<?php

namespace App\Services\Hosting;

use App\Models\HostedSite;
use App\Models\HostingAccount;
use App\Services\Hosting\Providers\SharedNodeProvider;
use Illuminate\Support\Facades\Log;

/**
 * Sales Centre used to stamp pending-setup.local as primary_domain (and sometimes a
 * primary HostedSite). Link Domain historically only created addons, so the
 * placeholder kept hijacking the account label. This service promotes a real
 * linked domain and retires placeholder primaries.
 */
class PlaceholderPrimaryDomainService
{
    public function __construct(
        private SharedNodeProvider $provider,
    ) {}

    public static function isPlaceholderDomain(?string $domain): bool
    {
        $domain = strtolower(trim((string) $domain));

        if ($domain === '' || $domain === 'pending-setup.local') {
            return true;
        }

        // Temporary nginx host used when an account is provisioned without a domain.
        return str_ends_with($domain, '.ladill.com');
    }

    public function accountNeedsPromotion(HostingAccount $account): bool
    {
        $account->loadMissing('sites');

        $primarySites = $account->sites->where('type', 'primary')->values();
        $hasPlaceholderPrimarySite = $primarySites->contains(
            fn (HostedSite $site): bool => static::isPlaceholderDomain($site->domain)
        );
        $hasRealPrimarySite = $primarySites->contains(
            fn (HostedSite $site): bool => ! static::isPlaceholderDomain($site->domain)
        );

        // Never steal primary from an account that already has a real primary site.
        if ($hasRealPrimarySite) {
            return false;
        }

        // Placeholder primary_domain (incl. null/empty) or only placeholder primary sites.
        if (static::isPlaceholderDomain($account->primary_domain) || $hasPlaceholderPrimarySite) {
            return true;
        }

        return false;
    }

    /**
     * Whether a newly linked host should be stored as the account primary site.
     */
    public function shouldBecomePrimary(HostingAccount $account, string $domainHost): bool
    {
        if ($this->accountNeedsPromotion($account)) {
            return true;
        }

        $primary = strtolower(trim((string) $account->primary_domain));

        return $primary !== ''
            && $primary === strtolower(trim($domainHost))
            && ! $account->sites->contains(
                fn (HostedSite $site): bool => $site->type === 'primary'
                    && ! static::isPlaceholderDomain($site->domain)
            );
    }

    /**
     * Prefer a real hosted site over a placeholder primary_domain for UI labels.
     */
    public function displayLabel(HostingAccount $account): string
    {
        $account->loadMissing('sites');

        $real = $account->sites
            ->filter(fn (HostedSite $site): bool => ! static::isPlaceholderDomain($site->domain))
            ->sortBy(fn (HostedSite $site): array => [$site->type !== 'primary', $site->domain])
            ->values();

        if ($real->isNotEmpty()) {
            if ($real->count() === 1) {
                return (string) $real->first()->domain;
            }

            $preview = $real->take(2)->pluck('domain')->implode(', ');

            return $real->count() > 2
                ? "{$preview} +".($real->count() - 2)
                : $preview;
        }

        if (! static::isPlaceholderDomain($account->primary_domain)) {
            return (string) $account->primary_domain;
        }

        return (string) $account->username;
    }

    public function promoteSite(HostingAccount $account, HostedSite $site): void
    {
        if (static::isPlaceholderDomain($site->domain)) {
            return;
        }

        $account->loadMissing(['sites', 'node']);

        $site->update(['type' => 'primary']);

        $account->update([
            'primary_domain' => $site->domain,
        ]);

        foreach ($account->sites as $other) {
            if ((int) $other->id === (int) $site->id) {
                continue;
            }

            if ($other->type === 'primary' && static::isPlaceholderDomain($other->domain)) {
                $this->retirePlaceholderSite($account, $other);
            } elseif ($other->type === 'primary') {
                $other->update(['type' => 'addon']);
            }
        }

        $account->unsetRelation('sites');
    }

    /**
     * Heal accounts that already have a real linked domain but still carry a
     * placeholder primary_domain / primary HostedSite.
     */
    public function healAccount(HostingAccount $account): bool
    {
        if (! $this->accountNeedsPromotion($account)) {
            return false;
        }

        $account->loadMissing(['sites', 'node']);

        $candidate = $account->sites
            ->filter(fn (HostedSite $site): bool => ! static::isPlaceholderDomain($site->domain)
                && in_array($site->type, ['primary', 'addon'], true))
            ->sortBy(fn (HostedSite $site): array => [$site->type !== 'primary', $site->id])
            ->first();

        if (! $candidate) {
            // No real site yet — just clear a stale placeholder label.
            if (static::isPlaceholderDomain($account->primary_domain) && filled($account->primary_domain)) {
                $account->update(['primary_domain' => null]);

                foreach ($account->sites->where('type', 'primary') as $placeholder) {
                    if (static::isPlaceholderDomain($placeholder->domain)) {
                        $this->retirePlaceholderSite($account, $placeholder);
                    }
                }

                return true;
            }

            return false;
        }

        $this->promoteSite($account, $candidate);

        return true;
    }

    protected function retirePlaceholderSite(HostingAccount $account, HostedSite $site): void
    {
        try {
            if ($account->node) {
                $this->provider->removeSite($site);
            }
        } catch (\Throwable $e) {
            Log::info('PlaceholderPrimaryDomainService: best-effort nginx cleanup failed', [
                'site_id' => $site->id,
                'domain' => $site->domain,
                'error' => $e->getMessage(),
            ]);
        }

        $site->delete();
    }
}