#pragma once

#include <cstdint>
#include <optional>
#include <span>
#include <string>
#include <vector>

// Small interface/vtable for L7 dissectors (PLAN.md's architecture
// sketch), so protocols can be registered and added incrementally
// without touching the L2-L4 decode path or main.cpp's dispatch logic.
namespace wireframe::net {

class L7Dissector {
public:
    virtual ~L7Dissector() = default;

    // The transport port this dissector claims (e.g. 53 for DNS). A
    // single fixed port is enough for the protocols in scope so far;
    // dissectors needing a port range or heuristic sniffing can widen
    // this later without changing the registry's shape.
    virtual std::uint16_t port() const = 0;

    // A one-line summary of the payload, or nullopt if it doesn't look
    // like this protocol (e.g. truncated/malformed).
    virtual std::optional<std::string> summarize(std::span<const unsigned char> payload) const = 0;
};

class L7Registry {
public:
    void add(const L7Dissector* dissector) { dissectors_.push_back(dissector); }

    std::optional<std::string> dissect(std::uint16_t port,
                                        std::span<const unsigned char> payload) const {
        for (const auto* dissector : dissectors_) {
            if (dissector->port() == port) return dissector->summarize(payload);
        }
        return std::nullopt;
    }

private:
    std::vector<const L7Dissector*> dissectors_;
};

}  // namespace wireframe::net