<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\DependencyInjection;

use Symfony\Component\DependencyInjection\Exception\EnvNotFoundException;
use Symfony\Component\DependencyInjection\Exception\ParameterCircularReferenceException;
use Symfony\Component\DependencyInjection\Exception\RuntimeException;
use Symfony\Contracts\Service\ResetInterface;

/**
 * @author Nicolas Grekas <p@tchwork.com>
 */
class EnvVarProcessor implements EnvVarProcessorInterface, ResetInterface
{
    private ContainerInterface $container;
    /** @var \Traversable<EnvVarLoaderInterface> */
    private \Traversable $loaders;
    /** @var \Traversable<EnvVarLoaderInterface> */
    private \Traversable $originalLoaders;
    private array $loadedVars = [];

    /**
     * @param \Traversable<EnvVarLoaderInterface>|null $loaders
     */
    public function __construct(ContainerInterface $container, ?\Traversable $loaders = null)
    {
        $this->container = $container;
        $this->originalLoaders = $this->loaders = $loaders ?? new \ArrayIterator();
    }

    public static function getProvidedTypes(): array
    {
        return [
            'base64' => 'string',
            'bool' => 'bool',
            'not' => 'bool',
            'const' => 'bool|int|float|string|array',
            'csv' => 'array',
            'file' => 'string',
            'float' => 'float',
            'int' => 'int',
            'json' => 'array',
            'key' => 'bool|int|float|string|array',
            'url' => 'array',
            'query_string' => 'array',
            'resolve' => 'string',
            'default' => 'bool|int|float|string|array',
            'string' => 'string',
            'trim' => 'string',
            'require' => 'bool|int|float|string|array',
            'enum' => \BackedEnum::class,
            'shuffle' => 'array',
            'defined' => 'bool',
            'urlencode' => 'string',
        ];
    }

    public function getEnv(string $prefix, string $name, \Closure $getEnv): mixed
    {
        $i = strpos($name, ':');

        if ('key' === $prefix) {
            if (false === $i) {
                throw new RuntimeException(sprintf('Invalid env "key:%s": a key specifier should be provided.', $name));
            }

            $next = substr($name, $i + 1);
            $key = substr($name, 0, $i);
            $array = $getEnv($next);

            if (!\is_array($array)) {
                throw new RuntimeException(sprintf('Resolved value of "%s" did not result in an array value.', $next));
            }

            if (!isset($array[$key]) && !\array_key_exists($key, $array)) {
                throw new EnvNotFoundException(sprintf('Key "%s" not found in %s (resolved from "%s").', $key, json_encode($array), $next));
            }

            return $array[$key];
        }

        if ('enum' === $prefix) {
            if (false === $i) {
                throw new RuntimeException(sprintf('Invalid env "enum:%s": a "%s" class-string should be provided.', $name, \BackedEnum::class));
            }

            $next = substr($name, $i + 1);
            $backedEnumClassName = substr($name, 0, $i);
            $backedEnumValue = $getEnv($next);

            if (!\is_string($backedEnumValue) && !\is_int($backedEnumValue)) {
                throw new RuntimeException(sprintf('Resolved value of "%s" did not result in a string or int value.', $next));
            }

            if (!is_subclass_of($backedEnumClassName, \BackedEnum::class)) {
                throw new RuntimeException(sprintf('"%s" is not a "%s".', $backedEnumClassName, \BackedEnum::class));
            }

            return $backedEnumClassName::tryFrom($backedEnumValue) ?? throw new RuntimeException(sprintf('Enum value "%s" is not backed by "%s".', $backedEnumValue, $backedEnumClassName));
        }

        if ('defined' === $prefix) {
            try {
                return '' !== ($getEnv($name) ?? '');
            } catch (EnvNotFoundException) {
                return false;
            }
        }

        if ('default' === $prefix) {
            if (false === $i) {
                throw new RuntimeException(sprintf('Invalid env "default:%s": a fallback parameter should be provided.', $name));
            }

            $next = substr($name, $i + 1);
            $default = substr($name, 0, $i);

            if ('' !== $default && !$this->container->hasParameter($default)) {
                throw new RuntimeException(sprintf('Invalid env fallback in "default:%s": parameter "%s" not found.', $name, $default));
            }

            try {
                $env = $getEnv($next);

                if ('' !== $env && null !== $env) {
                    return $env;
                }
            } catch (EnvNotFoundException) {
                // no-op
            }

            return '' === $default ? null : $this->container->getParameter($default);
        }

        if ('file' === $prefix || 'require' === $prefix) {
            if (!\is_scalar($file = $getEnv($name))) {
                throw new RuntimeException(sprintf('Invalid file name: env var "%s" is non-scalar.', $name));
            }
            if (!is_file($file)) {
                throw new EnvNotFoundException(sprintf('File "%s" not found (resolved from "%s").', $file, $name));
            }

            if ('file' === $prefix) {
                return file_get_contents($file);
            } else {
                return require $file;
            }
        }

        $returnNull = false;
        if ('' === $prefix) {
            if ('' === $name) {
                return null;
            }
            $returnNull = true;
            $prefix = 'string';
        }

        if (false !== $i || 'string' !== $prefix) {
            $env = $getEnv($name);
        } elseif ('' === ($env = $_ENV[$name] ?? (str_starts_with($name, 'HTTP_') ? null : ($_SERVER[$name] ?? null)))
            || (false !== $env && false === $env ??= getenv($name) ?? false) // null is a possible value because of thread safety issues
        ) {
            foreach ($this->loadedVars as $i => $vars) {
                if (false === $env = $vars[$name] ?? $env) {
                    continue;
                }
                if ($env instanceof \Stringable) {
                    $this->loadedVars[$i][$name] = $env = (string) $env;
                }
                if ('' !== ($env ?? '')) {
                    break;
                }
            }

            if (false === $env || '' === $env) {
                $loaders = $this->loaders;
                $this->loaders = new \ArrayIterator();

                try {
                    $i = 0;
                    $ended = true;
                    $count = $loaders instanceof \Countable ? $loaders->count() : 0;
                    foreach ($loaders as $loader) {
                        if (\count($this->loadedVars) > $i++) {
                            continue;
                        }
                        $this->loadedVars[] = $vars = $loader->loadEnvVars();
                        if (false === $env = $vars[$name] ?? $env) {
                            continue;
                        }
                        if ($env instanceof \Stringable) {
                            $this->loadedVars[array_key_last($this->loadedVars)][$name] = $env = (string) $env;
                        }
                        if ('' !== ($env ?? '')) {
                            $ended = false;
                            break;
                        }
                    }
                    if ($ended || $count === $i) {
                        $loaders = $this->loaders;
                    }
                } catch (ParameterCircularReferenceException) {
                    // skip loaders that need an env var that is not defined
                } finally {
                    $this->loaders = $loaders;
                }
            }

            if (false === $env) {
                if (!$this->container->hasParameter("env($name)")) {
                    throw new EnvNotFoundException(sprintf('Environment variable not found: "%s".', $name));
                }

                $env = $this->container->getParameter("env($name)");
            }
        }

        if (null === $env) {
            if ($returnNull) {
                return null;
            }

            if (!isset($this->getProvidedTypes()[$prefix])) {
                throw new RuntimeException(sprintf('Unsupported env var prefix "%s".', $prefix));
            }

            if (!\in_array($prefix, ['string', 'bool', 'not', 'int', 'float'], true)) {
                return null;
            }
        }

        if ('shuffle' === $prefix) {
            \is_array($env) ? shuffle($env) : throw new RuntimeException(sprintf('Env var "%s" cannot be shuffled, expected array, got "%s".', $name, get_debug_type($env)));

            return $env;
        }

        if (null !== $env && !\is_scalar($env)) {
            throw new RuntimeException(sprintf('Non-scalar env var "%s" cannot be cast to "%s".', $name, $prefix));
        }

        if ('string' === $prefix) {
            return (string) $env;
        }

        if (\in_array($prefix, ['bool', 'not'], true)) {
            $env = (bool) (filter_var($env, \FILTER_VALIDATE_BOOL) ?: filter_var($env, \FILTER_VALIDATE_INT) ?: filter_var($env, \FILTER_VALIDATE_FLOAT));

            return 'not' === $prefix xor $env;
        }

        if ('int' === $prefix) {
            if (null !== $env && false === $env = filter_var($env, \FILTER_VALIDATE_INT) ?: filter_var($env, \FILTER_VALIDATE_FLOAT)) {
                throw new RuntimeException(sprintf('Non-numeric env var "%s" cannot be cast to int.', $name));
            }

            return (int) $env;
        }

        if ('float' === $prefix) {
            if (null !== $env && false === $env = filter_var($env, \FILTER_VALIDATE_FLOAT)) {
                throw new RuntimeException(sprintf('Non-numeric env var "%s" cannot be cast to float.', $name));
            }

            return (float) $env;
        }

        if ('const' === $prefix) {
            if (!\defined($env)) {
                throw new RuntimeException(sprintf('Env var "%s" maps to undefined constant "%s".', $name, $env));
            }

            return \constant($env);
        }

        if ('base64' === $prefix) {
            return base64_decode(strtr($env, '-_', '+/'));
        }

        if ('json' === $prefix) {
            $env = json_decode($env, true);

            if (\JSON_ERROR_NONE !== json_last_error()) {
                throw new RuntimeException(sprintf('Invalid JSON in env var "%s": ', $name).json_last_error_msg());
            }

            if (null !== $env && !\is_array($env)) {
                throw new RuntimeException(sprintf('Invalid JSON env var "%s": array or null expected, "%s" given.', $name, get_debug_type($env)));
            }

            return $env;
        }

        if ('url' === $prefix) {
            $params = parse_url($env);

            if (false === $params) {
                throw new RuntimeException(sprintf('Invalid URL in env var "%s".', $name));
            }
            if (!isset($params['scheme'], $params['host'])) {
                throw new RuntimeException(sprintf('Invalid URL env var "%s": schema and host expected, "%s" given.', $name, $env));
            }
            $params += [
                'port' => null,
                'user' => null,
                'pass' => null,
                'path' => null,
                'query' => null,
                'fragment' => null,
            ];

            $params['user'] = null !== $params['user'] ? rawurldecode($params['user']) : null;
            $params['pass'] = null !== $params['pass'] ? rawurldecode($params['pass']) : null;

            // remove the '/' separator
            $params['path'] = '/' === ($params['path'] ?? '/') ? '' : substr($params['path'], 1);

            return $params;
        }

        if ('query_string' === $prefix) {
            $queryString = parse_url($env, \PHP_URL_QUERY) ?: $env;
            parse_str($queryString, $result);

            return $result;
        }

        if ('resolve' === $prefix) {
            return preg_replace_callback('/%%|%([^%\s]+)%/', function ($match) use ($name, $getEnv) {
                if (!isset($match[1])) {
                    return '%';
                }

                if (str_starts_with($match[1], 'env(') && str_ends_with($match[1], ')') && 'env()' !== $match[1]) {
                    $value = $getEnv(substr($match[1], 4, -1));
                } else {
                    $value = $this->container->getParameter($match[1]);
                }

                if (!\is_scalar($value)) {
                    throw new RuntimeException(sprintf('Parameter "%s" found when resolving env var "%s" must be scalar, "%s" given.', $match[1], $name, get_debug_type($value)));
                }

                return $value;
            }, $env);
        }

        if ('csv' === $prefix) {
            return '' === $env ? [] : str_getcsv($env, ',', '"', '');
        }

        if ('trim' === $prefix) {
            return trim($env);
        }

        if ('urlencode' === $prefix) {
            return rawurlencode($env);
        }

        throw new RuntimeException(sprintf('Unsupported env var prefix "%s" for env name "%s".', $prefix, $name));
    }

    public function reset(): void
    {
        $this->loadedVars = [];
        $this->loaders = $this->originalLoaders;
    }
}