<?php

namespace Drupal\ufc\Services;

use Drupal\Core\Datetime\DateFormatter;
use Drupal\Core\Entity\EntityTypeManager;
use Drupal\taxonomy\Entity\Term;
use Drupal\node\Entity\Node;
use GuzzleHttp\Client;
use Symfony\Component\DomCrawler\Crawler;

class FightImporter {

  const EVENTS_BASE = "https://www.espn.com/mma/schedule/_/year/";
  const EVENT_BASE = "https://www.espn.com";

  /**
   * The Guzzle HTTP Client.
   */
  protected $httpClient;

  /**
   * The entity type manager.
   */
  protected $entityTypeManager;

  /**
   * The date formatter.
   */
  protected $dateFormatter;

  /**
   * Public constructor.
   *
   *  @var \GuzzleHttp\Client $httpClient
   *    The guzzle http client.
   *
   *  @var \Drupal\Core\Entity\EntityTypeManager
   *    The entity type manager.
   *
   *  @var \Drupal\Core\Datetime\DateFormatter $dateFormatter
   *    The date formatter service.
   */
  public function __construct(
    Client $httpClient,
    EntityTypeManager $entityTypeManager,
    DateFormatter $dateFormatter
  ) {
    $this->httpClient = $httpClient;
    $this->entityTypeManager = $entityTypeManager;
    $this->dateFormatter = $dateFormatter;
  }

  /**
   * Import all events to taxonomy.
   */
  public function importEvents(): void {
    // First delete all events :-).
    $this->removeExistingEvents();
    // Old fashioned for loop to target years.
    for ($i = 2000; $i <= 2024; $i++) {
      $year_event_url = self::EVENTS_BASE . "{$i}/league/ufc";
      $event_listing = $this->httpClient
        ->get($year_event_url)->getBody()->getContents();
      $crawler = new Crawler($event_listing);
      $events = $crawler->filter('.Schedule__EventLeague--ufc tbody tr');
      foreach ($events as $event) {
        $term_build = $this->processEvent($event, $i);
        if (empty($term_build)) {
          continue;
        }
        if ($this->shouldSkipEvent($term_build['name'])) {
          \Drupal::logger('ufc')->warning("Skipping " . $term_build['name']);
          continue;
        }
        if (Term::create($term_build)->save()) {
          \Drupal::logger('ufc')->notice("Creating new term: " . $term_build['name']);
        }
        else {
          \Drupal::logger('ufc')->alert("Unable to save new event.");
        }
      }
    }
  }

  private function processEvent(\DOMElement $event, string $year): array {
    if ($event->childElementCount !== 4) {
      return [];
    }
    $term_build = [
      'vid' => 'ufc_events'
    ];
    for ($i = 0; $i < 4; $i++) {
      if ($i === 0) {
        $event_date = $this->convertDate($event->childNodes[0]->textContent . " $year");
        $term_build['field_event_date'] = $event_date;
      }
      if ($i === 1) {
        $name = $event->childNodes[1]->textContent;
        $term_build['name'] = $name;
        $event_url = $event->childNodes[1]->firstChild->getAttribute('href');
        $term_build['field_event_url'] = $event_url;
      }
    }

    return $term_build;
  }

  /**
   * If this event should be skipped.
   */
  private function shouldSkipEvent(string $term_name): bool {
    $events_to_avoid = [
      "Contender Series",
      "The Ultimate Fighter",
      "NEF: Fight Night",
      "TUF Brazil",
    ];
    foreach ($events_to_avoid as $avoid) {
      if (str_contains($term_name, $avoid)) {
        return TRUE;
      }
    }
    return FALSE;
  }

  /*
   * Converts a string into a database storable string.
   *
   *  Output format: YYYY-MM-DD.
   *
   */
  private function convertDate(string $date_str): string {
    return $this->dateFormatter->format(strtotime($date_str), 'custom', 'Y-m-d');
  }

  /**
   * Clear out all prior events in the vocab.
   */
  private function removeExistingEvents(): void {
    \Drupal::logger('ufc')->notice("Removing all former events.");
    $terms = $this->entityTypeManager->getStorage('taxonomy_term')->loadByProperties(['vid' => 'ufc_events']);
    foreach ($terms as $term) {
      $loaded = Term::load($term->id());
      $term_name = $term->name->value;
      \Drupal::logger('ufc')->notice("Removing $term_name.");
      try {
        $loaded->delete();
        \Drupal::logger('ufc')->notice("Operation successful.");
      } catch (\Exception $e) {
        \Drupal::logger('ufc')->alert($e->getMessage());
      }
    }
  }

  /**
   * Create fights from events.
   */
  public function createFights(): void {
    // Clear out past fights.
    $existing_fights = $this->entityTypeManager->getStorage('node')->loadByProperties(['type' => 'fight']);
    foreach ($existing_fights as $existing_fight) {
      $delete = $existing_fight->delete();
      if ($delete) {
        \Drupal::logger('ufc')->notice("Removed " . $existing_fight->getTitle());
      }
    }
    // Go get all events.
    $all_events = $this->entityTypeManager->getStorage('taxonomy_term')
      ->loadByProperties(['vid' => 'ufc_events']);
    foreach ($all_events as $event) {
      $event_page_html = $this->httpClient
        ->get(self::EVENT_BASE . $event->field_event_url->uri)
        ->getBody()->getContents();
      $crawler = new Crawler($event_page_html);
      $fight_result_rows = $crawler->filter(".MMAGamestrip");
      foreach ($fight_result_rows as $fight_result_row) {
        $result = $this->processFightResultRow($fight_result_row);
        if (empty($result)) {
          continue;
        }
        $result['event'] = $event->id();
        $this->createFightNodeFromResult($result);
      }
    }
  }

  /**
   *  Create fight node from results of extracted fight.
   */
  private function createFightNodeFromResult(array $result): void {
    // Result is fighter_1, fighter_2, winner -- all strings.
    // Need a way to look up fighters by name.
    $fighter_1_name = $result['fighter_1'];
    $fighter_2_name = $result['fighter_2'];
    $fight_winner = $result['winner'];
    $fighter_1_id = $this->getFighterIdByName($fighter_1_name);
    $fighter_2_id = $this->getFighterIdByName($fighter_2_name);
    $fight_winner_id = $this->getFighterIdByName($fight_winner);
    $fight = Node::create([
      'type' => 'fight',
      'title' => "$fighter_1_name vs. $fighter_2_name",
      'field_fighter_one' => [
        'target_id' => $fighter_1_id,
      ],
      'field_fighter_two' => [
        'target_id' => $fighter_2_id,
      ],
      'field_event' => [
        'target_id' => $result['event'],
      ],
      'field_result' => [
        'target_id' => $fight_winner_id,
      ],
    ]);

    if ($fight->save()) {
      \Drupal::logger('ufc')->notice("$fighter_1_name vs. $fighter_2_name Created");
    }
    else {
      \Drupal::logger('ufc')->alert("$fighter_1_name vs. $fighter_2_name FAILED");
    }
  }

  /**
   * Retrieve a fighter ID by name.
   */
  private function getFighterIdByName(string $name): int {
    $existing_node = reset($this->entityTypeManager->getStorage('node')->loadByProperties(['title' => $name]));
    if ($existing_node) {
      return $existing_node->id();
    }
    return 0;
  }

  /**
   * Iterate over fight result rows to extract results.
   */
  private function processFightResultRow(\DOMElement $row): array {
    $results = [
      'winner' => 0,
    ];
    $comp_crawler = new Crawler($this->getInnerHtml($row));
    $competitors = $comp_crawler->filter(".MMACompetitor");
    $fighter_num = 1;
    // @todo - this is crazy. Maybe do another crawler instead.
    foreach ($competitors as $competitor) {
      foreach ($competitor->childNodes as $child) {
        if ($child->tagName == 'div') {
          foreach ($child->childNodes as $grandchild) {
            foreach ($grandchild->childNodes as $gg_child) {
              if ($gg_child->tagName == 'h2') {
                $results["fighter_$fighter_num"] = $gg_child->textContent;
                if ($competitor->childElementCount == 2) {
                  $results['winner'] = $gg_child->textContent;
                }
                $fighter_num++;
              }
            }
          }
        }
      }
    }

    return $results;
  }

  /**
   * Get the inner html from a DOMElement.
   */
  private function getInnerHtml(\DOMElement $node) {
    $innerHTML= '';
    $children = $node->childNodes;
    foreach ($children as $child) {
      $innerHTML .= $child->ownerDocument->saveXML( $child );
    }

    return $innerHTML;
  }
}