"""Session and prompt routes."""

import json
import uuid
from typing import Any

from fastapi import APIRouter, HTTPException, WebSocket, WebSocketDisconnect

from fusionagi.api.dependencies import get_orchestrator, get_session_store, get_event_bus, get_safety_pipeline
from fusionagi.api.websocket import handle_stream
from fusionagi.core import run_dvadasa, select_heads_for_complexity, extract_sources_from_head_outputs
from fusionagi.schemas.commands import parse_user_input, UserIntent

router = APIRouter()


def _ensure_init():
    from fusionagi.api.dependencies import ensure_initialized
    ensure_initialized()


@router.post("")
def create_session(user_id: str | None = None) -> dict[str, Any]:
    """Create a new session."""
    _ensure_init()
    store = get_session_store()
    if not store:
        raise HTTPException(status_code=503, detail="Session store not initialized")
    session_id = str(uuid.uuid4())
    store.create(session_id, user_id)
    return {"session_id": session_id, "user_id": user_id}


@router.post("/{session_id}/prompt")
def submit_prompt(session_id: str, body: dict[str, Any]) -> dict[str, Any]:
    """Submit a prompt and receive FinalResponse (sync)."""
    _ensure_init()
    store = get_session_store()
    orch = get_orchestrator()
    bus = get_event_bus()
    if not store or not orch:
        raise HTTPException(status_code=503, detail="Service not initialized")

    sess = store.get(session_id)
    if not sess:
        raise HTTPException(status_code=404, detail="Session not found")

    prompt = body.get("prompt", "")
    parsed = parse_user_input(prompt)

    if not prompt or not parsed.cleaned_prompt.strip():
        if parsed.intent in (UserIntent.SHOW_DISSENT, UserIntent.RERUN_RISK, UserIntent.EXPLAIN_REASONING, UserIntent.SOURCES):
            hist = sess.get("history", [])
            if hist:
                prompt = hist[-1].get("prompt", "")
            if not prompt:
                raise HTTPException(status_code=400, detail="No previous prompt; provide a prompt for this command")
        else:
            raise HTTPException(status_code=400, detail="prompt is required")

    effective_prompt = parsed.cleaned_prompt.strip() or prompt
    pipeline = get_safety_pipeline()
    if pipeline:
        pre_result = pipeline.pre_check(effective_prompt)
        if not pre_result.allowed:
            raise HTTPException(status_code=400, detail=pre_result.reason or "Input moderation failed")

    task_id = orch.submit_task(goal=effective_prompt[:200])

    # Dynamic head selection
    head_ids = select_heads_for_complexity(effective_prompt)
    if parsed.intent.value == "head_strategy" and parsed.head_id:
        head_ids = [parsed.head_id]

    force_second = parsed.intent == UserIntent.RERUN_RISK
    return_heads = parsed.intent == UserIntent.SOURCES

    result = run_dvadasa(
        orchestrator=orch,
        task_id=task_id,
        user_prompt=effective_prompt,
        parsed=parsed,
        head_ids=head_ids if parsed.intent.value != "normal" or body.get("use_all_heads") else None,
        event_bus=bus,
        force_second_pass=force_second,
        return_head_outputs=return_heads,
    )

    if return_heads and isinstance(result, tuple):
        final, head_outputs = result
    else:
        final = result
        head_outputs = []

    if not final:
        raise HTTPException(status_code=500, detail="Failed to produce response")

    if pipeline:
        post_result = pipeline.post_check(final.final_answer)
        if not post_result.passed:
            raise HTTPException(
                status_code=400,
                detail=f"Output scan failed: {', '.join(post_result.flags)}",
            )

    entry = {
        "prompt": effective_prompt,
        "final_answer": final.final_answer,
        "confidence_score": final.confidence_score,
        "head_contributions": final.head_contributions,
    }
    store.append_history(session_id, entry)

    response: dict[str, Any] = {
        "task_id": task_id,
        "final_answer": final.final_answer,
        "transparency_report": final.transparency_report.model_dump(),
        "head_contributions": final.head_contributions,
        "confidence_score": final.confidence_score,
    }
    if parsed.intent == UserIntent.SHOW_DISSENT:
        response["response_mode"] = "show_dissent"
        response["disputed_claims"] = final.transparency_report.agreement_map.disputed_claims
    elif parsed.intent == UserIntent.EXPLAIN_REASONING:
        response["response_mode"] = "explain"
    elif parsed.intent == UserIntent.SOURCES and head_outputs:
        response["sources"] = extract_sources_from_head_outputs(head_outputs)
    return response


@router.websocket("/{session_id}/stream")
async def stream_websocket(websocket: WebSocket, session_id: str) -> None:
    """WebSocket for streaming Dvādaśa response. Send {\"prompt\": \"...\"} to start."""
    await websocket.accept()
    try:
        data = await websocket.receive_json()
        prompt = data.get("prompt", "")
        async def send_evt(evt: dict) -> None:
            await websocket.send_json(evt)
        await handle_stream(session_id, prompt, send_evt)
    except WebSocketDisconnect:
        pass
    except Exception as e:
        try:
            await websocket.send_json({"type": "error", "message": str(e)})
        except Exception:
            pass