<?php

namespace App\Services\LLM\Providers;

use App\Models\ModelPricing;
use Illuminate\Support\Facades\Cache;

class AnthropicProvider extends AbstractProvider
{
    protected string $baseUrl = 'https://api.anthropic.com/v1';
    private string $apiVersion = '2023-06-01';

    protected function buildRequest(array $messages, array $options): array
    {
        // Anthropic requires system message separate
        $systemMessage = null;
        $formattedMessages = [];

        foreach ($messages as $message) {
            if ($message['role'] === 'system') {
                $systemMessage = $message['content'];
            } else {
                $formattedMessages[] = $message;
            }
        }

        $request = array_filter([
            'model' => $options['model'] ?? 'claude-sonnet-4',
            'max_tokens' => $options['max_tokens'] ?? 4096,
            'messages' => $formattedMessages,
            'system' => $systemMessage,
            'temperature' => $options['temperature'] ?? null,
            'top_p' => $options['top_p'] ?? null,
            'stop_sequences' => $options['stop'] ?? null,
        ], fn($value) => $value !== null);

        return $request;
    }

    protected function getAuthHeaders(): array
    {
        return [
            'x-api-key' => $this->apiKey,
            'anthropic-version' => $this->apiVersion,
            'Content-Type' => 'application/json',
        ];
    }

    public function chatCompletion(array $messages, array $options = []): array
    {
        $data = $this->buildRequest($messages, $options);
        return $this->makeRequest('/messages', $data);
    }

    public function normalizeResponse(array $response): array
    {
        $content = '';
        if (isset($response['content']) && is_array($response['content'])) {
            foreach ($response['content'] as $block) {
                if ($block['type'] === 'text') {
                    $content .= $block['text'];
                }
            }
        }

        return [
            'id' => $response['id'] ?? null,
            'model' => $response['model'] ?? null,
            'content' => $content,
            'role' => $response['role'] ?? 'assistant',
            'finish_reason' => $response['stop_reason'] ?? null,
            'usage' => [
                'prompt_tokens' => $response['usage']['input_tokens'] ?? 0,
                'completion_tokens' => $response['usage']['output_tokens'] ?? 0,
                'total_tokens' => ($response['usage']['input_tokens'] ?? 0) + ($response['usage']['output_tokens'] ?? 0),
            ],
            'raw_response' => $response,
        ];
    }

    public function calculateCost(int $promptTokens, int $completionTokens, string $model): float
    {
        $cacheKey = "pricing:anthropic:{$model}";

        $pricing = Cache::remember($cacheKey, 3600, function () use ($model) {
            return ModelPricing::where('provider', 'anthropic')
                ->where('model', $model)
                ->where('is_active', true)
                ->first();
        });

        if (!$pricing) {
            return 0.0;
        }

        $promptCost = ($promptTokens / 1_000_000) * $pricing->input_price_per_million;
        $completionCost = ($completionTokens / 1_000_000) * $pricing->output_price_per_million;

        return round($promptCost + $completionCost, 6);
    }

    public function getSupportedModels(): array
    {
        return [
            'claude-opus-4',
            'claude-sonnet-4',
            'claude-haiku-4',
            'claude-3-opus',
            'claude-3-sonnet',
            'claude-3-haiku',
        ];
    }
}