<?php
namespace Psalm\Internal\Provider\ReturnTypeProvider;

use PhpParser;
use Psalm\CodeLocation;
use Psalm\Context;
use Psalm\StatementsSource;
use Psalm\Type;

class RangeReturnTypeProvider implements \Psalm\Plugin\Hook\FunctionReturnTypeProviderInterface
{
    public static function getFunctionIds() : array
    {
        return ['range'];
    }

    /**
     * @param  array<PhpParser\Node\Arg>    $call_args
     */
    public static function getFunctionReturnType(
        StatementsSource $statements_source,
        string $function_id,
        array $call_args,
        Context $context,
        CodeLocation $code_location
    ) : Type\Union {
        if (!$statements_source instanceof \Psalm\Internal\Analyzer\StatementsAnalyzer) {
            return Type::getMixed();
        }

        $all_ints = true;
        $all_strings = true;
        $all_floats = true;
        $all_numbers = true;

        foreach ($call_args as $call_arg) {
            $is_int = false;
            $is_float = false;
            $is_string = false;

            if ($call_arg_type = $statements_source->node_data->getType($call_arg->value)) {
                if ($call_arg_type->isInt()) {
                    $is_int = true;
                } elseif ($call_arg_type->isFloat()) {
                    $is_float = true;
                } elseif ($call_arg_type->isString()) {
                    $is_string = true;
                }
            }

            $all_ints = $all_ints && $is_int;

            $all_floats = $all_floats && $is_float;

            $all_strings = $all_strings && $is_string;

            $all_numbers = $all_numbers && ($is_int || $is_float);
        }

        if ($all_ints) {
            return new Type\Union([new Type\Atomic\TList(new Type\Union([new Type\Atomic\TInt]))]);
        }

        if ($all_strings) {
            return new Type\Union([new Type\Atomic\TList(new Type\Union([new Type\Atomic\TString]))]);
        }

        if ($all_floats) {
            return new Type\Union([new Type\Atomic\TList(new Type\Union([new Type\Atomic\TFloat]))]);
        }

        if ($all_numbers) {
            return new Type\Union([new Type\Atomic\TList(
                new Type\Union([new Type\Atomic\TInt, new Type\Atomic\TFloat])
            )]);
        }

        return new Type\Union([new Type\Atomic\TList(
            new Type\Union([new Type\Atomic\TInt, new Type\Atomic\TFloat, new Type\Atomic\TString])
        )]);
    }
}
