<?php
$GLOBALS['options'] = array(
	'analyze_input' => FALSE,
	'reduce_noise'  => FALSE,
	'ignore_noise'  => FALSE,
	'keep_noise'    => FALSE,
	'buffer_size'   => 8,
);

if (isset($_SERVER['argv'][1]) && $_SERVER['argv'][1] == 'a') {
	$GLOBALS['options']['analyze_input'] = TRUE;
} elseif (isset($_SERVER['argv'][1]) && $_SERVER['argv'][1] == 'r') {
	$GLOBALS['options']['reduce_noise'] = TRUE;
} elseif (isset($_SERVER['argv'][1]) && $_SERVER['argv'][1] == 'k') {
	$GLOBALS['options']['keep_noise'] = TRUE;
}

if (isset($_SERVER['argv'][1]) && $_SERVER['argv'][1] == 'i') {
	$GLOBALS['options']['ignore_noise'] = TRUE;
} elseif (isset($_SERVER['argv'][2]) && $_SERVER['argv'][2] == 'i') {
	$GLOBALS['options']['ignore_noise'] = TRUE;
} elseif (isset($_SERVER['argv'][2]) && $_SERVER['argv'][2] == 'k') {
	$GLOBALS['options']['keep_noise'] = TRUE;
}

function analyzeForNoiseOnly ($data) {
	$GLOBALS['analysis']['breakdown'] = array();
	$GLOBALS['analysis']['average']   = 0;

	for ($i = 0; $i < strlen($data); $i++) {
		$ord = ord(substr($data, $i, 1));
		$GLOBALS['analysis']['breakdown'][$ord] = TRUE;
		$GLOBALS['analysis']['average'] += $ord;
	}

	if (!$GLOBALS['options']['keep_noise'] && !$GLOBALS['options']['ignore_noise'] && count($GLOBALS['analysis']['breakdown']) == 2 && isset($GLOBALS['analysis']['breakdown'][127]) && isset($GLOBALS['analysis']['breakdown'][128])) {
		if ($GLOBALS['options']['analyze_input']) {
			//echo 'NOISE1!' . PHP_EOL;
		}
		return NULL;
	} elseif (!$GLOBALS['options']['keep_noise'] && !$GLOBALS['options']['ignore_noise'] && count($GLOBALS['analysis']['breakdown']) == 1 && isset($GLOBALS['analysis']['breakdown'][127])) {
		if ($GLOBALS['options']['analyze_input']) {
			//echo 'NOISE2!' . PHP_EOL;
		}
		return NULL;
	} elseif (!$GLOBALS['options']['keep_noise'] && $GLOBALS['options']['ignore_noise'] && count($GLOBALS['analysis']['breakdown']) < 2) {
		if ($GLOBALS['options']['analyze_input']) {
			//echo 'NOISE3!' . PHP_EOL;
		}
		return NULL;
	}

	// Return given data
	return $data;
}

//$pcm = fopen('output1.pcm', 'rb') or die('Cannot read from audio');
$pcm = fopen('/dev/dsp2', 'rb') or die('Cannot read from audio');

$empty = str_repeat(chr(128), $GLOBALS['options']['buffer_size']);

while (TRUE) {
	//usleep(100);
	$data = trim(fread($pcm, $GLOBALS['options']['buffer_size']));
	if ((empty($data)) || ($data == $empty)) {
		if ($GLOBALS['options']['analyze_input']) {
			//echo 'EMPTY!' . PHP_EOL;
		}
		continue;
	}

	// Detect noise
	$data = analyzeForNoiseOnly($data);

	// Empty?
	if (empty($data)) {
		// Skip this
		continue;
	} // END - if

	$GLOBALS['analysis']['average'] = floor($GLOBALS['analysis']['average'] / strlen($data));

	if ($GLOBALS['options']['analyze_input']) {
		$simpleAnalysis = '';
		for ($i = 0; $i < strlen($data); $i++) {
			$ord = ord(substr($data, $i, 1));
			$simpleAnalysis .= str_pad($ord, 3, '0', STR_PAD_LEFT) . '=0x' . str_pad(dechex($ord), 2, '0', STR_PAD_LEFT) . ',';
		}
		$simpleAnalysis = substr($simpleAnalysis, 0, -1) . ' (' . count($GLOBALS['analysis']['breakdown']) . ')' . PHP_EOL;

		echo $simpleAnalysis;
	} elseif ($GLOBALS['options']['reduce_noise']) {
		$out = '';
		for ($i = 0; $i < strlen($data); $i++) {
			$ord = ord(substr($data, $i, 1));
			// @TODO What do here to remove noise?
			$ord -= $GLOBALS['analysis']['average'];
			$out .= chr($ord);
		}

		$out = analyzeForNoiseOnly($out);

		if (empty($out)) {
			// Skip this
			continue;
		} // END - if

		echo $out;
	} else {
		echo $data;
	}

	if (feof($pcm)) {
		if ($GLOBALS['options']['analyze_input']) {
			echo 'EOF!' . PHP_EOL;
		}
		break;
	}
}

fclose($pcm);