#pragma once

#include <xrpl/basics/UnorderedContainers.h>
#include <xrpl/beast/utility/Journal.h>
#include <xrpl/ledger/AcceptedLedgerTx.h>
#include <xrpl/ledger/ReadView.h>
#include <xrpl/protocol/Asset.h>
#include <xrpl/protocol/Book.h>
#include <xrpl/protocol/UintTypes.h>

#include <memory>
#include <optional>
#include <vector>

namespace xrpl {

/**
 * Tracks order books in the ledger.
 *
 * This interface provides access to order book information, including:
 * - Which order books exist in the ledger
 * - Querying order books by issue
 * - Managing order book subscriptions
 *
 * The order book database is updated as ledgers are accepted and provides
 * efficient lookup of order book information for pathfinding and client
 * subscriptions.
 */
class OrderBookDB
{
public:
    virtual ~OrderBookDB() = default;

    /**
     * Initialize or update the order book database with a new ledger.
     *
     * This method should be called when a new ledger is accepted to update
     * the order book database with the current state of all order books.
     *
     * @param ledger The ledger to scan for order books
     */
    virtual void
    setup(std::shared_ptr<ReadView const> const& ledger) = 0;

    /**
     * Add an order book to track.
     *
     * @param book The order book to add
     */
    virtual void
    addOrderBook(Book const& book) = 0;

    /**
     * Get all order books that want a specific issue.
     *
     * Returns a list of all order books where the taker pays the specified
     * issue. This is useful for pathfinding to find all possible next hops
     * from a given currency.
     *
     * @param asset The asset to search for
     * @param domain Optional domain restriction for the order book
     * @return Vector of books that want this issue
     */
    virtual std::vector<Book>
    getBooksByTakerPays(Asset const& asset, std::optional<Domain> const& domain = std::nullopt) = 0;

    /**
     * Get the count of order books that want a specific issue.
     *
     * @param asset The asset to search for
     * @param domain Optional domain restriction for the order book
     * @return Number of books that want this issue
     */
    virtual int
    getBookSize(Asset const& asset, std::optional<Domain> const& domain = std::nullopt) = 0;

    /**
     * Check if an order book to XRP exists for the given issue.
     *
     * @param asset The asset to check
     * @param domain Optional domain restriction for the order book
     * @return true if a book from this issue to XRP exists
     */
    virtual bool
    isBookToXRP(Asset const& asset, std::optional<Domain> const& domain = std::nullopt) = 0;
};

/**
 * Extract the set of books affected by a transaction.
 *
 * Walks the transaction's metadata nodes and collects every order book
 * whose offers were created, modified, or deleted. Used by NetworkOPs to
 * fan transaction notifications out to book subscribers.
 *
 * @param alTx The accepted ledger transaction to inspect.
 * @param j Journal used to log per-node parsing failures. Inspecting an
 *          offer node can throw if a required field is missing; in that
 *          case the bad node is skipped and a warn-level message is
 *          emitted via @p j. Other affected books in the same transaction
 *          are still returned.
 * @return The set of books whose offers were created, modified, or
 *         deleted. May be empty for non-offer transactions.
 */
hash_set<Book>
affectedBooks(AcceptedLedgerTx const& alTx, beast::Journal const& j);

}  // namespace xrpl