from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session
from pydantic import BaseModel
from datetime import datetime
from typing import Optional, List

from backend.database import get_db
from backend.models import Emitter

router = APIRouter()


# Pydantic schemas for request/response validation
class EmitterReport(BaseModel):
    unit: str
    unit_type: str
    timestamp: str
    file: str
    status: str


class EmitterResponse(BaseModel):
    id: str
    unit_type: str
    last_seen: datetime
    last_file: str
    status: str
    notes: Optional[str] = None

    class Config:
        from_attributes = True


@router.post("/emitters/report", status_code=200)
def report_emitter(report: EmitterReport, db: Session = Depends(get_db)):
    """
    Endpoint for emitters to report their status.
    Creates a new emitter if it doesn't exist, or updates an existing one.
    """
    try:
        # Parse the timestamp
        timestamp = datetime.fromisoformat(report.timestamp.replace('Z', '+00:00'))
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid timestamp format")

    # Check if emitter already exists
    emitter = db.query(Emitter).filter(Emitter.id == report.unit).first()

    if emitter:
        # Update existing emitter
        emitter.unit_type = report.unit_type
        emitter.last_seen = timestamp
        emitter.last_file = report.file
        emitter.status = report.status
    else:
        # Create new emitter
        emitter = Emitter(
            id=report.unit,
            unit_type=report.unit_type,
            last_seen=timestamp,
            last_file=report.file,
            status=report.status
        )
        db.add(emitter)

    db.commit()
    db.refresh(emitter)

    return {
        "message": "Emitter report received",
        "unit": emitter.id,
        "status": emitter.status
    }


@router.get("/fleet/status", response_model=List[EmitterResponse])
def get_fleet_status(db: Session = Depends(get_db)):
    """
    Returns a list of all emitters and their current status.
    """
    emitters = db.query(Emitter).all()
    return emitters