<?php
if (!defined('ABSPATH')) exit;

class AIWEST_Image_Generator {
    public static function automatic_source() {
        if (get_option('aiwest_auto_images_library_enabled', 'no') === 'yes') {
            return 'library';
        }
        return get_option('aiwest_auto_images_enabled', 'no') === 'yes' ? 'ai' : 'none';
    }

    public static function enabled() {
        return self::automatic_source() === 'ai';
    }

    public static function library_enabled() {
        return self::automatic_source() === 'library';
    }

    public static function automatic_media_enabled() {
        return in_array(self::automatic_source(), ['ai', 'library'], true);
    }

    public static function default_style() {
        $style = trim((string) get_option('aiwest_image_style', 'Modern, bright, professional website image, realistic or semi-illustrative, no text inside the image.'));
        return $style ?: 'Modern professional website image, no text inside the image.';
    }

    public static function allowed_sizes() {
        return class_exists('AIWEST_Graphics_Rules') ? AIWEST_Graphics_Rules::generation_sizes() : ['1024x1024', '1536x1024', '1024x1536'];
    }

    public static function normalize_size($size) {
        $size = sanitize_text_field((string) $size);
        return in_array($size, self::allowed_sizes(), true) ? $size : '1024x1024';
    }

    public static function build_prompt($title, $context = '') {
        return "Generate a professional image for a WordPress website.\n" .
            "Topic: {$title}\n" .
            "Context: {$context}\n" .
            "Brand style: " . self::default_style() . "\n" .
            "Requirements: no words or letters inside the image, clean composition, professional look, consistent with the website topic and brand.";
    }

    public static function generate_for_post($post_id, $context = '', $args = []) {
        $post = get_post($post_id);
        if (!$post) return new WP_Error('aiwest_post_missing', __('The post or page was not found.', 'ai-webmaster-studio'));

        $args = is_array($args) ? $args : [];
        if (class_exists('AIWEST_Graphics_Rules')) {
            $args = AIWEST_Graphics_Rules::resolve($args ?: ['action' => 'site_default']);
        }
        $size = self::normalize_size($args['generation_size'] ?? ($args['size'] ?? '1024x1024'));
        $placement = sanitize_key($args['placement'] ?? 'featured');
        $allowed_placements = class_exists('AIWEST_Graphics_Rules') ? AIWEST_Graphics_Rules::placement_values() : ['featured', 'content_top', 'featured_and_content_top'];
        if (!in_array($placement, $allowed_placements, true)) {
            $placement = 'featured';
        }

        $prompt = self::build_prompt($post->post_title, $context ?: wp_trim_words(wp_strip_all_tags($post->post_content), 80, '...'));
        $image = AIWEST_OpenAI::image_generation($prompt, $size);

        if (is_wp_error($image)) {
            update_post_meta($post_id, '_aiwest_image_error', $image->get_error_message());
            return $image;
        }

        $filename = sanitize_file_name('aiwest-' . $post_id . '-' . time() . '.png');
        $binary = '';

        if ($image['type'] === 'b64_json') {
            $binary = base64_decode($image['data'], true);
            if (!$binary) return new WP_Error('aiwest_image_decode_failed', __('The generated image could not be decoded.', 'ai-webmaster-studio'));
        } elseif ($image['type'] === 'url') {
            $response = wp_safe_remote_get($image['data'], ['timeout' => 120]);
            if (is_wp_error($response)) return $response;
            $binary = wp_remote_retrieve_body($response);
            if (!$binary) return new WP_Error('aiwest_image_download_failed', __('The generated image could not be downloaded.', 'ai-webmaster-studio'));
        } else {
            return new WP_Error('aiwest_image_unknown_type', __('The image provider returned an unknown data type.', 'ai-webmaster-studio'));
        }

        $uploaded = wp_upload_bits($filename, null, $binary);
        if (!empty($uploaded['error']) || empty($uploaded['file'])) {
            return new WP_Error('aiwest_image_save_failed', sanitize_text_field($uploaded['error'] ?? __('The generated image could not be saved.', 'ai-webmaster-studio')));
        }
        $filepath = $uploaded['file'];
        $filename = wp_basename($filepath);

        // wp_generate_attachment_metadata() is defined in this core image helper.
        require_once ABSPATH . 'wp-admin/includes/image.php';

        $filetype = wp_check_filetype($filename, null);

        $attachment_id = wp_insert_attachment([
            'post_mime_type' => $filetype['type'] ?: 'image/png',
            'post_title' => sanitize_text_field($post->post_title . ' — AI image'),
            'post_content' => '',
            'post_status' => 'inherit',
        ], $filepath, $post_id);

        if (is_wp_error($attachment_id)) return $attachment_id;

        $metadata = wp_generate_attachment_metadata($attachment_id, $filepath);
        wp_update_attachment_metadata($attachment_id, $metadata);

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

        if (class_exists('AIWEST_Content_Engine') && method_exists('AIWEST_Content_Engine', 'apply_attachment_to_post')) {
            AIWEST_Content_Engine::apply_attachment_to_post($post_id, intval($attachment_id), $placement, $args);
        } else {
            set_post_thumbnail($post_id, $attachment_id);
        }

        update_post_meta($post_id, '_aiwest_featured_image_generated', 'yes');
        update_post_meta($post_id, '_aiwest_featured_image_id', intval($attachment_id));
        update_post_meta($post_id, '_aiwest_image_size', $size);
        update_post_meta($post_id, '_aiwest_image_placement', $placement);
        update_post_meta($post_id, '_aiwest_image_display_size', sanitize_key($args['display_size'] ?? 'large'));
        update_post_meta($post_id, '_aiwest_image_alignment', sanitize_key($args['alignment'] ?? 'none'));
        update_post_meta($post_id, '_aiwest_graphics_rules_used', $args);

        if (class_exists('AIWEST_Logger')) {
            AIWEST_Logger::info('AI image generated and assigned.', [
                'post_id' => $post_id,
                'attachment_id' => $attachment_id,
                'size' => $size,
                'placement' => $placement,
            ]);
        }

        return intval($attachment_id);
    }
}