<?php

namespace App\Services;

use App\Models\Like;
use App\Models\Status;
use App\Transformer\Api\StatusStatelessTransformer;
use Illuminate\Support\Facades\Cache;
use League\Fractal;
use League\Fractal\Serializer\ArraySerializer;

class StatusService
{
    const CACHE_KEY = 'pf:services:status:v1.1:';

    const MAX_PINNED = 3;

    public static function key($id, $publicOnly = true): string
    {
        $p = $publicOnly ? 'pub:' : 'all:';

        return self::CACHE_KEY.$p.$id;
    }

    public static function get(
        $id,
        $publicOnly = true,
        $mastodonMode = false,
        $viewerProfileId = null
    ) {
        $res = Cache::remember(self::key($id, $publicOnly), 21600, function () use ($id, $publicOnly) {
            if ($publicOnly) {
                $status = Status::whereScope('public')->find($id);
            } else {
                $status = Status::whereIn('scope', [
                    'public',
                    'private',
                    'unlisted',
                    'group',
                ])->find($id);
            }

            if (! $status) {
                return null;
            }

            $fractal = new Fractal\Manager;
            $fractal->setSerializer(new ArraySerializer);

            $resource = new Fractal\Resource\Item(
                $status,
                new StatusStatelessTransformer
            );

            $res = $fractal->createData($resource)->toArray();

            $res['_pid'] = isset($res['account'], $res['account']['id'])
                ? $res['account']['id']
                : null;

            if (isset($res['_pid'])) {
                unset($res['account']);
            }

            return $res;
        });

        if (! $res) {
            return null;
        }

        if ($viewerProfileId !== null) {
            $ownerProfileId = $res['_pid'] ?? null;
            $visibility = $res['visibility'] ?? null;

            if (! self::isVisibleTo(
                $ownerProfileId,
                $visibility,
                $viewerProfileId
            )) {
                return null;
            }
        }

        if (isset($res['_pid'])) {
            $res['account'] = $mastodonMode === true
                ? AccountService::getMastodon($res['_pid'], true)
                : AccountService::get($res['_pid'], true);

            unset($res['_pid']);
        }

        return $res;
    }

    public static function getMastodon(
        $id,
        $publicOnly = true,
        $viewerProfileId = null
    ) {
        $status = self::get(
            $id,
            $publicOnly,
            true,
            $viewerProfileId
        );

        if (! $status || ! isset($status['account'])) {
            return null;
        }

        $status['replies_count'] = $status['reply_count'];

        if (config('exp.emc') == false) {
            return $status;
        }

        // The shared status nests under `reblog` and needs Mastodon field names too
        if (! empty($status['reblog'])) {
            $status['reblog']['replies_count'] = $status['reblog']['reply_count'] ?? 0;
            $status['reblog']['favourited'] = false;
            $status['reblog']['muted'] = false;
            $status['reblog']['reblogged'] = false;
        }

        unset(
            $status['_v'],
            $status['comments_disabled'],
            $status['content_text'],
            $status['gid'],
            $status['liked_by'],
            $status['local'],
            $status['parent'],
            $status['pf_type'],
            $status['place'],
            $status['replies'],
            $status['reply_count'],
            $status['shortcode'],
            $status['taggedPeople'],
            $status['thread'],
            $status['account']['header_bg'],
            $status['account']['is_admin'],
            $status['account']['last_fetched_at'],
            $status['account']['local'],
            $status['account']['location'],
            $status['account']['note_text'],
            $status['account']['pronouns'],
            $status['account']['website'],
            $status['media_attachments'],
        );

        $status['account']['avatar_static'] = $status['account']['avatar'];
        $status['account']['bot'] = false;
        $status['account']['emojis'] = [];
        $status['account']['fields'] = [];
        $status['account']['header'] = url('/storage/headers/missing.png');
        $status['account']['header_static'] = url('/storage/headers/missing.png');
        $status['account']['last_status_at'] = null;

        $status['media_attachments'] = array_values(
            MediaService::getMastodon($status['id'])
        );

        $status['muted'] = false;
        $status['reblogged'] = false;

        return $status;
    }

    /**
     * Determine whether a status with the given visibility can be
     * returned to a viewer.
     */
    public static function isVisibleTo(
        $ownerProfileId,
        $visibility,
        $viewerProfileId
    ) {
        if (! $ownerProfileId || ! $visibility || ! $viewerProfileId) {
            return false;
        }

        $ownerProfileId = (int) $ownerProfileId;
        $viewerProfileId = (int) $viewerProfileId;

        if ($ownerProfileId === $viewerProfileId) {
            return true;
        }

        switch ($visibility) {
            case 'public':
            case 'unlisted':
                return true;

            case 'private':
                return FollowerService::follows(
                    $viewerProfileId,
                    $ownerProfileId
                );

            case 'group':
            default:
                return false;
        }
    }

    public static function clampReplyVisibility(
        $replyVisibility,
        $parentVisibility
    ): string {
        if ($parentVisibility === 'group') {
            return 'group';
        }

        $levels = [
            'private' => 0,
            'unlisted' => 1,
            'public' => 2,
        ];

        if (
            ! isset($levels[$replyVisibility]) ||
            ! isset($levels[$parentVisibility])
        ) {
            return 'private';
        }

        if ($levels[$replyVisibility] > $levels[$parentVisibility]) {
            return $parentVisibility;
        }

        return $replyVisibility;
    }

    public static function getState($id, $pid): array
    {
        $status = self::get($id, false);

        if (! $status || ! $pid) {
            return [
                'liked' => false,
                'shared' => false,
                'bookmarked' => false,
            ];
        }

        return [
            'liked' => LikeService::liked($pid, $id),
            'shared' => self::isShared($id, $pid),
            'bookmarked' => self::isBookmarked($id, $pid),
        ];
    }

    public static function getFull($id, $pid, $publicOnly = true)
    {
        $res = self::get($id, $publicOnly);
        if (! $res || ! isset($res['account']) || ! isset($res['account']['id'])) {
            return $res;
        }
        $res['relationship'] = RelationshipService::get($pid, $res['account']['id']);

        return $res;
    }

    public static function getDirectMessage($id)
    {
        $status = Status::whereScope('direct')->find($id);

        if (! $status) {
            return null;
        }

        return FractalService::item($status, new StatusStatelessTransformer);
    }

    public static function del($id, $purge = false)
    {
        if ($purge) {
            $status = self::get($id);
            if ($status && isset($status['account']) && isset($status['account']['id'])) {
                Cache::forget('profile:embed:'.$status['account']['id']);
            }
            Cache::forget('status:transformer:media:attachments:'.$id);
            MediaService::del($id);
            Cache::forget('pf:services:sh:id:'.$id);
            PublicTimelineService::rem($id);
            NetworkTimelineService::rem($id);
        }

        Cache::forget(self::key($id, false));

        return Cache::forget(self::key($id));
    }

    public static function refresh($id)
    {
        Cache::forget(self::key($id, false));
        Cache::forget(self::key($id, true));
        self::get($id, false);
        self::get($id, true);
    }

    public static function isShared($id, $pid = null)
    {
        return $pid ?
            ReblogService::get($pid, $id) :
            false;
    }

    public static function isBookmarked($id, $pid = null)
    {
        return $pid ?
            BookmarkService::get($pid, $id) :
            false;
    }

    public static function totalLocalStatuses()
    {
        return InstanceService::totalLocalStatuses();
    }

    public static function isPinned($id)
    {
        return Status::whereId($id)->whereNotNull('pinned_order')->exists();
    }

    public static function totalPins($pid)
    {
        return Status::whereProfileId($pid)->whereNotNull('pinned_order')->count();
    }

    public static function markPin($id): array
    {
        $status = Status::find($id);

        if (! $status) {
            return [
                'success' => false,
                'error' => 'Record not found',
            ];
        }

        if ($status->scope != 'public') {
            return [
                'success' => false,
                'error' => 'Validation failed: you can only pin public posts',
            ];
        }

        if (self::isPinned($id)) {
            return [
                'success' => false,
                'error' => 'This post is already pinned',
            ];
        }

        $totalPins = self::totalPins($status->profile_id);

        if ($totalPins >= self::MAX_PINNED) {
            return [
                'success' => false,
                'error' => 'Validation failed: You have already pinned the max number of posts',
            ];
        }

        $status->pinned_order = $totalPins + 1;
        $status->save();

        self::refresh($id);

        return [
            'success' => true,
            'error' => null,
        ];
    }

    public static function unmarkPin($id)
    {
        $status = Status::find($id);

        if (! $status || is_null($status->pinned_order)) {
            return false;
        }

        $removedOrder = $status->pinned_order;
        $profileId = $status->profile_id;

        $status->pinned_order = null;
        $status->save();

        Status::where('profile_id', $profileId)
            ->whereNotNull('pinned_order')
            ->where('pinned_order', '>', $removedOrder)
            ->orderBy('pinned_order', 'asc')
            ->chunk(10, function ($statuses) {
                foreach ($statuses as $s) {
                    $s->pinned_order = $s->pinned_order - 1;
                    $s->save();
                }
            });

        self::refresh($id);

        return true;
    }

    /**
     * Canonical source-of-truth like count for a status.
     */
    public static function recalculateLikeCount($id): int
    {
        return (int) Like::whereStatusId($id)->count();
    }

    /**
     * Canonical source-of-truth boost/reblog count for a status.
     */
    public static function recalculateReblogCount($id): int
    {
        return (int) Status::whereReblogOfId($id)->count();
    }

    /**
     * Canonical source-of-truth reply/comment count for a status.
     */
    public static function recalculateReplyCount($id): int
    {
        return (int) Status::whereInReplyToId($id)->count();
    }

    /**
     * Reconcile a status's cached count columns (likes_count, reblogs_count,
     * reply_count) against source-of-truth tables. Only writes and busts the
     * cache when a column actually drifted.
     *
     * @param  array<int, string>  $only  Restrict to a subset of
     *                                    ['likes','boosts','comments'].
     * @return array<string, array{cached:int,live:int,drifted:bool}>
     *                                                                Per-metric before/after summary.
     */
    public static function reconcileStatusCounts($status, array $only = ['likes', 'boosts', 'comments']): array
    {
        if (! $status instanceof Status) {
            $status = Status::find($status);
        }

        if (! $status) {
            return [];
        }

        $summary = [];
        $changed = false;

        if (in_array('likes', $only, true)) {
            $cached = (int) $status->likes_count;
            $live = self::recalculateLikeCount($status->id);
            $drift = $cached !== $live;
            if ($drift) {
                $status->likes_count = $live;
                $changed = true;
            }
            $summary['likes'] = ['cached' => $cached, 'live' => $live, 'drifted' => $drift];
        }

        if (in_array('boosts', $only, true)) {
            $cached = (int) $status->reblogs_count;
            $live = self::recalculateReblogCount($status->id);
            $drift = $cached !== $live;
            if ($drift) {
                $status->reblogs_count = $live;
                $changed = true;
            }
            $summary['boosts'] = ['cached' => $cached, 'live' => $live, 'drifted' => $drift];
        }

        if (in_array('comments', $only, true)) {
            $cached = (int) $status->reply_count;
            $live = self::recalculateReplyCount($status->id);
            $drift = $cached !== $live;
            if ($drift) {
                $status->reply_count = $live;
                $changed = true;
            }
            $summary['comments'] = ['cached' => $cached, 'live' => $live, 'drifted' => $drift];
        }

        if ($changed) {
            $status->save();
            self::del($status->id, true);
        }

        return $summary;
    }
}