from __future__ import annotations

import uuid
from typing import Literal

from pydantic import BaseModel, Field

from yuxi.gateway.protocol.version import negotiate_version


class ConnectParams(BaseModel):
    min_protocol: int = 1
    max_protocol: int = 1
    client_id: str = ""
    client_version: str = ""
    client_platform: str = ""
    auth_token: str | None = None
    caps: list[str] = Field(default_factory=list)

    client_display_name: str = ""
    client_device_family: str = ""
    client_model_identifier: str = ""
    client_mode: str = "default"
    client_instance_id: str = ""

    commands: list[str] = Field(default_factory=list)
    permissions: dict[str, bool] = Field(default_factory=dict)

    path_env: str = ""
    role: str = ""
    scopes: list[str] = Field(default_factory=list)

    locale: str = ""
    user_agent: str = ""


class HelloFeatures(BaseModel):
    methods: list[str] = Field(default_factory=list)
    events: list[str] = Field(default_factory=list)


class HelloOk(BaseModel):
    type: Literal["hello-ok"] = "hello-ok"
    protocol: int
    server_version: str
    server_id: str
    session_id: str
    features: HelloFeatures = Field(default_factory=HelloFeatures)
    snapshot: dict | None = None
    dm_policy: str = "pairing"
    group_policy: str = "allowlist"
    conn_id: str = ""
    max_payload: int = 1048576
    max_buffered_bytes: int = 10485760
    tick_interval_ms: int = 5000


async def handle_handshake(params: ConnectParams) -> HelloOk:
    protocol = negotiate_version(params.min_protocol, params.max_protocol)
    if protocol is None:
        raise ValueError("Protocol version negotiation failed")

    session_id = str(uuid.uuid4())
    conn_id = f"conn-{session_id[:8]}"
    return HelloOk(
        protocol=protocol,
        server_version="1.0.0",
        server_id="forcepilot-gateway",
        session_id=session_id,
        conn_id=conn_id,
        features=HelloFeatures(
            methods=["channel.status", "channel.start", "channel.stop", "chat.send", "chat.abort"],
            events=["channel.status_change", "tick", "chat", "channel.logout", "config.reload"],
        ),
    )