<?php

class ParserXsdAttributeAssert {

	public static function buildFromAssertCode($assertCode, $xsdType) { // @param string $assertCode
		$fieldNamesUpperCase = array_map('strtoupper', (!empty($xsdType['struct'])) ? array_keys($xsdType['struct']) : []);
		$instanceName = $xsdType['name'];

		$xsdAssertParser = new ParserXsdAttributeAssert();
		$xsdAssertParser->parseAssertCode($assertCode, [
			'instanceName' => $instanceName,
			'fields' => $fieldNamesUpperCase,
		]);
		return $xsdAssertParser;
	}
	public static function buildFromString($str, $xsdType) { // @param string $str
		$xsdAssertParser = new ParserXsdAttributeAssert();
		return $xsdAssertParser;
	}

	public function __construct() {
		$this->_state = [];
	}

	public function parseAssertCode($assertCode, $params = []) {
		if (empty($params['instanceName'])) throw new Exception("Missing instanceName");
		$instanceName = $params['instanceName'];
		$fieldNamesUpperCase = V::get('fields', [], $params, 'array');

		$this->_state = [
			'instanceName' => $instanceName,
			'fieldNamesUpperCase' => $fieldNamesUpperCase,
			'token_tree' => [],
		];

		$tokens = token_get_all("<?php " . $assertCode);
		$parsedTokens = array_map(function ($token) {
			if (is_string($token)) return [
				'type' => 'string',
				'value' => $token,
			];
			return [
				'type' => token_name($token[0]),
				'value' => $token[1]
			];
		}, $tokens);
		array_shift($parsedTokens); // remove first token: `<?php`
		$parsedTokens = array_map(function ($token) {
			if ('string' === $token['type'] && '(' === $token['value']) return array_merge($token, [ 'type' => 'opening parenthesis' ]);
			if ('string' === $token['type'] && ')' === $token['value']) return array_merge($token, [ 'type' => 'closing parenthesis' ]);
			if ('string' === $token['type'] && ',' === $token['value']) return array_merge($token, [ 'type' => 'comma' ]);
			return $token;
		}, $parsedTokens);
		$parsedTokens = array_filter($parsedTokens, function ($token) {
			return ('T_WHITESPACE' !== $token['type']);
		});
		// opening parenthesis
		// closing parenthesis
		// function array_reduce ( array $array , callable $callback [, mixed $initial = NULL ] ) // return mixed
		UI::table(['rows'=>$parsedTokens, 'caption'=>"parseAttributeWithAssertCode({$attrName})"]);
		$parser = array_reduce($parsedTokens, function ($parser, $token) use ($fieldNamesUpperCase, $instanceName) {
			if (!$parser) $parser = [ 'deep' => 0, 'cur' => '', 'tokens' => [] ];
			// 1. `concat(ID, ' ', DESC, ' ', DESC_PL)`
			// 1.1 $parser = { deep: 0, cur: 'concat', tokens: []}
			// 1.2 $parser = { deep: 1, cur: '', tokens: [ {'function', 'concat'}, {'('} ]}
			if (!empty($parser['cur'])) {
				switch ($parser['cur']) {
					case 'substring':
					case 'concat':
					{
						if ('opening parenthesis' === $token['type']) {
							$parser['deep'] = $parser['deep'] + 1;
							$parser['tokens'][] = [ 'type' => "function", 'value' => $parser['cur'] ];
							$parser['tokens'][] = [ 'type' => "opening parenthesis", 'value' => '(' ];
							$parser['cur'] = '';
							return $parser;
						}
					} break;
					case 'name': return array_merge($parser, [ 'cur' => 'name(' ]);
					case 'name(': {
						if ('closing parenthesis' === $token['type']) {
							$parser['tokens'][] = [ 'type' => "instanceName", 'value' => $instanceName ];
							$parser['cur'] = '';
							return $parser;
						}
					} break;
				}
				throw new Exception("Parse attribute assert code failed. Not implemented function '{$parser['cur']}'.");
			}
			if ('string' === $token['type']) throw new Exception("Parse attribute assert code failed. Not implemented string token '{$token['value']}'.");
			if ('comma' === $token['type']) {
				$parser['tokens'][] = $token;
				return $parser;
			}
			if ('T_CONSTANT_ENCAPSED_STRING' === $token['type']) {
				$parser['tokens'][] = array_merge($token, [ 'type' => 'encapsed string' ]);
				return $parser;
			}
			if ('T_LNUMBER' === $token['type']) {
				$parser['tokens'][] = array_merge($token, [ 'type' => 'number' ]);
				return $parser;
			}
			if ('closing parenthesis' === $token['type']) {
				if ($parser['deep'] <= 0) throw new Exception("Parse attribute assert code failed. Parenthesis not match.");
				$parser['tokens'][] = $token;
				$parser['deep'] = $parser['deep'] - 1;
				return $parser;
			}
			if ('T_STRING' === $token['type']) {
				if ('concat' === $token['value']) return array_merge($parser, [ 'cur' => 'concat' ]);
				if ('substring' === $token['value']) return array_merge($parser, [ 'cur' => 'substring' ]);
				if ('name' === $token['value']) return array_merge($parser, [ 'cur' => 'name' ]);
				if (in_array(strtoupper($token['value']), $fieldNamesUpperCase)) {
					$parser['tokens'][] = [ 'type' => 'field', 'value' => strtoupper($token['value']) ];
					return $parser;
				}
				throw new Exception("Parse attribute assert code failed. Not implemented T_STRING token '{$token['value']}'.");
			}
			throw new Exception("Parse attribute assert code failed. Not implemented {$token['type']} token '{$token['value']}'.");
			// return $parser;
		}, []);
		DBG::nicePrint($parser, "parseAttributeWithAssertCode({$attrName}) parsed tokens");
		$checkParenthesisDepth = array_reduce($parser['tokens'], function ($ret, $token) {
			switch ($token['type']) {
				case 'opening parenthesis': $ret['deep'] += 1; break;
				case 'closing parenthesis': $ret['deep'] -= 1; break;
			}
			switch ($token['type']) {
				case 'opening parenthesis': break;
				case 'closing parenthesis': break;
				default: $ret['tokens'][] = array_merge($token, [ 'deep' => $ret['deep'] ]);
			}
			return $ret;
		}, [ 'deep' => 1, 'tokens' => [] ]);
		if (1 !== $checkParenthesisDepth['deep']) throw new Exception("Parse attribute assert code failed. Parentheses do not match.");
		$parser['tokens'] = $checkParenthesisDepth['tokens'];
		UI::table(['rows'=>$parser['tokens'], 'caption'=>"parseAttributeWithAssertCode({$attrName}) parsed tokens"]);

		$tokenTree = array_reduce($parser['tokens'], function ($ret, $token) {
			static $counter = 0;
			$counter += 1;
			DBG::log($ret, 'array', "token_tree loop({$counter}) >>> \$ret");
			DBG::log($token, 'array', "token_tree loop({$counter}) >>> \$token");
			$funcIdx = $ret['funcIdx'];
			if ($ret['lastDeep'] < $token['deep']) { // 'starting parenthesis' was before => func arg
				$ret['lastDeep'] = $token['deep'];
			}
			else if ($ret['lastDeep'] > $token['deep']) { // 'closing parenthesis' was before =>
				$ret['lastDeep'] = $token['deep'];
				for ($idx = $funcIdx; $idx >= 0; $idx--) {
					if ($token['deep'] - 1 === $ret['token_tree'][$idx]['deep']) {
						$funcIdx = $idx;
						$ret['funcIdx'] = $funcIdx;
						break;
					}
				}
			}
			if ('function' === $token['type']) {
				$ret['token_tree'][] = array_merge($token, [ 'funcIdx' => $funcIdx, 'args' => [] ]);
				$ret['funcIdx'] = count($ret['token_tree']) - 1;
				if ($funcIdx >= 0) $ret['token_tree'][$funcIdx]['args'][] = [ 'type' => 'funcIdx', 'value' => $ret['funcIdx'] ];
				return $ret;
			} else {
				$ret['token_tree'][$funcIdx]['args'][] = $token;
			}
			return $ret;
		}, [ 'funcIdx' => -1, 'lastDeep' => 1, 'token_tree' => [] ]); // $token_tree = { 'type', 'value', 'deep', 'args' }
		DBG::nicePrint($parser['token_tree'], "parseAttributeWithAssertCode({$attrName}) token_tree");
		// TODO: validate $tokenTree
		$parser['token_tree'] = $tokenTree['token_tree'];

		$this->_state['token_tree'] = $parser['token_tree'];
	}

	public function toMysqlSelect($rootTableName, $primaryKeyField) {
		$sqlAssertCode = '';
		$sqlPrefix = 't';
		$tokenTree = array_map(function ($val) { return $val; }, $this->_state['token_tree']);
		for ($idx = count($tokenTree) - 1; $idx >= 0; $idx--) {
			$func = $tokenTree[$idx];
			switch ($func['value']) {
				case 'concat': $value = $this->_toMysqlConcat($func, $sqlPrefix); break;
				case 'substring': $value = $this->_toMysqlSubstring($func, $sqlPrefix); break;
				default: throw new Exception("Not implemented asser code function '{$func['value']}'");
			}
			for ($subIdx = $idx - 1; $subIdx >= 0; $subIdx--) {
				$tokenTree[$subIdx]['args'] = array_map(function ($arg) use ($value, $idx) {
					if ('funcIdx' === $arg['type'] && $arg['value'] == $idx) {
						return [
							'type' => 'raw string',
							'value' => $value,
						];
					}
					return $arg;
				}, $tokenTree[$subIdx]['args']);
			}
		}

		$func = $tokenTree[0];
		$sqlAssertCode .= "{$func['value']}(";
		$sqlAssertCode .= implode("", array_map(function ($arg) use ($sqlPrefix) {
			switch ($arg['type']) {
				case 'field': return "{$sqlPrefix}.{$arg['value']}";
				case 'number': return $arg['value'];
			}
			return $arg['value'];
		}, $func['args']));
		$sqlAssertCode .= ")";

		$sql = "
			select {$sqlPrefix}.{$primaryKeyField} as primary_key
				, {$sqlAssertCode} as label
			from `{$rootTableName}` {$sqlPrefix}
		";
		return $sql;
	}
	function _toMysqlConcat($func, $sqlPrefix) {
		return "concat(" . implode("", array_map(function ($arg) use ($sqlPrefix) {
			if ('field' == $arg['type']) return "{$sqlPrefix}.{$arg['value']}";
			return $arg['value'];
		}, $func['args'])) . ")";
	}
	function _toMysqlSubstring($func, $sqlPrefix) {
		return "substring(" . implode("", array_map(function ($arg) use ($sqlPrefix) {
			if ('field' == $arg['type']) return "{$sqlPrefix}.{$arg['value']}";
			return $arg['value'];
		}, $func['args'])) . ")";
	}

	public function evaluate($item) {
		$value = '';
		$uppserCaseItem = array_combine(
			array_map('strtoupper', array_keys($item)),
			array_values($item)
		);
		$tokenTree = array_map(function ($val) { return $val; }, $this->_state['token_tree']);
		for ($idx = count($tokenTree) - 1; $idx >= 0; $idx--) {
			$func = $tokenTree[$idx];
			switch ($func['value']) {
				case 'concat': $value = $this->_evaluateConcat($func, $uppserCaseItem); break;
				case 'substring': $value = $this->_evaluateSubstring($func, $uppserCaseItem); break;
				default: throw new Exception("Not implemented asser code function '{$func['value']}'");
			}
			for ($subIdx = $idx - 1; $subIdx >= 0; $subIdx--) {
				$tokenTree[$subIdx]['args'] = array_map(function ($arg) use ($value, $idx) {
					if ('funcIdx' === $arg['type'] && $arg['value'] == $idx) {
						return [
							'type' => 'raw string',
							'value' => $value,
						];
					}
					return $arg;
				}, $tokenTree[$subIdx]['args']);
			}
		}
		return $value;
	}
	public function _evaluateConcat($func, $item) {
		return implode('', array_map(function ($arg) use ($item) {
			switch ($arg['type']) {
				case 'field': return V::get($arg['value'], '', $item);
				case 'comma': return '';
				case 'encapsed string': return substr($arg['value'], 1, -1);
				case 'raw string': return $arg['value'];
			}
		}, $func['args']));
	}
	public function _evaluateSubstring($func, $item) {
		// PHP: substr( $str, $start [ , $length ] ) // NOTE $start with 0
		// XPath: substr( $str, $start [ , $length ] ) // NOTE $start with 1
		// SQL: substr( $str, $start [ , $length ] ) // NOTE $start with 1
		$str = '';
		$start = 0;
		$length = null;
		// $func ['args'] = [ string, comma, number, comma, number ]
		// or             = [ string, comma, number ]
		if (!in_array(count($func['args']), [3, 5])) throw new Exception("Sytax error for substring function in assert code");
		$arg = $func['args'][0];
		switch ($arg['type']) {
			case 'field': $str = V::get($arg['value'], '', $item); break;
			case 'encapsed string': $str = substr($arg['value'], 1, -1); break;
			case 'number': $str = (string)$arg['value']; break;
			case 'raw string': $str = $arg['value']; break;
		}
		if ('number' !== $func['args'][2]['type']) throw new Exception("Sytax error for substring function in assert code - expected second arguemnt type as number but '{$func['args'][2]['type']}' given");
		$start = (int)$func['args'][2]['value'] - 1;
		$start = ($start < 0) ? 0 : $start; // BUG in assert code
		if (5 === count($func['args'])) {
			if ('number' !== $func['args'][4]['type']) throw new Exception("Sytax error for substring function in assert code - expected third arguemnt type as number but '{$func['args'][2]['type']}' given");
			$length = (int)$func['args'][4]['value'];
		}
		return (null === $length)
			? substr($str, $start)
			: substr($str, $start, $length)
		;
	}

	public function toString() {
		throw new Exception("TODO: ParserXsdAttributeAssert->toString()");
	}
}