<?php

namespace Modules\Portal\Services;

use App\Business;
use App\Contact;
use App\User;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;
use Modules\Maintenance\Models\Equipment;
use Modules\Maintenance\Models\FieldMission;
use Modules\Project\Entities\Project;

class CustomerSpecialistService
{
    public function specialistsForContact(int $business_id, int $contact_id): Collection
    {
        $contact = Contact::where('business_id', $business_id)
            ->with(['userHavingAccess' => function ($q) {
                $q->where('users.user_type', 'user')->where('users.allow_login', 1);
            }])
            ->findOrFail($contact_id);

        $users = collect($contact->userHavingAccess);

        if ($users->isEmpty()) {
            $users = $this->specialistsFromProjects($business_id, $contact_id);
        }

        if ($users->isEmpty()) {
            $users = $this->specialistsFromMaintenance($business_id, $contact_id);
        }

        if ($users->isEmpty()) {
            $users = $this->fallbackSpecialists($business_id);
        }

        return $users->unique('id')->values()->map(function (User $user) {
            return [
                'id' => $user->id,
                'name' => trim($user->surname.' '.$user->first_name.' '.$user->last_name),
                'first_name' => $user->first_name,
                'last_name' => $user->last_name,
                'email' => $user->email,
                'mobile' => $user->contact_no,
                'username' => $user->username,
            ];
        });
    }

    public function assertSpecialistForContact(int $business_id, int $contact_id, int $specialist_id): User
    {
        $specialists = $this->specialistsForContact($business_id, $contact_id);
        $match = $specialists->firstWhere('id', $specialist_id);

        if (! $match) {
            abort(403, 'Unauthorized action.');
        }

        return User::where('business_id', $business_id)
            ->where('id', $specialist_id)
            ->where('user_type', 'user')
            ->firstOrFail();
    }

    private function specialistsFromProjects(int $business_id, int $contact_id): Collection
    {
        if (! Schema::hasTable('pjt_projects') || ! Schema::hasTable('pjt_project_members')) {
            return collect();
        }

        $projectIds = Project::where('business_id', $business_id)
            ->where('contact_id', $contact_id)
            ->pluck('id');

        if ($projectIds->isEmpty()) {
            return collect();
        }

        $leadIds = Project::whereIn('id', $projectIds)
            ->whereNotNull('lead_id')
            ->pluck('lead_id');

        $memberIds = DB::table('pjt_project_members')
            ->whereIn('project_id', $projectIds)
            ->pluck('user_id');

        $userIds = $leadIds->merge($memberIds)->unique()->filter();

        if ($userIds->isEmpty()) {
            return collect();
        }

        return User::where('business_id', $business_id)
            ->whereIn('id', $userIds)
            ->where('user_type', 'user')
            ->where('allow_login', 1)
            ->get();
    }

    private function specialistsFromMaintenance(int $business_id, int $contact_id): Collection
    {
        if (! Schema::hasTable('maintenance_equipment') || ! Schema::hasTable('maintenance_field_missions')) {
            return collect();
        }

        $equipmentIds = Equipment::where('business_id', $business_id)
            ->where('customer_id', $contact_id)
            ->pluck('id');

        if ($equipmentIds->isEmpty()) {
            return collect();
        }

        $leadIds = FieldMission::where('business_id', $business_id)
            ->whereIn('equipment_id', $equipmentIds)
            ->whereNotNull('lead_user_id')
            ->pluck('lead_user_id')
            ->unique();

        if ($leadIds->isEmpty()) {
            return collect();
        }

        return User::where('business_id', $business_id)
            ->whereIn('id', $leadIds)
            ->where('user_type', 'user')
            ->where('allow_login', 1)
            ->get();
    }

    private function fallbackSpecialists(int $business_id): Collection
    {
        $ownerId = Business::where('id', $business_id)->value('owner_id');

        $query = User::where('business_id', $business_id)
            ->where('user_type', 'user')
            ->where('allow_login', 1);

        if ($ownerId) {
            $owner = (clone $query)->where('id', $ownerId)->first();
            if ($owner) {
                return collect([$owner]);
            }
        }

        return $query->orderBy('id')->limit(3)->get();
    }
}