//////////////////////////////////////////////////////////////////////////
//
// DATAPACK
//
// Invocations contain a field 'datapack' which contains additional
// data for the invocation, packed up in a serialized format.  Executing
// the invocation involves unpacking the datapack.
//
// The actual contents of the datapack depends on the type of invocation:
//
// KIND_INVALID:
//
//   Nothing.
//
// KIND_ENGIO:
//
//   First, a function name is read from the datapack.  The function
//   name must be a lua function inside class "engio".  The function
//   is called with arguments: actor, place, and then additional
//   arguments of simple dynamic type read from the datapack.
// 
// KIND_LUA:
//
//   A block of lua source code, in plaintext.
//
// KIND_FLUSH_PRINTS:
//
//   Line number in ascii.
//
// KIND_TICK:
//
//   Nothing.
//
// KIND_LUA_SOURCE:
//
//   Packaged lua sourcecode.  See drvutil::package_lua_source.
//
//////////////////////////////////////////////////////////////////////////

#ifndef INVOCATION_HPP
#define INVOCATION_HPP

#include "wrap-string.hpp"
#include "wrap-map.hpp"
#include "wrap-deque.hpp"
#include "streambuffer.hpp"


class Invocation : public eng::opnew {
public:
    enum Kind {
        KIND_INVALID,
        KIND_ENGIO,
        KIND_LUA,
        KIND_FLUSH_PRINTS,
        KIND_TICK,
        KIND_LUA_SOURCE,
    };

private:
    Kind kind_;
    int64_t actor_;
    int64_t place_;
    eng::string datapack_;
public:
    Invocation();
    Invocation(Kind kind, int64_t actor, int64_t place, std::string_view datapack);
    
    bool valid() const { return kind_ != KIND_INVALID; }
    Kind kind() const { return kind_; }
    int64_t actor() const { return actor_; }
    int64_t place() const { return place_; }
    const eng::string &datapack() const { return datapack_; }

    void serialize(StreamBuffer *sb) const;
    void deserialize(StreamBuffer *sb);

    eng::string debug_string() const;
};

using UniqueInvocation = std::unique_ptr<Invocation>;

class InvocationQueue : public eng::deque<Invocation> {
};


#endif // INVOCATION_HPP