<?php

namespace App;

use PHPHtmlParser\Dom;

/**
 * Get the etymology of a word
 *
 * @author Phil Burton <phil@pgburton.com>
 */
class Etym
{
    protected $baseURL;
    protected $domSearch;
    protected $pasteCmd;

    /**
     * Initalise with config options
     *
     * @param string $baseURL
     * @param string $domSearch
     * @param string $pasteCmd
     * @author Phil Burton <phil@pgburton.com>
     */
    public function __construct(string $baseURL, string $domSearch, string $pasteCmd)
    {
        $this->baseURL = $baseURL;
        $this->domSearch = $domSearch;
        $this->pasteCmd = $pasteCmd;
    }

    /**
     * Search for and return etym defeiniton
     *
     * @return string
     * @author Phil Burton <phil@pgburton.com>
     */
    public function getDefinition(): string
    {
        $input = $this->readStdin();

        $targetURL = $this->baseURL . $input;

        $dom = new Dom;
        $dom->load($targetURL);
        $html = $dom->find($this->domSearch);

        if (!$html instanceof \PHPHtmlParser\Dom\Collection || count($html) <= 0) {
            echo "No entry found for '$input'!\n";
            exit(2);
        }

        $definition = $this->cleanUpHtml($html[0]->innerHtml());
        $definition = $this->handleTruncation($input, $definition, $targetURL);

        // echo $definition . "\n";
        return $definition;
    }

    /**
     * Get and return the user input
     *
     * @return string
     * @author Phil Burton <phil@pgburton.com>
     */
    protected function readStdin(): string
    {
        $input = fgets(STDIN);

        if ($input === false) {
            echo "No input supplied!\n";
            exit(1);
        }

        $input = rtrim($input, "\n");

        return $input;
    }

    /**
     * Tidy and return the hmtl
     *
     * @param string $input
     * @return string
     * @author Phil Burton <phil@pgburton.com>
     */
    protected function cleanUpHtml(string $input): string
    {
        // Strip HTML Tags
        $clear = strip_tags($input);
        // Clean up things like &amp;
        $clear = html_entity_decode($clear);
        // Strip out any url-encoded stuff
        $clear = urldecode($clear);
        // Replace Multiple spaces with single space
        $clear = preg_replace('/ +/', ' ', $clear);
        // Trim the string of leading/trailing space
        $clear = trim($clear);
        // Capitalise the first char.
        $clear = ucfirst($clear);

        return $clear;
    }

    /**
     * Handle when string is too long
     *
     * @param string $input
     * @param string $definition
     * @param string $url
     * @return string
     * @author Phil Burton <phil@pgburton.com>
     */
    protected function handleTruncation(string $input, string $definition, string $url): string
    {
        $truncated = $definition;

        $MAX_CHARACTERS = 350;
        if (strlen($truncated) >= $MAX_CHARACTERS) {
            // Create that povjee link.
            // Capitalise the first char of the input.
            $input   = ucfirst($input);
            $defAndUrl = "\"$input\"" . "\n\n" . $definition . "\n\n" . "[Original at: $url]";
            $safeDef = escapeshellarg($defAndUrl);

            $pasteBinCmd = "echo $safeDef | " . $this->pasteCmd;
            $pasteBinLink = exec($pasteBinCmd);
            $truncated = substr($truncated, 0, $MAX_CHARACTERS) . "... [More info at $pasteBinLink]";
        }

        return $truncated;
    }
}