<?php
declare(strict_types=1);
namespace App\Dashboard;

use App\Http\{Request, Response};
use App\Auth\{SessionStore, Rbac};
use App\Security\Csrf;
use App\Repository\{ActionRepository, EventRepository};

/**
 * Improvement actions (개선 조치): record a site fix against a camera, and let the data
 * answer "did it work?" — the report shows detection density before vs after the fix
 * over equal windows. This is the only path where a safety investment's ROI comes out
 * of the system as a number.
 */
final class ActionsController
{
    private const LIST_LIMIT = 20;
    private const EFFECT_WINDOW_S = 30 * 86400;   // 비교 창 상한: 조치 전후 각 30일
    private const EFFECT_MIN_S = 3 * 86400;       // 시행 3일 미만이면 "측정 중" — 성급한 결론 방지
    private const MAX_NOTE = 500;

    public function __construct(
        private ActionRepository $actions, private EventRepository $events,
        private SessionStore $sess
    ) {}

    public function save(Request $req): Response
    {
        if ($this->sess->get('user_id') === null) return Response::json(['error' => 'unauthorized'], 401);
        if (!Rbac::can((string)$this->sess->get('role'), 'edit_zones')) return Response::json(['error' => 'forbidden'], 403);
        if (!Csrf::check((string)$this->sess->get('csrf'), (string)$req->header('X-Csrf-Token'))) {
            return Response::json(['error' => 'csrf'], 403);
        }
        $b = $req->json();
        $camera = trim((string)($b['camera_id'] ?? ''));
        $note = trim((string)($b['note'] ?? ''));
        if ($camera === '' || mb_strlen($camera) > 64 || $note === '' || mb_strlen($note) > self::MAX_NOTE) {
            return Response::json(['error' => 'invalid_action'], 400);
        }
        $now = time();
        $takenAt = isset($b['taken_at']) && is_numeric($b['taken_at']) ? (int)$b['taken_at'] : $now;
        // 미래 시각·1년 초과 과거는 입력 실수: 전후 비교가 성립하지 않는다.
        if ($takenAt > $now || $takenAt < $now - 365 * 86400) {
            return Response::json(['error' => 'invalid_taken_at'], 400);
        }
        $id = $this->actions->insert([
            'camera_id' => $camera, 'note' => $note, 'taken_at' => $takenAt,
            'created_by' => (string)$this->sess->get('username'),
        ]);
        return Response::json(['action_id' => $id], 201);
    }

    public function json(Request $req): Response
    {
        if ($this->sess->get('user_id') === null) return Response::json(['error' => 'unauthorized'], 401);
        $scope = $this->sess->get('site_scope');
        $site = is_string($scope) ? $scope : null;
        $now = time();
        $out = [];
        foreach ($this->actions->recent(self::LIST_LIMIT) as $a) {
            // 동일 길이의 전후 창으로만 비교해야 공정하다: 시행 후 경과가 W보다 짧으면
            // 전 창도 그만큼으로 줄인다. 3일 미만은 표본이 아니라 소음 — "측정 중".
            $elapsed = $now - $a['taken_at'];
            $w = min(self::EFFECT_WINDOW_S, $elapsed);
            $effect = null;
            if ($w >= self::EFFECT_MIN_S) {
                $before = $this->events->countForCamera($a['camera_id'],
                    (float)($a['taken_at'] - $w), (float)$a['taken_at'], $site);
                $after = $this->events->countForCamera($a['camera_id'],
                    (float)$a['taken_at'], (float)($a['taken_at'] + $w), $site);
                $effect = ['before' => $before, 'after' => $after, 'window_days' => (int)round($w / 86400)];
            }
            $out[] = $a + ['effect' => $effect];
        }
        return Response::json(['actions' => $out], 200);
    }
}