<?php

namespace App\Services\Mail;

use App\Models\EmailDomain;
use App\Models\EmailServer;
use App\Models\Mailbox;
use Illuminate\Support\Collection;

class EmailServerPoolService
{
    public function poolRoot(EmailServer $server): EmailServer
    {
        return $server->poolRoot();
    }

    /**
     * @return Collection<int, EmailServer>
     */
    public function poolMembers(EmailServer $server): Collection
    {
        $root = $this->poolRoot($server);

        return EmailServer::query()
            ->where(function ($query) use ($root) {
                $query->where('id', $root->id)
                    ->orWhere('primary_email_server_id', $root->id);
            })
            ->whereNotIn('status', [EmailServer::STATUS_DECOMMISSIONED])
            ->orderBy('role')
            ->get();
    }

    public function poolDiskGb(EmailServer $server): int
    {
        return (int) $this->poolMembers($server)->sum('disk_gb');
    }

    public function poolUsedStorageMb(EmailServer $server): int
    {
        return (int) $this->poolMembers($server)->sum('used_storage_mb');
    }

    public function poolAllocatedStorageMb(EmailServer $server): int
    {
        $memberIds = $this->poolMembers($server)->pluck('id');

        $fromEmailDomains = EmailDomain::query()
            ->whereIn('email_server_id', $memberIds)
            ->withSum('mailboxes as quota_sum', 'quota_mb')
            ->get()
            ->sum(fn (EmailDomain $d) => (int) ($d->quota_sum ?? 0));

        $fromWebsiteDomains = Mailbox::query()
            ->whereHas('domain', fn ($q) => $q->whereIn('email_server_id', $memberIds))
            ->sum('quota_mb');

        return (int) ($fromEmailDomains + $fromWebsiteDomains);
    }

    public function poolDomainCount(EmailServer $server): int
    {
        $memberIds = $this->poolMembers($server)->pluck('id');

        $standalone = EmailDomain::query()->whereIn('email_server_id', $memberIds)->count();
        $website = \App\Models\Domain::query()->whereIn('email_server_id', $memberIds)->count();

        return $standalone + $website;
    }

    public function poolMailboxCount(EmailServer $server): int
    {
        $memberIds = $this->poolMembers($server)->pluck('id');

        $standalone = Mailbox::query()
            ->whereHas('emailDomain', fn ($q) => $q->whereIn('email_server_id', $memberIds))
            ->count();

        $website = Mailbox::query()
            ->whereHas('domain', fn ($q) => $q->whereIn('email_server_id', $memberIds))
            ->count();

        return $standalone + $website;
    }

    /**
     * Pick the pool member with the most free physical disk for new mail storage.
     */
    public function findStorageMember(EmailServer $poolRoot): ?EmailServer
    {
        $members = $this->poolMembers($poolRoot)
            ->filter(fn (EmailServer $m) => in_array($m->status, [EmailServer::STATUS_ACTIVE, EmailServer::STATUS_FULL], true));

        if ($members->isEmpty()) {
            return null;
        }

        return $members
            ->sortByDesc(function (EmailServer $member) {
                $disk = (int) ($member->disk_gb ?? 0);
                $usedGb = $this->memberUsedStorageGb($member);

                return max($disk - $usedGb, 0);
            })
            ->first();
    }

    public function memberUsedStorageGb(EmailServer $member): float
    {
        return ((int) $member->used_storage_mb) / 1024;
    }

    public function poolPressurePercent(EmailServer $server): float
    {
        $poolDisk = $this->poolDiskGb($server);
        if ($poolDisk <= 0) {
            return 0;
        }

        $usedGb = $this->poolUsedStorageMb($server) / 1024;

        return round(($usedGb / $poolDisk) * 100, 2);
    }

    public function syncExtensionCredentials(EmailServer $primary): void
    {
        if (! $primary->isPrimary()) {
            return;
        }

        $primary->extensions()->update([
            'mail_host' => $primary->mail_host,
            'db_host' => $primary->db_host,
            'db_port' => $primary->db_port,
            'db_database' => $primary->db_database,
            'db_username' => $primary->db_username,
            'db_password' => $primary->db_password,
        ]);
    }

    public function syncExtensionFromPrimary(EmailServer $extension, EmailServer $primary): void
    {
        $extension->update([
            'mail_host' => $primary->mail_host,
            'role' => EmailServer::ROLE_EXTENSION,
            'primary_email_server_id' => $primary->id,
            'db_host' => $primary->db_host,
            'db_port' => $primary->db_port,
            'db_database' => $primary->db_database,
            'db_username' => $primary->db_username,
            'db_password' => $primary->db_password,
        ]);
    }
}