<?php

namespace App\Http\Controllers\Dashboard;

use App\Http\Controllers\Controller;
use App\Support\AvatarUrl;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;

class FollowerController extends Controller
{
    public function index(Request $request)
    {
        $user = $request->user();
        $perPage = 30;
        $search = trim((string) $request->query('q', ''));
        $sort = (string) $request->query('sort', 'recent');
        $relationship = (string) $request->query('relationship', 'all');

        $allowedSorts = ['recent', 'oldest', 'name', 'uploads', 'followers'];
        $allowedRelationships = ['all', 'following-back', 'not-followed'];

        if (! in_array($sort, $allowedSorts, true)) {
            $sort = 'recent';
        }

        if (! in_array($relationship, $allowedRelationships, true)) {
            $relationship = 'all';
        }

        // People who follow $user (user_id = $user being followed)
        $baseQuery = DB::table('user_followers as uf')
            ->join('users as u', 'u.id', '=', 'uf.follower_id')
            ->leftJoin('user_profiles as up', 'up.user_id', '=', 'u.id')
            ->leftJoin('user_statistics as us', 'us.user_id', '=', 'u.id')
            ->leftJoin('user_followers as mutual', function ($join) use ($user): void {
                $join->on('mutual.user_id', '=', 'uf.follower_id')
                    ->where('mutual.follower_id', '=', $user->id);
            })
            ->where('uf.user_id', $user->id)
            ->whereNull('u.deleted_at')
            ->when($search !== '', function ($query) use ($search): void {
                $query->where(function ($inner) use ($search): void {
                    $inner->where('u.username', 'like', '%' . $search . '%')
                        ->orWhere('u.name', 'like', '%' . $search . '%');
                });
            })
            ->when($relationship === 'following-back', function ($query): void {
                $query->whereNotNull('mutual.created_at');
            })
            ->when($relationship === 'not-followed', function ($query): void {
                $query->whereNull('mutual.created_at');
            });

        $summaryBaseQuery = clone $baseQuery;

        $followers = $baseQuery
            ->when($sort === 'recent', fn ($query) => $query->orderByDesc('uf.created_at'))
            ->when($sort === 'oldest', fn ($query) => $query->orderBy('uf.created_at'))
            ->when($sort === 'name', fn ($query) => $query->orderByRaw('COALESCE(u.username, u.name) asc'))
            ->when($sort === 'uploads', fn ($query) => $query->orderByDesc('us.uploads_count')->orderByRaw('COALESCE(u.username, u.name) asc'))
            ->when($sort === 'followers', fn ($query) => $query->orderByDesc('us.followers_count')->orderByRaw('COALESCE(u.username, u.name) asc'))
            ->select([
                'u.id', 'u.username', 'u.name',
                'up.avatar_hash',
                'us.uploads_count',
                'us.followers_count',
                'uf.created_at as followed_at',
                'mutual.created_at as followed_back_at',
            ])
            ->paginate($perPage)
            ->withQueryString()
            ->through(fn ($row) => (object) [
                'id' => $row->id,
                'name' => $row->name,
                'username' => $row->username,
                'uname' => $row->username ?? $row->name,
                'avatar_url' => AvatarUrl::forUser((int) $row->id, $row->avatar_hash, 64),
                'profile_url' => '/@' . strtolower((string) ($row->username ?? $row->id)),
                'uploads' => $row->uploads_count ?? 0,
                'followers_count' => $row->followers_count ?? 0,
                'is_following_back' => $row->followed_back_at !== null,
                'followed_back_at' => $row->followed_back_at,
                'followed_at' => $row->followed_at,
            ]);

        $summary = [
            'total_followers' => (clone $summaryBaseQuery)->count(),
            'following_back' => (clone $summaryBaseQuery)->whereNotNull('mutual.created_at')->count(),
            'not_followed' => (clone $summaryBaseQuery)->whereNull('mutual.created_at')->count(),
        ];

        return view('dashboard.followers', [
            'followers' => $followers,
            'filters' => [
                'q' => $search,
                'sort' => $sort,
                'relationship' => $relationship,
            ],
            'summary' => $summary,
            'page_title' => 'My Followers',
        ]);
    }
}