enums.php

<?php

namespace App\Enums;

// Industry enum
enum IndustryEnum: string
{
    case HVAC       = 'HVAC';
    case LOGISTICS  = 'Logistics';
    case ENGINEERING = 'Engineering';
    case OIL_GAS    = 'Oil & Gas';
}

<?php

namespace App\Enums;

use App\Enums\IndustryEnum;

enum VariableEnum: string
{
    case TEMPERATURE = 'temperature';
    case HUMIDITY    = 'humidity';
    case PRESSURE    = 'pressure';
    case VELOCITY    = 'velocity';
    case VOLUME      = 'volume';
    case MASS        = 'mass';

    // Type-safe mapping to industries
    const INDUSTRY_MAPPING = [
        self::TEMPERATURE->value => IndustryEnum::HVAC,
        self::HUMIDITY->value    => IndustryEnum::HVAC,
        self::PRESSURE->value    => IndustryEnum::OIL_GAS,
        self::VELOCITY->value    => IndustryEnum::ENGINEERING,
        self::VOLUME->value      => IndustryEnum::LOGISTICS,
        self::MASS->value        => IndustryEnum::LOGISTICS,
    ];

    /**
     * Get the industry enum for a variable
     */
    public function industry(): IndustryEnum
    {
        return self::INDUSTRY_MAPPING[$this->value];
    }

    /**
     * Get all variables for a specific industry
     */
    public static function variablesForIndustry(IndustryEnum $industry): array
    {
        return array_map(
            fn($var) => self::from($var),
            array_keys(
                array_filter(self::INDUSTRY_MAPPING, fn($ind) => $ind === $industry)
            )
        );
    }
}



// In Controller: 

$var = VariableEnum::TEMPERATURE;

// Get industry
$industry = $var->industry();
echo $industry->value; // HVAC

// Get all variables for LOGISTICS
$logisticsVars = VariableEnum::variablesForIndustry(IndustryEnum::LOGISTICS);
foreach ($logisticsVars as $v) {
    echo $v->value . "\n"; // VOLUME, MASS
}

- obadva enuma primaju string i vraćaju nazad industriju kojoj varijabla pripada ili sve varijable od određene industrije 
 
// routes/api.php
use App\Http\Controllers\Api\VariableIndustryController;

Route::get('/variables-industries', [VariableIndustryController::class, 'index']);
Route::get('/industry-from-variable/{variable}', [VariableIndustryController::class, 'getIndustryFromVariable']);
Route::get('/variables-from-industry/{industry}', [VariableIndustryController::class, 'getVariablesFromIndustry']);


- primjer API kontroler: 


 <?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Enums\IndustryEnum;
use App\Enums\VariableEnum;

class VariableIndustryController extends Controller
{
    /**
     * Return JSON with industries and their variables in a nested structure
     */
    public function index()
    {
        $industries = [];
        foreach (IndustryEnum::cases() as $industry) {
            $industries[] = [
                'industry'  => $industry->value,
                'variables' => array_map(
                    fn($variable) => $variable->value,
                    VariableEnum::variablesForIndustry($industry)
                )
            ];
        }

        $allIndustries = array_map(fn($industry) => $industry->value, IndustryEnum::cases());
        $allVariables = array_map(fn($variable) => $variable->value, VariableEnum::cases());

        return response()->json([
            'industries' => $industries,
            'all_industries' => $allIndustries,
            'all_variables'  => $allVariables,
        ]);
    }
/*
    getIndustryFromVariable(string $variable) returns the industry of that variable.

getVariablesFromIndustry(string $industry) returns all variables for a given industry.
*/

  /**
     * Get industry from a variable
     */
    public function getIndustryFromVariable(string $variable): JsonResponse
    {
        try {
            $industry = VariableEnum::from($variable)->industry();
            return response()->json([
                'variable' => $variable,
                'industry' => $industry->value,
            ]);
        } catch (\ValueError $e) {
            return response()->json([
                'error' => "Variable '{$variable}' does not exist"
            ], 404);
        }
    }

    /**
     * Get variables from an industry
     */
    public function getVariablesFromIndustry(string $industry): JsonResponse
    {
        try {
            $industryEnum = IndustryEnum::from($industry);
            $variables = array_map(
                fn($variable) => $variable->value,
                VariableEnum::variablesForIndustry($industryEnum)
            );

            return response()->json([
                'industry'  => $industryEnum->value,
                'variables' => $variables,
            ]);
        } catch (\ValueError $e) {
            return response()->json([
                'error' => "Industry '{$industry}' does not exist"
            ], 404);
        }
    }
}

- evo ga kako će izgledati response: 

{
  "industries": [
    {
      "industry": "HVAC",
      "variables": ["temperature", "humidity"]
    },
    {
      "industry": "LOGISTICS",
      "variables": ["volume", "mass"]
    },
    {
      "industry": "ENGINEERING",
      "variables": ["velocity"]
    },
    {
      "industry": "OIL_GAS",
      "variables": ["pressure"]
    }
  ],
  "all_industries": ["HVAC", "LOGISTICS", "ENGINEERING", "OIL_GAS"],
  "all_variables": ["temperature", "humidity", "pressure", "velocity", "volume", "mass"]
}