<?php

namespace App\Services\Frontdesk;

use App\Models\AuditLog;
use App\Models\Host;
use App\Models\Organization;
use App\Models\Visit;
use App\Models\Visitor;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Support\Carbon;
use Illuminate\Support\Collection;

class ReportService
{
    /**
     * @return array<string, mixed>
     */
    public function summary(string $ownerRef, Organization $organization, Carbon $from, Carbon $to, ?int $branchId = null): array
    {
        $visits = $this->visitQuery($ownerRef, $organization->id, $from, $to, $branchId);

        $checkedIn = (clone $visits)->whereNotNull('checked_in_at');
        $durations = (clone $checkedIn)
            ->whereNotNull('checked_out_at')
            ->get(['checked_in_at', 'checked_out_at'])
            ->map(fn (Visit $v) => $v->checked_in_at->diffInMinutes($v->checked_out_at));

        return [
            'total_visits' => (clone $visits)->count(),
            'checked_in' => (clone $checkedIn)->count(),
            'checked_out' => (clone $visits)->where('status', Visit::STATUS_CHECKED_OUT)->count(),
            'cancelled' => (clone $visits)->where('status', Visit::STATUS_CANCELLED)->count(),
            'contractors' => (clone $checkedIn)->where('visitor_type', 'contractor')->count(),
            'deliveries' => (clone $checkedIn)->where('visitor_type', 'delivery')->count(),
            'avg_duration_minutes' => $durations->isEmpty() ? 0 : (int) round($durations->avg()),
            'unique_visitors' => (clone $checkedIn)->distinct('visitor_id')->count('visitor_id'),
        ];
    }

    /** @return array<int, array{hour: int, count: int}> */
    public function peakHours(string $ownerRef, Organization $organization, Carbon $from, Carbon $to, ?int $branchId = null): array
    {
        $counts = array_fill(0, 24, 0);

        $this->visitQuery($ownerRef, $organization->id, $from, $to, $branchId)
            ->whereNotNull('checked_in_at')
            ->pluck('checked_in_at')
            ->each(function ($checkedInAt) use (&$counts) {
                $counts[(int) Carbon::parse($checkedInAt)->format('G')]++;
            });

        $hours = [];
        for ($h = 0; $h < 24; $h++) {
            $hours[] = ['hour' => $h, 'count' => $counts[$h]];
        }

        return $hours;
    }

    /** @return Collection<int, object{department: string, count: int}> */
    public function visitsByDepartment(string $ownerRef, Organization $organization, Carbon $from, Carbon $to, ?int $branchId = null): Collection
    {
        return $this->visitQuery($ownerRef, $organization->id, $from, $to, $branchId)
            ->whereNotNull('frontdesk_visits.checked_in_at')
            ->join('frontdesk_hosts', 'frontdesk_visits.host_id', '=', 'frontdesk_hosts.id')
            ->selectRaw("coalesce(frontdesk_hosts.department, 'Unassigned') as department, count(*) as total")
            ->groupBy('department')
            ->orderByDesc('total')
            ->get()
            ->map(fn ($row) => (object) ['department' => $row->department, 'count' => (int) $row->total]);
    }

    /** @return Collection<int, Visitor> */
    public function frequentVisitors(string $ownerRef, Organization $organization, int $limit = 10): Collection
    {
        return Visitor::owned($ownerRef)
            ->where('organization_id', $organization->id)
            ->where('is_frequent', true)
            ->orderByDesc('visit_count')
            ->limit($limit)
            ->get();
    }

    /** @return array<string, int> */
    public function securityIncidents(string $ownerRef, Organization $organization, Carbon $from, Carbon $to): array
    {
        $query = AuditLog::owned($ownerRef)
            ->where('organization_id', $organization->id)
            ->whereBetween('created_at', [$from, $to])
            ->whereIn('action', [
                'watchlist.blocked_attempt',
                'watchlist.flagged_checkin',
                'badge.expired',
            ]);

        return [
            'blocked_attempts' => (clone $query)->where('action', 'watchlist.blocked_attempt')->count(),
            'flagged_checkins' => (clone $query)->where('action', 'watchlist.flagged_checkin')->count(),
            'expired_badges' => (clone $query)->where('action', 'badge.expired')->count(),
        ];
    }

    /** @return array<int, array{date: string, count: int}> */
    public function dailyCounts(string $ownerRef, Organization $organization, Carbon $from, Carbon $to, ?int $branchId = null): array
    {
        $rows = [];

        $this->visitQuery($ownerRef, $organization->id, $from, $to, $branchId)
            ->whereNotNull('checked_in_at')
            ->pluck('checked_in_at')
            ->each(function ($checkedInAt) use (&$rows) {
                $key = Carbon::parse($checkedInAt)->toDateString();
                $rows[$key] = ($rows[$key] ?? 0) + 1;
            });

        $days = [];
        for ($date = $from->copy()->startOfDay(); $date->lte($to); $date->addDay()) {
            $key = $date->toDateString();
            $days[] = ['date' => $key, 'count' => (int) ($rows[$key] ?? 0)];
        }

        return $days;
    }

    protected function visitQuery(string $ownerRef, int $organizationId, Carbon $from, Carbon $to, ?int $branchId): Builder
    {
        return Visit::query()
            ->from('frontdesk_visits')
            ->where('frontdesk_visits.owner_ref', $ownerRef)
            ->where('frontdesk_visits.organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('frontdesk_visits.branch_id', $branchId))
            ->where(function ($q) use ($from, $to) {
                $q->whereBetween('frontdesk_visits.checked_in_at', [$from, $to])
                    ->orWhereBetween('frontdesk_visits.scheduled_at', [$from, $to]);
            });
    }
}