<?php

namespace App\Http\Controllers\PublicAccess;

use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Str;
use Illuminate\View\View;

class AmazonReferralController
{
    public function index(Request $request): View
    {
        return view('public.amazon-referral', [
            'associateTag' => $this->associateTag(),
            'defaultQuery' => trim((string) $request->query('q', '')),
            'defaultAsin'  => trim((string) $request->query('asin', '')),
            'defaultUrl'   => trim((string) $request->query('url', '')),
        ]);
    }

    public function go(Request $request): RedirectResponse
    {
        $asin = $this->normalizeAsin((string) $request->query('asin', ''));
        if ($asin !== null) {
            return redirect()->away($this->appendAssociateTag('https://www.amazon.it/dp/' . rawurlencode($asin)));
        }

        $url = trim((string) $request->query('url', ''));
        if ($url !== '' && filter_var($url, FILTER_VALIDATE_URL)) {
            return redirect()->away($this->appendAssociateTag($this->normalizeAmazonUrl($url)));
        }

        $query = trim((string) $request->query('q', ''));
        if ($query !== '') {
            return redirect()->away($this->appendAssociateTag('https://www.amazon.it/s?k=' . rawurlencode($query)));
        }

        return redirect()->route('public.amazon.index');
    }

    private function associateTag(): string
    {
        $tag = trim((string) config('services.amazon.referral_tag', ''));

        if ($tag === '') {
            $tag = trim((string) config('catalog.amazon.associate_tag', 'netgescon-21'));
        }

        return $tag !== '' ? $tag : 'netgescon-21';
    }

    private function appendAssociateTag(string $url): string
    {
        $parts = parse_url($url);
        if (! is_array($parts)) {
            return $url;
        }

        $query = [];
        parse_str((string) ($parts['query'] ?? ''), $query);
        $query['tag'] = $this->associateTag();

        $base = ($parts['scheme'] ?? 'https') . '://' . ($parts['host'] ?? 'www.amazon.it') . ($parts['path'] ?? '');

        return $base . '?' . http_build_query($query);
    }

    private function normalizeAmazonUrl(string $url): string
    {
        $asin = $this->extractAsinFromUrl($url);

        if ($asin !== null) {
            return 'https://www.amazon.it/dp/' . rawurlencode($asin);
        }

        return $url;
    }

    private function extractAsinFromUrl(string $url): ?string
    {
        if (preg_match('~/(?:dp|gp/product)/([A-Z0-9]{10})(?:[/?]|$)~i', $url, $matches)) {
            return strtoupper($matches[1]);
        }

        return null;
    }

    private function normalizeAsin(string $value): ?string
    {
        $value = strtoupper(trim($value));
        $value = preg_replace('/[^A-Z0-9]/', '', $value) ?? '';

        return preg_match('/^[A-Z0-9]{10}$/', $value) ? $value : null;
    }
}