<?php
// SPDX-License-Identifier: GPL-2.0-or-later
//
// Managed async runner (poll-through). AI features run ONLY through the xpay
// backend, the merchant's session token authenticates; the Replicate token
// lives server-side in SSM and never touches wp_options. POST /process starts a
// prediction and returns immediately; we poll /process/status until it settles.
//
// - Manual single actions call run(): start + a short bounded poll; if it lands
//   in time we finish inline, otherwise we hand it to the local cron queue.
// - Bulk (local queue + dashboard-initiated) starts on one cron tick and polls
//   on later ticks, see class-product-images-job-queue.php.
if (!defined('ABSPATH')) { exit; }

class Acpimg_Managed {

	// Some plugin features map onto a different backend model call. auto_crop
	// asks the backend for a background cutout (mask), then crops locally.
	const BACKEND_FEATURE = ['auto_crop' => 'bg_remove'];

	// Manual-run bounded poll, admin-ajax runs on the WP server (not behind the
	// API's 30s ceiling), but we still cap it so a click never hangs a worker.
	const POLL_CAP_SECONDS = 18;
	const POLL_INTERVAL = 2;

	public static function backend_feature($feature) {
		return isset(self::BACKEND_FEATURE[$feature]) ? self::BACKEND_FEATURE[$feature] : $feature;
	}

	// Build the POST /process body for a feature + attachment.
	public static function build_payload($feature, $attachment_id, $extra, $tier) {
		$bf = self::backend_feature($feature);
		$opts = get_option('acpimg_settings', []);
		// site + image_id + email travel with every request so the backend can
		// key quota by site and record the per-site fixes log.
		$payload = [
			'feature'  => $bf,
			'tier'     => $tier === 'premium' ? 'premium' : 'default',
			'site'     => home_url(),
			'image_id' => (int) $attachment_id,
			'email'    => isset($opts['xpay_email']) ? (string) $opts['xpay_email'] : '',
		];
		if ($bf === 'scene_gen') {
			$payload['prompt'] = isset($extra['prompt']) ? (string) $extra['prompt'] : '';
		} else {
			$url = wp_get_attachment_url($attachment_id);
			if (!$url) return new WP_Error('acpimg_no_attachment', 'attachment not found');
			$payload['image_url'] = $url;
		}
		if ($bf === 'enhance') {
			$payload['scale'] = isset($extra['scale']) ? (int) $extra['scale'] : 2;
		}
		return $payload;
	}

	// Start a prediction. Returns prediction_id (string) or WP_Error.
	public static function start($feature, $attachment_id, $extra, $tier) {
		$payload = self::build_payload($feature, $attachment_id, $extra, $tier);
		if (is_wp_error($payload)) return $payload;
		$res = Acpimg_Provider_Xpay_Managed::post('/product-images/process', $payload);
		if (is_wp_error($res)) return $res;
		if (empty($res['prediction_id'])) return new WP_Error('acpimg_no_prediction', 'no prediction id returned');
		return (string) $res['prediction_id'];
	}

	// Poll a prediction. Returns ['status'=>..., 'output'=>...] or WP_Error.
	public static function poll($prediction_id) {
		return Acpimg_Provider_Xpay_Managed::status($prediction_id);
	}

	// Route a succeeded prediction's output to the feature's write-back.
	public static function finish($feature, $attachment_id, $output, $tier, $extra = []) {
		return apply_filters(
			'acpimg_finish_job',
			new WP_Error('acpimg_no_finisher', 'no finisher for ' . $feature),
			$feature,
			$attachment_id,
			$output,
			$tier,
			$extra
		);
	}

	// Manual single-action path: start + bounded poll. Finishes inline if the
	// prediction lands within POLL_CAP_SECONDS; otherwise defers to the cron
	// queue and returns a processing marker.
	public static function run($feature, $attachment_id, $extra = [], $tier = 'default') {
		if (Acpimg_Plugin::auth_mode() !== 'managed') {
			return new WP_Error('acpimg_no_auth', 'Sign in to xpay to use AI features.');
		}
		$pid = self::start($feature, $attachment_id, $extra, $tier);
		if (is_wp_error($pid)) return $pid;

		$deadline = time() + self::POLL_CAP_SECONDS;
		while (time() < $deadline) {
			sleep(self::POLL_INTERVAL);
			$st = self::poll($pid);
			if (is_wp_error($st)) continue;
			$status = isset($st['status']) ? $st['status'] : '';
			if ($status === 'succeeded') {
				return self::finish($feature, $attachment_id, isset($st['output']) ? $st['output'] : null, $tier, $extra);
			}
			if ($status === 'failed') {
				return new WP_Error('acpimg_failed', isset($st['error']) ? $st['error'] : 'prediction failed');
			}
		}
		// Still running, hand to the local queue so it completes on a later tick.
		Acpimg_Job_Queue::enqueue_awaiting($attachment_id, $feature, $pid, array_merge(['tier' => $tier], $extra));
		return ['status' => 'processing', 'prediction_id' => $pid];
	}
}