<?php declare(strict_types=1);

namespace Picea\Compiler;

use Picea\Compiler;

abstract class Context {

    public string $namespace = "";

    public string $extendFrom = "";

    public string $className = "";

    public string $compiledSource = "";

    public string $viewPath = "";
    
    public string $filePath = "";

    public array $switchStack = [];

    public array $iterateStack = [];

    public array $useStack = [];

    public int $functions = 0;
    
    public array $functionStack = [];

    public array $hooks = [];

    public Compiler $compiler;

    public function hook(string $path, Callable $callback) : self
    {
        $this->hooks[$path] ??= [];
        $this->hooks[$path][] = $callback;

        return $this;
    }

    public function run(string $path, ...$arguments) : self
    {
        if ( $this->hooks[$path] ?? false ) {
            while ( $callback = array_pop($this->hooks[$path]) ) {
                $callback(...$arguments);
            }
        }
    }

    public function renderUses() : string
    {
        return implode(",", $this->useStack ?? []);
    }

    public function renderFunctions() : string
    {
        if ($this->extendFrom) {
            return "parent::exportFunctions();";
        }
        else {
            $cls = $this->compiledClassPath();
            $ns = $this->namespace ? "\\{$this->namespace}\\" : "";

            $list = ['static $caching = [];'];

            foreach ($this->functionStack as $name => $function) {
                $list[] = <<<FUNC
                if ( false === ( ( \$caching['$ns$name'] ?? false) || function_exists( '$ns$name' ) ) ) {
                    \$caching['$ns$name'] = true;

                    function $name(...\$arguments) {
                        return $cls::\$context->functionStack['$name'](...\$arguments);
                    }
                }
            FUNC;
            }

            return implode(PHP_EOL, $list);
        }
    }

    public function exportFunctions() : void
    {
        
    }

    public function pushFunction($name, Callable $callable) : void
    {
        $this->functionStack[$name] = $callable;
    }

    public function compiledClassPath() : string
    {
        if ($this->namespace) {
            return "\\{$this->namespace}\\{$this->className}";
        }

        return $this->className;
    }
    
    public function cacheFilename() : string
    {
        return strtolower(str_replace("\\", DIRECTORY_SEPARATOR, $this->namespace)) . ".context";
    }
}