<?php

namespace App\Services;

use App\Models\Priority;
use App\Models\RequestType;
use App\Models\ServiceRequest;
use App\Models\Status;
use App\Models\User;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Support\Collection;

class ReportService
{
    public function requestBaseQuery(array $filters = []): Builder
    {
        return ServiceRequest::query()
            ->with(['assignee', 'type', 'status', 'priority'])
            ->when($filters['date_from'] ?? null, fn (Builder $q, $v) => $q->whereDate('created_at', '>=', $v))
            ->when($filters['date_to'] ?? null, fn (Builder $q, $v) => $q->whereDate('created_at', '<=', $v))
            ->when($filters['technician_id'] ?? null, fn (Builder $q, $v) => $q->where('assigned_to', $v))
            ->when($filters['type_id'] ?? null, fn (Builder $q, $v) => $q->where('type_id', $v))
            ->when($filters['status_id'] ?? null, fn (Builder $q, $v) => $q->where('status_id', $v));
    }

    public function requestsByStatus(array $filters = []): Collection
    {
        return $this->requestBaseQuery($filters)
            ->selectRaw('status_id, COUNT(*) as total')
            ->groupBy('status_id')
            ->get()
            ->map(function ($item) {
                $status = Status::query()->find($item->status_id);

                return [
                    'status' => $status?->name ?? 'Неизвестно',
                    'color' => $status?->color_hex ?? '#2563eb',
                    'total' => (int) $item->total,
                ];
            });
    }

    public function requestsByPriority(array $filters = []): Collection
    {
        return $this->requestBaseQuery($filters)
            ->selectRaw('priority_id, COUNT(*) as total')
            ->groupBy('priority_id')
            ->get()
            ->map(fn ($item) => [
                'priority' => Priority::query()->find($item->priority_id)?->name,
                'total' => (int) $item->total,
            ]);
    }

    public function technicianPerformance(array $filters = []): Collection
    {
        $technicians = User::query()->where('role', 'technician')->get();

        return $technicians->map(function (User $tech) use ($filters) {
            $query = $this->requestBaseQuery($filters)->where('assigned_to', $tech->id);
            $assigned = (clone $query)->count();
            $resolved = (clone $query)->whereHas('status', fn (Builder $q) => $q->whereIn('slug', ['resolved', 'closed']))->count();
            $overdue = (clone $query)->overdue()->count();
            $avgResolution = (clone $query)
                ->whereNotNull('completed_at')
                ->selectRaw('AVG(TIMESTAMPDIFF(HOUR, created_at, completed_at)) as avg_hours')
                ->value('avg_hours');
            $rating = (clone $query)->whereNotNull('client_rating')->avg('client_rating');

            return [
                'technician' => $tech->name,
                'assigned' => $assigned,
                'resolved' => $resolved,
                'avg_resolution_hours' => $avgResolution ? round((float) $avgResolution, 1) : 0,
                'rating' => $rating ? round((float) $rating, 2) : 0,
                'overdue' => $overdue,
            ];
        });
    }

    public function slaCompliance(array $filters = []): Collection
    {
        $rows = $this->requestBaseQuery($filters)->with('type')->get()->groupBy('type_id');

        return $rows->map(function (Collection $requests, $typeId) {
            $type = RequestType::query()->find($typeId);
            $total = $requests->count();
            $withinSla = $requests
                ->filter(fn (ServiceRequest $request) => $request->completed_at && $request->deadline_at && $request->completed_at->lte($request->deadline_at))
                ->count();

            return [
                'type' => $type?->name ?? 'Неизвестно',
                'total' => $total,
                'within_sla' => $withinSla,
                'percent' => $total > 0 ? round(($withinSla / $total) * 100, 2) : 0,
            ];
        })->values();
    }

    public function equipmentFailureFrequency(array $filters = []): Collection
    {
        return $this->requestBaseQuery($filters)
            ->whereNotNull('equipment_id')
            ->with('equipment')
            ->get()
            ->groupBy('equipment_id')
            ->map(fn (Collection $requests, $equipmentId) => [
                'equipment' => $requests->first()?->equipment?->name ?? 'Неизвестно',
                'total_requests' => $requests->count(),
                'open' => $requests->filter(fn (ServiceRequest $r) => !$r->status?->is_final)->count(),
                'closed' => $requests->filter(fn (ServiceRequest $r) => $r->status?->is_final)->count(),
            ])
            ->values();
    }
}