<?php

namespace App\Services\CardDav;

use App\Contracts\CardDav\CardDavClientInterface;
use App\Contracts\PhoneNumberNormalizerInterface;
use App\Models\Contact;
use App\Models\ContactGroup;
use App\Models\SourceSyncRun;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Str;
use Throwable;

class CardDavContactSyncService
{
    public function __construct(
        private readonly CardDavClientInterface $client,
        private readonly VCardParser $parser,
        private readonly PhoneNumberNormalizerInterface $phoneNumberNormalizer,
    ) {}

    public function sync(): SourceSyncRun
    {
        $run = SourceSyncRun::query()->create([
            'source' => 'carddav',
            'status' => 'running',
            'started_at' => Carbon::now(),
        ]);

        try {
            $cards = $this->client->fetchCards();

            DB::transaction(function () use ($run, $cards): void {
                $seenContactExternalIds = [];
                $seenGroupExternalIds = [];
                $syncedContacts = 0;

                foreach ($cards as $card) {
                    $parsedCard = $this->parser->parse($card->vcard);
                    $externalId = $this->externalId($parsedCard, $card);
                    $seenContactExternalIds[] = $externalId;

                    $contact = $this->upsertContact($externalId, $card, $parsedCard);
                    $this->replacePhoneNumbers($contact, $parsedCard);

                    $groupIds = [];

                    foreach ($parsedCard->categories as $category) {
                        $group = $this->upsertGroup($category);
                        $groupIds[] = $group->id;
                        $seenGroupExternalIds[] = (string) $group->external_id;
                    }

                    $this->syncCardDavGroupMemberships($contact, $groupIds);
                    $syncedContacts++;
                }

                $deletedContacts = $this->deleteMissingContacts($seenContactExternalIds);
                $this->deleteMissingGroups(array_values(array_unique($seenGroupExternalIds)));

                $run->update([
                    'status' => 'success',
                    'finished_at' => Carbon::now(),
                    'fetched_contacts' => count($cards),
                    'synced_contacts' => $syncedContacts,
                    'deleted_contacts' => $deletedContacts,
                    'message' => $syncedContacts.' contact(s) CardDAV synchronise(s).',
                ]);
            });
        } catch (Throwable $exception) {
            $run->update([
                'status' => 'failed',
                'finished_at' => Carbon::now(),
                'error' => $exception->getMessage(),
            ]);

            throw $exception;
        }

        return $run->refresh();
    }

    private function upsertContact(string $externalId, CardDavRemoteCard $card, ParsedVCard $parsedCard): Contact
    {
        $contact = Contact::withTrashed()
            ->where('source', 'carddav')
            ->where('external_id', $externalId)
            ->first();

        $attributes = [
            'source' => 'carddav',
            'external_id' => $externalId,
            'remote_url' => $card->href,
            'remote_etag' => $card->etag,
            'first_name' => $parsedCard->firstName,
            'last_name' => $this->lastName($parsedCard),
            'organization' => $parsedCard->organization,
            'email' => $parsedCard->email,
            'synced_at' => Carbon::now(),
        ];

        if (! $contact) {
            return Contact::query()->create($attributes);
        }

        $contact->fill($attributes);
        $contact->deleted_at = null;
        $contact->save();

        return $contact;
    }

    private function replacePhoneNumbers(Contact $contact, ParsedVCard $parsedCard): void
    {
        $contact->phoneNumbers()->delete();
        $defaultCountry = (string) config('relais_sms.default_settings.default_country');

        foreach ($parsedCard->phoneNumbers as $index => $phoneNumber) {
            $result = $this->phoneNumberNormalizer->normalize($phoneNumber->rawNumber, $defaultCountry);

            $contact->phoneNumbers()->create([
                'label' => $phoneNumber->label,
                'raw_number' => $result->rawNumber,
                'normalized_number' => $result->normalizedNumber,
                'country' => $result->country,
                'is_valid' => $result->isValid,
                'is_mobile' => $result->isMobile,
                'is_primary' => $index === 0,
                'validation_error' => $result->error,
            ]);
        }
    }

    private function upsertGroup(string $category): ContactGroup
    {
        $externalId = Str::slug($category);
        $slug = 'carddav-'.$externalId;
        $group = ContactGroup::withTrashed()
            ->where('source', 'carddav')
            ->where('external_id', $externalId)
            ->first();

        $attributes = [
            'source' => 'carddav',
            'external_id' => $externalId,
            'name' => $category,
            'slug' => $slug,
            'synced_at' => Carbon::now(),
        ];

        if (! $group) {
            return ContactGroup::query()->create($attributes);
        }

        $group->fill($attributes);
        $group->deleted_at = null;
        $group->save();

        return $group;
    }

    /**
     * @param  array<int, int>  $groupIds
     */
    private function syncCardDavGroupMemberships(Contact $contact, array $groupIds): void
    {
        $currentCardDavGroupIds = $contact->groups()
            ->where('contact_groups.source', 'carddav')
            ->pluck('contact_groups.id')
            ->all();

        if ($currentCardDavGroupIds !== []) {
            $contact->groups()->detach($currentCardDavGroupIds);
        }

        if ($groupIds !== []) {
            $contact->groups()->syncWithoutDetaching($groupIds);
        }
    }

    /**
     * @param  array<int, string>  $seenExternalIds
     */
    private function deleteMissingContacts(array $seenExternalIds): int
    {
        $contacts = Contact::query()
            ->where('source', 'carddav')
            ->whereNotIn('external_id', $seenExternalIds ?: [''])
            ->get();

        foreach ($contacts as $contact) {
            $cardDavGroupIds = $contact->groups()
                ->where('contact_groups.source', 'carddav')
                ->pluck('contact_groups.id')
                ->all();

            if ($cardDavGroupIds !== []) {
                $contact->groups()->detach($cardDavGroupIds);
            }

            $contact->delete();
        }

        return $contacts->count();
    }

    /**
     * @param  array<int, string>  $seenExternalIds
     */
    private function deleteMissingGroups(array $seenExternalIds): void
    {
        ContactGroup::query()
            ->where('source', 'carddav')
            ->whereNotIn('external_id', $seenExternalIds ?: [''])
            ->delete();
    }

    private function externalId(ParsedVCard $parsedCard, CardDavRemoteCard $card): string
    {
        return $parsedCard->uid ?: sha1($card->href);
    }

    private function lastName(ParsedVCard $parsedCard): string
    {
        if ($parsedCard->lastName) {
            return $parsedCard->lastName;
        }

        if ($parsedCard->fullName) {
            return $parsedCard->fullName;
        }

        if ($parsedCard->organization) {
            return $parsedCard->organization;
        }

        return 'Contact CardDAV';
    }
}