<?php
namespace HermesAiBridge;

defined('ABSPATH') or die();

class AiProvider {
    protected $api_key;
    protected $base_url;
    protected $model;
    protected $max_tokens;
    protected $provider;

    public function __construct() {
        $this->provider = get_option('hermes_ai_provider', 'openai');
        $this->model = get_option('hermes_ai_model', 'gpt-4');
        $this->max_tokens = intval(get_option('hermes_ai_max_tokens', 2048));
        $this->api_key = get_option('hermes_ai_api_key', '');
        $this->base_url = get_option('hermes_ai_base_url', 'https://api.openai.com/v1');
    }

    /**
     * Generate content from a prompt.
     */
    public function generate($prompt, $context = 'general') {
        $system_prompt = $this->get_system_prompt($context);
        return $this->call_ai_api($system_prompt, $prompt);
    }

    /**
     * Call the configured AI provider API.
     */
    protected function call_ai_api($system, $user_prompt) {
        if (empty($this->api_key)) {
            return new \WP_Error('no_api_key', 'AI provider API key not configured. Set it in WordPress Admin → Hermes AI.');
        }

        $body = [
            'model' => $this->model,
            'max_tokens' => $this->max_tokens,
            'messages' => [
                ['role' => 'system', 'content' => $system],
                ['role' => 'user', 'content' => $user_prompt],
            ],
        ];

        $response = wp_remote_post($this->base_url . '/chat/completions', [
            'timeout' => 120,
            'headers' => [
                'Authorization' => 'Bearer ' . $this->api_key,
                'Content-Type' => 'application/json',
            ],
            'body' => wp_json_encode($body),
        ]);

        if (is_wp_error($response)) {
            RestController::log('error', 'AI API call failed', ['error' => $response->get_error_message()]);
            return $response;
        }

        $status = wp_remote_retrieve_response_code($response);
        $body = json_decode(wp_remote_retrieve_body($response), true);

        if ($status !== 200) {
            $error_msg = $body['error']['message'] ?? 'Unknown API error';
            RestController::log('error', 'AI API error', ['status' => $status, 'error' => $error_msg]);
            return new \WP_Error('ai_api_error', "AI API returned $status: $error_msg");
        }

        $content = $body['choices'][0]['message']['content'] ?? '';
        RestController::log('info', 'AI content generated', ['model' => $this->model, 'tokens' => $body['usage']['total_tokens'] ?? 0]);

        return $content;
    }

    /**
     * Newsletter-specific batch generation.
     */
    public function generate_newsletter_content() {
        $prompt = "Write a newsletter for Falah Letter — Islamic fintech and community updates. "
                . "Include sections: featured article, community news, upcoming events, featured project. "
                . "Write in a professional but warm tone. Target length: 1500-2000 words.";

        $content = $this->generate($prompt, 'newsletter');
        if (is_wp_error($content)) return;

        $post_id = wp_insert_post([
            'post_title' => 'Falah Letter — ' . wp_date('F j, Y'),
            'post_content' => $content,
            'post_type' => 'post',
            'post_status' => 'draft',
            'tags_input' => ['newsletter', 'falah-letter', 'automated'],
        ]);

        if ($post_id) {
            RestController::log('info', 'Newsletter draft generated', ['post_id' => $post_id]);
        }
    }

    protected function get_system_prompt($context) {
        $prompts = [
            'post' => 'You are a content writer for FalahOS, an Islamic fintech platform. '
                    . 'Write engaging, well-structured content. Use markdown for formatting. '
                    . 'Keep paragraphs short and scannable.',
            'newsletter' => 'You are the editor of Falah Letter, a weekly newsletter about '
                          . 'Islamic fintech, community updates, and FalahOS platform news. '
                          . 'Write in a professional warm tone.',
            'social' => 'You are a social media manager for FalahOS. Create engaging posts '
                       . 'optimized for LinkedIn and Twitter. Use emojis sparingly.',
        ];
        return $prompts[$context] ?? $prompts['post'];
    }
}