Generate Code for Intermediate Steps

<?php
require 'examples/boot.php';

use Cognesy\Instructor\StructuredOutput;

enum Choice: string {
    case A = 'A';
    case B = 'B';
    case C = 'C';
    case D = 'D';
    case E = 'E';
}

class Prediction {
    public function __construct(
        public Choice $choice
    ) {}
}

class ProgramExecution {
    public function __construct(
        public string $program_code
    ) {}
}

class ProgramOfThoughtSolver {
    private const PREFIX = '\<?php
// Answer this question by implementing a solver()
// function, use for loop if necessary.
function solver() {
    // Let\'s write a PHP program step by step,
    // and then return the answer
    // Firstly, we need to define the following
    // variables:';
    
    public function __invoke(string $query, array $options): string {
        $reasoning = $this->generateIntermediateReasoning($query);
        $answer = $this->executeProgram($reasoning->program_code);
        $prediction = $this->generatePrediction($answer, $options, $query);
        return $prediction->choice->value;
    }
    
    private function generateIntermediateReasoning(string $query): ProgramExecution {
        return (new StructuredOutput)->with(
            messages: [
                [
                    'role' => 'system',
                    'content' => 'You are a world class AI system that excels at answering user queries in a systematic and detailed manner. Generate a valid PHP program that can be executed to answer the user query.

Make sure to begin your generated program with the following structure:
```php
<?php
function solver() {
    // Your step-by-step logic here
    // Define variables, perform calculations
    // Return the final answer
}
return solver();
```'
                ],
                ['role' => 'user', 'content' => $query],
            ],
            responseModel: ProgramExecution::class,
        )->get();
    }
    
    private function executeProgram(string $code): mixed {
        try {
            $result = eval($code);
            return $result;
        } catch (Throwable $e) {
            throw new Exception("Program execution failed: " . $e->getMessage());
        }
    }
    
    private function generatePrediction(mixed $predictedAnswer, array $options, string $query): Prediction {
        $formattedOptions = implode(', ', $options);
        
        return (new StructuredOutput)->with(
            messages: [
                [
                    'role' => 'system',
                    'content' => "Find the closest option based on the question and prediction.

Question: {$query}
Prediction: {$predictedAnswer}
Options: [{$formattedOptions}]"
                ],
            ],
            responseModel: Prediction::class,
        )->get();
    }
}

$result = (new ProgramOfThoughtSolver)(
    "A trader sold an article at a profit of 20% for Rs.360. What is the cost price of the article?",
    ["A)270", "B)300", "C)280", "D)320", "E)315"]
);

dump($result);
?>