#!/usr/bin/env php
<?php

declare(strict_types=1);

namespace JetBrains\PHPStormStub;

use DirectoryIterator;
use Exception;
use PhpParser\Node;
use PhpParser\NodeTraverser;
use PhpParser\NodeVisitor\NameResolver;
use PhpParser\NodeVisitorAbstract;
use PhpParser\ParserFactory;
use PhpParser\PrettyPrinter\Standard;
use RecursiveDirectoryIterator;
use RecursiveIteratorIterator;
use RuntimeException;
use SplFileInfo;
use function array_map;
use function count;
use function file_get_contents;
use function file_put_contents;
use function in_array;
use function ksort;
use function preg_match;
use function sprintf;
use function str_replace;
use function strlen;
use function strpos;
use function strtolower;
use function substr;
use function var_export;
use const PHP_EOL;

(function (): void {
    require __DIR__ . '/../../vendor/autoload.php';

    $mapFile = $GLOBALS['argv'][1] ?? __DIR__ . '/../../PhpStormStubsMap.php';

    class InvalidConstantNode extends RuntimeException
    {
        public static function create(Node $node): self
        {
            return new self(sprintf(
                'Invalid constant node (first 50 characters: %s)',
                substr((new Standard())->prettyPrint([$node]), 0, 50)
            ));
        }
    }

    class InvalidFileLocation extends RuntimeException
    {
    }

    /**
     * @throws InvalidFileLocation
     */
    function assertReadableFile(string $filename): void
    {
        if (empty($filename)) {
            throw new InvalidFileLocation('Filename was empty');
        }
        if (!file_exists($filename)) {
            throw new InvalidFileLocation(sprintf('File "%s" does not exist', $filename));
        }
        if (!is_readable($filename)) {
            throw new InvalidFileLocation(sprintf('File "%s" is not readable', $filename));
        }
        if (!is_file($filename)) {
            throw new InvalidFileLocation(sprintf('"%s" is not a file', $filename));
        }
    }

    /**
     * @throws InvalidConstantNode
     */
    function assertValidDefineFunctionCall(Node\Expr\FuncCall $node): void
    {
        if (!($node->name instanceof Node\Name)) {
            throw InvalidConstantNode::create($node);
        }
        if ($node->name->toLowerString() !== 'define') {
            throw InvalidConstantNode::create($node);
        }
        if (!in_array(count($node->args), [2, 3], true)) {
            throw InvalidConstantNode::create($node);
        }
        if (!($node->args[0]->value instanceof Node\Scalar\String_)) {
            throw InvalidConstantNode::create($node);
        }
        $valueNode = $node->args[1]->value;
        if ($valueNode instanceof Node\Expr\Variable) {
            throw InvalidConstantNode::create($node);
        }
    }

    $phpStormStubsDirectory = __DIR__ . '/../../';

    $fileVisitor = new class() extends NodeVisitorAbstract {
        /** @var string[] */
        private $classNames = [];

        /** @var string[] */
        private $functionNames = [];

        /** @var string[] */
        private $constantNames = [];

        /**
         * {@inheritdoc}
         */
        public function enterNode(Node $node): ?int
        {
            if ($node instanceof Node\Stmt\ClassLike) {
                if ($node->getDocComment() !== null && strpos($node->getDocComment()->getText(), '@internal') !== false) {
                    return NodeTraverser::DONT_TRAVERSE_CHILDREN;
                }

                $this->classNames[] = $node->namespacedName->toString();

                return NodeTraverser::DONT_TRAVERSE_CHILDREN;
            }

            if ($node instanceof Node\Stmt\Function_) {
                $this->functionNames[] = $node->namespacedName->toString();

                return NodeTraverser::DONT_TRAVERSE_CHILDREN;
            }

            if ($node instanceof Node\Const_) {
                $this->constantNames[] = $node->namespacedName->toString();

                return NodeTraverser::DONT_TRAVERSE_CHILDREN;
            }

            if ($node instanceof Node\Expr\FuncCall) {
                try {
                    assertValidDefineFunctionCall($node);
                } catch (InvalidConstantNode $e) {
                    return null;
                }

                /** @var Node\Scalar\String_ $nameNode */
                $nameNode = $node->args[0]->value;

                if (count($node->args) === 3
                    && $node->args[2]->value instanceof Node\Expr\ConstFetch
                    && $node->args[2]->value->name->toLowerString() === 'true'
                ) {
                    $this->constantNames[] = strtolower($nameNode->value);
                }

                $this->constantNames[] = $nameNode->value;

                return NodeTraverser::DONT_TRAVERSE_CHILDREN;
            }

            return null;
        }

        /**
         * @return string[]
         */
        public function getClassNames(): array
        {
            return $this->classNames;
        }

        /**
         * @return string[]
         */
        public function getFunctionNames(): array
        {
            return $this->functionNames;
        }

        /**
         * @return string[]
         */
        public function getConstantNames(): array
        {
            return $this->constantNames;
        }

        public function clear(): void
        {
            $this->classNames = [];
            $this->functionNames = [];
            $this->constantNames = [];
        }
    };

    $phpParser = (new ParserFactory())->create(ParserFactory::PREFER_PHP7);

    $nodeTraverser = new NodeTraverser();
    $nodeTraverser->addVisitor(new NameResolver());
    $nodeTraverser->addVisitor($fileVisitor);

    $map = ['classes' => [], 'functions' => [], 'constants' => []];

    foreach (new DirectoryIterator($phpStormStubsDirectory) as $directoryInfo) {
        /** @var DirectoryIterator $directoryInfo */
        if ($directoryInfo->isDot()) {
            continue;
        }

        if (!$directoryInfo->isDir()) {
            continue;
        }

        if (in_array($directoryInfo->getBasename(), ['tests', 'meta', 'vendor', 'couchbase_v2'], true)) {
            continue;
        }

        $iterator = new RecursiveIteratorIterator(
            new RecursiveDirectoryIterator($directoryInfo->getPathName(), RecursiveDirectoryIterator::SKIP_DOTS)
        );

        /** @var SplFileInfo $fileInfo */
        foreach ($iterator as $fileInfo) {
            if (!preg_match('/\.php$/', $fileInfo->getBasename())) {
                continue;
            }

            assertReadableFile($fileInfo->getPathname());

            echo sprintf('Parsing "%s"', $fileInfo->getPathname()) . PHP_EOL;

            $ast = $phpParser->parse(file_get_contents($fileInfo->getPathname()));

            $nodeTraverser->traverse($ast);

            foreach ($fileVisitor->getClassNames() as $className) {
                $map['classes'][$className] = $fileInfo->getPathname();
            }

            foreach ($fileVisitor->getFunctionNames() as $functionName) {
                $map['functions'][$functionName] = $fileInfo->getPathname();
            }

            foreach ($fileVisitor->getConstantNames() as $constantName) {
                $map['constants'][$constantName] = $fileInfo->getPathname();
            }

            $fileVisitor->clear();
        }
    }

    $mapWithRelativeFilePaths = array_map(static function (array $files) use ($phpStormStubsDirectory): array {
        ksort($files);

        return array_map(static function (string $filePath) use ($phpStormStubsDirectory): string {
            return str_replace('\\', '/', substr($filePath, strlen($phpStormStubsDirectory)));
        }, $files);
    }, $map);

    $exportedClasses = var_export($mapWithRelativeFilePaths['classes'], true);
    $exportedFunctions = var_export($mapWithRelativeFilePaths['functions'], true);
    $exportedConstants = var_export($mapWithRelativeFilePaths['constants'], true);

    $output = <<<"PHP"
<?php

declare(strict_types=1);

namespace JetBrains\PHPStormStub;

/**
 * This is a generated file, do not modify it directly!
 */
final class PhpStormStubsMap
{
const CLASSES = {$exportedClasses};

const FUNCTIONS = {$exportedFunctions};

const CONSTANTS = {$exportedConstants};
}
PHP;

    $bytesWritten = @file_put_contents($mapFile, $output, LOCK_EX);

    if ($bytesWritten === false) {
        throw new Exception(sprintf('File "%s" is not writeable.', $mapFile));
    }

    exit('Done' . PHP_EOL);
})();