<?php
/**
 * Plugin Name: DZS AI Featured Image Generator
 * Description: Lists posts without featured images and allows generating them using OpenAI or Google Gemini.
 * Version: 1.0.3
 * Author: DigitalZoomStudio
 * License: GPLv2 or later
 * Text Domain: add-missing-featured-image-dzs
 */

if (!defined('ABSPATH')) {
    exit;
}

// 1. Add Admin Menu
add_action('admin_menu', 'dzs_amfi_add_admin_menu');
function dzs_amfi_add_admin_menu()
{
    add_menu_page(
        'DZS AI Featured Image Generator',
        'DZS AI Featured Images',
        'manage_options',
        'add-missing-featured-image-dzs',
        'dzs_amfi_admin_page_html',
        'dashicons-format-image'
    );
    add_submenu_page(
        'add-missing-featured-image-dzs',
        'Settings',
        'Settings',
        'manage_options',
        'dzs-ai-featured-image-generator-settings',
        'dzs_amfi_settings_page_html'
    );
}

// 1.5. Enqueue Admin Scripts
add_action('admin_enqueue_scripts', 'dzs_amfi_admin_enqueue_scripts');
function dzs_amfi_admin_enqueue_scripts($hook)
{
    if ($hook === 'toplevel_page_add-missing-featured-image-dzs') {
        wp_enqueue_script(
            'dzs-amfi-admin-script',
            plugins_url('assets/js/admin-script.js', __FILE__),
            array('jquery'),
            '1.0.3',
            true
        );

        wp_localize_script('dzs-amfi-admin-script', 'dzsAmfiData', array(
            'ajaxUrl' => admin_url('admin-ajax.php'),
            'nonce'   => wp_create_nonce('dzs_amfi_generate_nonce'),
        ));
    } elseif ($hook === 'add-missing-featured-image-dzs_page_dzs-ai-featured-image-generator-settings') {
        wp_enqueue_script(
            'dzs-amfi-settings-script',
            plugins_url('assets/js/settings-script.js', __FILE__),
            array(),
            '1.0.3',
            true
        );
    }
}

// 2. Register Settings
add_action('admin_init', 'dzs_amfi_register_settings');
function dzs_amfi_register_settings()
{
    register_setting('dzs_amfi_settings_group', 'dzs_amfi_openai_api_key', array('sanitize_callback' => 'sanitize_text_field'));
    register_setting('dzs_amfi_settings_group', 'dzs_amfi_gemini_api_key', array('sanitize_callback' => 'sanitize_text_field'));
    register_setting('dzs_amfi_settings_group', 'dzs_amfi_resolution', array('sanitize_callback' => 'sanitize_text_field'));
    register_setting('dzs_amfi_settings_group', 'dzs_amfi_dalle_model', array('sanitize_callback' => 'sanitize_text_field'));
    register_setting('dzs_amfi_settings_group', 'dzs_amfi_gemini_model', array('sanitize_callback' => 'sanitize_text_field'));
    register_setting('dzs_amfi_settings_group', 'dzs_amfi_custom_prompt', array('sanitize_callback' => 'sanitize_textarea_field'));
}

function dzs_amfi_settings_page_html()
{
    require_once plugin_dir_path(__FILE__) . 'settings-page.php';
}

// 3. Admin Page HTML (List Posts)
function dzs_amfi_admin_page_html()
{
    require_once plugin_dir_path(__FILE__) . 'admin-page.php';
}

// 4. AJAX Handler for Generation
add_action('wp_ajax_dzs_amfi_generate_image', 'dzs_amfi_generate_image_ajax');
function dzs_amfi_generate_image_ajax()
{
    check_ajax_referer('dzs_amfi_generate_nonce', 'security');

    if (!current_user_can('manage_options')) {
        wp_send_json_error('Unauthorized');
    }

    if (!isset($_POST['post_id'])) {
        wp_send_json_error('Missing Post ID');
    }

    $post_id = intval($_POST['post_id']);
    if (!$post_id) {
        wp_send_json_error('Invalid Post ID');
    }

    $model = get_option('dzs_amfi_dalle_model', 'dall-e-2');

    if ($model === 'nano-banana-2') {
        $api_key = get_option('dzs_amfi_gemini_api_key');
        if (empty($api_key)) {
            wp_send_json_error('Gemini API Key is missing. Please set it in Settings.');
        }
    }
    else {
        $api_key = get_option('dzs_amfi_openai_api_key');
        if (empty($api_key)) {
            wp_send_json_error('OpenAI API Key is missing. Please set it in Settings.');
        }
    }

    $resolution = get_option('dzs_amfi_resolution', '1024x1024');

    // Support custom cropping for non-standard resolutions
    $supported_dalle2_sizes = array('256x256', '512x512', '1024x1024');
    $supported_dalle3_sizes = array('1024x1024', '1024x1792', '1792x1024');

    $api_size = '1024x1024';
    $custom_crop = false;
    $target_w = 1024;
    $target_h = 1024;

    if ($model === 'dall-e-2') {
        if (in_array($resolution, $supported_dalle2_sizes)) {
            $api_size = $resolution;
        }
        else {
            $custom_crop = true;
        }
    }
    elseif ($model === 'nano-banana-2') {
        // Assume nano-banana-2 works mechanically similarly to DALL-E 3 for base queries
        if (in_array($resolution, $supported_dalle3_sizes)) {
            $api_size = $resolution;
        }
        else {
            $custom_crop = true;
        }
    }
    else {
        if (in_array($resolution, $supported_dalle3_sizes)) {
            $api_size = $resolution;
        }
        else {
            $custom_crop = true;
        }
    }

    if ($custom_crop) {
        $parts = explode('x', strtolower(trim($resolution)));
        if (count($parts) === 2) {
            $target_w = intval($parts[0]);
            $target_h = intval($parts[1]);
        }
        else {
            $custom_crop = false;
        }
    }

    $post = get_post($post_id);

    $custom_prompt_template = get_option('dzs_amfi_custom_prompt');

    if (!empty(trim($custom_prompt_template))) {
        // Use custom prompt and replace placeholders
        $prompt = str_replace(
            array('{{post_title}}', '{{post_content}}'),
            array($post->post_title, wp_strip_all_tags(substr($post->post_content, 0, 500))),
            $custom_prompt_template
        );
    }
    else {
        // Fallback to default behavior
        $prompt = wp_strip_all_tags($post->post_title . '. ' . substr($post->post_content, 0, 500));
    }

    // Ensure prompt is not too long for OpenAI (max 1000 chars typically)
    $prompt = substr($prompt, 0, 1000);

    if (empty(trim($prompt))) {
        $prompt = "Abstract tech background image";
    }

    // Branch API payload logic depending on Model
    if ($model === 'nano-banana-2') {
        // Nano Banana 2 uses the Gemini API protocol
        $gemini_model = get_option('dzs_amfi_gemini_model', 'gemini-2.5-flash-image');
        $gemini_url = 'https://generativelanguage.googleapis.com/v1beta/models/' . $gemini_model . ':generateContent';

        $aspect_ratio = "1:1";
        if (!$custom_crop) {
            if ($api_size == '1024x1792')
                $aspect_ratio = "9:16";
            if ($api_size == '1792x1024')
                $aspect_ratio = "16:9";
        }

        $response = wp_remote_post($gemini_url, array(
            'timeout' => 60,
            'headers' => array(
                'x-goog-api-key' => $api_key,
                'Content-Type' => 'application/json'
            ),
            'body' => wp_json_encode(array(
                'contents' => array(
                    array(
                        'parts' => array(
                            array('text' => 'Generate a high quality image representing: ' . $prompt)
                        )
                    )
                ),
                'generationConfig' => array(
                    'imageConfig' => array(
                        'aspectRatio' => $aspect_ratio
                    )
                )
            ))
        ));

    }
    else {
        // Call OpenAI API
        $response = wp_remote_post('https://api.openai.com/v1/images/generations', array(
            'timeout' => 60,
            'headers' => array(
                'Authorization' => 'Bearer ' . $api_key,
                'Content-Type' => 'application/json'
            ),
            'body' => wp_json_encode(array(
                'model' => $model,
                'prompt' => $prompt,
                'n' => 1,
                'size' => $api_size
            ))
        ));
    }

    if (is_wp_error($response)) {
        wp_send_json_error($response->get_error_message());
    }

    $body = wp_remote_retrieve_body($response);
    $data = json_decode($body, true);

    if ($model === 'nano-banana-2') {

        if (isset($data['error'])) {
            wp_send_json_error('Gemini API Error: ' . $data['error']['message']);
        }

        $base64_data = '';
        $mime_type = 'image/png';
        if (!empty($data['candidates'][0]['content']['parts']) && is_array($data['candidates'][0]['content']['parts'])) {
            foreach ($data['candidates'][0]['content']['parts'] as $part) {
                if (!empty($part['inlineData']['data'])) {
                    $base64_data = $part['inlineData']['data'];
                    if (!empty($part['inlineData']['mimeType'])) {
                        $mime_type = $part['inlineData']['mimeType'];
                    }
                    break;
                }
                elseif (!empty($part['inline_data']['data'])) {
                    $base64_data = $part['inline_data']['data'];
                    if (!empty($part['inline_data']['mime_type'])) {
                        $mime_type = $part['inline_data']['mime_type'];
                    }
                    break;
                }
            }
        }

        if (empty($base64_data)) {
            wp_send_json_error('No image data returned from Gemini API. Raw response: ' . $body);
        }

        $image_data = base64_decode($base64_data);
        $upload_dir = wp_upload_dir();

        $api_ext = (strpos($mime_type, 'jpeg') !== false) ? '.jpg' : '.png';
        $filename_temp = 'gemini_raw_' . $post_id . '_' . time() . $api_ext;
        $file_path_temp = $upload_dir['path'] . '/' . $filename_temp;

        // Write the raw payload to disk
        file_put_contents($file_path_temp, $image_data);

        $filename = 'gemini_' . $post_id . '_' . time() . '.jpg';
        $file_path = $upload_dir['path'] . '/' . $filename;

        // Strictly enforce JPEG conversion for higher efficiency
        $image_editor = wp_get_image_editor($file_path_temp);
        if (!is_wp_error($image_editor)) {
            $saved_image = $image_editor->save($file_path, 'image/jpeg');
            if (!is_wp_error($saved_image)) {
                wp_delete_file($file_path_temp); // Clean up the raw file
            }
            else {
                $file_path = $file_path_temp; // Fallback if edit fails
                $filename = $filename_temp;
            }
        }
        else {
            $file_path = $file_path_temp; // Fallback if editor invalid
            $filename = $filename_temp;
        }

        $filetype = wp_check_filetype($filename, null);
        $attachment = array(
            'post_mime_type' => $filetype['type'],
            'post_title' => sanitize_file_name($filename),
            'post_content' => 'Generated by Nano Banana / Gemini for Post ' . $post_id,
            'post_status' => 'inherit'
        );

        require_once(ABSPATH . 'wp-admin/includes/image.php');
        require_once(ABSPATH . 'wp-admin/includes/file.php');
        require_once(ABSPATH . 'wp-admin/includes/media.php');

        $attachment_id = wp_insert_attachment($attachment, $file_path, $post_id);

        if (is_wp_error($attachment_id)) {
            wp_send_json_error($attachment_id->get_error_message());
        }

        $attach_data = wp_generate_attachment_metadata($attachment_id, $file_path);
        wp_update_attachment_metadata($attachment_id, $attach_data);

    }
    else {

        if (isset($data['error'])) {
            wp_send_json_error($data['error']['message']);
        }

        if (!isset($data['data'][0]['url'])) {
            wp_send_json_error('No image URL returned from OpenAI.');
        }

        $image_url = $data['data'][0]['url'];

        // Sideload Image
        require_once(ABSPATH . 'wp-admin/includes/media.php');
        require_once(ABSPATH . 'wp-admin/includes/file.php');
        require_once(ABSPATH . 'wp-admin/includes/image.php');

        $desc = 'Generated by OpenAI for Post ' . $post_id;

        // media_sideload_image returns attachment ID if 'id' is passed as 4th param
        $attachment_id = media_sideload_image($image_url, $post_id, $desc, 'id');

        if (is_wp_error($attachment_id)) {
            wp_send_json_error($attachment_id->get_error_message());
        }
    }

    if ($custom_crop && $target_w > 0 && $target_h > 0) {
        $img_path = get_attached_file($attachment_id);

        $image = wp_get_image_editor($img_path);
        if (!is_wp_error($image)) {
            $image->resize($target_w, $target_h, true); // true is for crop
            $image->save($img_path);

            $attach_data = wp_generate_attachment_metadata($attachment_id, $img_path);
            wp_update_attachment_metadata($attachment_id, $attach_data);
        }
    }

    update_post_meta($attachment_id, '_wp_attachment_image_alt', $post->post_title);

    set_post_thumbnail($post_id, $attachment_id);

    wp_send_json_success('Image generated and set successfully.');
}