<?php
/*
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

namespace Doctrine\Common\Annotations;

use Closure;
use ReflectionClass;

/**
 * A parser for docblock annotations.
 *
 * It is strongly discouraged to change the default annotation parsing process.
 *
 * @author Benjamin Eberlei <kontakt@beberlei.de>
 * @author Guilherme Blanco <guilhermeblanco@hotmail.com>
 * @author Jonathan Wage <jonwage@gmail.com>
 * @author Roman Borschel <roman@code-factory.org>
 * @author Johannes M. Schmitt <schmittjoh@gmail.com>
 */
final class DocParser
{
    /**
     * An array of all valid tokens for a class name.
     *
     * @var array
     */
    private static $classIdentifiers = array(DocLexer::T_IDENTIFIER, DocLexer::T_TRUE, DocLexer::T_FALSE, DocLexer::T_NULL);

    /**
     * The lexer.
     *
     * @var Doctrine\Common\Annotations\DocLexer
     */
    private $lexer;

    /**
     * Flag to control if the current annotation is nested or not.
     *
     * @var boolean
     */
    private $isNestedAnnotation = false;

    /**
     * Hashmap containing all use-statements that are to be used when parsing
     * the given doc block.
     *
     * @var array
     */
    private $imports = array();

    /**
     * This hashmap is used internally to cache results of class_exists()
     * look-ups.
     *
     * @var array
     */
    private $classExists = array();
    
    /**
     *
     * @var This hashmap is used internally to cache if a class is an annotation or not.
     * 
     * @var array
     */
    private $isAnnotation = array();

    /**
     * Whether annotations that have not been imported should be ignored.
     *
     * @var boolean
     */
    private $ignoreNotImportedAnnotations = false;

    /**
     * A list with annotations that are not causing exceptions when not resolved to an annotation class.
     *
     * The names must be the raw names as used in the class, not the fully qualified
     * class names.
     *
     * @var array
     */
    private $ignoredAnnotationNames = array();

    /**
     * @var array
     */
    private $namespaceAliases = array();

    /**
     * @var string
     */
    private $context = '';
    
    /**
     * @var Closure
     */
    private $creationFn = null;

    /**
     * Constructs a new DocParser.
     */
    public function __construct()
    {
        $this->lexer = new DocLexer;
    }

    /**
     * Sets the annotation names that are ignored during the parsing process.
     *
     * The names are supposed to be the raw names as used in the class, not the
     * fully qualified class names.
     *
     * @param array $names
     */
    public function setIgnoredAnnotationNames(array $names)
    {
        $this->ignoredAnnotationNames = $names;
    }
    
    /**
     * @deprecated Will be removed in 3.0
     * @param \Closure $func
     */
    public function setAnnotationCreationFunction(\Closure $func)
    {
        $this->creationFn = $func;
    }

    public function setImports(array $imports)
    {
        $this->imports = $imports;
    }

    public function setIgnoreNotImportedAnnotations($bool)
    {
        $this->ignoreNotImportedAnnotations = (Boolean) $bool;
    }

    public function setAnnotationNamespaceAlias($namespace, $alias)
    {
        $this->namespaceAliases[$alias] = $namespace;
    }

    /**
     * Parses the given docblock string for annotations.
     *
     * @param string $input The docblock string to parse.
     * @param string $context The parsing context.
     * @return array Array of annotations. If no annotations are found, an empty array is returned.
     */
    public function parse($input, $context = '')
    {
        if (false === $pos = strpos($input, '@')) {
            return array();
        }

        // also parse whatever character is before the @
        if ($pos > 0) {
            $pos -= 1;
        }

        $this->context = $context;
        $this->lexer->setInput(trim(substr($input, $pos), '* /'));
        $this->lexer->moveNext();

        return $this->Annotations();
    }

    /**
     * Attempts to match the given token with the current lookahead token.
     * If they match, updates the lookahead token; otherwise raises a syntax error.
     *
     * @param int Token type.
     * @return bool True if tokens match; false otherwise.
     */
    private function match($token)
    {
        if ( ! $this->lexer->isNextToken($token) ) {
            $this->syntaxError($this->lexer->getLiteral($token));
        }

        return $this->lexer->moveNext();
    }

    /**
     * Attempts to match the current lookahead token with any of the given tokens.
     *
     * If any of them matches, this method updates the lookahead token; otherwise
     * a syntax error is raised.
     *
     * @param array $tokens
     * @return bool
     */
    private function matchAny(array $tokens)
    {
        if ( ! $this->lexer->isNextTokenAny($tokens)) {
            $this->syntaxError(implode(' or ', array_map(array($this->lexer, 'getLiteral'), $tokens)));
        }

        return $this->lexer->moveNext();
    }

    /**
     * Generates a new syntax error.
     *
     * @param string $expected Expected string.
     * @param array $token Optional token.
     * @throws SyntaxException
     */
    private function syntaxError($expected, $token = null)
    {
        if ($token === null) {
            $token = $this->lexer->lookahead;
        }

        $message =  "Expected {$expected}, got ";

        if ($this->lexer->lookahead === null) {
            $message .= 'end of string';
        } else {
            $message .= "'{$token['value']}' at position {$token['position']}";
        }

        if (strlen($this->context)) {
            $message .= ' in ' . $this->context;
        }

        $message .= '.';

        throw AnnotationException::syntaxError($message);
    }

    /**
     * Attempt to check if a class exists or not. This never goes through the PHP autoloading mechanism
     * but uses the {@link AnnotationRegistry} to load classes.
     *
     * @param string $fqcn
     * @return boolean
     */
    private function classExists($fqcn)
    {
        if (isset($this->classExists[$fqcn])) {
            return $this->classExists[$fqcn];
        }
        
        // first check if the class already exists, maybe loaded through another AnnotationReader
        if (class_exists($fqcn, false)) {
            return $this->classExists[$fqcn] = true;
        }

        // final check, does this class exist?
        return $this->classExists[$fqcn] = AnnotationRegistry::loadAnnotationClass($fqcn);
    }

    /**
     * Annotations ::= Annotation {[ "*" ]* [Annotation]}*
     *
     * @return array
     */
    private function Annotations()
    {
        $annotations = array();

        while (null !== $this->lexer->lookahead) {
            if (DocLexer::T_AT !== $this->lexer->lookahead['type']) {
                $this->lexer->moveNext();
                continue;
            }

            // make sure the @ is preceded by non-catchable pattern
            if (null !== $this->lexer->token && $this->lexer->lookahead['position'] === $this->lexer->token['position'] + strlen($this->lexer->token['value'])) {
                $this->lexer->moveNext();
                continue;
            }

            // make sure the @ is followed by either a namespace separator, or
            // an identifier token
            if ((null === $peek = $this->lexer->glimpse())
                || (DocLexer::T_NAMESPACE_SEPARATOR !== $peek['type'] && !in_array($peek['type'], self::$classIdentifiers, true))
                || $peek['position'] !== $this->lexer->lookahead['position'] + 1) {
                $this->lexer->moveNext();
                continue;
            }

            $this->isNestedAnnotation = false;
            if (false !== $annot = $this->Annotation()) {
                $annotations[] = $annot;
            }
        }

        return $annotations;
    }

    /**
     * Annotation     ::= "@" AnnotationName ["(" [Values] ")"]
     * AnnotationName ::= QualifiedName | SimpleName
     * QualifiedName  ::= NameSpacePart "\" {NameSpacePart "\"}* SimpleName
     * NameSpacePart  ::= identifier | null | false | true
     * SimpleName     ::= identifier | null | false | true
     *
     * @return mixed False if it is not a valid annotation.
     */
    private function Annotation()
    {
        $this->match(DocLexer::T_AT);

        // check if we have an annotation
        if ($this->lexer->isNextTokenAny(self::$classIdentifiers)) {
            $this->lexer->moveNext();
            $name = $this->lexer->token['value'];
        } else if ($this->lexer->isNextToken(DocLexer::T_NAMESPACE_SEPARATOR)) {
            $name = '';
        } else {
            $this->syntaxError('namespace separator or identifier');
        }

        while ($this->lexer->lookahead['position'] === $this->lexer->token['position'] + strlen($this->lexer->token['value']) && $this->lexer->isNextToken(DocLexer::T_NAMESPACE_SEPARATOR)) {
            $this->match(DocLexer::T_NAMESPACE_SEPARATOR);
            $this->matchAny(self::$classIdentifiers);
            $name .= '\\'.$this->lexer->token['value'];
        }

        if (strpos($name, ":") !== false) {
            list ($alias, $name) = explode(':', $name);
            // If the namespace alias doesnt exist, skip until next annotation
            if ( ! isset($this->namespaceAliases[$alias])) {
                $this->lexer->skipUntil(DocLexer::T_AT);
                return false;
            }
            $name = $this->namespaceAliases[$alias] . $name;
        }

        // only process names which are not fully qualified, yet
        if ('\\' !== $name[0] && !$this->classExists($name)) {
            $alias = (false === $pos = strpos($name, '\\'))? $name : substr($name, 0, $pos);

            if (isset($this->imports[$loweredAlias = strtolower($alias)])) {
                if (false !== $pos) {
                    $name = $this->imports[$loweredAlias].substr($name, $pos);
                } else {
                    $name = $this->imports[$loweredAlias];
                }
            } elseif (isset($this->imports['__DEFAULT__']) && $this->classExists($this->imports['__DEFAULT__'].$name)) {
                 $name = $this->imports['__DEFAULT__'].$name;
            } elseif (isset($this->imports['__NAMESPACE__']) && $this->classExists($this->imports['__NAMESPACE__'].'\\'.$name)) {
                 $name = $this->imports['__NAMESPACE__'].'\\'.$name;
            } else {
                if ($this->ignoreNotImportedAnnotations || isset($this->ignoredAnnotationNames[$name])) {
                    return false;
                }

                throw AnnotationException::semanticalError(sprintf('The annotation "@%s" in %s was never imported.', $name, $this->context));
            }
        }

        if (!$this->classExists($name)) {
            throw AnnotationException::semanticalError(sprintf('The annotation "@%s" in %s does not exist, or could not be auto-loaded.', $name, $this->context));
        }
        
        if (!$this->isAnnotation($name)) {
            return false;
        }

        // Verifies that the annotation class extends any class that contains "Annotation".
        // This is done to avoid coupling of Doctrine Annotations against other libraries.
        

        // at this point, $name contains the fully qualified class name of the
        // annotation, and it is also guaranteed that this class exists, and
        // that it is loaded

        // Next will be nested
        $this->isNestedAnnotation = true;

        $values = array();
        if ($this->lexer->isNextToken(DocLexer::T_OPEN_PARENTHESIS)) {
            $this->match(DocLexer::T_OPEN_PARENTHESIS);

            if ( ! $this->lexer->isNextToken(DocLexer::T_CLOSE_PARENTHESIS)) {
                $values = $this->Values();
            }

            $this->match(DocLexer::T_CLOSE_PARENTHESIS);
        }
        
        return $this->newAnnotation($name, $values);
    }
    
    /**
     * Verify that the found class is actually an annotation.
     * 
     * This can be detected through two mechanisms:
     * 1. Class extends Doctrine\Common\Annotations\Annotation
     * 2. The class level docblock contains the string "@Annotation"
     * 
     * @param string $name
     * @return bool
     */
    private function isAnnotation($name)
    {
        if (!isset($this->isAnnotation[$name])) {
            if (is_subclass_of($name, 'Doctrine\Common\Annotations\Annotation')) {
                $this->isAnnotation[$name] = true;
            } else {
                $reflClass = new \ReflectionClass($name);
                $this->isAnnotation[$name] = strpos($reflClass->getDocComment(), "@Annotation") !== false;
            }
        }
        return $this->isAnnotation[$name];
    }
    
    private function newAnnotation($name, $values)
    {
        if ($this->creationFn !== null) {
            $fn = $this->creationFn;
            return $fn($name, $values);
        }
        
        return new $name($values);
    }

    /**
     * Values ::= Array | Value {"," Value}*
     *
     * @return array
     */
    private function Values()
    {
        $values = array();

        // Handle the case of a single array as value, i.e. @Foo({....})
        if ($this->lexer->isNextToken(DocLexer::T_OPEN_CURLY_BRACES)) {
            $values['value'] = $this->Value();
            return $values;
        }

        $values[] = $this->Value();

        while ($this->lexer->isNextToken(DocLexer::T_COMMA)) {
            $this->match(DocLexer::T_COMMA);
            $token = $this->lexer->lookahead;
            $value = $this->Value();

            if ( ! is_object($value) && ! is_array($value)) {
                $this->syntaxError('Value', $token);
            }

            $values[] = $value;
        }

        foreach ($values as $k => $value) {
            if (is_object($value) && $value instanceof \stdClass) {
                $values[$value->name] = $value->value;
            } else if ( ! isset($values['value'])){
                $values['value'] = $value;
            } else {
                if ( ! is_array($values['value'])) {
                    $values['value'] = array($values['value']);
                }

                $values['value'][] = $value;
            }

            unset($values[$k]);
        }

        return $values;
    }

    /**
     * Value ::= PlainValue | FieldAssignment
     *
     * @return mixed
     */
    private function Value()
    {
        $peek = $this->lexer->glimpse();

        if (DocLexer::T_EQUALS === $peek['type']) {
            return $this->FieldAssignment();
        }

        return $this->PlainValue();
    }

    /**
     * PlainValue ::= integer | string | float | boolean | Array | Annotation
     *
     * @return mixed
     */
    private function PlainValue()
    {
        if ($this->lexer->isNextToken(DocLexer::T_OPEN_CURLY_BRACES)) {
            return $this->Arrayx();
        }

        if ($this->lexer->isNextToken(DocLexer::T_AT)) {
            return $this->Annotation();
        }

        switch ($this->lexer->lookahead['type']) {
            case DocLexer::T_STRING:
                $this->match(DocLexer::T_STRING);
                return $this->lexer->token['value'];

            case DocLexer::T_INTEGER:
                $this->match(DocLexer::T_INTEGER);
                return (int)$this->lexer->token['value'];

            case DocLexer::T_FLOAT:
                $this->match(DocLexer::T_FLOAT);
                return (float)$this->lexer->token['value'];

            case DocLexer::T_TRUE:
                $this->match(DocLexer::T_TRUE);
                return true;

            case DocLexer::T_FALSE:
                $this->match(DocLexer::T_FALSE);
                return false;

            case DocLexer::T_NULL:
                $this->match(DocLexer::T_NULL);
                return null;

            default:
                $this->syntaxError('PlainValue');
        }
    }

    /**
     * FieldAssignment ::= FieldName "=" PlainValue
     * FieldName ::= identifier
     *
     * @return array
     */
    private function FieldAssignment()
    {
        $this->match(DocLexer::T_IDENTIFIER);
        $fieldName = $this->lexer->token['value'];

        $this->match(DocLexer::T_EQUALS);

        $item = new \stdClass();
        $item->name  = $fieldName;
        $item->value = $this->PlainValue();

        return $item;
    }

    /**
     * Array ::= "{" ArrayEntry {"," ArrayEntry}* "}"
     *
     * @return array
     */
    private function Arrayx()
    {
        $array = $values = array();

        $this->match(DocLexer::T_OPEN_CURLY_BRACES);
        $values[] = $this->ArrayEntry();

        while ($this->lexer->isNextToken(DocLexer::T_COMMA)) {
            $this->match(DocLexer::T_COMMA);
            $values[] = $this->ArrayEntry();
        }

        $this->match(DocLexer::T_CLOSE_CURLY_BRACES);

        foreach ($values as $value) {
            list ($key, $val) = $value;

            if ($key !== null) {
                $array[$key] = $val;
            } else {
                $array[] = $val;
            }
        }

        return $array;
    }

    /**
     * ArrayEntry ::= Value | KeyValuePair
     * KeyValuePair ::= Key "=" PlainValue
     * Key ::= string | integer
     *
     * @return array
     */
    private function ArrayEntry()
    {
        $peek = $this->lexer->glimpse();

        if (DocLexer::T_EQUALS === $peek['type']) {
            $this->match(
                $this->lexer->isNextToken(DocLexer::T_INTEGER) ? DocLexer::T_INTEGER : DocLexer::T_STRING
            );

            $key = $this->lexer->token['value'];
            $this->match(DocLexer::T_EQUALS);

            return array($key, $this->PlainValue());
        }

        return array(null, $this->Value());
    }
}