<?php declare(strict_types=1);

namespace Picea;

use Closure;
use Picea\Language\LanguageRegistration;
use Psr\Http\Message\ResponseInterface;

class Picea implements LanguageRegistration
{
    const DEFAULT_BUILDER_TEMPLATE = "/Builder/ClassTemplate.php";

    public Compiler\Context $context;

    public Compiler $compiler;

    public LanguageRegistration $languageRegistration;

    public string $builderTemplatePath;

    public Closure $responseHtml;

    public Caching\Cache $cache;

    public FileFetcher $fileFetcher;

    public bool $debug;

    public function __construct(
        ? Closure $responseHtml = null,
        ? Compiler\Context $context = null,
        ? Caching\Cache $cache = null,
        ? Compiler $compiler = null,
        ? LanguageRegistration $languageRegistration = null,
        ? FileFetcher $fileFetcher = null,
        ? string $builderTemplatePath = null,
        bool $debug = false
    ){
        $this->response = $responseHtml;
        $this->cache = $cache ?? new Caching\Memory("");
        $this->context = $context ?? new Compiler\BaseContext();
        $this->languageRegistration = $languageRegistration ?? new Language\DefaultRegistrations();
        $this->builderTemplatePath = $builderTemplatePath ?? dirname(__FILE__) . static::DEFAULT_BUILDER_TEMPLATE;
        $this->compiler = $compiler ?? $this->instanciateCompiler();
        $this->fileFetcher = $fileFetcher ?? $this->instanciateFileFetcher();
        $this->debug = $debug;
        
        #$this->context->exportFunctions();
        $this->renderContext($this->context);
    }

    public function renderHtml(string $viewPath, array $variables = [], ?object $proxy = null) : string
    {
        if ( null === $object = $this->fetchFromCache($viewPath, $variables, $proxy) ) {
            throw new \RuntimeException("An error occured while trying to save a compiled template.");
        }

        return $object();
    }

    public function renderContext(Compiler\Context $context) : object
    {
        if ( null === $object = $this->contextFromCache($context) ) {
            throw new \RuntimeException("An error occured while trying to save a compiled template.");
        }

        return $object;
    }


    #public function outputHtml(string $viewPath, array $variables) : ResponseInterface
    #{
    #    if ( $this->response ?? false ) {
    #        if ( false === $content = $this->cache->handle($viewPath) ) {
    #
    #        }

    #        $source = $this->compileSource($source ?? "test");
    #        $response = $this->response;
    #        return $response("abc");
    #    }

    #    throw new \InvalidArgumentException("No \Psr\Http\Message\ResponseInterface closure provided. Please provide one using the constructor or assigning it to the class variable `responseHtml`.");
    #}

    public function compileSource(string $source) : array
    {
        $this->compiler->loadSourceCode($source);

        return [
            'context' => $context = clone $this->context,
            'source'  => $this->compiler->compile($context),
        ];
    }

    public function compileFile(string $viewPath) : array
    {
        if (! file_exists($viewPath) ) {
            throw new \InvalidArgumentException("File `$viewPath` cannot be found or there is a permission problem.");
        }

        if ( false === $fileContent = file_get_contents($viewPath) ) {
            throw new \ErrorException("Given file could not be opened `$viewPath`. This could indicate a permission misconfiguration on your file or folder.");
        }

        $this->compiler->loadSourceCode($fileContent);
        $context = clone $this->context;
        $context->viewPath = $viewPath;
        $context->source = $this->compiler->compile($context);
        
        return $context;
    }

    public function buildFromSource(string $source) : array
    {
        $tmpFolder = sys_get_temp_dir();
        $builder = $this->instanciateBuilder();
        $compiledSource = $this->compileSource($source);
        list($namespace, $className, $compiledSource) = $builder->build($compiledSource['context'], $compiledSource['source']) ;

        $path = "$tmpFolder/$className.php";
        file_put_contents($path, $compiledSource);

        return [
            'path' => $path,
            'namespace' => $namespace,
            'className' => $className,
        ];
    }

    public function fetchFromCache(string $viewPath, array $variables = [], ?object $proxy = null) : ?object
    {
        if ( $this->debug || ! $this->cache->compiled($viewPath) ) {
            $context = $this->compileView($viewPath);
            $this->cache->save($context);

            if ( $context->extendFrom ) {
                $this->fetchFromCache($context->extendFrom, $variables, $proxy);
            }
        }

        return $this->cache->load($viewPath, $this, $variables, $proxy);
    }

    public function contextFromCache(Compiler\Context $context) : ?object
    {
        if ( $this->debug || ! $this->cache->compiled( $context->cacheFilename() ) ) {
            $context = $this->compileContext($context);
            $this->cache->save($context);
        }

        return $this->cache->load($context->cacheFilename(), $this);
    }
    
    public function instanciateCompiler() : Compiler
    {
        return new Compiler($this->languageRegistration);
    }

    public function instanciateBuilder() : Builder
    {
        return new Builder($this->builderTemplatePath);
    }

    public function instanciateFileFetcher() : FileFetcher
    {
        return new FileFetcher();
    }

    public function registerAll(Compiler $compiler) : void
    {
        $this->registerSyntax($compiler);
        $this->registerControlStructure($compiler);
        $this->registerExtension($compiler);
    }

    public function registerSyntax(Compiler $compiler) : void
    {
        $this->languageRegistration->registerSyntax($compiler);
    }

    public function registerControlStructure(Compiler $compiler) : void
    {
        $this->languageRegistration->registerControlStructure($compiler);
    }

    public function registerExtension(Compiler $compiler) : void
    {
        $this->languageRegistration->registerExtension($compiler);
    }

    protected function compileView(string $viewPath) : Compiler\Context
    {
        $tmpFolder = sys_get_temp_dir();
        $builder = $this->instanciateBuilder();
        $compiled = $this->compileSource($this->fileFetcher->getFileContent($viewPath));
        $context = $compiled['context'];
        $context->viewPath = $viewPath;
        $context = $builder->build($compiled['context'], $compiled['source']) ;
        $context->classPath = $tmpFolder . DIRECTORY_SEPARATOR . $context->className . ".php";

        if ( $context->extendFrom ) {
            $this->compileView($context->extendFrom);
        }

        return $context;
    }
    
    protected function compileContext(Compiler\Context $context) : Compiler\Context
    {
        $tmpFolder = sys_get_temp_dir();
        $builder = $this->instanciateBuilder();
        $compiled = $this->compileSource("");
        $context->viewPath = $context->cacheFilename();
        $builder->build($context, "");
        $context->classPath = $tmpFolder . DIRECTORY_SEPARATOR . $context->cacheFilename() . ".php";

        return $context;
    }
}