<?php

namespace Livewire\Mechanisms\ExtendBlade;

use Illuminate\Support\Facades\Blade;
use Livewire\Mechanisms\Mechanism;
use function Livewire\invade;
use function Livewire\on;

class ExtendBlade extends Mechanism
{
    protected $directives = [];
    protected $precompilers = [];
    protected $renderCounter = 0;

    protected static $livewireComponents = [];

    function startLivewireRendering($component)
    {
        static::$livewireComponents[] = $component;
    }

    function endLivewireRendering()
    {
        array_pop(static::$livewireComponents);
    }

    static function currentRendering()
    {
        return end(static::$livewireComponents);
    }

    static function isRenderingLivewireComponent()
    {
        return ! empty(static::$livewireComponents);
    }

    function boot()
    {
        Blade::directive('this', fn() => "window.Livewire.find('{{ \$_instance->getId() }}')");

        on('render', function ($target, $view) {
            $this->startLivewireRendering($target);

            $undo = $this->livewireifyBladeCompiler();

            $this->renderCounter++;

            return function ($html) use ($view, $undo, $target) {
                $this->endLivewireRendering();

                $this->renderCounter--;

                if ($this->renderCounter === 0) {
                    $undo();
                }

                return $html;
            };
        });

        // This is a custom view engine that gets used when rendering
        // Livewire views. Things like letting certain exceptions bubble
        // to the handler, and registering custom directives like: "@this".
        app()->make('view.engine.resolver')->register('blade', function () {
            return new ExtendedCompilerEngine(app('blade.compiler'));
        });

        app()->singleton(DeterministicBladeKeys::class);

        // Reset this singleton between tests and Octane requests...
        on('flush-state', function () {
            app()->singleton(DeterministicBladeKeys::class);

            static::$livewireComponents = [];
        });

        // We're using "precompiler" as a hook for the point in time when
        // Laravel compiles a Blade view...
        app('blade.compiler')->precompiler(function ($value) {
            app(DeterministicBladeKeys::class)->hookIntoCompile(app('blade.compiler'), $value);

            return $value;
        });
    }

    function livewireOnlyDirective($name, $handler)
    {
        $this->directives[$name] = $handler;
    }

    function livewireOnlyPrecompiler($handler)
    {
        $this->precompilers[] = $handler;
    }

    function livewireifyBladeCompiler() {
        $removals = [];

        if ($this->renderCounter === 0) {
            $customDirectives = app('blade.compiler')->getCustomDirectives();
            $precompilers = invade(app('blade.compiler'))->precompilers;

            foreach ($this->directives as $name => $handler) {
                if (! isset($customDirectives[$name])) {
                    $customDirectives[$name] = $handler;

                    invade(app('blade.compiler'))->customDirectives = $customDirectives;

                    $removals[] = function () use ($name) {
                        $customDirectives = app('blade.compiler')->getCustomDirectives();

                        unset($customDirectives[$name]);

                        invade(app('blade.compiler'))->customDirectives = $customDirectives;
                    };
                }
            }

            foreach ($this->precompilers as $handler) {
                if (array_search($handler, $precompilers) === false) {
                    array_unshift($precompilers, $handler);

                    invade(app('blade.compiler'))->precompilers = $precompilers;

                    $removals[] = function () use ($handler) {
                        $precompilers = invade(app('blade.compiler'))->precompilers;

                        $index = array_search($handler, $precompilers);

                        if ($index === false) return;

                        unset($precompilers[$index]);

                        invade(app('blade.compiler'))->precompilers = $precompilers;
                    };
                }
            }
        }

        return function () use ($removals) {
            while ($removals) array_pop($removals)();
        };
    }
}
