"""
JARVIS — Chat API Route
POST /api/chat/message   — send a message, get AI response
GET  /api/chat/history   — retrieve session history
"""

import uuid
from typing import Optional, List

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel, Field
from loguru import logger

from app.db.database import (
    AsyncSession, get_db,
    create_session, get_session, get_messages, add_message,
)
from app.agents.react_agent import ReActAgent
from app.core.config import settings


router = APIRouter()


# ─────────────────────────────────────────────
# Request / Response schemas
# ─────────────────────────────────────────────
class ChatRequest(BaseModel):
    message: str = Field(..., min_length=1, max_length=4096)
    session_id: Optional[str] = None
    image_caption: Optional[str] = None    # pre-analyzed image context
    stream: bool = False

    class Config:
        json_schema_extra = {
            "example": {
                "message": "What is the capital of France?",
                "session_id": "abc-123",
            }
        }


class AgentStepOut(BaseModel):
    step_type: str
    content: str
    tool_name: Optional[str] = None


class ChatResponse(BaseModel):
    response:    str
    session_id:  str
    message_id:  int
    steps:       List[AgentStepOut] = []
    used_tools:  List[str] = []
    memory_hits: int = 0
    iterations:  int = 1


# ─────────────────────────────────────────────
# Routes
# ─────────────────────────────────────────────
@router.post("/message", response_model=ChatResponse)
async def chat_message(
    request: ChatRequest,
    db: AsyncSession = Depends(get_db),
):
    """
    Send a message to JARVIS and get an AI response.
    Creates a new session if session_id not provided.
    """
    # Ensure session exists
    session_id = request.session_id or str(uuid.uuid4())
    session = await get_session(db, session_id)
    if not session:
        title = request.message[:50] + ("..." if len(request.message) > 50 else "")
        await create_session(db, session_id, title=title)

    # Load conversation history (last 20 messages)
    messages = await get_messages(db, session_id, limit=20)
    history = [
        {"role": msg.role, "content": msg.content}
        for msg in messages
    ]

    # Save user message to DB
    user_msg = await add_message(
        db, session_id,
        role="user",
        content=request.message,
        modality="text",
    )

    # Run ReAct agent
    try:
        agent = ReActAgent()
        result = agent.run(
            user_message=request.message,
            conversation_history=history,
            session_id=session_id,
            image_caption=request.image_caption,
        )
    except Exception as e:
        logger.error(f"Agent error: {e}")
        raise HTTPException(status_code=500, detail=f"Agent error: {str(e)}")

    # Save assistant response to DB
    asst_msg = await add_message(
        db, session_id,
        role="assistant",
        content=result.final_response,
        modality="text",
    )

    return ChatResponse(
        response=result.final_response,
        session_id=session_id,
        message_id=asst_msg.id,
        steps=[
            AgentStepOut(
                step_type=s.step_type.value,
                content=s.content,
                tool_name=s.tool_name,
            )
            for s in result.steps
        ],
        used_tools=result.used_tools,
        memory_hits=result.memory_hits,
        iterations=result.iterations,
    )


@router.get("/history/{session_id}")
async def get_history(
    session_id: str,
    limit: int = 50,
    db: AsyncSession = Depends(get_db),
):
    """Retrieve conversation history for a session."""
    session = await get_session(db, session_id)
    if not session:
        raise HTTPException(status_code=404, detail="Session not found")

    messages = await get_messages(db, session_id, limit=limit)
    return {
        "session_id": session_id,
        "title": session.title,
        "messages": [
            {
                "id": msg.id,
                "role": msg.role,
                "content": msg.content,
                "modality": msg.modality,
                "created_at": msg.created_at.isoformat(),
            }
            for msg in messages
        ],
    }