1 files changed, 193 insertions, 0 deletions
diff --git a/src/Components/Condition.php b/src/Components/Condition.php
new file mode 100644
index 0000000..b170356
--- /dev/null
+++ b/src/Components/Condition.php
@@ -0,0 +1,193 @@
+<?php
+
+/**
+ * `WHERE` keyword parser.
+ *
+ * @package    SqlParser
+ * @subpackage Components
+ */
+namespace SqlParser\Components;
+
+use SqlParser\Component;
+use SqlParser\Parser;
+use SqlParser\Token;
+use SqlParser\TokensList;
+
+/**
+ * `WHERE` keyword parser.
+ *
+ * @category   Keywords
+ * @package    SqlParser
+ * @subpackage Components
+ * @author     Dan Ungureanu <udan1107@gmail.com>
+ * @license    http://opensource.org/licenses/GPL-2.0 GNU Public License
+ */
+class Condition extends Component
+{
+
+    /**
+     * Logical operators that can be used to delimit expressions.
+     *
+     * @var array
+     */
+    public static $DELIMITERS = array('&&', 'AND', 'OR', 'XOR', '||');
+
+    /**
+     * Hash map containing reserved keywords that are also operators.
+     *
+     * @var array
+     */
+    public static $OPERATORS = array('AND' => 1, 'BETWEEN' => 1, 'LIKE' => 1,
+        'OR' => 1, 'XOR' => 1
+    );
+
+    /**
+     * Identifiers recognized.
+     *
+     * @var array
+     */
+    public $identifiers = array();
+
+    /**
+     * Whether this component is an operator.
+     *
+     * @var bool
+     */
+    public $isOperator = false;
+
+    /**
+     * The condition.
+     *
+     * @var string
+     */
+    public $expr;
+
+    /**
+     * Constructor.
+     *
+     * @param string $expr The condition or the operator.
+     */
+    public function __construct($expr = null)
+    {
+        $this->expr = trim($expr);
+    }
+
+    /**
+     * @param Parser     $parser  The parser that serves as context.
+     * @param TokensList $list    The list of tokens that are being parsed.
+     * @param array      $options Parameters for parsing.
+     *
+     * @return Condition[]
+     */
+    public static function parse(Parser $parser, TokensList $list, array $options = array())
+    {
+        $ret = array();
+
+        $expr = new Condition();
+
+        /**
+         * Counts brackets.
+         * @var int $brackets
+         */
+        $brackets = 0;
+
+        /**
+         * Whether there was a `BETWEEN` keyword before or not.
+         * It is required to keep track of them because their structure contains
+         * the keyword `AND`, which is also an operator that delimits
+         * expressions.
+         * @var bool
+         */
+        $betweenBefore = false;
+
+        for (; $list->idx < $list->count; ++$list->idx) {
+
+            /**
+             * Token parsed at this moment.
+             * @var Token $token
+             */
+            $token = $list->tokens[$list->idx];
+
+            // End of statement.
+            if ($token->type === Token::TYPE_DELIMITER) {
+                break;
+            }
+
+            // Skipping whitespaces and comments.
+            if ($token->type === Token::TYPE_COMMENT) {
+                continue;
+            }
+
+            // Conditions are delimited by logical operators.
+            if (in_array($token->value, static::$DELIMITERS, true)) {
+                if (($betweenBefore) && ($token->value === 'AND')) {
+                    $betweenBefore = false;
+                } else {
+                    $expr->expr = trim($expr->expr);
+                    if (!empty($expr->expr)) {
+                        // Adding the condition that is delimited by this operator.
+                        $ret[] = $expr;
+                    }
+
+                    // Adding the operator.
+                    $expr = new Condition($token->value);
+                    $expr->isOperator = true;
+                    $ret[] = $expr;
+
+                    $expr = new Condition();
+                    continue;
+                }
+            }
+
+            if ($token->type === Token::TYPE_OPERATOR) {
+                if ($token->value === '(') {
+                    ++$brackets;
+                } elseif ($token->value === ')') {
+                    --$brackets;
+                }
+            }
+
+            // No keyword is expected.
+            if (($token->type === Token::TYPE_KEYWORD) && ($token->flags & Token::FLAG_KEYWORD_RESERVED)) {
+                if ($token->value === 'BETWEEN') {
+                    $betweenBefore = true;
+                }
+                if (($brackets === 0) && (empty(static::$OPERATORS[$token->value]))) {
+                    break;
+                }
+            }
+
+            $expr->expr .= $token->token;
+            if (($token->type === Token::TYPE_NONE)
+                || (($token->type === Token::TYPE_KEYWORD) && (!($token->flags & Token::FLAG_KEYWORD_RESERVED)))
+                || ($token->type === Token::TYPE_STRING)
+                || ($token->type === Token::TYPE_SYMBOL)
+            ) {
+                $expr->identifiers[] = $token->value;
+            }
+        }
+
+        // Last iteration was not processed.
+        $expr->expr = trim($expr->expr);
+        if (!empty($expr->expr)) {
+            $ret[] = $expr;
+        }
+
+        --$list->idx;
+        return $ret;
+    }
+
+    /**
+     * @param Condition[] $component The component to be built.
+     *
+     * @return string
+     */
+    public static function build($component)
+    {
+        $ret = array();
+        foreach ($component as $f) {
+            $ret[] = $f->expr;
+        }
+        return implode(' ', $ret);
+    }
+}