Context cache structured

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

use Cognesy\Instructor\StructuredOutput;
use Cognesy\Instructor\StructuredOutputRuntime;
use Cognesy\Instructor\Enums\OutputMode;
use Cognesy\Polyglot\Inference\Exceptions\ProviderAuthenticationException;
use Cognesy\Polyglot\Inference\LLMProvider;
use Cognesy\Schema\Attributes\Description;
class Project {
    public string $name;
    public string $targetAudience;
    /** @var string[] */
    #[Description('Technology platform and libraries used in the project')]
    public array $technologies;
    /** @var string[] */
    #[Description('Target audience domain specific features and capabilities of the project')]
    public array $features;
    /** @var string[] */
    #[Description('Target audience domain specific applications and potential use cases of the project')]
    public array $applications;
    #[Description('Explain the purpose of the project and the target audience domain specific problems it solves')]
    public string $description;
    #[Description('Target audience domain specific example code in Markdown demonstrating an application of the library')]
    public string $code;
}
?>

<?php
$content = file_get_contents(__DIR__ . '/../../../README.md');
$cachedSystem = 'Your goal is to respond questions about the project described in the README.md file'
    . "\n\n# README.md\n\n" . $content;
$cachedPrompt = 'Respond with strict JSON object using schema:' . "\n<|json_schema|>";

$providerName = getenv('INSTRUCTOR_CONTEXT_CACHE_PROVIDER') ?: 'anthropic';
$firstRuntime = StructuredOutputRuntime::fromProvider(LLMProvider::using($providerName))
    ->withOutputMode(OutputMode::MdJson);
$secondRuntime = StructuredOutputRuntime::fromProvider(LLMProvider::using($providerName))
    ->withOutputMode(OutputMode::MdJson);

echo "Using {$providerName} provider for context caching example.\n";
?>

<?php
// get StructuredOutputResponse object to get access to usage and other metadata
try {
    $response1 = (new StructuredOutput($firstRuntime))
        ->withCachedContext(
            system: $cachedSystem,
            prompt: $cachedPrompt,
        )
        ->with(
            messages: 'Describe the project in a way compelling to my audience: P&C insurance CIOs.',
            responseModel: Project::class,
            options: ['max_tokens' => 4096],
        )->create();
    $project1 = $response1->get();
} catch (ProviderAuthenticationException) {
    echo "Provider authentication failed for '{$providerName}'. Check the matching API key.\n";
    return;
}

// get processed value - instance of Project class
dump($project1);
assert($project1 instanceof Project);
assert($project1->name !== '');
assert($project1->description !== '');

// get usage information from inferenceResponse() when you need transport-level metadata
$usage1 = $response1->inferenceResponse()->usage();
echo "Usage: {$usage1->inputTokens} prompt tokens, {$usage1->cacheWriteTokens} cache write tokens, {$usage1->cacheReadTokens} cache read tokens\n";
?>

<?php
// get StructuredOutputResponse object to get access to usage and other metadata
try {
    $response2 = (new StructuredOutput($secondRuntime))
        ->withCachedContext(
            system: $cachedSystem,
            prompt: $cachedPrompt,
        )
        ->with(
            messages: "Describe the project in a way compelling to my audience: boutique CMS consulting company owner.",
            responseModel: Project::class,
            options: ['max_tokens' => 4096],
        )->create();
    $project2 = $response2->get();
} catch (ProviderAuthenticationException) {
    echo "Provider authentication failed for '{$providerName}'. Check the matching API key.\n";
    return;
}

// get the processed value - instance of Project class
dump($project2);
assert($project2 instanceof Project);
assert($project2->name !== '');
assert($project2->description !== '');

// get usage information from inferenceResponse() when you need transport-level metadata
$usage2 = $response2->inferenceResponse()->usage();
echo "Usage: {$usage2->inputTokens} prompt tokens, {$usage2->cacheReadTokens} cache read tokens\n";
if ($usage2->cacheReadTokens === 0) {
    echo "Note: cacheReadTokens is 0. Cache hits depend on model/provider eligibility.\n";
}
?>