"""Telemetry endpoint — read flight metadata from an uploaded image.

Lets the dashboard auto-fill survey geometry (altitude, FOV, nadir/oblique)
from a drone frame's EXIF/XMP instead of asking the user to type it.
"""

from __future__ import annotations

import shutil
import tempfile
from pathlib import Path

from fastapi import APIRouter, File, HTTPException, UploadFile

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


@router.post("/read")
async def read_telemetry(file: UploadFile = File(...)) -> dict:
    """Parse EXIF/XMP flight telemetry from an uploaded image.

    Returns what was found (altitude, gimbal angle → nadir/oblique, FOV, GPS),
    whether it's enough to georeference, and which fields are missing. Never
    guesses — missing stays missing.
    """
    try:
        from src.geolocation.telemetry import parse_telemetry
    except ImportError as exc:
        raise HTTPException(status_code=503, detail="Pillow not installed.") from exc

    suffix = Path(file.filename or "frame.jpg").suffix or ".jpg"
    with tempfile.NamedTemporaryFile(suffix=suffix, delete=False) as tmp:
        shutil.copyfileobj(file.file, tmp)
        tmp_path = tmp.name
    try:
        tel = parse_telemetry(tmp_path)
    finally:
        Path(tmp_path).unlink(missing_ok=True)

    return {
        "source": tel.source,                 # "xmp", "exif", "xmp+exif", "none"
        "viewpoint": tel.viewpoint,            # "nadir" | "oblique" | None
        "has_geometry": tel.to_camera() is not None,
        "missing": tel.missing(),
        "altitude_m": tel.altitude_m,
        "gimbal_pitch_deg": tel.gimbal_pitch_deg,
        "cam_pitch_deg": tel.cam_pitch_deg,
        "gimbal_yaw_deg": tel.gimbal_yaw_deg,
        "hfov_deg": tel.hfov_deg,
        "focal_35mm": tel.focal_35mm,
        "gps_lat": tel.gps_lat,
        "gps_lon": tel.gps_lon,
        "image_width": tel.image_width,
        "image_height": tel.image_height,
    }