The common library provides foundational components for a drone-based network simulation in Rust, supporting packet routing, fragmentation, reassembly, and node management in an unreliable network environment. It integrates with wg_internal for core packet and node primitives. Key design principles include idempotent operations, flood-based discovery, source routing, and resilience to packet drops or node crashes via acknowledgments and retries.

Defines core data structures and enums for network entities, files, requests/responses, commands, and events.

• MediaReference: Represents a reference to media stored at a specific node (NodeId) with a UUID.
• TextFile: Encapsulates a text file with title, content, and embedded media references.
• MediaFile: Handles binary media files, chunked into 1024-byte segments for transmission.
• File: Composite of a TextFile and associated MediaFiles.
• WebRequest/WebResponse: Enums for web-like queries (e.g., server type, file lists, media retrieval) and responses (e.g., data delivery, errors like not found or UUID parsing failures).
• ChatRequest/ChatResponse: Enums for chat operations (e.g., registration, client lists, messaging) and responses (e.g., message delivery, client lists).
• Event/Command: Traits and enums for node-specific events (e.g., NodeEvent for packet sent/flood started) and commands (e.g., NodeCommand for adding/removing senders, shutdown).
• ChatEvent/WebEvent/NodeEvent: Specific event variants for chat (e.g., message received, registration), web (e.g., file added/removed, queries), and general node operations.
• ClientType/ServerType/NodeType: Enums classifying nodes (e.g., ChatClient, TextServer, Drone).

Manages packet fragmentation and reassembly.

• FragmentAssembler: Tracks fragments by session ID and sender NodeId. Adds fragments, checks completeness via expected/received counts, and reassembles data into a complete message when all fragments arrive.

Utilities for converting local files to library types.

• file_to_media_file: Reads binary file content, chunks it, and creates a MediaFile.
• file_to_text_file: Reads text file content and creates a TextFile (without media refs by default).

Models the network topology and operations.

• NetworkError: Enum for errors like path not found, node removal, or send failures.
• Node: Represents a network node with ID, type (NodeType), and adjacent nodes.
• Network: Maintains a list of nodes; supports adding/removing/updating nodes, changing types, finding shortest paths via BFS, and filtering by type (e.g., get_servers, get_clients).

Handles routing logic, including discovery and packet transmission.

• RoutingHandler: Core struct managing node ID, network view (Network), neighbors (senders by NodeId), flood tracking, and buffers for packets/fragments.
  • Initiates floods for discovery (start_flood).
  • Handles flood requests/responses to update topology.
  • Sends messages with fragmentation if >128 bytes (send_message).
  • Processes acks (mark fragments received), nacks (retry or remove faulty nodes), and retries (retry_send).
  • Manages neighbor addition/removal and buffering for pending packets.

Defines processing loop for packets and commands.

• Processor: Trait for entities that handle incoming packets and commands.
  • Integrates FragmentAssembler and RoutingHandler.
  • Processes packets (e.g., fragments to reassemble messages, acks/nacks/floods via routing handler).
  • Runs an event loop selecting between controller commands (handle_command) and packets (handle_packet), with flood initiation on start.
  • Subtypes must implement message handling (handle_msg) and command processing.