<?php

namespace App\Http\Controllers\UI;

use App\Http\Controllers\Controller;
use App\Models\Domain;
use App\Models\MailUser;

class DashboardController extends Controller
{
    public function index()
    {
        return view('ui.dashboard.index');
    }

    public function redesign()
    {
        $services = [
            ['name' => 'Postfix',  'type' => 'MTA',   'online' => $this->isRunning('postfix')],
            ['name' => 'Dovecot',  'type' => 'IMAP',  'online' => $this->isRunning('dovecot')],
            ['name' => 'Rspamd',   'type' => 'Spam',  'online' => $this->isRunning('rspamd')],
            ['name' => 'OpenDKIM', 'type' => 'DKIM',  'online' => $this->isRunning('opendkim')],
            ['name' => 'MariaDB',  'type' => 'DB',    'online' => $this->isRunning('mariadb')],
            ['name' => 'Redis',    'type' => 'Cache', 'online' => $this->isRunning('redis')],
            ['name' => 'Nginx',    'type' => 'Web',   'online' => $this->isRunning('nginx')],
            ['name' => 'ClamAV',   'type' => 'AV',    'online' => $this->isRunning('clamav')],
        ];

        $servicesActive = count(array_filter($services, fn($s) => $s['online']));
        $servicesTotal  = count($services);

        [$cpu, $cpuCores, $cpuMhz]            = $this->getCpu();
        [$ramPercent, $ramUsed, $ramTotal]     = $this->getRam();
        [$load1, $load5, $load15]              = $this->getLoad();
        [$uptimeDays, $uptimeHours]            = $this->getUptime();
        [$diskUsedPercent, $diskUsedGb, $diskFreeGb, $diskTotalGb] = $this->getDisk();

        return view('ui.dashboard.redesign', [
            'domainCount'    => Domain::count(),
            'mailboxCount'   => MailUser::count(),
            'servicesActive' => $servicesActive,
            'servicesTotal'  => $servicesTotal,
            'alertCount'     => 0,
            'mailHostname'   => gethostname() ?: 'mailserver',
            'services'       => $services,

            'cpu'       => $cpu,
            'cpuCores'  => $cpuCores,
            'cpuMhz'    => $cpuMhz,

            'ramPercent' => $ramPercent,
            'ramUsed'    => $ramUsed,
            'ramTotal'   => $ramTotal,

            'load1'  => $load1,
            'load5'  => $load5,
            'load15' => $load15,

            'uptimeDays'  => $uptimeDays,
            'uptimeHours' => $uptimeHours,

            'diskUsedPercent' => $diskUsedPercent,
            'diskUsedGb'      => $diskUsedGb,
            'diskFreeGb'      => $diskFreeGb,
            'diskTotalGb'     => $diskTotalGb,

            'bounceCount'     => 0,
            'spamCount'       => 0,
            'lastBackup'      => '—',
            'backupSize'      => '—',
            'backupDuration'  => '—',
        ]);
    }

    private function isRunning(string $service): bool
    {
        exec("systemctl is-active --quiet " . escapeshellarg($service) . " 2>/dev/null", $out, $code);
        return $code === 0;
    }

    private function getCpu(): array
    {
        $cores = (int) shell_exec("nproc 2>/dev/null") ?: 1;
        $mhz   = round((float) shell_exec("awk '/^cpu MHz/{sum+=$4; n++} END{if(n)print sum/n}' /proc/cpuinfo 2>/dev/null") / 1000, 1);

        $s1 = $this->readStat();
        usleep(400000);
        $s2 = $this->readStat();

        // /proc/stat fields: user(0) nice(1) system(2) idle(3) iowait(4) irq(5) softirq(6) steal(7)
        $idle1  = $s1[3] + ($s1[4] ?? 0);
        $idle2  = $s2[3] + ($s2[4] ?? 0);
        $total1 = array_sum($s1);
        $total2 = array_sum($s2);
        $dt  = $total2 - $total1;
        $di  = $idle2  - $idle1;
        $cpu = $dt > 0 ? max(0, min(100, round(($dt - $di) / $dt * 100))) : 0;

        return [$cpu, $cores, $mhz ?: '—'];
    }

    private function readStat(): array
    {
        $raw  = trim(shell_exec("head -1 /proc/stat 2>/dev/null") ?: '');
        $parts = preg_split('/\s+/', $raw);
        array_shift($parts); // remove 'cpu' label
        return array_map('intval', $parts);
    }

    private function getRam(): array
    {
        $raw = shell_exec("cat /proc/meminfo 2>/dev/null") ?: '';
        preg_match('/MemTotal:\s+(\d+)/', $raw, $mt);
        preg_match('/MemAvailable:\s+(\d+)/', $raw, $ma);
        $total   = isset($mt[1]) ? (int)$mt[1] : 0;
        $avail   = isset($ma[1]) ? (int)$ma[1] : 0;
        $used    = $total - $avail;
        $percent = $total > 0 ? round($used / $total * 100) : 0;
        return [
            $percent,
            round($used  / 1048576, 1),
            round($total / 1048576, 1),
        ];
    }

    private function getLoad(): array
    {
        $raw = trim(shell_exec("cat /proc/loadavg 2>/dev/null") ?: '');
        $p   = explode(' ', $raw);
        return [$p[0] ?? '0.00', $p[1] ?? '0.00', $p[2] ?? '0.00'];
    }

    private function getUptime(): array
    {
        $secs = (int)(float)(shell_exec("awk '{print $1}' /proc/uptime 2>/dev/null") ?: 0);
        return [intdiv($secs, 86400), intdiv($secs % 86400, 3600)];
    }

    private function getDisk(): array
    {
        $raw = trim(shell_exec("df -BG / 2>/dev/null | tail -1") ?: '');
        $p   = preg_split('/\s+/', $raw);
        $total   = isset($p[1]) ? (int)$p[1] : 0;
        $used    = isset($p[2]) ? (int)$p[2] : 0;
        $free    = isset($p[3]) ? (int)$p[3] : 0;
        $percent = $total > 0 ? round($used / $total * 100) : 0;
        return [$percent, $used, $free, $total];
    }
}