<?php

namespace App\Services\Care;

use App\Models\Appointment;
use App\Models\Bill;
use App\Models\Diagnosis;
use App\Models\InvestigationRequest;
use App\Models\Patient;
use App\Models\Payment;
use App\Models\Visit;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Support\Carbon;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\DB;

class ReportService
{
    /**
     * @return array<string, mixed>
     */
    public function dashboardStats(string $ownerRef, int $organizationId, ?int $branchId = null): array
    {
        $today = now()->startOfDay();

        $patientsToday = Patient::owned($ownerRef)
            ->where('organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
            ->whereDate('created_at', $today)
            ->count();

        $appointmentsToday = Appointment::owned($ownerRef)
            ->where('organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
            ->whereDate('scheduled_at', $today)
            ->count();

        $openBills = Bill::owned($ownerRef)
            ->where('organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
            ->whereIn('status', [Bill::STATUS_OPEN, Bill::STATUS_PARTIAL])
            ->count();

        $revenueToday = Payment::owned($ownerRef)
            ->whereHas('bill', function (Builder $q) use ($organizationId, $branchId) {
                $q->where('organization_id', $organizationId);
                if ($branchId) {
                    $q->where('branch_id', $branchId);
                }
            })
            ->whereDate('paid_at', $today)
            ->sum('amount_minor');

        $pendingLab = InvestigationRequest::owned($ownerRef)
            ->where('organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
            ->whereIn('status', InvestigationRequest::activeStatuses())
            ->count();

        return [
            'patients_today' => $patientsToday,
            'appointments_today' => $appointmentsToday,
            'open_bills' => $openBills,
            'revenue_today_minor' => (int) $revenueToday,
            'pending_lab' => $pendingLab,
        ];
    }

    /**
     * @return array<string, mixed>
     */
    public function patientsReport(string $ownerRef, int $organizationId, Carbon $from, Carbon $to, ?int $branchId = null): array
    {
        $newPatients = Patient::owned($ownerRef)
            ->where('organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
            ->whereBetween('created_at', [$from, $to])
            ->count();

        $returningPatients = Visit::owned($ownerRef)
            ->where('organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
            ->whereBetween('checked_in_at', [$from, $to])
            ->distinct('patient_id')
            ->count('patient_id');

        $visits = Visit::owned($ownerRef)
            ->where('organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
            ->whereBetween('checked_in_at', [$from, $to])
            ->count();

        return [
            'new_patients' => $newPatients,
            'returning_patients' => $returningPatients,
            'total_visits' => $visits,
        ];
    }

    /**
     * @return array<string, mixed>
     */
    public function appointmentsReport(string $ownerRef, int $organizationId, Carbon $from, Carbon $to, ?int $branchId = null): array
    {
        $base = Appointment::owned($ownerRef)
            ->where('organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
            ->whereBetween('scheduled_at', [$from, $to]);

        return [
            'total' => (clone $base)->count(),
            'completed' => (clone $base)->where('status', Appointment::STATUS_COMPLETED)->count(),
            'cancelled' => (clone $base)->where('status', Appointment::STATUS_CANCELLED)->count(),
            'no_show' => (clone $base)->where('status', Appointment::STATUS_NO_SHOW)->count(),
        ];
    }

    /**
     * @return array<string, mixed>
     */
    public function laboratoryReport(string $ownerRef, int $organizationId, Carbon $from, Carbon $to, ?int $branchId = null): array
    {
        $base = InvestigationRequest::owned($ownerRef)
            ->where('organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
            ->whereBetween('created_at', [$from, $to]);

        $completed = (clone $base)
            ->whereIn('status', [InvestigationRequest::STATUS_COMPLETED, InvestigationRequest::STATUS_DELIVERED])
            ->get();

        $turnaroundHours = $completed
            ->filter(fn ($r) => $r->completed_at && $r->created_at)
            ->map(fn ($r) => $r->created_at->diffInHours($r->completed_at))
            ->avg();

        return [
            'requested' => (clone $base)->count(),
            'completed' => $completed->count(),
            'pending' => (clone $base)->whereIn('status', InvestigationRequest::activeStatuses())->count(),
            'avg_turnaround_hours' => $turnaroundHours ? round($turnaroundHours, 1) : null,
        ];
    }

    /**
     * @return array<string, mixed>
     */
    public function financeReport(string $ownerRef, int $organizationId, Carbon $from, Carbon $to, ?int $branchId = null): array
    {
        $billed = Bill::owned($ownerRef)
            ->where('organization_id', $organizationId)
            ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
            ->whereBetween('created_at', [$from, $to])
            ->where('status', '!=', Bill::STATUS_VOID);

        $payments = Payment::owned($ownerRef)
            ->whereHas('bill', function (Builder $q) use ($organizationId, $branchId) {
                $q->where('organization_id', $organizationId);
                if ($branchId) {
                    $q->where('branch_id', $branchId);
                }
            })
            ->whereBetween('paid_at', [$from, $to]);

        return [
            'invoiced_minor' => (int) (clone $billed)->sum('total_minor'),
            'collected_minor' => (int) (clone $payments)->sum('amount_minor'),
            'outstanding_minor' => (int) Bill::owned($ownerRef)
                ->where('organization_id', $organizationId)
                ->when($branchId, fn ($q) => $q->where('branch_id', $branchId))
                ->whereIn('status', [Bill::STATUS_OPEN, Bill::STATUS_PARTIAL])
                ->sum('balance_minor'),
            'invoice_count' => (clone $billed)->count(),
        ];
    }

    /**
     * @return Collection<int, object>
     */
    public function clinicalReport(string $ownerRef, int $organizationId, Carbon $from, Carbon $to): Collection
    {
        return Diagnosis::owned($ownerRef)
            ->whereHas('consultation.visit', function (Builder $q) use ($organizationId, $from, $to) {
                $q->where('organization_id', $organizationId)
                    ->whereBetween('checked_in_at', [$from, $to]);
            })
            ->select('description', DB::raw('count(*) as total'))
            ->groupBy('description')
            ->orderByDesc('total')
            ->limit(20)
            ->get();
    }
}