<?php

namespace App\Services\Whatsapp;

use App\Events\WhatsappInvitesSend;
use App\Models\ParentModel;
use Illuminate\Support\Facades\Event;
use Illuminate\Support\Facades\Log;

class WhatsappInviteNotificationService
{
    public function dispatch(array $bundles, string $schoolYear, string $semester): array
    {
        $listenerCount = Event::hasListeners(WhatsappInvitesSend::class) ? 1 : 0;
        if ($listenerCount === 0) {
            Log::warning('WhatsappInvitesSend has no listeners registered.');

            return [
                'ok' => false,
                'message' => 'No event listener registered for WhatsappInvitesSend.',
                'triggered' => 0,
            ];
        }

        $normalize = static function (array $list): array {
            $out = [];
            foreach ($list as $e) {
                $e = strtolower(trim((string) $e));
                if ($e !== '' && filter_var($e, FILTER_VALIDATE_EMAIL)) {
                    $out[$e] = true;
                }
            }

            return array_keys($out);
        };

        $triggered = 0;
        foreach ($bundles as $bundle) {
            try {
                $primaryEmails = $normalize((array) ($bundle['emails'] ?? []));
                $secondaryEmails = $this->extractSecondaryEmails($bundle, $normalize);

                if (empty($secondaryEmails)) {
                    Log::info('No secondary emails for WhatsApp invite.', [
                        'parent_id' => $bundle['parent']['id'] ?? null,
                    ]);
                }

                $to = $primaryEmails;
                $cc = [];

                if (! empty($primaryEmails) && ! empty($secondaryEmails)) {
                    $cc = array_values(array_diff($secondaryEmails, $primaryEmails));
                } elseif (empty($primaryEmails) && ! empty($secondaryEmails)) {
                    $to = $secondaryEmails;
                }

                if (empty($to)) {
                    Log::warning('Skipping WhatsApp invite: no recipient email(s).', [
                        'parent_id' => $bundle['parent']['id'] ?? null,
                    ]);

                    continue;
                }

                event(new WhatsappInvitesSend([
                    'parent' => $bundle['parent'] ?? null,
                    'sections' => $bundle['sections'] ?? [],
                    'schoolYear' => $schoolYear,
                    'semester' => $semester,
                    'links' => $bundle['links'] ?? [],
                    'teachers' => $bundle['teachers'] ?? [],
                    'to_emails' => $to,
                    'cc_emails' => $cc,
                ]));

                $triggered++;
            } catch (\Throwable $e) {
                Log::error('WhatsappInvitesSend dispatch failed: '.$e->getMessage());
            }
        }

        return [
            'ok' => true,
            'triggered' => $triggered,
        ];
    }

    private function extractSecondaryEmails(array $bundle, callable $normalize): array
    {
        $collected = [];

        if (! empty($bundle['emails_secondary'])) {
            $collected = array_merge($collected, (array) $bundle['emails_secondary']);
        }
        if (! empty($bundle['secondary_parents'])) {
            foreach ((array) $bundle['secondary_parents'] as $sp) {
                if (! empty($sp['email'])) {
                    $collected[] = $sp['email'];
                }
            }
        }

        $parent = $bundle['parent'] ?? [];
        foreach (['secondary_email', 'secondparent_email', 'sec_email', 'email_secondary'] as $key) {
            if (! empty($parent[$key])) {
                $collected[] = $parent[$key];
            }
        }
        if (! empty($parent['secondparent']['email'])) {
            $collected[] = $parent['secondparent']['email'];
        }

        try {
            $primaryId = (int) ($parent['id'] ?? 0);
            if ($primaryId > 0) {
                $row = ParentModel::query()
                    ->select('secondparent_email')
                    ->where('firstparent_id', $primaryId)
                    ->orderByDesc('updated_at')
                    ->first();
                if (! empty($row?->secondparent_email)) {
                    $collected[] = $row->secondparent_email;
                }
            }
        } catch (\Throwable $e) {
            Log::warning('Secondary email DB lookup failed: '.$e->getMessage());
        }

        return $normalize($collected);
    }
}