"""
A2A Protocol for Fleet-Wizard Delegation

Implements Google's Agent2Agent (A2A) protocol v1.0 for the Timmy
Foundation fleet. Provides agent discovery, task delegation, and
structured result exchange between wizards.

Components:
    types.py    — A2A data types (Agent Card, Task, Message, Part)
    card.py     — Agent Card generation from YAML config
    client.py   — Async client for sending tasks to remote agents
    server.py   — FastAPI server for receiving A2A tasks
    registry.py — Fleet agent discovery (local file + Gitea backends)
"""

from nexus.a2a.types import (
    AgentCard,
    AgentCapabilities,
    AgentInterface,
    AgentSkill,
    Artifact,
    DataPart,
    FilePart,
    JSONRPCError,
    JSONRPCRequest,
    JSONRPCResponse,
    Message,
    Part,
    Role,
    Task,
    TaskState,
    TaskStatus,
    TextPart,
    part_from_dict,
    part_to_dict,
)

from nexus.a2a.card import (
    AgentCard,
    build_card,
    get_auth_headers,
    load_agent_card,
    load_card_config,
)

from nexus.a2a.registry import (
    GiteaRegistry,
    LocalFileRegistry,
    discover_agents,
)

__all__ = [
    "A2AClient",
    "A2AClientConfig",
    "A2AServer",
    "AgentCard",
    "AgentCapabilities",
    "AgentInterface",
    "AgentSkill",
    "Artifact",
    "DataPart",
    "FilePart",
    "GiteaRegistry",
    "JSONRPCError",
    "JSONRPCRequest",
    "JSONRPCResponse",
    "LocalFileRegistry",
    "Message",
    "Part",
    "Role",
    "Task",
    "TaskState",
    "TaskStatus",
    "TextPart",
    "build_card",
    "discover_agents",
    "echo_handler",
    "get_auth_headers",
    "load_agent_card",
    "load_card_config",
    "part_from_dict",
    "part_to_dict",
]

# Lazy imports for optional deps
def get_client(**kwargs):
    """Get A2AClient (avoids aiohttp import at module level)."""
    from nexus.a2a.client import A2AClient, A2AClientConfig
    config = kwargs.pop("config", None)
    if config is None:
        config = A2AClientConfig(**kwargs)
    return A2AClient(config=config)


def get_server(card: AgentCard, **kwargs):
    """Get A2AServer (avoids fastapi import at module level)."""
    from nexus.a2a.server import A2AServer, echo_handler
    return A2AServer(card=card, **kwargs)