<?php

namespace Modules\EcommerceFinance\Services;

use Illuminate\Database\ConnectionInterface;
use Illuminate\Support\Facades\Schema;

/** Derived lookup only: the upstream strings and financial values stay intact. */
class GoodsProfitAfsLookupSchema
{
    public const TABLE = 'ops_jst_goods_profit_kpi_items_afs';

    public const DATE_COLUMN = '_mirror_afs_order_time';

    public const INDEXES = [
        'idx_afs_order_time_id' => ['_mirror_afs_order_time', 'id'],
        'idx_afs_shop_order_time_id' => ['undefined8', '_mirror_afs_order_time', 'id'],
    ];

    public function ensure(ConnectionInterface $db): void
    {
        if (! in_array($db->getDriverName(), ['mysql', 'mariadb'], true)) {
            return;
        }

        $schema = Schema::connection($db->getName());
        if (! $schema->hasTable(self::TABLE)
            || ! $schema->hasColumns(self::TABLE, ['id', 'undefined7', 'undefined8'])) {
            return;
        }

        $statements = [];
        if (! $schema->hasColumn(self::TABLE, self::DATE_COLUMN)) {
            $expression = $this->dateExpression();
            // MariaDB requires the virtual column and its indexes in separate
            // ALTER statements to allow concurrent writes with LOCK=NONE.
            $statements[] = 'ADD COLUMN `' . self::DATE_COLUMN
                . '` VARCHAR(19) CHARACTER SET ascii COLLATE ascii_bin GENERATED ALWAYS AS (' . $expression . ') VIRTUAL';
        }
        $indexes = [];
        foreach (self::INDEXES as $name => $columns) {
            if (! $schema->hasIndex(self::TABLE, $name)) {
                $indexes[] = 'ADD INDEX `' . $name . '` (`' . implode('`, `', $columns) . '`)';
            }
        }
        if ($indexes !== []) $statements[] = implode(', ', $indexes);

        if ($statements !== []) {
            // Fail rather than silently copying/locking this multi-million-row table.
            $wait = (int) $db->selectOne('SELECT @@SESSION.lock_wait_timeout AS seconds')->seconds;
            $db->statement('SET SESSION lock_wait_timeout = 5');
            try {
                foreach ($statements as $statement) {
                    $db->statement('ALTER TABLE `' . self::TABLE . '` ' . $statement . ', ALGORITHM=INPLACE, LOCK=NONE');
                }
            } finally {
                $db->statement('SET SESSION lock_wait_timeout = ' . $wait);
            }
        }
    }

    public function dateExpression(): string
    {
        $raw = "REPLACE(TRIM(`undefined7`), '/', '-')";
        $pattern = '^[0-9]{1,4}-(0?[1-9]|1[0-2])-(0?[1-9]|[12][0-9]|3[01])'
            . '([[:space:]]+([01]?[0-9]|2[0-3])(:[0-5]?[0-9]){0,2}([.][0-9]+)?)?$';

        // Guard malformed strings so a future bad source value cannot break an
        // indexed-column update in strict mode. Fractional seconds were already
        // ignored by the original format. CHAR preserves its calendar semantics
        // (e.g. 2026-02-31), unlike coercing the result into a DATETIME column.
        return "CASE WHEN {$raw} REGEXP '{$pattern}' THEN CAST(STR_TO_DATE("
            . "SUBSTRING_INDEX({$raw}, '.', 1), '%Y-%m-%d %H:%i:%s') AS CHAR(19)) ELSE NULL END";
    }
}