE;
    $css_file_path = dirname( __FILE__ ) . "/" . $filename;

    if ( file_exists( $css_file_path ) )
    {
        $contents = file_get_contents( $css_file_path );
    }

    return $contents;
}

function QuasiReplace( $content, $array )
{
    foreach ( $array as $key => $value )
    {
        $content = str_replace( $key, $value, $content );
    }

    return $content;
}