<?php
namespace Psalm\Internal\Provider;

use PhpParser;
use Psalm\CodeLocation;
use Psalm\Context;
use Psalm\Plugin\EventHandler\Event\MethodParamsProviderEvent;
use Psalm\Plugin\Hook\MethodParamsProviderInterface as LegacyMethodParamsProviderInterface;
use Psalm\Plugin\EventHandler\MethodParamsProviderInterface;
use Psalm\StatementsSource;
use function strtolower;
use function is_subclass_of;

class MethodParamsProvider
{
    /**
     * @var array<
     *   lowercase-string,
     *   array<\Closure(MethodParamsProviderEvent) : ?array<int, \Psalm\Storage\FunctionLikeParameter>>
     * >
     */
    private static $handlers = [];

    /**
     * @var array<
     *   lowercase-string,
     *   array<\Closure(
     *     string,
     *     string,
     *     ?list<PhpParser\Node\Arg>=,
     *     ?StatementsSource=,
     *     ?Context=,
     *     ?CodeLocation=
     *   ) : ?array<int, \Psalm\Storage\FunctionLikeParameter>>
     * >
     */
    private static $legacy_handlers = [];

    public function __construct()
    {
        self::$handlers = [];
        self::$legacy_handlers = [];

        $this->registerClass(ReturnTypeProvider\PdoStatementSetFetchMode::class);
    }

    /**
     * @param class-string $class
     */
    public function registerClass(string $class): void
    {
        if (is_subclass_of($class, LegacyMethodParamsProviderInterface::class, true)) {
            $callable = \Closure::fromCallable([$class, 'getMethodParams']);

            foreach ($class::getClassLikeNames() as $fq_classlike_name) {
                $this->registerLegacyClosure($fq_classlike_name, $callable);
            }
        } elseif (is_subclass_of($class, MethodParamsProviderInterface::class, true)) {
            $callable = \Closure::fromCallable([$class, 'getMethodParams']);

            foreach ($class::getClassLikeNames() as $fq_classlike_name) {
                $this->registerClosure($fq_classlike_name, $callable);
            }
        }
    }

    /**
     * @param  \Closure(MethodParamsProviderEvent) : ?array<int, \Psalm\Storage\FunctionLikeParameter> $c
     */
    public function registerClosure(string $fq_classlike_name, \Closure $c): void
    {
        self::$handlers[strtolower($fq_classlike_name)][] = $c;
    }

    /**
     * @param  \Closure(
     *     string,
     *     string,
     *     ?list<PhpParser\Node\Arg>=,
     *     ?StatementsSource=,
     *     ?Context=,
     *     ?CodeLocation=
     *   ) : ?array<int, \Psalm\Storage\FunctionLikeParameter> $c
     */
    public function registerLegacyClosure(string $fq_classlike_name, \Closure $c): void
    {
        self::$legacy_handlers[strtolower($fq_classlike_name)][] = $c;
    }

    public function has(string $fq_classlike_name) : bool
    {
        return isset(self::$handlers[strtolower($fq_classlike_name)]) ||
            isset(self::$legacy_handlers[strtolower($fq_classlike_name)]);
    }

    /**
     * @param ?list<PhpParser\Node\Arg>  $call_args
     *
     * @return  ?array<int, \Psalm\Storage\FunctionLikeParameter>
     */
    public function getMethodParams(
        string $fq_classlike_name,
        string $method_name_lowercase,
        ?array $call_args = null,
        ?StatementsSource $statements_source = null,
        ?Context $context = null,
        ?CodeLocation $code_location = null
    ): ?array {
        foreach (self::$handlers[strtolower($fq_classlike_name)] ?? [] as $class_handler) {
            $event = new MethodParamsProviderEvent(
                $fq_classlike_name,
                $method_name_lowercase,
                $call_args,
                $statements_source,
                $context,
                $code_location
            );
            $result = $class_handler($event);

            if ($result !== null) {
                return $result;
            }
        }

        foreach (self::$legacy_handlers[strtolower($fq_classlike_name)] ?? [] as $class_handler) {
            $result = $class_handler(
                $fq_classlike_name,
                $method_name_lowercase,
                $call_args,
                $statements_source,
                $context,
                $code_location
            );

            if ($result !== null) {
                return $result;
            }
        }

        return null;
    }
}
