rippled/include/xrpl/beast/utility/PropertyStream.h

#pragma once

#include <xrpl/beast/core/List.h>

#include <mutex>
#include <ostream>
#include <sstream>
#include <string>
#include <utility>

namespace beast {

//------------------------------------------------------------------------------

/**
 * Abstract stream with RAII containers that produce a property tree.
 */
class PropertyStream
{
public:
    class Map;
    class Set;
    class Source;

    PropertyStream() = default;
    virtual ~PropertyStream() = default;

protected:
    virtual void
    mapBegin() = 0;
    virtual void
    mapBegin(std::string const& key) = 0;
    virtual void
    mapEnd() = 0;

    virtual void
    add(std::string const& key, std::string const& value) = 0;

    void
    add(std::string const& key, char const* value)
    {
        add(key, std::string(value));
    }

    template <typename Value>
    void
    lexicalAdd(std::string const& key, Value value)
    {
        std::stringstream ss;
        ss << value;
        add(key, ss.str());
    }

    virtual void
    add(std::string const& key, bool value);
    virtual void
    add(std::string const& key, char value);
    virtual void
    add(std::string const& key, signed char value);
    virtual void
    add(std::string const& key, unsigned char value);
    virtual void
    add(std::string const& key, short value);
    virtual void
    add(std::string const& key, unsigned short value);
    virtual void
    add(std::string const& key, int value);
    virtual void
    add(std::string const& key, unsigned int value);
    virtual void
    add(std::string const& key, long value);
    virtual void
    add(std::string const& key, unsigned long value);
    virtual void
    add(std::string const& key, long long value);
    virtual void
    add(std::string const& key, unsigned long long value);
    virtual void
    add(std::string const& key, float value);
    virtual void
    add(std::string const& key, double value);
    virtual void
    add(std::string const& key, long double value);

    virtual void
    arrayBegin() = 0;
    virtual void
    arrayBegin(std::string const& key) = 0;
    virtual void
    arrayEnd() = 0;

    virtual void
    add(std::string const& value) = 0;

    void
    add(char const* value)
    {
        add(std::string(value));
    }

    template <typename Value>
    void
    lexicalAdd(Value value)
    {
        std::stringstream ss;
        ss << value;
        add(ss.str());
    }

    virtual void
    add(bool value);
    virtual void
    add(char value);
    virtual void
    add(signed char value);
    virtual void
    add(unsigned char value);
    virtual void
    add(short value);
    virtual void
    add(unsigned short value);
    virtual void
    add(int value);
    virtual void
    add(unsigned int value);
    virtual void
    add(long value);
    virtual void
    add(unsigned long value);
    virtual void
    add(long long value);
    virtual void
    add(unsigned long long value);
    virtual void
    add(float value);
    virtual void
    add(double value);
    virtual void
    add(long double value);

private:
    class Item;
    class Proxy;
};

//------------------------------------------------------------------------------
//
// Item
//
//------------------------------------------------------------------------------

class PropertyStream::Item : public List<Item>::Node
{
public:
    explicit Item(Source* source);
    [[nodiscard]] Source&
    source() const;
    Source*
    operator->() const;
    Source&
    operator*() const;

private:
    Source* source_;
};

//------------------------------------------------------------------------------
//
// Proxy
//
//------------------------------------------------------------------------------

class PropertyStream::Proxy
{
private:
    Map const* map_;
    std::string key_;
    std::ostringstream mutable ostream_;

public:
    Proxy(Map const& map, std::string key);
    Proxy(Proxy const& other);
    ~Proxy();

    template <typename Value>
    Proxy&
    operator=(Value value);

    std::ostream&
    operator<<(std::ostream& manip(std::ostream&)) const;

    template <typename T>
    std::ostream&
    operator<<(T const& t) const
    {
        return ostream_ << t;
    }
};

//------------------------------------------------------------------------------
//
// Map
//
//------------------------------------------------------------------------------

class PropertyStream::Map
{
private:
    PropertyStream& stream_;

public:
    explicit Map(PropertyStream& stream);
    explicit Map(Set& parent);
    Map(std::string const& key, Map& parent);
    Map(std::string const& key, PropertyStream& stream);
    ~Map();

    Map(Map const&) = delete;
    Map&
    operator=(Map const&) = delete;

    PropertyStream&
    stream();
    [[nodiscard]] PropertyStream const&
    stream() const;

    template <typename Value>
    void
    add(std::string const& key, Value value) const
    {
        stream_.add(key, value);
    }

    template <typename Key, typename Value>
    void
    add(Key key, Value value) const
    {
        std::stringstream ss;
        ss << key;
        add(ss.str(), value);
    }

    Proxy
    operator[](std::string const& key);

    Proxy
    operator[](char const* key)
    {
        return Proxy(*this, key);
    }

    template <typename Key>
    Proxy
    operator[](Key key) const
    {
        std::stringstream ss;
        ss << key;
        return Proxy(*this, ss.str());
    }
};

//--------------------------------------------------------------------------

template <typename Value>
PropertyStream::Proxy&
PropertyStream::Proxy::operator=(Value value)
{
    map_->add(key_, value);
    return *this;
}

//--------------------------------------------------------------------------
//
// Set
//
//------------------------------------------------------------------------------

class PropertyStream::Set
{
private:
    PropertyStream& stream_;

public:
    Set(std::string const& key, Map& map);
    Set(std::string const& key, PropertyStream& stream);
    ~Set();

    Set(Set const&) = delete;
    Set&
    operator=(Set const&) = delete;

    PropertyStream&
    stream();
    [[nodiscard]] PropertyStream const&
    stream() const;

    template <typename Value>
    void
    add(Value value) const
    {
        stream_.add(value);
    }
};

//------------------------------------------------------------------------------
//
// Source
//
//------------------------------------------------------------------------------

/**
 * Subclasses can be called to write to a stream and have children.
 */
class PropertyStream::Source
{
private:
    std::string const name_;
    std::recursive_mutex lock_;
    Item item_;
    Source* parent_{nullptr};
    List<Item> children_;

public:
    explicit Source(std::string name);
    virtual ~Source();

    Source(Source const&) = delete;
    Source&
    operator=(Source const&) = delete;

    /**
     * Returns the name of this source.
     */
    [[nodiscard]] std::string const&
    name() const;

    /**
     * Add a child source.
     */
    void
    add(Source& source);

    /**
     * Add a child source by pointer.
     * The source pointer is returned so it can be used in ctor-initializers.
     */
    template <class Derived>
    Derived*
    add(Derived* child)
    {
        add(*static_cast<Source*>(child));
        return child;
    }

    /**
     * Remove a child source from this Source.
     */
    void
    remove(Source& child);

    /**
     * Remove all child sources from this Source.
     */
    void
    removeAll();

    /**
     * Write only this Source to the stream.
     */
    void
    writeOne(PropertyStream& stream);

    /**
     * write this source and all its children recursively to the stream.
     */
    void
    write(PropertyStream& stream);

    /**
     * Parse the path and write the corresponding Source and optional children.
     * If the source is found, it is written. If the wildcard character '*'
     * exists as the last character in the path, then all the children are
     * written recursively.
     */
    void
    write(PropertyStream& stream, std::string const& path);

    /**
     * Parse the dot-delimited Source path and return the result.
     *  The first value will be a pointer to the Source object corresponding
     *  to the given path. If no Source object exists, then the first value
     *  will be nullptr and the second value will be undefined.
     *  The second value is a boolean indicating whether or not the path string
     *  specifies the wildcard character '*' as the last character.
     *
     *  print statement examples
     *  "parent.child" prints child and all of its children
     *  "parent.child." start at the parent and print down to child
     *  "parent.grandchild" prints nothing- grandchild not direct descendent
     *  "parent.grandchild." starts at the parent and prints down to grandchild
     *  "parent.grandchild.*" starts at parent, print through grandchild
     * children
     */
    std::pair<Source*, bool>
    find(std::string path);

    Source*
    findOneDeep(std::string const& name);
    PropertyStream::Source*
    findPath(std::string path);
    PropertyStream::Source*
    findOne(std::string const& name);

    static bool
    peelLeadingSlash(std::string* path);
    static bool
    peelTrailingSlashstar(std::string* path);
    static std::string
    peelName(std::string* path);

    //--------------------------------------------------------------------------

    /**
     * Subclass override.
     * The default version does nothing.
     */
    virtual void
    onWrite(Map&);
};

}  // namespace beast