<?php declare(strict_types = 1);

namespace PHPStan\PhpDocParser\Parser;

use LogicException;
use PHPStan\PhpDocParser\Ast;
use PHPStan\PhpDocParser\Ast\ConstExpr\ConstExprIntegerNode;
use PHPStan\PhpDocParser\Ast\ConstExpr\ConstExprStringNode;
use PHPStan\PhpDocParser\Ast\ConstExpr\ConstFetchNode;
use PHPStan\PhpDocParser\Ast\PhpDoc\Doctrine;
use PHPStan\PhpDocParser\Ast\Type\IdentifierTypeNode;
use PHPStan\PhpDocParser\Lexer\Lexer;
use PHPStan\ShouldNotHappenException;
use function array_key_exists;
use function array_values;
use function count;
use function rtrim;
use function str_replace;
use function trim;

/**
 * @phpstan-import-type ValueType from Doctrine\DoctrineArgument as DoctrineValueType
 */
class PhpDocParser
{

	private const DISALLOWED_DESCRIPTION_START_TOKENS = [
		Lexer::TOKEN_UNION,
		Lexer::TOKEN_INTERSECTION,
	];

	/** @var TypeParser */
	private $typeParser;

	/** @var ConstExprParser */
	private $constantExprParser;

	/** @var ConstExprParser */
	private $doctrineConstantExprParser;

	/** @var bool */
	private $requireWhitespaceBeforeDescription;

	/** @var bool */
	private $preserveTypeAliasesWithInvalidTypes;

	/** @var bool */
	private $parseDoctrineAnnotations;

	/** @var bool */
	private $useLinesAttributes;

	/** @var bool */
	private $useIndexAttributes;

	/** @var bool */
	private $textBetweenTagsBelongsToDescription;

	/**
	 * @param array{lines?: bool, indexes?: bool} $usedAttributes
	 */
	public function __construct(
		TypeParser $typeParser,
		ConstExprParser $constantExprParser,
		bool $requireWhitespaceBeforeDescription = false,
		bool $preserveTypeAliasesWithInvalidTypes = false,
		array $usedAttributes = [],
		bool $parseDoctrineAnnotations = false,
		bool $textBetweenTagsBelongsToDescription = false
	)
	{
		$this->typeParser = $typeParser;
		$this->constantExprParser = $constantExprParser;
		$this->doctrineConstantExprParser = $constantExprParser->toDoctrine();
		$this->requireWhitespaceBeforeDescription = $requireWhitespaceBeforeDescription;
		$this->preserveTypeAliasesWithInvalidTypes = $preserveTypeAliasesWithInvalidTypes;
		$this->parseDoctrineAnnotations = $parseDoctrineAnnotations;
		$this->useLinesAttributes = $usedAttributes['lines'] ?? false;
		$this->useIndexAttributes = $usedAttributes['indexes'] ?? false;
		$this->textBetweenTagsBelongsToDescription = $textBetweenTagsBelongsToDescription;
	}


	public function parse(TokenIterator $tokens): Ast\PhpDoc\PhpDocNode
	{
		$tokens->consumeTokenType(Lexer::TOKEN_OPEN_PHPDOC);
		$tokens->tryConsumeTokenType(Lexer::TOKEN_PHPDOC_EOL);

		$children = [];

		if ($this->parseDoctrineAnnotations) {
			if (!$tokens->isCurrentTokenType(Lexer::TOKEN_CLOSE_PHPDOC)) {
				$lastChild = $this->parseChild($tokens);
				$children[] = $lastChild;
				while (!$tokens->isCurrentTokenType(Lexer::TOKEN_CLOSE_PHPDOC)) {
					if (
						$lastChild instanceof Ast\PhpDoc\PhpDocTagNode
						&& (
							$lastChild->value instanceof Doctrine\DoctrineTagValueNode
							|| $lastChild->value instanceof Ast\PhpDoc\GenericTagValueNode
						)
					) {
						$tokens->tryConsumeTokenType(Lexer::TOKEN_PHPDOC_EOL);
						if ($tokens->isCurrentTokenType(Lexer::TOKEN_CLOSE_PHPDOC)) {
							break;
						}
						$lastChild = $this->parseChild($tokens);
						$children[] = $lastChild;
						continue;
					}

					if (!$tokens->tryConsumeTokenType(Lexer::TOKEN_PHPDOC_EOL)) {
						break;
					}
					if ($tokens->isCurrentTokenType(Lexer::TOKEN_CLOSE_PHPDOC)) {
						break;
					}

					$lastChild = $this->parseChild($tokens);
					$children[] = $lastChild;
				}
			}
		} else {
			if (!$tokens->isCurrentTokenType(Lexer::TOKEN_CLOSE_PHPDOC)) {
				$children[] = $this->parseChild($tokens);
				while ($tokens->tryConsumeTokenType(Lexer::TOKEN_PHPDOC_EOL) && !$tokens->isCurrentTokenType(Lexer::TOKEN_CLOSE_PHPDOC)) {
					$children[] = $this->parseChild($tokens);
				}
			}
		}

		try {
			$tokens->consumeTokenType(Lexer::TOKEN_CLOSE_PHPDOC);
		} catch (ParserException $e) {
			$name = '';
			$startLine = $tokens->currentTokenLine();
			$startIndex = $tokens->currentTokenIndex();
			if (count($children) > 0) {
				$lastChild = $children[count($children) - 1];
				if ($lastChild instanceof Ast\PhpDoc\PhpDocTagNode) {
					$name = $lastChild->name;
					$startLine = $tokens->currentTokenLine();
					$startIndex = $tokens->currentTokenIndex();
				}
			}

			$tag = new Ast\PhpDoc\PhpDocTagNode(
				$name,
				$this->enrichWithAttributes(
					$tokens,
					new Ast\PhpDoc\InvalidTagValueNode($e->getMessage(), $e),
					$startLine,
					$startIndex
				)
			);

			$tokens->forwardToTheEnd();

			return $this->enrichWithAttributes($tokens, new Ast\PhpDoc\PhpDocNode([$this->enrichWithAttributes($tokens, $tag, $startLine, $startIndex)]), 1, 0);
		}

		return $this->enrichWithAttributes($tokens, new Ast\PhpDoc\PhpDocNode(array_values($children)), 1, 0);
	}


	/** @phpstan-impure */
	private function parseChild(TokenIterator $tokens): Ast\PhpDoc\PhpDocChildNode
	{
		if ($tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_TAG)) {
			$startLine = $tokens->currentTokenLine();
			$startIndex = $tokens->currentTokenIndex();
			return $this->enrichWithAttributes($tokens, $this->parseTag($tokens), $startLine, $startIndex);
		}

		if ($tokens->isCurrentTokenType(Lexer::TOKEN_DOCTRINE_TAG)) {
			$startLine = $tokens->currentTokenLine();
			$startIndex = $tokens->currentTokenIndex();
			$tag = $tokens->currentTokenValue();
			$tokens->next();

			$tagStartLine = $tokens->currentTokenLine();
			$tagStartIndex = $tokens->currentTokenIndex();

			return $this->enrichWithAttributes($tokens, new Ast\PhpDoc\PhpDocTagNode(
				$tag,
				$this->enrichWithAttributes(
					$tokens,
					$this->parseDoctrineTagValue($tokens, $tag),
					$tagStartLine,
					$tagStartIndex
				)
			), $startLine, $startIndex);
		}

		$startLine = $tokens->currentTokenLine();
		$startIndex = $tokens->currentTokenIndex();
		$text = $this->parseText($tokens);

		return $this->enrichWithAttributes($tokens, $text, $startLine, $startIndex);
	}

	/**
	 * @template T of Ast\Node
	 * @param T $tag
	 * @return T
	 */
	private function enrichWithAttributes(TokenIterator $tokens, Ast\Node $tag, int $startLine, int $startIndex): Ast\Node
	{
		if ($this->useLinesAttributes) {
			$tag->setAttribute(Ast\Attribute::START_LINE, $startLine);
			$tag->setAttribute(Ast\Attribute::END_LINE, $tokens->currentTokenLine());
		}

		if ($this->useIndexAttributes) {
			$tag->setAttribute(Ast\Attribute::START_INDEX, $startIndex);
			$tag->setAttribute(Ast\Attribute::END_INDEX, $tokens->endIndexOfLastRelevantToken());
		}

		return $tag;
	}


	private function parseText(TokenIterator $tokens): Ast\PhpDoc\PhpDocTextNode
	{
		$text = '';

		$endTokens = [Lexer::TOKEN_PHPDOC_EOL, Lexer::TOKEN_CLOSE_PHPDOC, Lexer::TOKEN_END];
		if ($this->textBetweenTagsBelongsToDescription) {
			$endTokens = [Lexer::TOKEN_CLOSE_PHPDOC, Lexer::TOKEN_END];
		}

		$savepoint = false;

		// if the next token is EOL, everything below is skipped and empty string is returned
		while ($this->textBetweenTagsBelongsToDescription || !$tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_EOL)) {
			$tmpText = $tokens->getSkippedHorizontalWhiteSpaceIfAny() . $tokens->joinUntil(Lexer::TOKEN_PHPDOC_EOL, ...$endTokens);
			$text .= $tmpText;

			// stop if we're not at EOL - meaning it's the end of PHPDoc
			if (!$tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_EOL, Lexer::TOKEN_CLOSE_PHPDOC)) {
				break;
			}

			if ($this->textBetweenTagsBelongsToDescription) {
				if (!$savepoint) {
					$tokens->pushSavePoint();
					$savepoint = true;
				} elseif ($tmpText !== '') {
					$tokens->dropSavePoint();
					$tokens->pushSavePoint();
				}
			}

			$tokens->pushSavePoint();
			$tokens->next();

			// if we're at EOL, check what's next
			// if next is a PHPDoc tag, EOL, or end of PHPDoc, stop
			if ($tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_TAG, Lexer::TOKEN_DOCTRINE_TAG, ...$endTokens)) {
				$tokens->rollback();
				break;
			}

			// otherwise if the next is text, continue building the description string

			$tokens->dropSavePoint();
			$text .= $tokens->getDetectedNewline() ?? "\n";
		}

		if ($savepoint) {
			$tokens->rollback();
			$text = rtrim($text, $tokens->getDetectedNewline() ?? "\n");
		}

		return new Ast\PhpDoc\PhpDocTextNode(trim($text, " \t"));
	}


	private function parseOptionalDescriptionAfterDoctrineTag(TokenIterator $tokens): string
	{
		$text = '';

		$endTokens = [Lexer::TOKEN_PHPDOC_EOL, Lexer::TOKEN_CLOSE_PHPDOC, Lexer::TOKEN_END];
		if ($this->textBetweenTagsBelongsToDescription) {
			$endTokens = [Lexer::TOKEN_CLOSE_PHPDOC, Lexer::TOKEN_END];
		}

		$savepoint = false;

		// if the next token is EOL, everything below is skipped and empty string is returned
		while ($this->textBetweenTagsBelongsToDescription || !$tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_EOL)) {
			$tmpText = $tokens->getSkippedHorizontalWhiteSpaceIfAny() . $tokens->joinUntil(Lexer::TOKEN_PHPDOC_TAG, Lexer::TOKEN_DOCTRINE_TAG, Lexer::TOKEN_PHPDOC_EOL, ...$endTokens);
			$text .= $tmpText;

			// stop if we're not at EOL - meaning it's the end of PHPDoc
			if (!$tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_EOL, Lexer::TOKEN_CLOSE_PHPDOC)) {
				if (!$tokens->isPrecededByHorizontalWhitespace()) {
					return trim($text . $this->parseText($tokens)->text, " \t");
				}
				if ($tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_TAG)) {
					$tokens->pushSavePoint();
					$child = $this->parseChild($tokens);
					if ($child instanceof Ast\PhpDoc\PhpDocTagNode) {
						if (
							$child->value instanceof Ast\PhpDoc\GenericTagValueNode
							|| $child->value instanceof Doctrine\DoctrineTagValueNode
						) {
							$tokens->rollback();
							break;
						}
						if ($child->value instanceof Ast\PhpDoc\InvalidTagValueNode) {
							$tokens->rollback();
							$tokens->pushSavePoint();
							$tokens->next();
							if ($tokens->isCurrentTokenType(Lexer::TOKEN_OPEN_PARENTHESES)) {
								$tokens->rollback();
								break;
							}
							$tokens->rollback();
							return trim($text . $this->parseText($tokens)->text, " \t");
						}
					}

					$tokens->rollback();
					return trim($text . $this->parseText($tokens)->text, " \t");
				}
				break;
			}

			if ($this->textBetweenTagsBelongsToDescription) {
				if (!$savepoint) {
					$tokens->pushSavePoint();
					$savepoint = true;
				} elseif ($tmpText !== '') {
					$tokens->dropSavePoint();
					$tokens->pushSavePoint();
				}
			}

			$tokens->pushSavePoint();
			$tokens->next();

			// if we're at EOL, check what's next
			// if next is a PHPDoc tag, EOL, or end of PHPDoc, stop
			if ($tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_TAG, Lexer::TOKEN_DOCTRINE_TAG, ...$endTokens)) {
				$tokens->rollback();
				break;
			}

			// otherwise if the next is text, continue building the description string

			$tokens->dropSavePoint();
			$text .= $tokens->getDetectedNewline() ?? "\n";
		}

		if ($savepoint) {
			$tokens->rollback();
			$text = rtrim($text, $tokens->getDetectedNewline() ?? "\n");
		}

		return trim($text, " \t");
	}


	public function parseTag(TokenIterator $tokens): Ast\PhpDoc\PhpDocTagNode
	{
		$tag = $tokens->currentTokenValue();
		$tokens->next();
		$value = $this->parseTagValue($tokens, $tag);

		return new Ast\PhpDoc\PhpDocTagNode($tag, $value);
	}


	public function parseTagValue(TokenIterator $tokens, string $tag): Ast\PhpDoc\PhpDocTagValueNode
	{
		$startLine = $tokens->currentTokenLine();
		$startIndex = $tokens->currentTokenIndex();

		try {
			$tokens->pushSavePoint();

			switch ($tag) {
				case '@param':
				case '@phpstan-param':
				case '@psalm-param':
				case '@phan-param':
					$tagValue = $this->parseParamTagValue($tokens);
					break;

				case '@param-immediately-invoked-callable':
				case '@phpstan-param-immediately-invoked-callable':
					$tagValue = $this->parseParamImmediatelyInvokedCallableTagValue($tokens);
					break;

				case '@param-later-invoked-callable':
				case '@phpstan-param-later-invoked-callable':
					$tagValue = $this->parseParamLaterInvokedCallableTagValue($tokens);
					break;

				case '@param-closure-this':
				case '@phpstan-param-closure-this':
					$tagValue = $this->parseParamClosureThisTagValue($tokens);
					break;

				case '@pure-unless-callable-is-impure':
				case '@phpstan-pure-unless-callable-is-impure':
					$tagValue = $this->parsePureUnlessCallableIsImpureTagValue($tokens);
					break;

				case '@var':
				case '@phpstan-var':
				case '@psalm-var':
				case '@phan-var':
					$tagValue = $this->parseVarTagValue($tokens);
					break;

				case '@return':
				case '@phpstan-return':
				case '@psalm-return':
				case '@phan-return':
				case '@phan-real-return':
					$tagValue = $this->parseReturnTagValue($tokens);
					break;

				case '@throws':
				case '@phpstan-throws':
					$tagValue = $this->parseThrowsTagValue($tokens);
					break;

				case '@mixin':
				case '@phan-mixin':
					$tagValue = $this->parseMixinTagValue($tokens);
					break;

				case '@psalm-require-extends':
				case '@phpstan-require-extends':
					$tagValue = $this->parseRequireExtendsTagValue($tokens);
					break;

				case '@psalm-require-implements':
				case '@phpstan-require-implements':
					$tagValue = $this->parseRequireImplementsTagValue($tokens);
					break;

				case '@deprecated':
					$tagValue = $this->parseDeprecatedTagValue($tokens);
					break;

				case '@property':
				case '@property-read':
				case '@property-write':
				case '@phpstan-property':
				case '@phpstan-property-read':
				case '@phpstan-property-write':
				case '@psalm-property':
				case '@psalm-property-read':
				case '@psalm-property-write':
				case '@phan-property':
				case '@phan-property-read':
				case '@phan-property-write':
					$tagValue = $this->parsePropertyTagValue($tokens);
					break;

				case '@method':
				case '@phpstan-method':
				case '@psalm-method':
				case '@phan-method':
					$tagValue = $this->parseMethodTagValue($tokens);
					break;

				case '@template':
				case '@phpstan-template':
				case '@psalm-template':
				case '@phan-template':
				case '@template-covariant':
				case '@phpstan-template-covariant':
				case '@psalm-template-covariant':
				case '@template-contravariant':
				case '@phpstan-template-contravariant':
				case '@psalm-template-contravariant':
					$tagValue = $this->typeParser->parseTemplateTagValue(
						$tokens,
						function ($tokens) {
							return $this->parseOptionalDescription($tokens);
						}
					);
					break;

				case '@extends':
				case '@phpstan-extends':
				case '@phan-extends':
				case '@phan-inherits':
				case '@template-extends':
					$tagValue = $this->parseExtendsTagValue('@extends', $tokens);
					break;

				case '@implements':
				case '@phpstan-implements':
				case '@template-implements':
					$tagValue = $this->parseExtendsTagValue('@implements', $tokens);
					break;

				case '@use':
				case '@phpstan-use':
				case '@template-use':
					$tagValue = $this->parseExtendsTagValue('@use', $tokens);
					break;

				case '@phpstan-type':
				case '@psalm-type':
				case '@phan-type':
					$tagValue = $this->parseTypeAliasTagValue($tokens);
					break;

				case '@phpstan-import-type':
				case '@psalm-import-type':
					$tagValue = $this->parseTypeAliasImportTagValue($tokens);
					break;

				case '@phpstan-assert':
				case '@phpstan-assert-if-true':
				case '@phpstan-assert-if-false':
				case '@psalm-assert':
				case '@psalm-assert-if-true':
				case '@psalm-assert-if-false':
				case '@phan-assert':
				case '@phan-assert-if-true':
				case '@phan-assert-if-false':
					$tagValue = $this->parseAssertTagValue($tokens);
					break;

				case '@phpstan-this-out':
				case '@phpstan-self-out':
				case '@psalm-this-out':
				case '@psalm-self-out':
					$tagValue = $this->parseSelfOutTagValue($tokens);
					break;

				case '@param-out':
				case '@phpstan-param-out':
				case '@psalm-param-out':
					$tagValue = $this->parseParamOutTagValue($tokens);
					break;

				default:
					if ($this->parseDoctrineAnnotations) {
						if ($tokens->isCurrentTokenType(Lexer::TOKEN_OPEN_PARENTHESES)) {
							$tagValue = $this->parseDoctrineTagValue($tokens, $tag);
						} else {
							$tagValue = new Ast\PhpDoc\GenericTagValueNode($this->parseOptionalDescriptionAfterDoctrineTag($tokens));
						}
						break;
					}

					$tagValue = new Ast\PhpDoc\GenericTagValueNode($this->parseOptionalDescription($tokens));

					break;
			}

			$tokens->dropSavePoint();

		} catch (ParserException $e) {
			$tokens->rollback();
			$tagValue = new Ast\PhpDoc\InvalidTagValueNode($this->parseOptionalDescription($tokens), $e);
		}

		return $this->enrichWithAttributes($tokens, $tagValue, $startLine, $startIndex);
	}


	private function parseDoctrineTagValue(TokenIterator $tokens, string $tag): Ast\PhpDoc\PhpDocTagValueNode
	{
		$startLine = $tokens->currentTokenLine();
		$startIndex = $tokens->currentTokenIndex();

		return new Doctrine\DoctrineTagValueNode(
			$this->enrichWithAttributes(
				$tokens,
				new Doctrine\DoctrineAnnotation($tag, $this->parseDoctrineArguments($tokens, false)),
				$startLine,
				$startIndex
			),
			$this->parseOptionalDescriptionAfterDoctrineTag($tokens)
		);
	}


	/**
	 * @return list<Doctrine\DoctrineArgument>
	 */
	private function parseDoctrineArguments(TokenIterator $tokens, bool $deep): array
	{
		if (!$tokens->isCurrentTokenType(Lexer::TOKEN_OPEN_PARENTHESES)) {
			return [];
		}

		if (!$deep) {
			$tokens->addEndOfLineToSkippedTokens();
		}

		$arguments = [];

		try {
			$tokens->consumeTokenType(Lexer::TOKEN_OPEN_PARENTHESES);

			do {
				if ($tokens->isCurrentTokenType(Lexer::TOKEN_CLOSE_PARENTHESES)) {
					break;
				}
				$arguments[] = $this->parseDoctrineArgument($tokens);
			} while ($tokens->tryConsumeTokenType(Lexer::TOKEN_COMMA));
		} finally {
			if (!$deep) {
				$tokens->removeEndOfLineFromSkippedTokens();
			}
		}

		$tokens->consumeTokenType(Lexer::TOKEN_CLOSE_PARENTHESES);

		return $arguments;
	}


	private function parseDoctrineArgument(TokenIterator $tokens): Doctrine\DoctrineArgument
	{
		if (!$tokens->isCurrentTokenType(Lexer::TOKEN_IDENTIFIER)) {
			$startLine = $tokens->currentTokenLine();
			$startIndex = $tokens->currentTokenIndex();

			return $this->enrichWithAttributes(
				$tokens,
				new Doctrine\DoctrineArgument(null, $this->parseDoctrineArgumentValue($tokens)),
				$startLine,
				$startIndex
			);
		}

		$startLine = $tokens->currentTokenLine();
		$startIndex = $tokens->currentTokenIndex();

		try {
			$tokens->pushSavePoint();
			$currentValue = $tokens->currentTokenValue();
			$tokens->consumeTokenType(Lexer::TOKEN_IDENTIFIER);

			$key = $this->enrichWithAttributes(
				$tokens,
				new IdentifierTypeNode($currentValue),
				$startLine,
				$startIndex
			);
			$tokens->consumeTokenType(Lexer::TOKEN_EQUAL);

			$value = $this->parseDoctrineArgumentValue($tokens);

			$tokens->dropSavePoint();

			return $this->enrichWithAttributes(
				$tokens,
				new Doctrine\DoctrineArgument($key, $value),
				$startLine,
				$startIndex
			);
		} catch (ParserException $e) {
			$tokens->rollback();

			return $this->enrichWithAttributes(
				$tokens,
				new Doctrine\DoctrineArgument(null, $this->parseDoctrineArgumentValue($tokens)),
				$startLine,
				$startIndex
			);
		}
	}


	/**
	 * @return DoctrineValueType
	 */
	private function parseDoctrineArgumentValue(TokenIterator $tokens)
	{
		$startLine = $tokens->currentTokenLine();
		$startIndex = $tokens->currentTokenIndex();

		if ($tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_TAG, Lexer::TOKEN_DOCTRINE_TAG)) {
			$name = $tokens->currentTokenValue();
			$tokens->next();

			return $this->enrichWithAttributes(
				$tokens,
				new Doctrine\DoctrineAnnotation($name, $this->parseDoctrineArguments($tokens, true)),
				$startLine,
				$startIndex
			);
		}

		if ($tokens->tryConsumeTokenType(Lexer::TOKEN_OPEN_CURLY_BRACKET)) {
			$items = [];
			do {
				if ($tokens->isCurrentTokenType(Lexer::TOKEN_CLOSE_CURLY_BRACKET)) {
					break;
				}
				$items[] = $this->parseDoctrineArrayItem($tokens);
			} while ($tokens->tryConsumeTokenType(Lexer::TOKEN_COMMA));

			$tokens->consumeTokenType(Lexer::TOKEN_CLOSE_CURLY_BRACKET);

			return $this->enrichWithAttributes(
				$tokens,
				new Doctrine\DoctrineArray($items),
				$startLine,
				$startIndex
			);
		}

		$currentTokenValue = $tokens->currentTokenValue();
		$tokens->pushSavePoint(); // because of ConstFetchNode
		if ($tokens->tryConsumeTokenType(Lexer::TOKEN_IDENTIFIER)) {
			$identifier = $this->enrichWithAttributes(
				$tokens,
				new Ast\Type\IdentifierTypeNode($currentTokenValue),
				$startLine,
				$startIndex
			);
			if (!$tokens->isCurrentTokenType(Lexer::TOKEN_DOUBLE_COLON)) {
				$tokens->dropSavePoint();
				return $identifier;
			}

			$tokens->rollback(); // because of ConstFetchNode
		} else {
			$tokens->dropSavePoint(); // because of ConstFetchNode
		}

		$currentTokenValue = $tokens->currentTokenValue();
		$currentTokenType = $tokens->currentTokenType();
		$currentTokenOffset = $tokens->currentTokenOffset();
		$currentTokenLine = $tokens->currentTokenLine();

		try {
			$constExpr = $this->doctrineConstantExprParser->parse($tokens, true);
			if ($constExpr instanceof Ast\ConstExpr\ConstExprArrayNode) {
				throw new ParserException(
					$currentTokenValue,
					$currentTokenType,
					$currentTokenOffset,
					Lexer::TOKEN_IDENTIFIER,
					null,
					$currentTokenLine
				);
			}

			return $constExpr;
		} catch (LogicException $e) {
			throw new ParserException(
				$currentTokenValue,
				$currentTokenType,
				$currentTokenOffset,
				Lexer::TOKEN_IDENTIFIER,
				null,
				$currentTokenLine
			);
		}
	}


	private function parseDoctrineArrayItem(TokenIterator $tokens): Doctrine\DoctrineArrayItem
	{
		$startLine = $tokens->currentTokenLine();
		$startIndex = $tokens->currentTokenIndex();

		try {
			$tokens->pushSavePoint();

			$key = $this->parseDoctrineArrayKey($tokens);
			if (!$tokens->tryConsumeTokenType(Lexer::TOKEN_EQUAL)) {
				if (!$tokens->tryConsumeTokenType(Lexer::TOKEN_COLON)) {
					$tokens->consumeTokenType(Lexer::TOKEN_EQUAL); // will throw exception
				}
			}

			$value = $this->parseDoctrineArgumentValue($tokens);

			$tokens->dropSavePoint();

			return $this->enrichWithAttributes(
				$tokens,
				new Doctrine\DoctrineArrayItem($key, $value),
				$startLine,
				$startIndex
			);
		} catch (ParserException $e) {
			$tokens->rollback();

			return $this->enrichWithAttributes(
				$tokens,
				new Doctrine\DoctrineArrayItem(null, $this->parseDoctrineArgumentValue($tokens)),
				$startLine,
				$startIndex
			);
		}
	}


	/**
	 * @return ConstExprIntegerNode|ConstExprStringNode|IdentifierTypeNode|ConstFetchNode
	 */
	private function parseDoctrineArrayKey(TokenIterator $tokens)
	{
		$startLine = $tokens->currentTokenLine();
		$startIndex = $tokens->currentTokenIndex();

		if ($tokens->isCurrentTokenType(Lexer::TOKEN_INTEGER)) {
			$key = new Ast\ConstExpr\ConstExprIntegerNode(str_replace('_', '', $tokens->currentTokenValue()));
			$tokens->next();

		} elseif ($tokens->isCurrentTokenType(Lexer::TOKEN_DOCTRINE_ANNOTATION_STRING)) {
			$key = new Ast\ConstExpr\DoctrineConstExprStringNode(Ast\ConstExpr\DoctrineConstExprStringNode::unescape($tokens->currentTokenValue()));

			$tokens->next();

		} elseif ($tokens->isCurrentTokenType(Lexer::TOKEN_DOUBLE_QUOTED_STRING)) {
			$value = $tokens->currentTokenValue();
			$tokens->next();
			$key = $this->doctrineConstantExprParser->parseDoctrineString($value, $tokens);

		} else {
			$currentTokenValue = $tokens->currentTokenValue();
			$tokens->pushSavePoint(); // because of ConstFetchNode
			if (!$tokens->tryConsumeTokenType(Lexer::TOKEN_IDENTIFIER)) {
				$tokens->dropSavePoint();
				throw new ParserException(
					$tokens->currentTokenValue(),
					$tokens->currentTokenType(),
					$tokens->currentTokenOffset(),
					Lexer::TOKEN_IDENTIFIER,
					null,
					$tokens->currentTokenLine()
				);
			}

			if (!$tokens->isCurrentTokenType(Lexer::TOKEN_DOUBLE_COLON)) {
				$tokens->dropSavePoint();

				return $this->enrichWithAttributes(
					$tokens,
					new IdentifierTypeNode($currentTokenValue),
					$startLine,
					$startIndex
				);
			}

			$tokens->rollback();
			$constExpr = $this->doctrineConstantExprParser->parse($tokens, true);
			if (!$constExpr instanceof Ast\ConstExpr\ConstFetchNode) {
				throw new ParserException(
					$tokens->currentTokenValue(),
					$tokens->currentTokenType(),
					$tokens->currentTokenOffset(),
					Lexer::TOKEN_IDENTIFIER,
					null,
					$tokens->currentTokenLine()
				);
			}

			return $constExpr;
		}

		return $this->enrichWithAttributes($tokens, $key, $startLine, $startIndex);
	}


	/**
	 * @return Ast\PhpDoc\ParamTagValueNode|Ast\PhpDoc\TypelessParamTagValueNode
	 */
	private function parseParamTagValue(TokenIterator $tokens): Ast\PhpDoc\PhpDocTagValueNode
	{
		if (
			$tokens->isCurrentTokenType(Lexer::TOKEN_REFERENCE, Lexer::TOKEN_VARIADIC, Lexer::TOKEN_VARIABLE)
		) {
			$type = null;
		} else {
			$type = $this->typeParser->parse($tokens);
		}

		$isReference = $tokens->tryConsumeTokenType(Lexer::TOKEN_REFERENCE);
		$isVariadic = $tokens->tryConsumeTokenType(Lexer::TOKEN_VARIADIC);
		$parameterName = $this->parseRequiredVariableName($tokens);
		$description = $this->parseOptionalDescription($tokens);

		if ($type !== null) {
			return new Ast\PhpDoc\ParamTagValueNode($type, $isVariadic, $parameterName, $description, $isReference);
		}

		return new Ast\PhpDoc\TypelessParamTagValueNode($isVariadic, $parameterName, $description, $isReference);
	}


	private function parseParamImmediatelyInvokedCallableTagValue(TokenIterator $tokens): Ast\PhpDoc\ParamImmediatelyInvokedCallableTagValueNode
	{
		$parameterName = $this->parseRequiredVariableName($tokens);
		$description = $this->parseOptionalDescription($tokens);

		return new Ast\PhpDoc\ParamImmediatelyInvokedCallableTagValueNode($parameterName, $description);
	}


	private function parseParamLaterInvokedCallableTagValue(TokenIterator $tokens): Ast\PhpDoc\ParamLaterInvokedCallableTagValueNode
	{
		$parameterName = $this->parseRequiredVariableName($tokens);
		$description = $this->parseOptionalDescription($tokens);

		return new Ast\PhpDoc\ParamLaterInvokedCallableTagValueNode($parameterName, $description);
	}


	private function parseParamClosureThisTagValue(TokenIterator $tokens): Ast\PhpDoc\ParamClosureThisTagValueNode
	{
		$type = $this->typeParser->parse($tokens);
		$parameterName = $this->parseRequiredVariableName($tokens);
		$description = $this->parseOptionalDescription($tokens);

		return new Ast\PhpDoc\ParamClosureThisTagValueNode($type, $parameterName, $description);
	}

	private function parsePureUnlessCallableIsImpureTagValue(TokenIterator $tokens): Ast\PhpDoc\PureUnlessCallableIsImpureTagValueNode
	{
		$parameterName = $this->parseRequiredVariableName($tokens);
		$description = $this->parseOptionalDescription($tokens);

		return new Ast\PhpDoc\PureUnlessCallableIsImpureTagValueNode($parameterName, $description);
	}

	private function parseVarTagValue(TokenIterator $tokens): Ast\PhpDoc\VarTagValueNode
	{
		$type = $this->typeParser->parse($tokens);
		$variableName = $this->parseOptionalVariableName($tokens);
		$description = $this->parseOptionalDescription($tokens, $variableName === '');
		return new Ast\PhpDoc\VarTagValueNode($type, $variableName, $description);
	}


	private function parseReturnTagValue(TokenIterator $tokens): Ast\PhpDoc\ReturnTagValueNode
	{
		$type = $this->typeParser->parse($tokens);
		$description = $this->parseOptionalDescription($tokens, true);
		return new Ast\PhpDoc\ReturnTagValueNode($type, $description);
	}


	private function parseThrowsTagValue(TokenIterator $tokens): Ast\PhpDoc\ThrowsTagValueNode
	{
		$type = $this->typeParser->parse($tokens);
		$description = $this->parseOptionalDescription($tokens, true);
		return new Ast\PhpDoc\ThrowsTagValueNode($type, $description);
	}

	private function parseMixinTagValue(TokenIterator $tokens): Ast\PhpDoc\MixinTagValueNode
	{
		$type = $this->typeParser->parse($tokens);
		$description = $this->parseOptionalDescription($tokens, true);
		return new Ast\PhpDoc\MixinTagValueNode($type, $description);
	}

	private function parseRequireExtendsTagValue(TokenIterator $tokens): Ast\PhpDoc\RequireExtendsTagValueNode
	{
		$type = $this->typeParser->parse($tokens);
		$description = $this->parseOptionalDescription($tokens, true);
		return new Ast\PhpDoc\RequireExtendsTagValueNode($type, $description);
	}

	private function parseRequireImplementsTagValue(TokenIterator $tokens): Ast\PhpDoc\RequireImplementsTagValueNode
	{
		$type = $this->typeParser->parse($tokens);
		$description = $this->parseOptionalDescription($tokens, true);
		return new Ast\PhpDoc\RequireImplementsTagValueNode($type, $description);
	}

	private function parseDeprecatedTagValue(TokenIterator $tokens): Ast\PhpDoc\DeprecatedTagValueNode
	{
		$description = $this->parseOptionalDescription($tokens);
		return new Ast\PhpDoc\DeprecatedTagValueNode($description);
	}


	private function parsePropertyTagValue(TokenIterator $tokens): Ast\PhpDoc\PropertyTagValueNode
	{
		$type = $this->typeParser->parse($tokens);
		$parameterName = $this->parseRequiredVariableName($tokens);
		$description = $this->parseOptionalDescription($tokens);
		return new Ast\PhpDoc\PropertyTagValueNode($type, $parameterName, $description);
	}


	private function parseMethodTagValue(TokenIterator $tokens): Ast\PhpDoc\MethodTagValueNode
	{
		$staticKeywordOrReturnTypeOrMethodName = $this->typeParser->parse($tokens);

		if ($staticKeywordOrReturnTypeOrMethodName instanceof Ast\Type\IdentifierTypeNode && $staticKeywordOrReturnTypeOrMethodName->name === 'static') {
			$isStatic = true;
			$returnTypeOrMethodName = $this->typeParser->parse($tokens);

		} else {
			$isStatic = false;
			$returnTypeOrMethodName = $staticKeywordOrReturnTypeOrMethodName;
		}

		if ($tokens->isCurrentTokenType(Lexer::TOKEN_IDENTIFIER)) {
			$returnType = $returnTypeOrMethodName;
			$methodName = $tokens->currentTokenValue();
			$tokens->next();

		} elseif ($returnTypeOrMethodName instanceof Ast\Type\IdentifierTypeNode) {
			$returnType = $isStatic ? $staticKeywordOrReturnTypeOrMethodName : null;
			$methodName = $returnTypeOrMethodName->name;
			$isStatic = false;

		} else {
			$tokens->consumeTokenType(Lexer::TOKEN_IDENTIFIER); // will throw exception
			exit;
		}

		$templateTypes = [];

		if ($tokens->tryConsumeTokenType(Lexer::TOKEN_OPEN_ANGLE_BRACKET)) {
			do {
				$startLine = $tokens->currentTokenLine();
				$startIndex = $tokens->currentTokenIndex();
				$templateTypes[] = $this->enrichWithAttributes(
					$tokens,
					$this->typeParser->parseTemplateTagValue($tokens),
					$startLine,
					$startIndex
				);
			} while ($tokens->tryConsumeTokenType(Lexer::TOKEN_COMMA));
			$tokens->consumeTokenType(Lexer::TOKEN_CLOSE_ANGLE_BRACKET);
		}

		$parameters = [];
		$tokens->consumeTokenType(Lexer::TOKEN_OPEN_PARENTHESES);
		if (!$tokens->isCurrentTokenType(Lexer::TOKEN_CLOSE_PARENTHESES)) {
			$parameters[] = $this->parseMethodTagValueParameter($tokens);
			while ($tokens->tryConsumeTokenType(Lexer::TOKEN_COMMA)) {
				$parameters[] = $this->parseMethodTagValueParameter($tokens);
			}
		}
		$tokens->consumeTokenType(Lexer::TOKEN_CLOSE_PARENTHESES);

		$description = $this->parseOptionalDescription($tokens);
		return new Ast\PhpDoc\MethodTagValueNode($isStatic, $returnType, $methodName, $parameters, $description, $templateTypes);
	}

	private function parseMethodTagValueParameter(TokenIterator $tokens): Ast\PhpDoc\MethodTagValueParameterNode
	{
		$startLine = $tokens->currentTokenLine();
		$startIndex = $tokens->currentTokenIndex();

		switch ($tokens->currentTokenType()) {
			case Lexer::TOKEN_IDENTIFIER:
			case Lexer::TOKEN_OPEN_PARENTHESES:
			case Lexer::TOKEN_NULLABLE:
				$parameterType = $this->typeParser->parse($tokens);
				break;

			default:
				$parameterType = null;
		}

		$isReference = $tokens->tryConsumeTokenType(Lexer::TOKEN_REFERENCE);
		$isVariadic = $tokens->tryConsumeTokenType(Lexer::TOKEN_VARIADIC);

		$parameterName = $tokens->currentTokenValue();
		$tokens->consumeTokenType(Lexer::TOKEN_VARIABLE);

		if ($tokens->tryConsumeTokenType(Lexer::TOKEN_EQUAL)) {
			$defaultValue = $this->constantExprParser->parse($tokens);

		} else {
			$defaultValue = null;
		}

		return $this->enrichWithAttributes(
			$tokens,
			new Ast\PhpDoc\MethodTagValueParameterNode($parameterType, $isReference, $isVariadic, $parameterName, $defaultValue),
			$startLine,
			$startIndex
		);
	}

	private function parseExtendsTagValue(string $tagName, TokenIterator $tokens): Ast\PhpDoc\PhpDocTagValueNode
	{
		$startLine = $tokens->currentTokenLine();
		$startIndex = $tokens->currentTokenIndex();
		$baseType = new IdentifierTypeNode($tokens->currentTokenValue());
		$tokens->consumeTokenType(Lexer::TOKEN_IDENTIFIER);

		$type = $this->typeParser->parseGeneric(
			$tokens,
			$this->typeParser->enrichWithAttributes($tokens, $baseType, $startLine, $startIndex)
		);

		$description = $this->parseOptionalDescription($tokens);

		switch ($tagName) {
			case '@extends':
				return new Ast\PhpDoc\ExtendsTagValueNode($type, $description);
			case '@implements':
				return new Ast\PhpDoc\ImplementsTagValueNode($type, $description);
			case '@use':
				return new Ast\PhpDoc\UsesTagValueNode($type, $description);
		}

		throw new ShouldNotHappenException();
	}

	private function parseTypeAliasTagValue(TokenIterator $tokens): Ast\PhpDoc\TypeAliasTagValueNode
	{
		$alias = $tokens->currentTokenValue();
		$tokens->consumeTokenType(Lexer::TOKEN_IDENTIFIER);

		// support phan-type/psalm-type syntax
		$tokens->tryConsumeTokenType(Lexer::TOKEN_EQUAL);

		if ($this->preserveTypeAliasesWithInvalidTypes) {
			$startLine = $tokens->currentTokenLine();
			$startIndex = $tokens->currentTokenIndex();
			try {
				$type = $this->typeParser->parse($tokens);
				if (!$tokens->isCurrentTokenType(Lexer::TOKEN_CLOSE_PHPDOC)) {
					if (!$tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_EOL)) {
						throw new ParserException(
							$tokens->currentTokenValue(),
							$tokens->currentTokenType(),
							$tokens->currentTokenOffset(),
							Lexer::TOKEN_PHPDOC_EOL,
							null,
							$tokens->currentTokenLine()
						);
					}
				}

				return new Ast\PhpDoc\TypeAliasTagValueNode($alias, $type);
			} catch (ParserException $e) {
				$this->parseOptionalDescription($tokens);
				return new Ast\PhpDoc\TypeAliasTagValueNode(
					$alias,
					$this->enrichWithAttributes($tokens, new Ast\Type\InvalidTypeNode($e), $startLine, $startIndex)
				);
			}
		}

		$type = $this->typeParser->parse($tokens);

		return new Ast\PhpDoc\TypeAliasTagValueNode($alias, $type);
	}

	private function parseTypeAliasImportTagValue(TokenIterator $tokens): Ast\PhpDoc\TypeAliasImportTagValueNode
	{
		$importedAlias = $tokens->currentTokenValue();
		$tokens->consumeTokenType(Lexer::TOKEN_IDENTIFIER);

		$tokens->consumeTokenValue(Lexer::TOKEN_IDENTIFIER, 'from');

		$identifierStartLine = $tokens->currentTokenLine();
		$identifierStartIndex = $tokens->currentTokenIndex();
		$importedFrom = $tokens->currentTokenValue();
		$tokens->consumeTokenType(Lexer::TOKEN_IDENTIFIER);
		$importedFromType = $this->enrichWithAttributes(
			$tokens,
			new IdentifierTypeNode($importedFrom),
			$identifierStartLine,
			$identifierStartIndex
		);

		$importedAs = null;
		if ($tokens->tryConsumeTokenValue('as')) {
			$importedAs = $tokens->currentTokenValue();
			$tokens->consumeTokenType(Lexer::TOKEN_IDENTIFIER);
		}

		return new Ast\PhpDoc\TypeAliasImportTagValueNode($importedAlias, $importedFromType, $importedAs);
	}

	/**
	 * @return Ast\PhpDoc\AssertTagValueNode|Ast\PhpDoc\AssertTagPropertyValueNode|Ast\PhpDoc\AssertTagMethodValueNode
	 */
	private function parseAssertTagValue(TokenIterator $tokens): Ast\PhpDoc\PhpDocTagValueNode
	{
		$isNegated = $tokens->tryConsumeTokenType(Lexer::TOKEN_NEGATED);
		$isEquality = $tokens->tryConsumeTokenType(Lexer::TOKEN_EQUAL);
		$type = $this->typeParser->parse($tokens);
		$parameter = $this->parseAssertParameter($tokens);
		$description = $this->parseOptionalDescription($tokens);

		if (array_key_exists('method', $parameter)) {
			return new Ast\PhpDoc\AssertTagMethodValueNode($type, $parameter['parameter'], $parameter['method'], $isNegated, $description, $isEquality);
		} elseif (array_key_exists('property', $parameter)) {
			return new Ast\PhpDoc\AssertTagPropertyValueNode($type, $parameter['parameter'], $parameter['property'], $isNegated, $description, $isEquality);
		}

		return new Ast\PhpDoc\AssertTagValueNode($type, $parameter['parameter'], $isNegated, $description, $isEquality);
	}

	/**
	 * @return array{parameter: string}|array{parameter: string, property: string}|array{parameter: string, method: string}
	 */
	private function parseAssertParameter(TokenIterator $tokens): array
	{
		if ($tokens->isCurrentTokenType(Lexer::TOKEN_THIS_VARIABLE)) {
			$parameter = '$this';
			$tokens->next();
		} else {
			$parameter = $tokens->currentTokenValue();
			$tokens->consumeTokenType(Lexer::TOKEN_VARIABLE);
		}

		if ($tokens->isCurrentTokenType(Lexer::TOKEN_ARROW)) {
			$tokens->consumeTokenType(Lexer::TOKEN_ARROW);

			$propertyOrMethod = $tokens->currentTokenValue();
			$tokens->consumeTokenType(Lexer::TOKEN_IDENTIFIER);

			if ($tokens->tryConsumeTokenType(Lexer::TOKEN_OPEN_PARENTHESES)) {
				$tokens->consumeTokenType(Lexer::TOKEN_CLOSE_PARENTHESES);

				return ['parameter' => $parameter, 'method' => $propertyOrMethod];
			}

			return ['parameter' => $parameter, 'property' => $propertyOrMethod];
		}

		return ['parameter' => $parameter];
	}

	private function parseSelfOutTagValue(TokenIterator $tokens): Ast\PhpDoc\SelfOutTagValueNode
	{
		$type = $this->typeParser->parse($tokens);
		$description = $this->parseOptionalDescription($tokens);

		return new Ast\PhpDoc\SelfOutTagValueNode($type, $description);
	}

	private function parseParamOutTagValue(TokenIterator $tokens): Ast\PhpDoc\ParamOutTagValueNode
	{
		$type = $this->typeParser->parse($tokens);
		$parameterName = $this->parseRequiredVariableName($tokens);
		$description = $this->parseOptionalDescription($tokens);

		return new Ast\PhpDoc\ParamOutTagValueNode($type, $parameterName, $description);
	}

	private function parseOptionalVariableName(TokenIterator $tokens): string
	{
		if ($tokens->isCurrentTokenType(Lexer::TOKEN_VARIABLE)) {
			$parameterName = $tokens->currentTokenValue();
			$tokens->next();
		} elseif ($tokens->isCurrentTokenType(Lexer::TOKEN_THIS_VARIABLE)) {
			$parameterName = '$this';
			$tokens->next();

		} else {
			$parameterName = '';
		}

		return $parameterName;
	}


	private function parseRequiredVariableName(TokenIterator $tokens): string
	{
		$parameterName = $tokens->currentTokenValue();
		$tokens->consumeTokenType(Lexer::TOKEN_VARIABLE);

		return $parameterName;
	}

	private function parseOptionalDescription(TokenIterator $tokens, bool $limitStartToken = false): string
	{
		if ($limitStartToken) {
			foreach (self::DISALLOWED_DESCRIPTION_START_TOKENS as $disallowedStartToken) {
				if (!$tokens->isCurrentTokenType($disallowedStartToken)) {
					continue;
				}

				$tokens->consumeTokenType(Lexer::TOKEN_OTHER); // will throw exception
			}

			if (
				$this->requireWhitespaceBeforeDescription
				&& !$tokens->isCurrentTokenType(Lexer::TOKEN_PHPDOC_EOL, Lexer::TOKEN_CLOSE_PHPDOC, Lexer::TOKEN_END)
				&& !$tokens->isPrecededByHorizontalWhitespace()
			) {
				$tokens->consumeTokenType(Lexer::TOKEN_HORIZONTAL_WS); // will throw exception
			}
		}

		return $this->parseText($tokens)->text;
	}

}
