<?php

namespace App\Livewire;

use App\Livewire\Concerns\WithFleetContext;
use App\Models\AuditEvent;
use App\Models\Server;
use App\Services\FleetService;
use Illuminate\Support\Facades\Cache;
use Livewire\Attributes\Layout;
use Livewire\Attributes\Title;
use Livewire\Component;
use Throwable;

#[Layout('layouts.app')]
#[Title('Clusev — Dashboard')]
class Dashboard extends Component
{
    use WithFleetContext;

    /** Deterministic wavy series around a base — seeds the sparklines/chart. */
    private function series(float $base, int $n = 40, float $amp = 9): array
    {
        $out = [];
        for ($i = 0; $i < $n; $i++) {
            $v = $base + sin($i / 3.0) * $amp + sin($i / 6.5) * ($amp * 0.55) + cos($i / 2.0) * 2;
            $out[] = (int) max(2, min(98, round($v)));
        }

        return $out;
    }

    /** @param  array<int,int>  $series */
    private function trend(array $series, string $suffix = '%'): array
    {
        $cur = (int) (end($series) ?: 0);
        $prev = (int) ($series[max(0, count($series) - 8)] ?? $cur);
        $d = $cur - $prev;

        return [
            'dir' => $d > 1 ? 'up' : ($d < -1 ? 'down' : 'flat'),
            'text' => ($d >= 0 ? '+' : '').$d.$suffix,
        ];
    }

    /** Live metrics for the active server (briefly cached), DB values as fallback. */
    private function liveMetrics(FleetService $fleet, ?Server $active): array
    {
        $fallback = [
            'cpu' => (int) ($active?->cpu ?? 0),
            'mem' => (int) ($active?->mem ?? 0),
            'disk' => (int) ($active?->disk ?? 0),
            'load' => 0.0,
        ];

        if (! $active || ! $active->credential_exists) {
            return $fallback;
        }

        try {
            return Cache::remember("metrics:{$active->id}", 10, fn () => $fleet->metrics($active));
        } catch (Throwable) {
            return $fallback;
        }
    }

    /** A handful of notable systemd units (failed + running first). */
    private function liveServices(FleetService $fleet, ?Server $active): array
    {
        if (! $active || ! $active->credential_exists) {
            return [];
        }

        try {
            $svc = Cache::remember("svc:{$active->id}", 15, fn () => $fleet->systemd($active, 1)['services']);
        } catch (Throwable) {
            return [];
        }

        $rank = fn (array $s): int => match ($s['sub']) {
            'failed' => 0,
            'running' => 1,
            default => 2,
        };
        usort($svc, fn ($a, $b) => [$rank($a), $a['name']] <=> [$rank($b), $b['name']]);

        return array_slice($svc, 0, 8);
    }

    public function render(FleetService $fleet)
    {
        $active = $this->activeServer();
        $m = $this->liveMetrics($fleet, $active);
        $cpu = $m['cpu'];
        $mem = $m['mem'];
        $disk = $m['disk'];

        $cpuSeries = $this->series(max(8, $cpu), 40, 10);
        $memSeries = $this->series(max(8, $mem), 40, 7);
        $diskSeries = $this->series(max(4, $disk), 40, 2);
        $loadSeries = $this->series(max(8, (int) round($cpu * 0.8)), 40, 12);

        return view('livewire.dashboard', [
            'active' => $active,
            'cpu' => $cpu,
            'mem' => $mem,
            'disk' => $disk,
            'load' => round($m['load'], 2),
            'cpuSeries' => $cpuSeries,
            'memSeries' => $memSeries,
            'diskSeries' => $diskSeries,
            'loadSeries' => $loadSeries,
            'cpuTrend' => $this->trend($cpuSeries),
            'memTrend' => $this->trend($memSeries),
            'diskTrend' => $this->trend($diskSeries),
            'loadTrend' => $this->trend($loadSeries, ''),
            'services' => $this->liveServices($fleet, $active),
            'events' => AuditEvent::with('server')->latest()->limit(6)->get(),
        ]);
    }
}