<?php

namespace App\Services;

use App\Models\AlertState;
use App\Models\EtsyConnection;
use App\Models\User;
use App\Notifications\DashboardAlert;
use Illuminate\Support\Facades\Notification;
use Throwable;

/**
 * Looks at the cached integration data and publishes a notification for each new event.
 */
class AlertScanner
{
    private const PRINT_MILESTONES = [25, 50, 75];

    private const LOW_FILAMENT_PERCENT = 20;

    private const FILAMENT_REARM_PERCENT = 25;

    private const DUE_WINDOW_SECONDS = 86400;

    private const SEEN_ORDER_LIMIT = 500;

    private int $published = 0;

    public function __construct(private Etsy $etsy, private Bambuddy $bambuddy, private Display $display) {}

    /** Run every detector and return how many notifications were published. */
    public function scan(): int
    {
        $this->published = 0;
        foreach ([$this->scanOrders(...), $this->scanPrints(...), $this->scanFilament(...)] as $detector) {
            try {
                $detector();
            } catch (Throwable $exception) {
                report($exception);
            }
        }

        return $this->published;
    }

    private function scanOrders(): void
    {
        $connection = EtsyConnection::first();
        if (! $connection || ! $this->etsy->configured()) {
            return;
        }

        $receipts = $this->etsy->receipts($connection)['results'] ?? [];
        $previous = AlertState::read('etsy.orders');
        $seen = $previous['seen'] ?? [];
        $stages = $previous['stages'] ?? [];
        $now = time();
        $currentIds = [];

        foreach ($receipts as $receipt) {
            $id = (string) ($receipt['receipt_id'] ?? '');
            if ($id === '') {
                continue;
            }
            $currentIds[] = $id;
            $buyer = $receipt['name'] ?? $receipt['buyer_email'] ?? 'a buyer';
            $total = $receipt['grandtotal'] ?? [];
            $value = ($total['currency_code'] ?? 'GBP').' '.number_format((float) ($total['amount'] ?? 0) / max(1, (int) ($total['divisor'] ?? 1)), 2);

            if ($previous !== null && ! in_array($id, $seen, true)) {
                $this->publish('admins', 'order', 'New Etsy order #'.$id, $buyer.' · '.$value, 'success', route('shipping'));
            }

            $shipBy = $this->shipByTimestamp($receipt);
            if ($shipBy === null) {
                continue;
            }
            $stage = $now >= $shipBy ? 2 : (($shipBy - $now) <= self::DUE_WINDOW_SECONDS ? 1 : 0);
            if ($stage > ($stages[$id] ?? 0)) {
                $when = $this->display->dateTime($shipBy);
                $this->publish(
                    'admins', 'shipment',
                    $stage === 2 ? 'Order #'.$id.' is overdue to ship' : 'Order #'.$id.' is due to ship within 24 hours',
                    $buyer.' · ship by '.$when,
                    $stage === 2 ? 'danger' : 'warning',
                    route('shipping'),
                );
                $stages[$id] = $stage;
            }
        }

        AlertState::write('etsy.orders', [
            'seen' => array_slice(array_values(array_unique([...$seen, ...$currentIds])), -self::SEEN_ORDER_LIMIT),
            'stages' => array_intersect_key($stages, array_flip($currentIds)),
        ]);
    }

    /** @param array<string, mixed> $receipt */
    private function shipByTimestamp(array $receipt): ?int
    {
        $dates = collect($receipt['transactions'] ?? [])
            ->map(fn ($transaction): int => (int) ($transaction['expected_ship_date'] ?? 0))
            ->filter(fn (int $date): bool => $date > 0);

        return $dates->isEmpty() ? null : $dates->min();
    }

    private function scanPrints(): void
    {
        if (! $this->bambuddy->configured()) {
            return;
        }

        foreach ($this->bambuddy->printers() as $printer) {
            $live = $printer['live'] ?? [];
            if ($live === [] || ($live['connected'] ?? true) === false) {
                continue;
            }
            $this->scanPrinter((int) $printer['id'], (string) ($printer['name'] ?? 'Printer'), $live);
        }
    }

    /** @param array<string, mixed> $live */
    private function scanPrinter(int $id, string $name, array $live): void
    {
        $key = 'print.'.$id;
        $last = AlertState::read($key);
        $state = $last ?? ['active' => false, 'job' => null, 'progress' => 0.0, 'notified' => [], 'errors' => null, 'failed' => false];
        $status = strtoupper((string) ($live['state'] ?? ''));
        $job = (string) ($live['subtask_name'] ?? $live['current_print'] ?? '');
        $progress = (float) ($live['progress'] ?? 0);
        $label = $job !== '' ? $name.' · '.$job : $name;
        $url = route('printers.index');

        if (in_array($status, ['RUNNING', 'PRINTING', 'PREPARE', 'PAUSE'], true)) {
            if (! $state['active'] || $state['job'] !== $job || $progress < $state['progress'] - 10) {
                $state['notified'] = $last === null ? array_values(array_filter(self::PRINT_MILESTONES, fn (int $milestone): bool => $progress >= $milestone)) : [];
                $state['failed'] = false;
            }
            $crossed = array_values(array_filter(self::PRINT_MILESTONES, fn (int $milestone): bool => $progress >= $milestone && ! in_array($milestone, $state['notified'], true)));
            if ($crossed !== []) {
                $this->publish('everyone', 'print', $label.' is '.max($crossed).'% complete', $this->remaining($live), 'info', $url);
                $state['notified'] = [...$state['notified'], ...$crossed];
            }
            $state['active'] = true;
            $state['job'] = $job;
            $state['progress'] = $progress;
        } elseif ($status === 'FINISH') {
            if ($state['active']) {
                $this->publish('everyone', 'print', $label.' is 100% complete', 'The print has finished.', 'success', $url);
            }
            $state['active'] = false;
            $state['progress'] = 0.0;
        } elseif (in_array($status, ['FAILED', 'FAIL'], true)) {
            if (! $state['failed'] && $last !== null) {
                $this->publish('everyone', 'print-error', $label.' failed', 'The print stopped at '.round($state['progress']).'%.', 'danger', $url);
            }
            $state['failed'] = true;
            $state['active'] = false;
            $state['progress'] = 0.0;
        } else {
            if ($state['active']) {
                $this->publish('everyone', 'print-error', $label.' stopped early', 'The print ended at '.round($state['progress']).'%.', 'warning', $url);
            }
            $state['active'] = false;
            $state['progress'] = 0.0;
        }

        $errors = is_array($live['hms_errors'] ?? null) ? $live['hms_errors'] : [];
        $errorHash = $errors === [] ? null : md5((string) json_encode($errors));
        if ($errorHash !== null && $errorHash !== $state['errors']) {
            $this->publish('everyone', 'print-error', $name.' reports '.count($errors).' alert'.(count($errors) === 1 ? '' : 's'), (string) ($errors[0]['description'] ?? 'Open BamBuddy for details.'), 'danger', $url);
        }
        $state['errors'] = $errorHash;

        AlertState::write($key, $state);
    }

    /** @param array<string, mixed> $live */
    private function remaining(array $live): string
    {
        $minutes = (int) ($live['remaining_time'] ?? 0);

        return $minutes > 0 ? $this->display->duration($minutes * 60).' remaining' : 'Print in progress.';
    }

    private function scanFilament(): void
    {
        if (! $this->bambuddy->configured()) {
            return;
        }

        $state = AlertState::read('filament.low') ?? ['alerted' => []];
        $alerted = $state['alerted'];

        foreach ($this->bambuddy->spools() as $spool) {
            $capacity = (float) ($spool['label_weight'] ?? 0);
            if (filled($spool['archived_at'] ?? null) || $capacity <= 0) {
                continue;
            }
            $id = (string) ($spool['id'] ?? '');
            $remaining = max(0.0, $capacity - (float) ($spool['weight_used'] ?? 0));
            $percent = $remaining / $capacity * 100;

            if ($percent < self::LOW_FILAMENT_PERCENT && ! in_array($id, $alerted, true)) {
                $name = trim(($spool['color_name'] ?? '').' '.($spool['material'] ?? 'filament'));
                $this->publish('everyone', 'filament', 'Low filament: '.$name, trim(($spool['brand'] ?? '').' · '.round($percent).'% (about '.round($remaining).' g) left', ' ·'), 'warning', route('printers.index'));
                $alerted[] = $id;
            } elseif ($percent >= self::FILAMENT_REARM_PERCENT) {
                $alerted = array_values(array_diff($alerted, [$id]));
            }
        }

        AlertState::write('filament.low', ['alerted' => array_values($alerted)]);
    }

    /** @param 'admins'|'everyone' $audience */
    private function publish(string $audience, string $kind, string $title, string $body, string $level, ?string $url): void
    {
        $recipients = User::query()->where('disabled', false)
            ->when($audience === 'admins', fn ($query) => $query->where('role', 'admin'))->get();
        Notification::send($recipients, new DashboardAlert($kind, $title, $body, $level, $url));
        $this->published++;
    }
}