<?php
namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\Device;
use App\Models\Reading;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;

class DeviceController extends Controller
{
    public function index(): JsonResponse
    {
        return response()->json(Device::select('id','slug','name','type','last_seen_at')->get());
    }

    public function show(string $slug): JsonResponse
    {
        $d = Device::where('slug',$slug)->firstOrFail();
        return response()->json($d);
    }

    public function latest(string $slug): JsonResponse
    {
        $d = Device::where('slug',$slug)->firstOrFail();
        $sql = "SELECT metric, value, value_text, recorded_at FROM (SELECT metric, value, value_text, recorded_at, ROW_NUMBER() OVER (PARTITION BY metric ORDER BY recorded_at DESC) rn FROM readings WHERE device_id=?) t WHERE rn=1";
        $rows = DB::select($sql, [$d->id]);
        $m = [];
        foreach ($rows as $r) {
            $m[$r->metric] = [
                'value' => $r->value !== null ? (float)$r->value : null,
                'text' => $r->value_text,
                'at' => $r->recorded_at,
            ];
        }
        return response()->json(['device' => $d->only(['slug','name','last_seen_at']), 'metrics' => $m]);
    }

    public function history(string $slug, Request $r): JsonResponse
    {
        $d = Device::where('slug',$slug)->firstOrFail();
        $metric = $r->query('metric');
        $hours = min(168, max(1, (int)$r->query('hours', 24)));
        $since = now()->subHours($hours);
        $q = Reading::where('device_id',$d->id)->where('recorded_at','>=',$since);
        if ($metric) $q->where('metric',$metric);
        $rows = $q->orderBy('recorded_at')->limit(5000)->get(['metric','value','recorded_at']);
        return response()->json(['from'=>$since,'count'=>$rows->count(),'data'=>$rows]);
    }
}