import os
import uuid
from datetime import datetime, timedelta
from typing import Any, Dict, List, Optional

from fastapi import Depends, FastAPI, Header, HTTPException

API_KEY = os.getenv("ONEOK_ADAPTER_API_KEY", "").strip()
DEFAULT_TZ = os.getenv("ONEOK_SCHEDULE_TZ", "Europe/Kyiv")

app = FastAPI(title="1OK Schedule Adapter", version="1.0.0")


def _auth(authorization: Optional[str] = Header(default=None)) -> None:
    if not API_KEY:
        return
    expected = f"Bearer {API_KEY}"
    if authorization != expected:
        raise HTTPException(status_code=401, detail="Unauthorized")


def _next_work_slots(count: int = 3) -> List[Dict[str, Any]]:
    now = datetime.utcnow()
    slots: List[Dict[str, Any]] = []
    d = now
    while len(slots) < count:
        d += timedelta(days=1)
        if d.weekday() >= 5:
            continue
        day = d.strftime("%Y-%m-%d")
        for hour in (10, 13, 16):
            slots.append(
                {
                    "slot_id": str(uuid.uuid4()),
                    "start_local": f"{day}T{hour:02d}:00:00",
                    "end_local": f"{day}T{hour+1:02d}:00:00",
                    "timezone": DEFAULT_TZ,
                }
            )
            if len(slots) >= count:
                break
    return slots


@app.get("/health")
def health() -> Dict[str, Any]:
    return {"status": "ok", "service": "oneok-schedule-adapter", "timezone": DEFAULT_TZ}


@app.post("/schedule/propose_slots")
def propose_slots(params: Dict[str, Any], _: None = Depends(_auth)) -> Dict[str, Any]:
    count = int(params.get("count") or 3)
    count = 3 if count < 1 else min(count, 8)
    return {"slots": _next_work_slots(count=count)}


@app.post("/schedule/confirm_slot")
def confirm_slot(body: Dict[str, Any], _: None = Depends(_auth)) -> Dict[str, Any]:
    job_id = body.get("job_id")
    slot = body.get("slot")
    if not job_id or slot is None:
        raise HTTPException(status_code=400, detail="job_id and slot required")
    return {
        "job_id": job_id,
        "confirmed_slot": slot,
        "status": "confirmed",
    }