<?php

namespace FlatFileForms;

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Yosymfony\Toml\Toml;
use Yosymfony\Toml\TomlBuilder;

class App
{
  /**
   * App constructor.
   */
  public function __construct()
  {
    $request = Request::createFromGlobals();
    $response = new Response();

    $content = [
      'data' => [],
    ];
    $contentRoot = dirname(__DIR__) . '/content';

    $method = $request->getMethod();
    $path = $request->getPathInfo();

    try {
      $config = $this->buildConfig($contentRoot . $path);

      // check api key
      $apiKey = $_GET['key'] ?? $_POST['key'] ?? null;
      if (empty($apiKey)) {
	$response->setStatusCode(Response::HTTP_BAD_REQUEST);
	throw new \Exception('API key missing');
      }
      if (! in_array($apiKey, $config['api']['keys'])) {
	$response->setStatusCode(Response::HTTP_UNAUTHORIZED);
	throw new \Exception('API key does not match');
      }

      // GET
      if ($method == 'GET')  {
	if (str_ends_with($path, '/fields')) {
	  $formPath = $contentRoot . str_replace('/fields', '', $path);

	  $content['data'] = $this->buildFields($formPath);
	}
	else {
	  $content['data'] = Toml::parseFile($contentRoot . $path . '.toml');
	}
      }

      // POST
      else if ($method == 'POST') {
	if (str_ends_with($path, '/submit')) {
	  $formPath = $contentRoot . str_replace('/submit', '', $path);

	  $fields = $this->buildFields($formPath);
	  $fields = $this->validateFields($fields);

	  // remove surplus fields from response
	  $fields = array_map(function ($field) {
	    return array_intersect_key($field, array_flip([
	      'is_valid',
	    ]));
	  }, $fields);

	  $content['data'] = $fields;

	  $hasInvalidFields = in_array(false, array_column($fields, 'is_valid'));
	  if ($hasInvalidFields) {
	    $content['error'] = 'Invalid fields';
	  } else {
	    $date = new \Datetime();
	    $entry = [
	      'fields' => $_POST,
	      'date' => $date->format('c'),
	    ];

	    $builder = new TomlBuilder();
	    $builder->addValue('date', $entry['date']);
	    $builder->addTable('fields');
	    foreach ($entry['fields'] as $entryKey => $entryValue) {
	      $builder->addValue($entryKey, $entryValue);
	    }

	    $entryDirectory = $formPath . '/entries/' . $date->format('Y/m/d');
	    @mkdir($entryDirectory, 0774, true);
	    $entryFilename = $date->format('Ymd_Hi_') . hash('adler32', serialize($entry)) . '.toml';
	    file_put_contents(
	      $entryDirectory . '/' . $entryFilename,
	      $builder->getTomlString()
	    );
	  }
	}
      }
    } catch (\Exception $exception) {
      $content['error'] = $exception->getMessage();
    }

    $response->headers->set('Content-Type', 'application/json');
    $response->setContent(json_encode($content));
    $response->send();
  }

  /**
   * @param string $formPath
   */
  public function buildFields($formPath)
  {
    $fields = Toml::parseFile($formPath . '/fields/_fields.toml')['field'] ?? [];
    foreach ($fields as $key => $field) {
      if (! empty($field['file'])) {
	$field = array_replace_recursive($field, Toml::parseFile($formPath . '/fields/' . $field['file']));
      }

      if (empty($field['name'])) {
	$field['name'] = $key;
      }

      $fields[$key] = $field;
    }

    return $fields;
  }

  /**
   * @param array $fields
   */
  public function validateFields($fields)
  {
    foreach ($fields as $key => &$field) {
      $field['is_valid'] = true;

      if (($field['required'] ?? false) && empty($_POST[$field['name']])) {
	$field['is_valid'] = false;
      }
    }

    return $fields;
  }

  /**
   * @param string $formPath
   */
  public function buildConfig($formPath)
  {
    $config = [];
    $currentFolder = $formPath;
    while (true) {
      $configFile = $currentFolder . '/config/config.toml';
      if (file_exists($configFile)) {
	$parsedConfig = Toml::parseFile($configFile);

	$apiKeys = array_merge($parsedConfig['api']['keys'] ?? [], $config['api']['keys'] ?? []);
	$config = array_replace_recursive($parsedConfig, $config);
	$config['api']['keys'] = $apiKeys;
      }

      if (str_ends_with($currentFolder, '/content') || $currentFolder == '/') {
	break;
      }

      $currentFolder = dirname($currentFolder);
    }

    return $config;
  }
}