"""
Waitlist / email-capture routes for the marketing landing page.

Public endpoint: POST /api/v1/waitlist (no auth) — deduplicated by email,
persisted in data/waitlist.json (same JSON-file pattern as provider settings).
"""

import json
import logging
import threading
from datetime import datetime, timezone
from typing import List, Optional

from fastapi import APIRouter
from fastapi.responses import JSONResponse
from pydantic import BaseModel, EmailStr

from config import config

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/v1/waitlist", tags=["Waitlist"])

WAITLIST_FILE = config.BASE_DIR / "data" / "waitlist.json"
_write_lock = threading.Lock()


class WaitlistEntry(BaseModel):
    email: EmailStr
    interest: Optional[str] = None


def _load_waitlist() -> List[dict]:
    if not WAITLIST_FILE.exists():
        return []
    try:
        with open(WAITLIST_FILE, encoding="utf-8") as f:
            data = json.load(f)
        return data if isinstance(data, list) else []
    except Exception as e:
        logger.warning(f"Failed to load waitlist: {e}")
        return []


def _save_waitlist(entries: List[dict]) -> None:
    WAITLIST_FILE.parent.mkdir(parents=True, exist_ok=True)
    with open(WAITLIST_FILE, "w", encoding="utf-8") as f:
        json.dump(entries, f, indent=2)


@router.post("", status_code=201, summary="Join the waitlist")
async def join_waitlist(entry: WaitlistEntry):
    email = entry.email.lower().strip()
    now = datetime.now(timezone.utc).isoformat()

    with _write_lock:
        entries = _load_waitlist()
        for existing in entries:
            if existing.get("email", "").lower() == email:
                existing["updated_at"] = now
                if entry.interest:
                    existing["interest"] = entry.interest
                _save_waitlist(entries)
                logger.info(f"Waitlist rejoin: {email}")
                return JSONResponse(
                    status_code=200,
                    content={
                        "data": {"email": email, "status": "already_joined"},
                        "message": "You are already on the list.",
                    },
                )

        entries.append(
            {
                "email": email,
                "interest": entry.interest,
                "joined_at": now,
                "updated_at": now,
            }
        )
        _save_waitlist(entries)
        logger.info(f"Waitlist join: {email} (total={len(entries)})")

    return JSONResponse(
        status_code=201,
        content={
            "data": {"email": email, "status": "joined"},
            "message": "Welcome aboard!",
        },
    )


@router.get("/count", summary="Waitlist count")
async def waitlist_count():
    return JSONResponse(
        status_code=200,
        content={"data": {"count": len(_load_waitlist())}},
    )