<?php

namespace StoreSuit;

defined( 'ABSPATH' ) || exit;
// phpcs:disable WordPress.Security.EscapeOutput.ExceptionNotEscaped -- Messages are returned as JSON by Admin::ajax() and shown with textContent.
/**
 * Home's "Selling fast, worth buying again" card (Almira's owner, 31 Oct 2026; every store): products that sold in the last
 * 30 days and are sold out or will be within two weeks at that pace, with what restocking would earn. Read only.
 *
 * Sales are the reporting facts' lines (DashboardFacts: every channel's orders, web and marketplaces alike, returns and
 * refunds taken off; never a cancelled, failed or pending order or a quote), in the store's currency. Options that share
 * their product's stock count as that product. The unit price is what the 30 days' sales really brought per unit (after
 * discounts, before tax). The unit cost is the one every screen uses (StoreRuler Pro: the purchase engine's, which is
 * WooCommerce's cost of goods when that is on; the free build: WooCommerce's cost of goods only), shown with the margin to
 * people with the finance permission only. Restocking means 30 more days of sales at the same pace. Kept 10 minutes.
 */
final class RestockPicks {
    public const DAYS = 30;

    /** Sold out, or out within this many days at the last 30 days' pace. */
    public const SOON = 14;

    /** At least this many units in the 30 days: one sale is no pace. */
    public const MIN_UNITS = 2;

    public const LIMIT = 10;

    private const CACHE = 'storesuit_restock_picks_';

    private const SCAN = 400;

    public static function read() : array {
        Store::require_cap( 'manage_woocommerce' );
        $finance = current_user_can( 'storesuit_finance' );
        if ( get_option( 'storesuit_dashboard_facts_ready' ) !== '1' ) {
            return array(
                'building' => true,
            );
        }
        $key = self::CACHE . (( $finance ? 'f' : 's' )) . '_' . get_woocommerce_currency();
        $kept = get_transient( $key );
        if ( is_array( $kept ) ) {
            return $kept;
        }
        $out = self::build( $finance );
        set_transient( $key, $out, 10 * MINUTE_IN_SECONDS );
        return $out;
    }

    /** Drops the kept cards (tests; a product's stock change waits the 10 minutes otherwise). */
    public static function forget() : void {
        foreach ( array('f', 's') as $who ) {
            delete_transient( self::CACHE . $who . '_' . get_woocommerce_currency() );
        }
    }

    /** Units and net amount per product or option over the last 30 days, from the facts (the same keyset walk as DashboardTotals::top()). */
    public static function sold( string $currency ) : array {
        global $wpdb;
        $today = new \DateTimeImmutable('today', wp_timezone());
        $at = $today->modify( '-' . (self::DAYS - 1) . ' days' )->format( 'Y-m-d' ) . ' 00:00:00';
        $stop = $today->format( 'Y-m-d' ) . ' 23:59:59';
        $after = 0;
        $deadline = microtime( true ) + 2.5;
        $sold = array();
        do {
            if ( microtime( true ) > $deadline ) {
                throw new \RuntimeException(I18n::t( 'This list is taking too long to prepare. Try again in a moment.' ));
            }
            $rows = DashboardTotals::rows( $wpdb->get_results( $wpdb->prepare( 'SELECT f.order_id,f.created_at,f.items_json FROM %i f FORCE INDEX (`period`) JOIN %i i ON i.order_id=f.order_id WHERE f.currency=%s AND f.created_at>=%s AND f.created_at<=%s AND (f.created_at>%s OR f.order_id>%d) AND f.status NOT IN (' . implode( ',', array_fill( 0, count( SaleStatus::NOT_SALES ), '%s' ) ) . ') ORDER BY f.created_at,f.order_id LIMIT 500', array_merge( array(
                DashboardFacts::table(),
                OrderIndex::table(),
                $currency,
                $at,
                $stop,
                $at,
                $after
            ), SaleStatus::NOT_SALES ) ), ARRAY_A ) );
            foreach ( $rows as $row ) {
                foreach ( (array) json_decode( (string) $row['items_json'], true ) as $item ) {
                    $id = ( is_array( $item ) ? (int) ($item['id'] ?? 0) : 0 );
                    if ( $id <= 0 ) {
                        continue;
                    }
                    $sold[$id] = array(
                        'qty' => ($sold[$id]['qty'] ?? 0.0) + (float) ($item['qty'] ?? 0),
                        'net' => ($sold[$id]['net'] ?? 0.0) + (float) ($item['net'] ?? 0),
                    );
                }
                $at = (string) $row['created_at'];
                $after = (int) $row['order_id'];
            }
        } while ( count( $rows ) === 500 );
        return $sold;
    }

    /** A product's unit cost, or null when none is known (a missing cost is not 0). */
    private static function cost( \WC_Product $p ) : ?float {
        $cost = null;
        // WooCommerce's own cost of goods (9.5+), when the store switched it on.
        if ( class_exists( 'Automattic\\WooCommerce\\Utilities\\FeaturesUtil' ) && \Automattic\WooCommerce\Utilities\FeaturesUtil::feature_is_enabled( 'cost_of_goods_sold' ) && method_exists( $p, 'get_cogs_effective_value' ) ) {
            $value = $p->get_cogs_effective_value();
            $cost = ( is_numeric( $value ) && (float) $value > 0 ? (float) $value : null );
        }
        return $cost;
    }

    /** An option's values ("Red, 3-6 months"), else what its own name adds to its product's ("Socks - Red"). */
    private static function option_name( \WC_Product $option, \WC_Product $parent ) : string {
        $values = Store::plain( wc_get_formatted_variation(
            $option,
            true,
            false,
            false
        ) );
        if ( $values !== '' ) {
            return $values;
        }
        $name = Store::plain( $option->get_name() );
        $base = Store::plain( $parent->get_name() );
        return ( $name !== $base && str_starts_with( $name, $base ) ? trim( (string) preg_replace( '/^[\\s\\-–]+/u', '', substr( $name, strlen( $base ) ) ) ) : '' );
    }

    private static function build( bool $finance ) : array {
        $currency = get_woocommerce_currency();
        $sold = self::sold( $currency );
        // Options that share their product's stock add up on the product that holds it.
        uasort( $sold, static fn( $a, $b ) => $b['qty'] <=> $a['qty'] );
        $groups = array();
        foreach ( array_slice(
            $sold,
            0,
            self::SCAN,
            true
        ) as $id => $s ) {
            if ( $s['qty'] <= 0 ) {
                continue;
            }
            $p = wc_get_product( $id );
            if ( !$p || $p->get_status() !== 'publish' && !$p->is_type( 'variation' ) ) {
                continue;
            }
            $holder = ( $p->managing_stock() ? (int) $p->get_stock_managed_by_id() : $id );
            $groups[$holder]['ids'][] = $id;
            $groups[$holder]['qty'] = ($groups[$holder]['qty'] ?? 0.0) + $s['qty'];
            $groups[$holder]['net'] = ($groups[$holder]['net'] ?? 0.0) + $s['net'];
        }
        $rows = array();
        $pictures = array();
        $decimals = wc_get_price_decimals();
        foreach ( $groups as $holder => $g ) {
            if ( $g['qty'] < self::MIN_UNITS ) {
                continue;
            }
            $p = wc_get_product( $holder );
            if ( !$p ) {
                continue;
            }
            $parent = ( $p->is_type( 'variation' ) ? wc_get_product( $p->get_parent_id() ) : null );
            if ( $parent && $parent->get_status() !== 'publish' ) {
                continue;
            }
            $managed = $p->managing_stock();
            $stock = ( $managed ? (float) $p->get_stock_quantity() : null );
            $out = ( $managed ? $stock <= 0 : $p->get_stock_status() === 'outofstock' );
            $per_day = $g['qty'] / self::DAYS;
            $days_left = ( $managed && $stock > 0 ? $stock / $per_day : (( $out ? 0.0 : null )) );
            if ( !$out && ($days_left === null || $days_left > self::SOON) ) {
                continue;
            }
            $price = $g['net'] / $g['qty'];
            $restock = (int) max( 0, ceil( round( $g['qty'] - max( 0.0, (float) $stock ), 6 ) ) );
            $row = array(
                'id'          => $holder,
                'name'        => Store::plain( ( $parent ? $parent->get_name() : $p->get_name() ) ),
                'variant'     => ( $parent ? self::option_name( $p, $parent ) : (( count( $g['ids'] ) > 1 || $p->is_type( 'variable' ) ? I18n::t( 'All options' ) : '' )) ),
                'sku'         => (string) $p->get_sku(),
                'sold'        => round( $g['qty'], 2 ),
                'stock'       => $stock,
                'out'         => $out,
                'days_left'   => ( $days_left === null ? null : round( $days_left, 1 ) ),
                'per_day'     => round( $per_day, 2 ),
                'restock'     => $restock,
                'revenue_day' => round( $g['net'] / self::DAYS, $decimals ),
                'url'         => admin_url( 'admin.php?page=storesuit-products&id=' . (( $parent ? $parent->get_id() : $holder )) ),
            );
            if ( $finance ) {
                $cost = self::cost( $p );
                $unit = ( $cost === null ? null : $price - $cost );
                $row += array(
                    'price'          => round( $price, $decimals ),
                    'cost'           => ( $cost === null ? null : round( $cost, $decimals ) ),
                    'margin'         => ( $unit === null || $price <= 0 ? null : round( 100 * $unit / $price, 1 ) ),
                    'profit_day'     => ( $unit === null ? null : round( $unit * $per_day, $decimals ) ),
                    'profit_restock' => ( $unit === null ? null : round( $unit * $restock, $decimals ) ),
                );
            }
            $rows[] = $row;
            $pictures[$holder] = array($holder, ( $parent ? $parent->get_id() : 0 ));
        }
        // Profit per day first where the cost is known; otherwise (or without the finance permission) sales per day.
        usort( $rows, static function ( $a, $b ) use($finance) {
            if ( $finance && ($a['profit_day'] === null) !== ($b['profit_day'] === null) ) {
                return ( $a['profit_day'] === null ? 1 : -1 );
            }
            if ( $finance && $a['profit_day'] !== null ) {
                return array($b['profit_day'], $b['per_day']) <=> array($a['profit_day'], $a['per_day']);
            }
            return array($b['per_day'], $b['revenue_day']) <=> array($a['per_day'], $a['revenue_day']);
        } );
        $buy = '';
        // Money stays with the finance permission: the sales amount per day only orders the rows for everyone else.
        $shown = array_slice( $rows, 0, self::LIMIT );
        if ( !$finance ) {
            $shown = array_map( static function ( $r ) {
                unset($r['revenue_day']);
                return $r;
            }, $shown );
        }
        // The picture left of the name (owner, 2 Nov 2026), for the rows shown only.
        $images = Store::thumbnails( array_intersect_key( $pictures, array_flip( array_column( $shown, 'id' ) ) ) );
        foreach ( $shown as $i => $row ) {
            $shown[$i]['image'] = $images[$row['id']] ?? '';
        }
        return array(
            'rows'     => $shown,
            'total'    => count( $rows ),
            'days'     => self::DAYS,
            'soon'     => self::SOON,
            'currency' => $currency,
            'finance'  => $finance,
            'costs'    => ( $finance ? count( array_filter( $rows, static fn( $r ) => $r['cost'] !== null ) ) : null ),
            'buy_url'  => $buy,
        );
    }

}