<?php

/**!info**

{

  "Plugin Name"  : "Halftone",

  "Plugin URI"   : "http://enanocms.org/plugin/halftone",

  "Description"  : "Allows semantic input and transposition of chord sheets.",

  "Author"       : "Dan Fuhry",

  "Version"      : "0.1",

  "Author URI"   : "http://enanocms.org/",

  "Version list" : ['0.1']

}

**!*/

$plugins->attachHook('render_wikiformat_posttemplates', 'halftone_process_tags($text);');

$plugins->attachHook('html_attribute_whitelist', '$whitelist["halftone"] = array("title", "key");');

$plugins->attachHook('session_started', 'register_special_page(\'HalftoneRender\', \'Halftone AJAX render handler\', false);');

define('KEY_C', 0);

define('KEY_D', 2);

define('KEY_E', 4);

define('KEY_F', 5);

define('KEY_G', 7);

define('KEY_A', 9);

define('KEY_B', 11);

define('KEY_C_SHARP', 1);

define('KEY_E_FLAT', 3);

define('KEY_F_SHARP', 6);

define('KEY_G_SHARP', 8);

define('KEY_B_FLAT', 10);

define('ACC_FLAT', -1);

define('ACC_SHARP', 1);

$circle_of_fifths = array(KEY_C, KEY_G, KEY_D, KEY_A, KEY_E, KEY_B, KEY_F_SHARP, KEY_C_SHARP, KEY_G_SHARP, KEY_E_FLAT, KEY_B_FLAT, KEY_F);

$accidentals = array(

	KEY_C => ACC_FLAT,

	KEY_G => ACC_SHARP,

	KEY_D => ACC_SHARP,

	KEY_A => ACC_SHARP,

	KEY_E => ACC_SHARP,

	KEY_B => ACC_SHARP,

	KEY_F_SHARP => ACC_SHARP,

	KEY_C_SHARP => ACC_SHARP,

	KEY_G_SHARP => ACC_FLAT,

	KEY_E_FLAT => ACC_FLAT,

	KEY_B_FLAT => ACC_FLAT,

	KEY_F => ACC_FLAT

);

function get_consonants($root_key)

{

	global $circle_of_fifths;

	$first = $root_key;

	$key = array_search($root_key, $circle_of_fifths);

	$fourth = $circle_of_fifths[(($key - 1) + count($circle_of_fifths)) % count($circle_of_fifths)];

	$fifth = $circle_of_fifths[($key + 1) % count($circle_of_fifths)];

	$minor1 = $circle_of_fifths[($key + 2) % count($circle_of_fifths)];

	$minor2 = $circle_of_fifths[($key + 3) % count($circle_of_fifths)];

	$minor3 = $circle_of_fifths[($key + 4) % count($circle_of_fifths)];

	$result = array(

			'first' => $first,

			'fourth' => $fourth,

			'fifth' => $fifth,

			'minors' => array($minor1, $minor2, $minor3)

		);

	return $result;

}

function get_sharp($chord)

{

	return key_to_name(name_to_key($chord), ACC_SHARP);

}

function detect_key($chord_list)

{

	$majors = array();

	$minors = array();

	$sharp_or_flat = ACC_SHARP;

	// index which chords are used in the song

	foreach ( $chord_list as $chord )

	{

		// discard bass note

		list($chord) = explode('/', $chord);

		$match = array();

		preg_match('/((?:m?7?|2|add9|sus4|[Mm]aj[79])?)$/', $chord, $match);

		if ( !empty($match[1]) )

			$chord = str_replace_once($match[1], '', $chord);

		$sharp_or_flat = get_sharp($chord) == $chord ? ACC_SHARP : ACC_FLAT;

		$chord = get_sharp($chord);

		if ( $match[1] == 'm' || $match[1] == 'm7' )

		{

			// minor chord

			if ( !isset($minors[$chord]) )

				$minors[$chord] = 0;

			$minors[$chord]++;

		}

		else

		{

			// major chord

			if ( !isset($majors[$chord]) )

				$majors[$chord] = 0;

			$majors[$chord]++;

		}

	}

	// now we go through each of the detected major chords, calculate its consonants, and determine how many of its consonants are present in the song.

	$scores = array();

	foreach ( $majors as $key => $count )

	{

		$scores[$key] = 0;

		$consonants = get_consonants(name_to_key($key));

		if ( isset($majors[key_to_name($consonants['fourth'])]) )

			$scores[$key] += 2;

		if ( isset($majors[key_to_name($consonants['fifth'])]) )

			$scores[$key] += 2;

		if ( isset($majors[key_to_name($consonants['minors'][0])]) )

			$scores[$key] += 1;

		if ( isset($majors[key_to_name($consonants['minors'][1])]) )

			$scores[$key] += 2;

		if ( isset($majors[key_to_name($consonants['minors'][2])]) )

			$scores[$key] += 1;

	}

	$winner_val = -1;

	$winner_key = '';

	foreach ( $scores as $key => $score )

	{

		if ( $score > $winner_val )

		{

			$winner_val = $score;

			$winner_key = $key;

		}

	}

	$winner_key = key_to_name(name_to_key($winner_key), $sharp_or_flat);

	return $winner_key;

}

function key_to_name($root_key, $accidental = ACC_SHARP)

{

	switch($root_key)

	{

		case KEY_C:

			return 'C';

		case KEY_D:

			return 'D';

		case KEY_E:

			return 'E';

		case KEY_F:

			return 'F';

		case KEY_G:

			return 'G';

		case KEY_A:

			return 'A';

		case KEY_B:

			return 'B';

		case KEY_C_SHARP:

			return $accidental == ACC_FLAT ? 'Db' : 'C#';

		case KEY_E_FLAT:

			return $accidental == ACC_FLAT ? 'Eb' : 'D#';

		case KEY_F_SHARP:

			return $accidental == ACC_FLAT ? 'Gb' : 'F#';

		case KEY_G_SHARP:

			return $accidental == ACC_FLAT ? 'Ab' : 'G#';

		case KEY_B_FLAT:

			return $accidental == ACC_FLAT ? 'Bb' : 'A#';

		default:

			return false;

	}

}

function name_to_key($name)

{

	switch($name)

	{

		case 'C': return KEY_C;

		case 'D': return KEY_D;

		case 'E': return KEY_E;

		case 'F': return KEY_F;

		case 'G': return KEY_G;

		case 'A': return KEY_A;

		case 'B': return KEY_B;

		case 'C#': case 'Db': return KEY_C_SHARP;

		case 'D#': case 'Eb': return KEY_E_FLAT;

		case 'F#': case 'Gb': return KEY_F_SHARP;

		case 'G#': case 'Ab': return KEY_G_SHARP;

		case 'A#': case 'Bb': return KEY_B_FLAT;

		default: return false;

	}

}

function prettify_accidentals($chord)

{

	if ( count(explode('/', $chord)) > 1 )

	{

		list($upper, $lower) = explode('/', $chord);

		return prettify_accidentals($upper) . '/' . prettify_accidentals($lower);

	}

	if ( strlen($chord) < 2 )

		return $chord;

	if ( $chord{1} == 'b' )

	{

		$chord = $chord{0} . '♭' . substr($chord, 2);

	}

	else if ( $chord{1} == '#' )

	{

		$chord = $chord{0} . '♯' . substr($chord, 2);

	}

	return $chord;

}

function transpose_chord($chord, $increment, $accidental = false)

{

	global $circle_of_fifths;

	if ( count(explode('/', $chord)) > 1 )

	{

		list($upper, $lower) = explode('/', $chord);

		return transpose_chord($upper, $increment, $accidental) . '/' . transpose_chord($lower, $increment, $accidental);

	}

	// shave off any wacky things we're doing to the chord (minor, seventh, etc.)

	preg_match('/((?:m?7?|2|add9|sus4|[Mm]aj[79])?)$/', $chord, $match);

	// find base chord

	if ( !empty($match[1]) )

		$chord = str_replace($match[1], '', $chord);

	// what's our accidental? allow it to be specified, and autodetect if it isn't

	if ( !$accidental )

		$accidental = strstr($chord, '#') ? ACC_SHARP : ACC_FLAT;

	// convert to numeric value

	$key = name_to_key($chord);

	if ( $key === false )

		// should never happen

		return "[TRANSPOSITION FAILED: " . $chord . $match[1] . "]";

	// transpose

	$key = (($key + $increment) + count($circle_of_fifths)) % count($circle_of_fifths);

	// return result

	$kname = key_to_name($key, $accidental);

	if ( !$kname )

		// again, should never happen

		return "[TRANSPOSITION FAILED: " . $chord . $match[1] . " + $increment (->$key)]";

	$result = $kname . $match[1];

	// echo "$chord{$match[1]} + $increment = $result<br />";

	return $result;

}

function halftone_process_tags(&$text)

{

	static $css_added = false;

	if ( !$css_added )

	{

		global $template;

		$template->preload_js(array('jquery', 'jquery-ui'));

		$template->add_header('

			<style type="text/css">

					page-break-before: always;

				}

				span.halftone-line {

					display: block;

					padding-top: 10pt;

					position: relative; /* allows the absolute positioning in chords to work */

				}

				span.halftone-chord {

					position: absolute;

					top: 0pt;

					color: rgb(27, 104, 184);

				}

				span.halftone-chord.sequential {

					padding-left: 20pt;

				}

				div.halftone-key-select {

					float: right;

				}

			</style>

			<script type="text/javascript">

				addOnloadHook(function()

					{

						$("select.halftone-key").change(function()

							{

								var me = this;

								var src = $(this.parentNode.parentNode).attr("halftone:src");

								ajaxPost(makeUrlNS("Special", "HalftoneRender", "transpose=" + $(this).val()) + "&tokey=" + $("option:selected", this).attr("halftone:abs"), "src=" + encodeURIComponent(src), function(ajax)

									{

										if ( ajax.readyState == 4 && ajax.status == 200 )

										{

											var $songbody = $("div.halftone-song", me.parentNode.parentNode);

											$songbody.html(ajax.responseText);

										}

									});

							});

					});

			</script>

			');

		$css_added = true;

	}

	if ( preg_match_all('/<halftone(.*?)>(.+?)<\/halftone>/s', $text, $matches) )

	{

		foreach ( $matches[0] as $i => $whole_match )

		{

			$attribs = decodeTagAttributes($matches[1][$i]);

			$song_title = isset($attribs['title']) ? $attribs['title'] : 'Untitled song';

			$chord_list = array();

			$inner = trim($matches[2][$i]);

			$song = halftone_render_body($inner, $chord_list);

			$src = base64_encode($whole_match);

			$key = name_to_key(detect_key($chord_list));

			$select = '<select class="halftone-key">';

			for ( $i = 0; $i < 12; $i++ )

			{

				$label = in_array($i, array(KEY_C_SHARP, KEY_E_FLAT, KEY_F_SHARP, KEY_G_SHARP, KEY_B_FLAT)) ? sprintf("%s/%s", key_to_name($i, ACC_SHARP), key_to_name($i, ACC_FLAT)) : key_to_name($i);

				$label = prettify_accidentals($label);

				$sel = $key == $i ? ' selected="selected"' : '';

				$select .= sprintf("<option%s value=\"%d\" halftone:abs=\"%d\">%s</option>", $sel, $i - $key, $i, $label);

			}

			$select .= '</select>';

		}

	}

}

function halftone_render_body($inner, &$chord_list, $inkey = false)

{

	global $accidentals;

	$chord_list = array();

	$transpose = isset($_GET['transpose']) ? intval($_GET['transpose']) : 0;

	$transpose_accidental = $inkey ? $accidentals[$inkey] : false;

	foreach ( explode("\n", $inner) as $line )

	{

		$chordline = false;

		$chords_regex = '/(\((?:[A-G][#b]?(?:m?7?|2|add9|sus4|[Mm]aj[79])?(?:\/[A-G][#b]?)?)\))/';

		$line_split = preg_split($chords_regex, $line, -1, PREG_SPLIT_DELIM_CAPTURE);

		if ( preg_match_all($chords_regex, $line, $chords) )

		{

			// this is a line with lyrics + chords

			// echo out the line, adding spans around chords. here is where we also do transposition

			// (if requested) and 

			$line_final = array();

			$last_was_chord = false;

			foreach ( $line_split as $entry )

			{

				if ( preg_match($chords_regex, $entry) )

				{

					if ( $last_was_chord )

					{

						while ( !($pop = array_pop($line_final)) );

						$new_entry = preg_replace('#</span>$#', '', $pop);

						$new_entry .= str_repeat(' ', 4);

						$new_entry .= prettify_accidentals($chord_list[] = transpose_chord(trim($entry, '()'), $transpose, $transpose_accidental)) . '</span>';

						$line_final[] = $new_entry;

					}

					else

					{

						$line_final[] = '<span class="halftone-chord">' . prettify_accidentals($chord_list[] = transpose_chord(trim($entry, '()'), $transpose, $transpose_accidental)) . '</span>';

					}

					$last_was_chord = true;

				}

				else

				{

					if ( trim($entry) != "" )

					{

						$last_was_chord = false;

						$line_final[] = $entry;

					}

				}

			}

			$song .= '<span class="halftone-line">' . implode("", $line_final) . "</span>\n";

		}

		else if ( preg_match('/^=\s*(.+?)\s*=$/', $line, $match) )

		{

		} 

		else if ( trim($line) == '' )

		{

			continue;

		}

		else

		{

			$song .= "$line<br />\n";

		}

	}

}

function page_Special_HalftoneRender()

{

	global $accidentals;

	$text = isset($_POST['src']) ? base64_decode($_POST['src']) : '';

	if ( preg_match('/<halftone(.*?)>(.+?)<\/halftone>/s', $text, $match) )

	{

		require_once(ENANO_ROOT . '/includes/wikiformat.php');

		$carp = new Carpenter();

		$carp->exclusive_rule('heading');

		$tokey = isset($_GET['tokey']) ? intval($_GET['tokey']) : false;

		echo $carp->render(halftone_render_body($match[2], $chord_list, $tokey));

	}

}