<?php

namespace App\Services\Team;

use App\Models\CollectionTeam;
use App\Models\TeamMember;
use App\Models\Truck;

class TeamConflictDetector
{
    /**
     * Returns an array of human-readable conflict messages for the given
     * team composition. Empty array means no conflicts.
     */
    public function check(
        ?int $driverId,
        ?int $scannerId,
        ?int $truckId,
        array $helperIds = [],
        ?int $excludeTeamId = null,
    ): array {
        $conflicts = [];

        if ($driverId) {
            $existing = CollectionTeam::query()
                ->where('status', CollectionTeam::STATUS_ACTIVE)
                ->where('driver_id', $driverId)
                ->when($excludeTeamId, fn ($q, $id) => $q->where('id', '!=', $id))
                ->first();
            if ($existing) {
                $conflicts[] = "Driver already on team {$existing->name}";
            }
        }

        if ($scannerId) {
            $existing = CollectionTeam::query()
                ->where('status', CollectionTeam::STATUS_ACTIVE)
                ->where('scanner_id', $scannerId)
                ->when($excludeTeamId, fn ($q, $id) => $q->where('id', '!=', $id))
                ->first();
            if ($existing) {
                $conflicts[] = "Scanner already on team {$existing->name}";
            }
        }

        if ($truckId) {
            $existing = CollectionTeam::query()
                ->where('status', CollectionTeam::STATUS_ACTIVE)
                ->where('truck_id', $truckId)
                ->when($excludeTeamId, fn ($q, $id) => $q->where('id', '!=', $id))
                ->first();
            if ($existing) {
                $conflicts[] = "Truck already on team {$existing->name}";
            }

            $truck = Truck::find($truckId);
            if ($truck && $truck->status !== Truck::STATUS_ACTIVE) {
                $conflicts[] = "Truck status is {$truck->status}, not active";
            }
        }

        if (! empty($helperIds)) {
            $today = now()->toDateString();
            $assigned = TeamMember::query()
                ->whereIn('user_id', $helperIds)
                ->where('role_in_team', TeamMember::ROLE_HELPER)
                ->whereDate('assigned_from', '<=', $today)
                ->where(function ($q) use ($today) {
                    $q->whereNull('assigned_until')->orWhereDate('assigned_until', '>=', $today);
                })
                ->when($excludeTeamId, fn ($q, $id) => $q->where('team_id', '!=', $id))
                ->with('user:id,first_name,last_name')
                ->get();

            foreach ($assigned as $tm) {
                $conflicts[] = "Helper {$tm->user?->first_name} {$tm->user?->last_name} already assigned to another team";
            }
        }

        return $conflicts;
    }
}