<?php

declare(strict_types=1);

namespace WordPress\PerplexityAiProvider\Metadata;

use WordPress\AiClient\Messages\Enums\ModalityEnum;
use WordPress\AiClient\Providers\ApiBasedImplementation\AbstractApiBasedModelMetadataDirectory;
use WordPress\AiClient\Providers\Models\DTO\ModelMetadata;
use WordPress\AiClient\Providers\Models\DTO\SupportedOption;
use WordPress\AiClient\Providers\Models\Enums\CapabilityEnum;
use WordPress\AiClient\Providers\Models\Enums\OptionEnum;

/**
 * Class for the Perplexity (Sonar) model metadata directory.
 *
 * Unlike most providers, Perplexity does not expose a model listing endpoint for its
 * Sonar chat models (its `/v1/models` endpoint lists a separate model gateway, not the
 * Sonar chat API). The supported Sonar models are therefore defined statically here.
 *
 * @since 1.0.0
 */
class PerplexityModelMetadataDirectory extends AbstractApiBasedModelMetadataDirectory
{
    /**
     * The supported Sonar models, mapped to their human-readable display names.
     *
     * @since 1.0.0
     *
     * @var array<string, string>
     */
    private const MODELS = [
        'sonar'               => 'Sonar',
        'sonar-pro'           => 'Sonar Pro',
        'sonar-reasoning'     => 'Sonar Reasoning',
        'sonar-reasoning-pro' => 'Sonar Reasoning Pro',
        'sonar-deep-research' => 'Sonar Deep Research',
    ];

    /**
     * {@inheritDoc}
     *
     * Returns the statically defined Sonar models. No HTTP request is made because
     * Perplexity does not provide a listing endpoint for these chat models.
     *
     * @since 1.0.0
     *
     * @return array<string, ModelMetadata> Map of model ID to model metadata.
     */
    protected function sendListModelsRequest(): array
    {
        $capabilities = [
            CapabilityEnum::textGeneration(),
            CapabilityEnum::chatHistory(),
        ];

        $options = [
            new SupportedOption(OptionEnum::systemInstruction()),
            new SupportedOption(OptionEnum::maxTokens()),
            new SupportedOption(OptionEnum::temperature()),
            new SupportedOption(OptionEnum::topP()),
            new SupportedOption(OptionEnum::stopSequences()),
            new SupportedOption(OptionEnum::presencePenalty()),
            new SupportedOption(OptionEnum::frequencyPenalty()),
            new SupportedOption(OptionEnum::outputMimeType(), ['text/plain', 'application/json']),
            new SupportedOption(OptionEnum::outputSchema()),
            new SupportedOption(OptionEnum::customOptions()),
            new SupportedOption(OptionEnum::inputModalities(), [[ModalityEnum::text()]]),
            new SupportedOption(OptionEnum::outputModalities(), [[ModalityEnum::text()]]),
        ];

        $models = [];
        foreach (self::MODELS as $modelId => $displayName) {
            $models[$modelId] = new ModelMetadata(
                $modelId,
                $displayName,
                $capabilities,
                $options
            );
        }

        return $models;
    }
}