<?php
class StockSourceManager
{
    private PDO $pdo;
    private int $companyId;

    public function __construct(PDO $pdo, int $company_id)
    {
        $this->pdo       = $pdo;
        $this->companyId = $company_id;
    }

    public function getBySource(string $source, int $source_id): array
    {
        $source = trim($source);
        if ($source === '' || $source_id <= 0) {
            throw new Exception('source and source_id are required.');
        }

        $warehouses = $this->getWarehouseNames();
        $rows = [];

        foreach ($this->getStockTables() as $table) {
            if (!preg_match('/^td_stock_(\d+)$/', $table, $match)) continue;

            $warehouse_id = (int)$match[1];
            $sth = $this->pdo->prepare(
                "SELECT s.id, s.type, s.product_sku, s.`in`, s.`out`,
                        s.zone, s.aisle, s.rack, s.lot_number, s.serial_number,
                        s.status, s.date, s.price,
                        p.product_name
                 FROM `{$table}` s
                 LEFT JOIN md_product p
                     ON p.company_id = s.company_id
                    AND p.sku        = s.product_sku
                 WHERE s.company_id = :company_id
                   AND s.source     = :source
                   AND s.source_id  = :source_id
                 ORDER BY s.date ASC"
            );
            $sth->execute([
                ':company_id' => $this->companyId,
                ':source'     => $source,
                ':source_id'  => $source_id,
            ]);

            foreach ($sth->fetchAll(PDO::FETCH_ASSOC) as $row) {
                $row['warehouse_id']   = $warehouse_id;
                $row['warehouse_name'] = $warehouses[$warehouse_id] ?? "WH {$warehouse_id}";
                $row['quantity']       = $row['type'] === 'out' ? (float)$row['out'] : (float)$row['in'];
                $rows[] = $row;
            }
        }

        return $rows;
    }

    private function getWarehouseNames(): array
    {
        $sth = $this->pdo->prepare(
            "SELECT id, warehouse_name
             FROM md_warehouse
             WHERE company_id = :company_id"
        );
        $sth->execute([':company_id' => $this->companyId]);

        $warehouses = [];
        foreach ($sth->fetchAll(PDO::FETCH_ASSOC) as $warehouse) {
            $warehouses[(int)$warehouse['id']] = $warehouse['warehouse_name'];
        }
        return $warehouses;
    }

    private function getStockTables(): array
    {
        $sth = $this->pdo->prepare(
            "SELECT table_name
             FROM information_schema.tables
             WHERE table_schema = DATABASE()
               AND table_name LIKE 'td_stock_%'"
        );
        $sth->execute();
        return $sth->fetchAll(PDO::FETCH_COLUMN);
    }
}
?>