The start of a laravel api that tracks leads. This is the controller for leads showing get and post requests (functions index and store)

ApiLeadsController.php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Models\Lead;
use App\Models\LeadMeta;
use App\Transformers\LeadTransformer;

class ApiLeadsController extends Controller
{
    // The transformer reformats the data to uncouple it from the shcema structure
    function __construct(LeadTransformer $leadTransformer) {
        $this->leadTransformer = $leadTransformer;
    }


    public function index() {
        $leads = Lead::all(); // Retrieve the entire collection of leads, and let the transformer handle pagination

        return response()->json([
            'data' => $this->leadTransformer->transformCollection($leads->all())
        ], 200);
    }

    public function show($id) {
        $lead = Lead::find($id);

        // Simple response for if a lead is not found. All "code" responses correspond with a readme entry
        if (!$lead) {
            return response()->json([
                'error' => array(
                    'message' => 'Resource not found',
                    'code' => '415'
                )
            ], 404);
        }

        // If there is a lead, pass it to the transformer for de-coupling
        return response()->json([
            'data' => $this->leadTransformer->transformCollection($lead)
        ], 200);
    }

    public function store(Request $request) {
        // We only want to retrieve certain objects from the request at different stages. Empty string are automatically set to null by middleware
        // Step 1 is to make sure a tracking number has been provided. This ensures we are only storing leads we can track through cookies
        $trackingNumber = $request->tracking_number;

        if (!trackingNumber) {
          return response()->json([
                'error' => array(
                    'message' => 'Tracking number not present or undefined',
                    'code' => '425',
                    'Data Sent' => $request->json()
                )
            ], 400);
        }
        
        // Step 2 is determining if a lead already exists in the database

        $leadID = $request->leadID;

        if (!leadID) {
            // If there is no lead id in the post request we can still determine if we are working with an existing lead by a tracking number
            $lead = Lead::where('tracking_number', $trackingNumber;

            if (!$lead) {
                // If we are here we know that we have a tracking number that is new, meaning we can create a new lead
                $lead = new Lead;

                $lead->tracking_number = $trackingNumber;
                $lead->status = 0; // All new leads start with a status of 0
                
                // We need to make sure the lead saves. if it doesn't we need to return an error stating there is problem with the model
              
                try{
                  $lead->save();
                }
                catch(\Exception $e){
                   // this is much better than a generic 500 error
                   return response()->json([
                      'error' => array(
                          'message' => $e->getMessage();,
                          'code' => '530',
                      )
                    ], 500);
                }
                
                // Here we make sure the LeadMeta item is saved in the database, with the newly saved lead id as a foreignkey
                $leadMeta = new LeadMeta;
                $leadMeta->lead_id = $lead->id;

                try{
                  $leadMeta->save();
                }
                catch(\Exception $e){
                   // this is much better than a generic 500 error
                    $lead->delete(); // we want to delete the lead if there is an error creating it's meta. A lead must have meta
                   return response()->json([
                      'error' => array(
                          'message' => $e->getMessage();,
                          'code' => '530',
                      )
                    ], 500);
                }

                
                return response()->json([
                    'success' => array(
                        'message' => 'Lead saved',
                        'leadID' => $lead->id
                    )
                ], 201);
            }
            // We end up here if the lead already exists
            else {
                return response()->json([
                    'error' => array(
                        'message' => 'Lead already exists',
                        'code' => '260'
                    )
                ], 400);
            }

        }
    }
}