<?php
/**
 * AI-referred revenue: once the store is connected, the plugin sends 7BE what WooCommerce already records about
 * each order's visit (its order attribution) and the order's net total, so 7BE can show how much ChatGPT, Gemini,
 * Perplexity and Copilot brought the store. Per order: its ID, date, net total, status, where the visit came from
 * (source type, utm_source, the referrer's host) and, since 0.9.3, a one-way SHA-256 hash of the buyer's email, so
 * 7BE can count a buyer AI brought for 12 months (an AI customer). Never a buyer's name, email, address, IP or the
 * items bought.
 *
 * - The last 60 days are sent once, in the background (WP-Cron), after connecting and after updating to 0.9.3.
 * - An order is sent again when its status changes or it is refunded.
 * - Once a day the orders changed in the last 3 days are sent again, so nothing is missed.
 *
 * Every request is signed with the store's key (see sevenbe_signed_api() in reviews.php).
 *
 * @package SevenBE_AI_Shelf
 */

defined( 'ABSPATH' ) || exit;

define( 'SEVENBE_ORDERS_OPTION', 'sevenbe_ai_shelf_orders' );
define( 'SEVENBE_ORDERS_DAYS', 60 );
define( 'SEVENBE_ORDERS_PAGE', 250 );
define( 'SEVENBE_ORDERS_TRIES', 5 );

/**
 * @return bool Whether the store is connected to 7BE (it has its signing key).
 */
function sevenbe_orders_connected() {
	$options = sevenbe_options();
	return '' !== $options['key'];
}

/**
 * The order statuses 7BE needs: the ones that count, and the ones that take an order back out.
 *
 * @return string[]
 */
function sevenbe_orders_statuses() {
	return array( 'processing', 'completed', 'on-hold', 'refunded', 'cancelled' );
}

/**
 * Where the history send stands. Not autoloaded: it is read only in the admin, by WP-Cron and when an order changes.
 *
 * @return array {
 *     @type string $version Plugin version that last set up the order send ('' before 0.9.0).
 *     @type int    $done    Time the 60-day history was sent (0 while it is not).
 *     @type int    $since   Start of the 60 days, fixed when the history send begins.
 *     @type int    $page    Next page of the history to send.
 *     @type int    $tries   Failed attempts so far.
 * }
 */
function sevenbe_orders_state() {
	return wp_parse_args(
		get_option( SEVENBE_ORDERS_OPTION, array() ),
		array(
			'version' => '',
			'done'    => 0,
			'since'   => 0,
			'page'    => 1,
			'tries'   => 0,
		)
	);
}

/**
 * @param array $state Order send state.
 */
function sevenbe_orders_save_state( $state ) {
	update_option( SEVENBE_ORDERS_OPTION, $state, false );
}

/**
 * What 7BE needs to know about one order: the order's money, where the visit came from and a one-way hash of the buyer's email.
 *
 * @param WC_Order $order The order.
 * @return array|null Null when this is not an order.
 */
function sevenbe_attribution_payload( $order ) {
	if ( ! $order instanceof WC_Order ) {
		return null;
	}
	$created = $order->get_date_created();
	// Net of tax and shipping (shipping tax is part of the total tax) and of the goods refunded: a refund's own tax and
	// shipping are already left out above, so only the rest of it comes off.
	$refunded = (float) $order->get_total_refunded() - (float) $order->get_total_tax_refunded() - (float) $order->get_total_shipping_refunded();
	$net      = max( 0, round( (float) $order->get_total() - (float) $order->get_total_tax() - (float) $order->get_shipping_total() - $refunded, 2 ) );

	// WooCommerce's order attribution keeps these on the order; the plugin reads them through the order API (HPOS-safe).
	$referrer = trim( (string) $order->get_meta( '_wc_order_attribution_referrer' ) );
	if ( '' !== $referrer && false === strpos( $referrer, '//' ) ) {
		$referrer = '//' . $referrer;
	}
	$host = '' !== $referrer ? wp_parse_url( $referrer, PHP_URL_HOST ) : '';

	// The buyer, only as a one-way hash of the email: 7BE never receives the email itself.
	$email = strtolower( trim( (string) $order->get_billing_email() ) );

	return array(
		'id'          => (string) $order->get_id(),
		'at'          => gmdate( 'c', $created ? $created->getTimestamp() : time() ),
		'net'         => $net,
		'status'      => preg_replace( '/^wc-/', '', (string) $order->get_status() ),
		'source_type' => mb_substr( sanitize_text_field( (string) $order->get_meta( '_wc_order_attribution_source_type' ) ), 0, 40 ),
		'utm_source'  => mb_substr( sanitize_text_field( (string) $order->get_meta( '_wc_order_attribution_utm_source' ) ), 0, 120 ),
		'referrer'    => is_string( $host ) ? mb_substr( strtolower( $host ), 0, 120 ) : '',
		'customer'    => '' !== $email ? hash( 'sha256', $email ) : '',
	);
}

/**
 * Send orders to 7BE (POST /api/apps/orders, at most 250 at a time).
 *
 * @param WC_Order[] $orders   The orders.
 * @param bool       $backfill Whether this is a page of the 60-day history.
 * @param bool       $blocking Wait for the answer; false sends without slowing the request down.
 * @param bool       $done     The history's last page: 7BE then has all 60 days, even when this page is empty.
 * @return bool Whether 7BE took them (always true for a send that does not wait).
 */
function sevenbe_orders_send( $orders, $backfill = false, $blocking = true, $done = false ) {
	$rows = array_values( array_filter( array_map( 'sevenbe_attribution_payload', $orders ) ) );
	if ( ! $rows && ! $done ) {
		return true;
	}
	$body = array(
		'plugin'   => SEVENBE_VERSION,
		'currency' => get_woocommerce_currency(),
		'backfill' => (bool) $backfill,
		'orders'   => $rows,
	);
	if ( $done ) {
		$body['done'] = true;
	}
	$result = sevenbe_signed_api( $body, $blocking, '/api/apps/orders' );
	if ( ! $blocking ) {
		return true;
	}
	return ! empty( $result['ok'] ) && ! isset( $result['error'] );
}

/**
 * Send the orders a query matches, 250 a page, until they are all sent or the time budget is used.
 *
 * @param array $query    wc_get_orders() arguments (without limit and paged).
 * @param bool  $backfill Whether these pages are the 60-day history.
 * @param int   $page     First page to send.
 * @param int   $deadline Time after which no new page starts (0 for no limit).
 * @return array { ok: bool, page: int } ok is false when 7BE did not take a page (page is that page); otherwise
 *               page is the next page still to send, or 0 when everything was sent.
 */
function sevenbe_orders_send_pages( $query, $backfill, $page = 1, $deadline = 0 ) {
	$query['limit']  = SEVENBE_ORDERS_PAGE;
	$query['return'] = 'objects';
	do {
		$query['paged'] = $page;
		$orders         = wc_get_orders( $query );
		$count          = count( $orders );
		$last           = SEVENBE_ORDERS_PAGE !== $count;
		// The history's last page says it is the last, even when it is empty (a store without orders in the 60 days),
		// so 7BE knows the history is in and shows the report.
		$done = $backfill && $last;
		if ( ( $count || $done ) && ! sevenbe_orders_send( $orders, $backfill, true, $done ) ) {
			return array(
				'ok'   => false,
				'page' => $page,
			);
		}
		++$page;
		if ( ! $last && $deadline && time() >= $deadline ) {
			return array(
				'ok'   => true,
				'page' => $page,
			);
		}
	} while ( ! $last );
	return array(
		'ok'   => true,
		'page' => 0,
	);
}

// ---------- The 60-day history ----------

/**
 * Schedule the history send in the background. Does nothing when one is already scheduled.
 *
 * @param int $delay Seconds from now.
 */
function sevenbe_orders_schedule_backfill( $delay = 15 ) {
	if ( ! wp_next_scheduled( 'sevenbe_orders_backfill' ) ) {
		wp_schedule_single_event( time() + $delay, 'sevenbe_orders_backfill' );
	}
}

/**
 * Make sure the daily resend is scheduled while the store is connected.
 */
function sevenbe_orders_schedule_daily() {
	if ( ! wp_next_scheduled( 'sevenbe_orders_daily' ) ) {
		wp_schedule_event( time() + HOUR_IN_SECONDS, 'daily', 'sevenbe_orders_daily' );
	}
}

/**
 * Start the 60-day history send from the beginning (after connecting, and after updating to 0.9.3).
 */
function sevenbe_orders_start() {
	sevenbe_orders_save_state(
		array(
			'version' => SEVENBE_VERSION,
			'done'    => 0,
			'since'   => 0,
			'page'    => 1,
			'tries'   => 0,
		)
	);
	sevenbe_orders_schedule_backfill();
	sevenbe_orders_schedule_daily();
}

/**
 * Forget the order send: the store disconnects, or the plugin is switched off.
 */
function sevenbe_orders_stop() {
	wp_clear_scheduled_hook( 'sevenbe_orders_backfill' );
	wp_clear_scheduled_hook( 'sevenbe_orders_daily' );
}

/**
 * WP-Cron: send the last 60 days of orders, a page of 250 at a time. A long history carries on in a new event;
 * a failure is tried again in an hour, up to 5 attempts.
 */
function sevenbe_orders_backfill_run() {
	if ( ! sevenbe_orders_connected() || ! function_exists( 'wc_get_orders' ) ) {
		return;
	}
	$state = sevenbe_orders_state();
	if ( $state['done'] ) {
		return;
	}
	if ( ! $state['since'] ) {
		$state['since'] = time() - SEVENBE_ORDERS_DAYS * DAY_IN_SECONDS;
	}
	$run = sevenbe_orders_send_pages(
		array(
			'status'       => sevenbe_orders_statuses(),
			'date_created' => '>' . $state['since'],
			'orderby'      => 'date',
			'order'        => 'ASC',
		),
		true,
		max( 1, (int) $state['page'] ),
		time() + 25
	);

	$state['page'] = $run['page'] ? $run['page'] : 1;
	if ( ! $run['ok'] ) {
		++$state['tries'];
		sevenbe_orders_save_state( $state );
		if ( $state['tries'] < SEVENBE_ORDERS_TRIES ) {
			sevenbe_orders_schedule_backfill( HOUR_IN_SECONDS );
		}
		return;
	}
	if ( $run['page'] ) {
		// More pages than fit in one run: carry on in a minute.
		sevenbe_orders_save_state( $state );
		sevenbe_orders_schedule_backfill( MINUTE_IN_SECONDS );
		return;
	}
	$state['done']  = time();
	$state['tries'] = 0;
	sevenbe_orders_save_state( $state );
}
add_action( 'sevenbe_orders_backfill', 'sevenbe_orders_backfill_run' );

// In the admin: after the plugin is updated to 0.9.3 (or later; 0.9.3 adds the buyer's hash) send the history once, pick up one that did not finish,
// and keep the daily resend scheduled.
add_action(
	'admin_init',
	function () {
		if ( wp_doing_ajax() || ! sevenbe_orders_connected() ) {
			return;
		}
		$state = sevenbe_orders_state();
		if ( version_compare( $state['version'], '0.9.3', '<' ) ) {
			sevenbe_orders_start();
			return;
		}
		if ( SEVENBE_VERSION !== $state['version'] ) {
			$state['version'] = SEVENBE_VERSION;
			sevenbe_orders_save_state( $state );
		}
		// A history send that was cleared before it finished (the plugin was switched off and on) is picked up again.
		if ( ! $state['done'] && $state['tries'] < SEVENBE_ORDERS_TRIES ) {
			sevenbe_orders_schedule_backfill();
		}
		sevenbe_orders_schedule_daily();
	}
);

// ---------- Live: an order is sent when it changes ----------

/**
 * Orders to send when the request ends: one send per order even if it changed several times, with its final totals.
 *
 * @param int $order_id An order to add; 0 returns the queue and empties it.
 * @return int[] The queued order IDs (when called with 0).
 */
function sevenbe_orders_queue( $order_id = 0 ) {
	static $ids = array();
	if ( $order_id ) {
		$ids[ (int) $order_id ] = (int) $order_id;
		return array();
	}
	$queued = array_values( $ids );
	$ids    = array();
	return $queued;
}

/**
 * @param int $order_id The order that changed.
 */
function sevenbe_orders_changed( $order_id ) {
	if ( sevenbe_orders_connected() ) {
		sevenbe_orders_queue( $order_id );
	}
}
add_action( 'woocommerce_order_status_changed', 'sevenbe_orders_changed', 20 );
add_action( 'woocommerce_order_refunded', 'sevenbe_orders_changed', 20 );

/**
 * At the end of the request, send the orders that changed. The request does not wait for 7BE's answer.
 */
function sevenbe_orders_flush() {
	$ids = sevenbe_orders_queue();
	if ( ! $ids || ! function_exists( 'wc_get_order' ) ) {
		return;
	}
	$orders = array();
	foreach ( $ids as $id ) {
		$order = wc_get_order( $id );
		// Carts that are not orders yet are not sent.
		if ( $order && ! in_array( $order->get_status(), array( 'checkout-draft', 'auto-draft', 'draft' ), true ) ) {
			$orders[] = $order;
		}
	}
	foreach ( array_chunk( $orders, SEVENBE_ORDERS_PAGE ) as $chunk ) {
		sevenbe_orders_send( $chunk, false, false );
	}
}
add_action( 'shutdown', 'sevenbe_orders_flush' );

// ---------- Daily resend ----------

/**
 * WP-Cron, daily: send the orders changed in the last 3 days again, and pick up a history send that never finished.
 */
function sevenbe_orders_daily_run() {
	if ( ! sevenbe_orders_connected() || ! function_exists( 'wc_get_orders' ) ) {
		return;
	}
	$state = sevenbe_orders_state();
	if ( ! $state['done'] ) {
		// A history send that used up its attempts (7BE down for hours) gets a new round each day.
		if ( $state['tries'] >= SEVENBE_ORDERS_TRIES ) {
			$state['tries'] = 0;
			sevenbe_orders_save_state( $state );
		}
		sevenbe_orders_schedule_backfill();
	}
	sevenbe_orders_send_pages(
		array(
			'status'        => sevenbe_orders_statuses(),
			'date_modified' => '>' . ( time() - 3 * DAY_IN_SECONDS ),
			'orderby'       => 'date',
			'order'         => 'ASC',
		),
		false,
		1,
		time() + 25
	);
}
add_action( 'sevenbe_orders_daily', 'sevenbe_orders_daily_run' );