"""API endpoints, SSE, polling."""

import asyncio
import hashlib
import json
import logging
from asyncio import Queue
from pathlib import Path

from fastapi import Depends, HTTPException, Query, WebSocket, WebSocketDisconnect
from starlette.responses import StreamingResponse

import httpx

from .auth import AUTH_ENABLED, ZITADEL_ISSUER, _validate_token, require_auth
from .runtime import Runtime, TRACE_FILE

log = logging.getLogger("runtime")

# Active runtime reference (set by WS endpoint)
_active_runtime: Runtime | None = None

# SSE subscribers
_sse_subscribers: list[Queue] = []


def _broadcast_sse(event: dict):
    """Push an event to all SSE subscribers."""
    for q in _sse_subscribers:
        try:
            q.put_nowait(event)
        except asyncio.QueueFull:
            pass


def _state_hash() -> str:
    if not _active_runtime:
        return "no_session"
    raw = json.dumps({
        "mem": _active_runtime.memorizer.state,
        "hlen": len(_active_runtime.history),
    }, sort_keys=True)
    return hashlib.md5(raw.encode()).hexdigest()[:12]


def register_routes(app):
    """Register all API routes on the FastAPI app."""

    @app.get("/health")
    async def health():
        return {"status": "ok"}

    @app.get("/auth/config")
    async def auth_config():
        from .auth import ZITADEL_ISSUER, ZITADEL_CLIENT_ID, ZITADEL_PROJECT_ID, AUTH_ENABLED
        return {
            "enabled": AUTH_ENABLED,
            "issuer": ZITADEL_ISSUER,
            "clientId": ZITADEL_CLIENT_ID,
            "projectId": ZITADEL_PROJECT_ID,
        }

    @app.websocket("/ws")
    async def ws_endpoint(ws: WebSocket, token: str | None = Query(None),
                          access_token: str | None = Query(None)):
        global _active_runtime
        user_claims = {"sub": "anonymous"}
        if AUTH_ENABLED and token:
            try:
                user_claims = await _validate_token(token)
                if not user_claims.get("name") and access_token:
                    async with httpx.AsyncClient() as client:
                        resp = await client.get(f"{ZITADEL_ISSUER}/oidc/v1/userinfo",
                                                headers={"Authorization": f"Bearer {access_token}"})
                        if resp.status_code == 200:
                            info = resp.json()
                            log.info(f"[auth] userinfo enrichment: {info}")
                            user_claims["name"] = info.get("name")
                            user_claims["preferred_username"] = info.get("preferred_username")
                            user_claims["email"] = info.get("email")
            except HTTPException:
                await ws.close(code=4001, reason="Invalid token")
                return
        origin = ws.headers.get("origin", ws.headers.get("host", ""))
        await ws.accept()
        runtime = Runtime(ws, user_claims=user_claims, origin=origin, broadcast=_broadcast_sse)
        _active_runtime = runtime
        try:
            while True:
                data = await ws.receive_text()
                msg = json.loads(data)
                if msg.get("type") == "action":
                    await runtime.handle_action(msg.get("action", "unknown"), msg.get("data"))
                elif msg.get("type") == "cancel_process":
                    runtime.process_manager.cancel(msg.get("pid", 0))
                else:
                    await runtime.handle_message(msg.get("text", ""))
        except WebSocketDisconnect:
            runtime.sensor.stop()
            if _active_runtime is runtime:
                _active_runtime = None

    @app.get("/api/events")
    async def sse_events(user=Depends(require_auth)):
        q: Queue = Queue(maxsize=100)
        _sse_subscribers.append(q)

        async def generate():
            try:
                while True:
                    event = await q.get()
                    yield f"data: {json.dumps(event)}\n\n"
            except asyncio.CancelledError:
                pass
            finally:
                _sse_subscribers.remove(q)

        return StreamingResponse(generate(), media_type="text/event-stream",
                                headers={"Cache-Control": "no-cache", "X-Accel-Buffering": "no"})

    @app.get("/api/poll")
    async def poll(since: str = "", user=Depends(require_auth)):
        h = _state_hash()
        if since and since == h:
            return {"changed": False, "hash": h}
        return {
            "changed": True,
            "hash": h,
            "state": _active_runtime.memorizer.state if _active_runtime else None,
            "history_len": len(_active_runtime.history) if _active_runtime else 0,
            "last_messages": _active_runtime.history[-3:] if _active_runtime else [],
        }

    @app.post("/api/send")
    async def api_send(body: dict, user=Depends(require_auth)):
        if not _active_runtime:
            raise HTTPException(status_code=409, detail="No active session -- someone must be connected via WS first")
        text = body.get("text", "").strip()
        if not text:
            raise HTTPException(status_code=400, detail="Missing 'text' field")
        await _active_runtime.handle_message(text)
        return {
            "status": "ok",
            "response": _active_runtime.history[-1]["content"] if _active_runtime.history else "",
            "memorizer": _active_runtime.memorizer.state,
        }

    @app.post("/api/clear")
    async def api_clear(user=Depends(require_auth)):
        if not _active_runtime:
            raise HTTPException(status_code=409, detail="No active session")
        _active_runtime.history.clear()
        _active_runtime.ui_node.state.clear()
        _active_runtime.ui_node.bindings.clear()
        _active_runtime.ui_node.current_controls.clear()
        return {"status": "cleared"}

    @app.get("/api/state")
    async def get_state(user=Depends(require_auth)):
        if not _active_runtime:
            return {"status": "no_session"}
        return {
            "status": "active",
            "memorizer": _active_runtime.memorizer.state,
            "history_len": len(_active_runtime.history),
        }

    @app.get("/api/history")
    async def get_history(last: int = 10, user=Depends(require_auth)):
        if not _active_runtime:
            return {"status": "no_session", "messages": []}
        return {
            "status": "active",
            "messages": _active_runtime.history[-last:],
        }

    @app.get("/api/tests")
    async def get_tests():
        """Latest test results from runtime_test.py."""
        results_path = Path(__file__).parent.parent / "testcases" / "results.json"
        if not results_path.exists():
            return {}
        return json.loads(results_path.read_text(encoding="utf-8"))

    @app.get("/api/trace")
    async def get_trace(last: int = 30, user=Depends(require_auth)):
        if not TRACE_FILE.exists():
            return {"lines": []}
        lines = TRACE_FILE.read_text(encoding="utf-8").strip().split("\n")
        parsed = []
        for line in lines[-last:]:
            try:
                parsed.append(json.loads(line))
            except json.JSONDecodeError:
                pass
        return {"lines": parsed}