import base64
from datetime import date, timedelta
from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session
import httpx

from auth import get_current_user
from database import get_db
from models import Batch, BatchStatus, NotificationLog, Settings, User, Variety

router = APIRouter(prefix="/notifications", tags=["notifications"])

ACTIVE_STATUSES = [
    BatchStatus.planned, BatchStatus.germinating, BatchStatus.seedling,
    BatchStatus.potted_up, BatchStatus.hardening, BatchStatus.garden,
]


def build_daily_summary(db: Session, user_id: int) -> str:
    settings = db.query(Settings).filter(Settings.user_id == user_id).first()
    today = date.today()
    lines = [f"Sproutly Daily Summary — {today.strftime('%A, %B %d')}"]
    lines.append("")

    tasks = []

    if settings and settings.last_frost_date:
        last_frost = settings.last_frost_date.replace(year=today.year)
        if last_frost < today - timedelta(days=60):
            last_frost = last_frost.replace(year=today.year + 1)

        days_to_frost = (last_frost - today).days
        if 0 <= days_to_frost <= 14:
            lines.append(f"Last frost in {days_to_frost} days ({last_frost.strftime('%B %d')})!")
            lines.append("")

        varieties = db.query(Variety).filter(Variety.user_id == user_id).all()
        for v in varieties:
            full_name = f"{v.name} ({v.variety_name})" if v.variety_name else v.name

            if v.weeks_to_start:
                sd = last_frost - timedelta(weeks=v.weeks_to_start)
                d = (sd - today).days
                if -1 <= d <= 3:
                    tasks.append(f"Start seeds: {full_name} (due {sd.strftime('%b %d')})")

            if v.weeks_to_greenhouse:
                gd = last_frost - timedelta(weeks=v.weeks_to_greenhouse)
                d = (gd - today).days
                if -1 <= d <= 3:
                    tasks.append(f"Pot up: {full_name} (due {gd.strftime('%b %d')})")

            if v.weeks_to_garden is not None:
                if v.weeks_to_garden >= 0:
                    td = last_frost + timedelta(weeks=v.weeks_to_garden)
                else:
                    td = last_frost - timedelta(weeks=abs(v.weeks_to_garden))
                d = (td - today).days
                if -1 <= d <= 3:
                    tasks.append(f"Transplant to garden: {full_name} (due {td.strftime('%b %d')})")

    batches = (
        db.query(Batch)
        .filter(Batch.user_id == user_id, Batch.status.in_(ACTIVE_STATUSES))
        .all()
    )
    for b in batches:
        v = b.variety
        full_name = f"{v.name} ({v.variety_name})" if v.variety_name else v.name
        label = b.label or full_name

        if b.status == BatchStatus.hardening:
            tasks.append(f"Harden off: {label}")

        if b.status == BatchStatus.germinating and b.sow_date:
            expected = b.sow_date + timedelta(days=v.days_to_germinate or 7)
            d = (expected - today).days
            if -2 <= d <= 1:
                tasks.append(f"Check germination: {label}")

    if tasks:
        lines.append("Today's tasks:")
        for t in tasks:
            lines.append(f"  - {t}")
    else:
        lines.append("No urgent tasks today. Keep it up!")

    active_count = sum(1 for b in batches if b.status not in [BatchStatus.harvested, BatchStatus.failed])
    lines.append("")
    lines.append(f"Active batches: {active_count}")

    return "\n".join(lines)


async def send_ntfy(settings: Settings, title: str, message: str, db: Session, priority: str = "default"):
    if not settings or not settings.ntfy_topic:
        return False, "ntfy topic not configured"

    server = (settings.ntfy_server or "https://ntfy.sh").rstrip("/")
    url = f"{server}/{settings.ntfy_topic}"

    headers = {
        "Title": title,
        "Priority": priority,
        "Tags": "seedling",
    }
    if settings.ntfy_api_key:
        headers["Authorization"] = f"Bearer {settings.ntfy_api_key}"
    elif settings.ntfy_username:
        creds = base64.b64encode(
            f"{settings.ntfy_username}:{settings.ntfy_password or ''}".encode()
        ).decode()
        headers["Authorization"] = f"Basic {creds}"

    try:
        async with httpx.AsyncClient(timeout=10) as client:
            resp = await client.post(url, content=message.encode("utf-8"), headers=headers)
            resp.raise_for_status()

        log = NotificationLog(message=message, status="sent", user_id=settings.user_id)
        db.add(log)
        db.commit()
        return True, "sent"

    except Exception as e:
        log = NotificationLog(message=message, status="failed", error=str(e), user_id=settings.user_id)
        db.add(log)
        db.commit()
        return False, str(e)


@router.post("/test")
async def send_test_notification(db: Session = Depends(get_db), current_user: User = Depends(get_current_user)):
    settings = db.query(Settings).filter(Settings.user_id == current_user.id).first()
    ok, detail = await send_ntfy(settings, "Sproutly Test", "Your Sproutly notifications are working!", db)
    if not ok:
        raise HTTPException(status_code=400, detail=detail)
    return {"status": "sent"}


@router.post("/daily")
async def send_daily_summary(db: Session = Depends(get_db), current_user: User = Depends(get_current_user)):
    settings = db.query(Settings).filter(Settings.user_id == current_user.id).first()
    summary = build_daily_summary(db, current_user.id)
    ok, detail = await send_ntfy(settings, "Sproutly Daily Summary", summary, db)
    if not ok:
        raise HTTPException(status_code=400, detail=detail)
    return {"status": "sent", "message": summary}


@router.get("/log")
def get_notification_log(db: Session = Depends(get_db), current_user: User = Depends(get_current_user)):
    logs = (
        db.query(NotificationLog)
        .filter(NotificationLog.user_id == current_user.id)
        .order_by(NotificationLog.sent_at.desc())
        .limit(50)
        .all()
    )
    return [{"id": l.id, "sent_at": l.sent_at, "status": l.status, "message": l.message, "error": l.error} for l in logs]