<?php

/**
 * This file is part of the Nette Framework (http://nette.org)
 * Copyright (c) 2004 David Grudl (http://davidgrudl.com)
 */

namespace Nette\Database;

use Nette,
	Tracy;


/**
 * Database helpers.
 *
 * @author     David Grudl
 */
class Helpers
{
	/** @var int maximum SQL length */
	static public $maxLength = 100;

	/** @var array */
	public static $typePatterns = array(
		'^_' => IReflection::FIELD_TEXT, // PostgreSQL arrays
		'BYTEA|BLOB|BIN' => IReflection::FIELD_BINARY,
		'TEXT|CHAR|POINT|INTERVAL' => IReflection::FIELD_TEXT,
		'YEAR|BYTE|COUNTER|SERIAL|INT|LONG|SHORT|^TINY$' => IReflection::FIELD_INTEGER,
		'CURRENCY|REAL|MONEY|FLOAT|DOUBLE|DECIMAL|NUMERIC|NUMBER' => IReflection::FIELD_FLOAT,
		'^TIME$' => IReflection::FIELD_TIME,
		'TIME' => IReflection::FIELD_DATETIME, // DATETIME, TIMESTAMP
		'DATE' => IReflection::FIELD_DATE,
		'BOOL' => IReflection::FIELD_BOOL,
	);


	/**
	 * Displays complete result set as HTML table for debug purposes.
	 * @return void
	 */
	public static function dumpResult(ResultSet $result)
	{
		echo "\n<table class=\"dump\">\n<caption>" . htmlSpecialChars($result->getQueryString()) . "</caption>\n";
		if (!$result->getColumnCount()) {
			echo "\t<tr>\n\t\t<th>Affected rows:</th>\n\t\t<td>", $result->getRowCount(), "</td>\n\t</tr>\n</table>\n";
			return;
		}
		$i = 0;
		foreach ($result as $row) {
			if ($i === 0) {
				echo "<thead>\n\t<tr>\n\t\t<th>#row</th>\n";
				foreach ($row as $col => $foo) {
					echo "\t\t<th>" . htmlSpecialChars($col) . "</th>\n";
				}
				echo "\t</tr>\n</thead>\n<tbody>\n";
			}
			echo "\t<tr>\n\t\t<th>", $i, "</th>\n";
			foreach ($row as $col) {
				echo "\t\t<td>", htmlSpecialChars($col), "</td>\n";
			}
			echo "\t</tr>\n";
			$i++;
		}

		if ($i === 0) {
			echo "\t<tr>\n\t\t<td><em>empty result set</em></td>\n\t</tr>\n</table>\n";
		} else {
			echo "</tbody>\n</table>\n";
		}
	}


	/**
	 * Returns syntax highlighted SQL command.
	 * @param  string
	 * @return string
	 */
	public static function dumpSql($sql, array $params = NULL)
	{
		static $keywords1 = 'SELECT|(?:ON\s+DUPLICATE\s+KEY)?UPDATE|INSERT(?:\s+INTO)?|REPLACE(?:\s+INTO)?|DELETE|CALL|UNION|FROM|WHERE|HAVING|GROUP\s+BY|ORDER\s+BY|LIMIT|OFFSET|SET|VALUES|LEFT\s+JOIN|INNER\s+JOIN|TRUNCATE';
		static $keywords2 = 'ALL|DISTINCT|DISTINCTROW|IGNORE|AS|USING|ON|AND|OR|IN|IS|NOT|NULL|[RI]?LIKE|REGEXP|TRUE|FALSE';

		// insert new lines
		$sql = " $sql ";
		$sql = preg_replace("#(?<=[\\s,(])($keywords1)(?=[\\s,)])#i", "\n\$1", $sql);

		// reduce spaces
		$sql = preg_replace('#[ \t]{2,}#', ' ', $sql);

		$sql = wordwrap($sql, 100);
		$sql = preg_replace('#([ \t]*\r?\n){2,}#', "\n", $sql);

		// syntax highlight
		$sql = htmlSpecialChars($sql);
		$sql = preg_replace_callback("#(/\\*.+?\\*/)|(\\*\\*.+?\\*\\*)|(?<=[\\s,(])($keywords1)(?=[\\s,)])|(?<=[\\s,(=])($keywords2)(?=[\\s,)=])#is", function($matches) {
			if (!empty($matches[1])) { // comment
				return '<em style="color:gray">' . $matches[1] . '</em>';

			} elseif (!empty($matches[2])) { // error
				return '<strong style="color:red">' . $matches[2] . '</strong>';

			} elseif (!empty($matches[3])) { // most important keywords
				return '<strong style="color:blue">' . $matches[3] . '</strong>';

			} elseif (!empty($matches[4])) { // other keywords
				return '<strong style="color:green">' . $matches[4] . '</strong>';
			}
		}, $sql);

		// parameters
		$sql = preg_replace_callback('#\?#', function() use ($params) {
			static $i = 0;
			if (!isset($params[$i])) {
				return '?';
			}
			$param = $params[$i++];
			if (is_string($param) && (preg_match('#[^\x09\x0A\x0D\x20-\x7E\xA0-\x{10FFFF}]#u', $param) || preg_last_error())) {
				return '<i title="Length ' . strlen($param) . ' bytes">&lt;binary&gt;</i>';

			} elseif (is_string($param)) {
				return '<span title="Length ' . Nette\Utils\Strings::length($param) . ' characters">\'' . htmlspecialchars(Nette\Utils\Strings::truncate($param, Helpers::$maxLength)) . "'</span>";

			} elseif (is_resource($param)) {
				$type = get_resource_type($param);
				if ($type === 'stream') {
					$info = stream_get_meta_data($param);
				}
				return '<i' . (isset($info['uri']) ? ' title="' . htmlspecialchars($info['uri']) . '"' : NULL) . '>&lt;' . htmlSpecialChars($type) . ' resource&gt;</i> ';

			} else {
				return htmlspecialchars($param);
			}
		}, $sql);

		return '<pre class="dump">' . trim($sql) . "</pre>\n";
	}


	/**
	 * Common column type detection.
	 * @return array
	 */
	public static function detectTypes(\PDOStatement $statement)
	{
		$types = array();
		$count = $statement->columnCount(); // driver must be meta-aware, see PHP bugs #53782, #54695
		for ($col = 0; $col < $count; $col++) {
			$meta = $statement->getColumnMeta($col);
			if (isset($meta['native_type'])) {
				$types[$meta['name']] = self::detectType($meta['native_type']);
			}
		}
		return $types;
	}


	/**
	 * Heuristic column type detection.
	 * @param  string
	 * @return string
	 * @internal
	 */
	public static function detectType($type)
	{
		static $cache;
		if (!isset($cache[$type])) {
			$cache[$type] = 'string';
			foreach (self::$typePatterns as $s => $val) {
				if (preg_match("#$s#i", $type)) {
					return $cache[$type] = $val;
				}
			}
		}
		return $cache[$type];
	}


	/**
	 * Import SQL dump from file - extremely fast.
	 * @return int  count of commands
	 */
	public static function loadFromFile(Connection $connection, $file)
	{
		@set_time_limit(0); // intentionally @

		$handle = @fopen($file, 'r'); // intentionally @
		if (!$handle) {
			throw new Nette\FileNotFoundException("Cannot open file '$file'.");
		}

		$count = 0;
		$delimiter = ';';
		$sql = '';
		while (!feof($handle)) {
			$s = rtrim(fgets($handle));
			if (!strncasecmp($s, 'DELIMITER ', 10)) {
				$delimiter = substr($s, 10);

			} elseif (substr($s, -strlen($delimiter)) === $delimiter) {
				$sql .= substr($s, 0, -strlen($delimiter));
				$connection->query($sql); // native query without logging
				$sql = '';
				$count++;

			} else {
				$sql .= $s . "\n";
			}
		}
		if (trim($sql) !== '') {
			$connection->query($sql);
			$count++;
		}
		fclose($handle);
		return $count;
	}


	public static function createDebugPanel($connection, $explain = TRUE, $name = NULL)
	{
		$panel = new Nette\Bridges\DatabaseTracy\ConnectionPanel($connection);
		$panel->explain = $explain;
		$panel->name = $name;
		Tracy\Debugger::getBar()->addPanel($panel);
		return $panel;
	}


	/**
	 * Reformat source to key -> value pairs.
	 * @return array
	 */
	public static function toPairs(array $rows, $key = NULL, $value = NULL)
	{
		if (!$rows) {
			return array();
		}

		$keys = array_keys((array) reset($rows));
		if (!count($keys)) {
			throw new \LogicException('Result set does not contain any column.');

		} elseif ($key === NULL && $value === NULL) {
			if (count($keys) === 1) {
				list($value) = $keys;
			} else {
				list($key, $value) = $keys;
			}
		}

		$return = array();
		if ($key === NULL) {
			foreach ($rows as $row) {
				$return[] = ($value === NULL ? $row : $row[$value]);
			}
		} else {
			foreach ($rows as $row) {
				$return[is_object($row[$key]) ? (string) $row[$key] : $row[$key]] = ($value === NULL ? $row : $row[$value]);
			}
		}

		return $return;
	}

}
