<?php
namespace Luracast\Restler\UI;

use Luracast\Restler\UI\Tags as T;
use Luracast\Restler\Util;

class Emmet
{
    const DELIMITERS = '.#*>+^[=" ]{$@-#}';

    /**
     * Create the needed tag hierarchy from emmet string
     *
     * @param string       $string
     *
     * @param array|string $data
     *
     * @return array|T
     */
    public static function make($string, $data = null)
    {
        if (!strlen($string))
            return array();

        $implicitTag =
            function () use (& $tag) {
                if (empty($tag->tag)) {
                    switch ($tag->parent->tag) {
                        case 'ul':
                        case 'ol':
                            $tag->tag = 'li';
                            break;
                        case 'em':
                            $tag->tag = 'span';
                            break;
                        case 'table':
                        case 'tbody':
                        case 'thead':
                        case 'tfoot':
                            $tag->tag = 'tr';
                            break;
                        case 'tr':
                            $tag->tag = 'td';
                            break;
                        case 'select':
                        case 'optgroup':
                            $tag->tag = 'option';
                            break;
                        default:
                            $tag->tag = 'div';
                    }
                }
            };

        $parseText =
            function (
                $text, $round, $total, $data, $delimiter = null
            )
            use (
                & $tokens, & $tag
            ) {
                $digits = 0;
                if ($delimiter == null)
                    $delimiter = array(
                        '.' => true,
                        '#' => true,
                        '*' => true,
                        '>' => true,
                        '+' => true,
                        '^' => true,
                        '[' => true,
                        ']' => true,
                        '=' => true,
                    );
                while (!empty($tokens) &&
                    !isset($delimiter[$t = array_shift($tokens)])) {
                    while ('$' === $t) {
                        $digits++;
                        $t = array_shift($tokens);
                    }
                    if ($digits) {
                        $negative = false;
                        $offset = 0;
                        if ('@' == $t) {
                            if ('-' == ($t = array_shift($tokens))) {
                                $negative = true;
                                if (is_numeric(reset($tokens))) {
                                    $offset = array_shift($tokens);
                                }
                            } elseif (is_numeric($t)) {
                                $offset = $t;
                            } else {
                                array_unshift($tokens, $t);
                            }
                        } elseif ('#' == ($h = array_shift($tokens))) {
                            if (!empty($t)) {
                                $data = Util::nestedValue($data, $t);
                                if (is_null($data)) {
                                    return null;
                                }
                            }
                            if (is_numeric($data)) {
                                $text .= sprintf("%0{$digits}d", (int)$data);
                            } elseif (is_string($data)) {
                                $text .= $data;
                            }
                            $digits = 0;
                            continue;
                        } else {
                            array_unshift($tokens, $t, $h);
                        }
                        if ($negative) {
                            $n = $total + 1 - $round + $offset;
                        } else {
                            $n = $round + $offset;
                        }
                        $text .= sprintf("%0{$digits}d", $n);
                        $digits = 0;
                    } else {
                        $text .= $t;
                    }
                }
                if (isset($t))
                    array_unshift($tokens, $t);
                return $text;
            };

        $parseAttributes =
            function (Callable $self, $round, $total, $data)
            use (& $tokens, & $tag, $parseText) {
                $a = $parseText(
                    '', $round, $total, $data
                );
                if (is_null($a))
                    return;
                if ('=' == ($v = array_shift($tokens))) {
                    //value
                    if ('"' == ($v = array_shift($tokens))) {
                        $text = '';
                        $tag->$a($parseText(
                            $text, $round, $total, $data,
                            array('"' => true)
                        ));
                    } else {
                        array_unshift($tokens, $v);
                        $text = '';
                        $tag->$a($parseText(
                            $text, $round, $total, $data,
                            array(' ' => true, ']' => true)
                        ));
                    }
                    if (' ' == ($v = array_shift($tokens))) {
                        $self($self, $round, $total, $data);
                    }
                } elseif (']' == $v) {
                    //end
                    $tag->$a('');
                    return;
                } elseif (' ' == $v) {
                    $tag->$a('');
                    $self($self, $round, $total, $data);
                }
            };

        $tokens = static::tokenize($string);
        $tag = new T(array_shift($tokens));
        $parent = $root = new T;

        $parse =
            function (
                Callable $self, $round = 1, $total = 1
            )
            use (
                & $tokens, & $parent, & $tag, & $data,
                $parseAttributes, $implicitTag, $parseText
            ) {
                $offsetTokens = null;
                $parent[] = $tag;
                $isInChild = false;
                while ($tokens) {
                    switch (array_shift($tokens)) {
                        //class
                        case '.':
                            $offsetTokens = array_values($tokens);
                            array_unshift($offsetTokens, '.');
                            $implicitTag();
                            $e = array_filter(explode(' ', $tag->class));
                            $e[] = $parseText('', $round, $total, $data);
                            $tag->class(implode(' ', array_unique($e)));
                            break;
                        //id
                        case '#':
                            $offsetTokens = array_values($tokens);
                            array_unshift($offsetTokens, '#');
                            $implicitTag();
                            $tag->id(
                                $parseText(
                                    array_shift($tokens), $round, $total, $data
                                )
                            );
                            break;
                        //attributes
                        case '[':
                            $offsetTokens = array_values($tokens);
                            array_unshift($offsetTokens, '[');
                            $implicitTag();
                            $parseAttributes(
                                $parseAttributes, $round, $total, $data
                            );
                            break;
                        //child
                        case '{':
                            $text = '';
                            $tag[] = $parseText(
                                $text, $round, $total, $data, array('}' => true)
                            );
                            break;
                        case '>':
                            $isInChild = true;
                            $offsetTokens = null;
                            if ('{' == ($t = array_shift($tokens))) {
                                array_unshift($tokens, $t);
                                $child = new T();
                                $tag[] = $child;
                                $parent = $tag;
                                $tag = $child;
                            } elseif ('[' == $t) {
                                array_unshift($tokens, $t);
                            } else {
                                $child = new T($t);
                                $tag[] = $child;
                                $parent = $tag;
                                $tag = $child;
                            }
                            break;
                        //sibling
                        case '+':
                            $offsetTokens = null;
                            if (!$isInChild && $round != $total) {
                                $tokens = array();
                                break;
                            }
                            if ('{' == ($t = array_shift($tokens))) {
                                $tag = $tag->parent;
                                array_unshift($tokens, $t);
                                break;
                            } elseif ('[' == $t) {
                                array_unshift($tokens, $t);
                            } else {
                                $child = new T($t);
                                $tag = $tag->parent;
                                $tag[] = $child;
                                $tag = $child;
                            }
                            break;
                        //sibling of parent
                        case '^':
                            if ($round != $total) {
                                $tokens = array();
                                break;
                            }
                            $tag = $tag->parent;
                            if ($tag->parent)
                                $tag = $tag->parent;
                            while ('^' == ($t = array_shift($tokens))) {
                                if ($tag->parent)
                                    $tag = $tag->parent;
                            }
                            $child = new T($t);
                            $tag[] = $child;
                            $tag = $child;
                            break;
                        //clone
                        case '*':
                            $times = array_shift($tokens);
                            $removeCount = 2;
                            $delimiter = array(
                                '.' => true,
                                '#' => true,
                                '*' => true,
                                '>' => true,
                                '+' => true,
                                '^' => true,
                                '[' => true,
                                ']' => true,
                                '=' => true,
                            );
                            if (!is_numeric($times)) {
                                if (is_string($times)) {
                                    if (!isset($delimiter[$times])) {
                                        $data = Util::nestedValue($data, $times)
                                            ? : $data;
                                    } else {
                                        array_unshift($tokens, $times);
                                        $removeCount = 1;
                                    }
                                }
                                $indexed = array_values($data);
                                $times = is_array($data) && $indexed == $data
                                    ? count($data) : 0;
                            }
                            $source = $tag;
                            if (!empty($offsetTokens)) {
                                if (false !== strpos($source->class, ' ')) {
                                    $class = explode(' ', $source->class);
                                    array_pop($class);
                                    $class = implode(' ', $class);
                                } else {
                                    $class = null;
                                }
                                $tag->class($class);
                                $star = array_search('*', $offsetTokens);
                                array_splice($offsetTokens, $star, $removeCount);
                                $remainingTokens = $offsetTokens;
                            } else {
                                $remainingTokens = $tokens;
                            }
                            $source->parent = null;
                            $sourceData = $data;
                            $currentParent = $parent;
                            for ($i = 1; $i <= $times; $i++) {
                                $tag = clone $source;
                                $parent = $currentParent;
                                $data = is_array($sourceData)
                                && isset($sourceData[$i - 1])
                                    ? $sourceData[$i - 1]
                                    : @(string)$sourceData;
                                $tokens = array_values($remainingTokens);
                                $self($self, $i, $times);
                            }
                            $round = 1;
                            $offsetTokens = null;
                            $tag = $source;
                            $tokens = array(); //$remainingTokens;
                            break;
                    }
                }
            };
        $parse($parse);
        return count($root) == 1 ? $root[0] : $root;
    }

    public static function tokenize($string)
    {
        $r = array();
        $f = strtok($string, static::DELIMITERS);
        $pos = 0;
        do {
            $start = $pos;
            $pos = strpos($string, $f, $start);
            $tokens = array();
            for ($i = $start; $i < $pos; $i++) {
                $token = $string{$i};
                if (('#' == $token || '.' == $token) &&
                    (!empty($tokens) || $i == 0)
                ) {
                    $r[] = '';
                }
                $r[] = $tokens[] = $token;
            }
            $pos += strlen($f);
            $r[] = $f;
        } while (false != ($f = strtok(static::DELIMITERS)));
        for ($i = $pos; $i < strlen($string); $i++) {
            $token = $string{$i};
            $r[] = $tokens[] = $token;
        }
        return $r;
        /* sample output produced by ".row*3>.col*3"
        [0] => div
        [1] => .
        [2] => row
        [3] => *
        [4] => 3
        [5] => >
        [6] => div
        [7] => .
        [8] => col
        [9] => *
        [10] => 4
         */
    }
}