<?php

declare(strict_types=1);

namespace Modules\Helpdesk\Services;

use App\Models\User;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Mail;
use Illuminate\Support\Facades\Route;
use Illuminate\Support\Facades\URL;
use Illuminate\Support\Str;
use Modules\Helpdesk\Models\Ticket;
use Modules\Helpdesk\Models\WorkflowLog;
use Modules\Helpdesk\Models\WorkflowTemplate;
use Throwable;

final class WorkflowNotificationService
{
    /**
     * Send all active workflow messages for the supplied ticket event.
     */
    public function dispatch(Ticket $ticket, string $event, ?User $actor = null): void
    {
        $this->hydrateTicketUsers($ticket);
        $ticket->loadMissing(['status', 'priority', 'category', 'project', 'team', 'product']);
        $actor?->loadMissing('company');

        WorkflowTemplate::query()
            ->where('event', $event)
            ->where('is_active', true)
            ->get()
            ->each(function (WorkflowTemplate $template) use ($ticket, $event, $actor): void {
                $recipient = $this->recipient($template->to_role, $ticket, $actor);

                if ($recipient === null || blank($recipient->email ?? null)) {
                    $this->log($template, $ticket, $event, null, 'skipped', 'No recipient email was available.');

                    return;
                }

                $trackingToken = Str::random(48);
                $subject = $this->renderText($template->subject, $ticket, $actor);
                $html = $this->wrapHtml($this->renderText($template->html_body, $ticket, $actor), $ticket, $trackingToken);
                $text = $this->renderText($template->text_body ?: strip_tags($template->html_body), $ticket, $actor);

                try {
                    Mail::html($html, function ($message) use ($recipient, $template, $subject): void {
                        $message->to($recipient->email, $recipient->name ?? null)->subject($subject);

                        if (filled($template->cc)) {
                            $message->cc(array_map('trim', explode(',', (string) $template->cc)));
                        }

                        if (filled($template->bcc)) {
                            $message->bcc(array_map('trim', explode(',', (string) $template->bcc)));
                        }
                    });

                    $this->log($template, $ticket, $event, (string) $recipient->email, 'sent', null, $subject, $trackingToken);
                } catch (Throwable $exception) {
                    Log::warning('Helpdesk workflow email failed.', ['event' => $event, 'ticket_id' => $ticket->id, 'error' => $exception->getMessage()]);
                    $this->log($template, $ticket, $event, (string) $recipient->email, 'failed', $exception->getMessage(), $subject);
                }
            });
    }

    /**
     * Load requester/agent with one query if the caller has not already attached them.
     */
    private function hydrateTicketUsers(Ticket $ticket): void
    {
        if ($ticket->relationLoaded('owner') && $ticket->relationLoaded('agent')) {
            return;
        }

        $userIds = collect([$ticket->user_id, $ticket->agent_id])
            ->filter()
            ->map(static fn (mixed $id): int => (int) $id)
            ->unique()
            ->values();

        if ($userIds->isEmpty()) {
            $ticket->setRelation('user', null);
            $ticket->setRelation('owner', null);
            $ticket->setRelation('agent', null);

            return;
        }

        $users = User::query()
            ->with('company')
            ->whereIn('id', $userIds)
            ->get()
            ->keyBy('id');

        $owner = $users->get((int) $ticket->user_id);
        $agent = $ticket->agent_id === null ? null : $users->get((int) $ticket->agent_id);

        $ticket->setRelation('user', $owner);
        $ticket->setRelation('owner', $owner);
        $ticket->setRelation('agent', $agent);
    }

    private function recipient(string $role, Ticket $ticket, ?User $actor): ?User
    {
        return match ($role) {
            'agent' => $ticket->agent,
            'actor' => $actor,
            default => $ticket->owner,
        };
    }

    private function renderText(string $template, Ticket $ticket, ?User $actor): string
    {
        $tokens = [
            '{{ ticket.reference }}' => $ticket->reference,
            '{{ ticket.subject }}' => $ticket->subject,
            '{{ ticket.status }}' => (string) ($ticket->status?->name ?? ''),
            '{{ ticket.priority }}' => (string) ($ticket->priority?->name ?? ''),
            '{{ ticket.category }}' => (string) ($ticket->category?->name ?? ''),
            '{{ ticket.project }}' => (string) ($ticket->project?->title ?? ''),
            '{{ ticket.team }}' => (string) ($ticket->team?->name ?? ''),
            '{{ requester.name }}' => (string) ($ticket->owner?->name ?? ''),
            '{{ agent.name }}' => (string) ($ticket->agent?->name ?? ''),
            '{{ actor.name }}' => (string) ($actor?->name ?? ''),
            '{{ ticket.url }}' => route('helpdesk.tickets.show', ['ticket' => $ticket->getKey()]),
        ];

        return strtr($template, $tokens);
    }

    private function wrapHtml(string $body, Ticket $ticket, ?string $trackingToken = null): string
    {
        return '<div style="font-family:Inter,Arial,sans-serif;background:#f6f8fb;padding:24px">'
            .'<div style="max-width:720px;margin:0 auto;background:#ffffff;border:1px solid #d8dee8;border-radius:18px;overflow:hidden">'
            .'<div style="background:#0f172a;color:#ffffff;padding:24px 28px">'
            .'<div style="font-size:12px;letter-spacing:.18em;text-transform:uppercase;color:#bfdbfe">Helpdesk notification</div>'
            .'<h1 style="margin:8px 0 0;font-size:22px">'.e($ticket->reference).'</h1>'
            .'<p style="margin:8px 0 0;color:#dbeafe">'.e($ticket->subject).'</p>'
            .'</div><div style="padding:28px;color:#1f2937;line-height:1.65">'
            .$body
            .'<p style="margin-top:28px"><a href="'.e(route('helpdesk.tickets.show', ['ticket' => $ticket->getKey()])).'" style="display:inline-block;background:#2563eb;color:#ffffff;text-decoration:none;padding:11px 16px;border-radius:10px">Open ticket</a></p>'
            .$this->trackingPixel($trackingToken)
            .'</div></div></div>';
    }

    private function trackingPixel(?string $trackingToken): string
    {
        if ($trackingToken === null) {
            return '';
        }

        $url = Route::has('helpdesk.workflow.open')
            ? route('helpdesk.workflow.open', ['token' => $trackingToken])
            : URL::to('/'.trim((string) config('helpdesk.route_prefix', 'helpdesk'), '/').'/workflow/open/'.$trackingToken);

        return '<img src="'.e($url).'" width="1" height="1" alt="" style="display:none" />';
    }

    private function log(WorkflowTemplate $template, Ticket $ticket, string $event, ?string $recipient, string $status, ?string $error = null, ?string $subject = null, ?string $trackingToken = null): void
    {
        WorkflowLog::query()->create([
            'template_id' => $template->id,
            'ticket_id' => $ticket->id,
            'event' => $event,
            'recipient' => $recipient,
            'subject' => $subject,
            'status' => $status,
            'tracking_token' => $trackingToken,
            'error' => $error,
        ]);
    }
}