import datetime
import os
from subprocess import Popen, PIPE
from typing import List

import cv2
import dateutil.parser
from opensfm import context
from opensfm import geotag_from_gpx
from opensfm import io


def video_orientation(video_file) -> int:
    # Rotation
    # pyre-fixme[16]: Optional type has no attribute `read`.
    rotation = Popen(
        ["exiftool", "-Rotation", "-b", video_file], stdout=PIPE
    ).stdout.read()
    if rotation:
        rotation = float(rotation)
        if rotation == 0:
            orientation = 1
        elif rotation == 90:
            orientation = 6
        elif rotation == 180:
            orientation = 3
        elif rotation == 270:
            orientation = 8
        else:
            raise RuntimeError(f"rotation {rotation} has no valid orientation!")
    else:
        orientation = 1
    return orientation


def import_video_with_gpx(
    video_file,
    gpx_file,
    output_path: str,
    dx: float,
    dt=None,
    start_time=None,
    visual: bool = False,
    image_description=None,
) -> List[str]:

    points = geotag_from_gpx.get_lat_lon_time(gpx_file)

    orientation = video_orientation(video_file)

    if start_time:
        video_start_time = dateutil.parser.parse(start_time)
    else:
        try:
            # pyre-fixme[16]: Optional type has no attribute `read`.
            exifdate = Popen(
                ["exiftool", "-CreateDate", "-b", video_file], stdout=PIPE
            ).stdout.read()
            video_start_time = datetime.datetime.strptime(exifdate, "%Y:%m:%d %H:%M:%S")
        except Exception:
            print("Video recording timestamp not found. Using first GPS point time.")
            video_start_time = points[0][0]

    print("GPS track starts at: {}".format(points[0][0]))
    print("Video starts at: {}".format(video_start_time))

    # Extract video frames.
    io.mkdir_p(output_path)
    key_points = geotag_from_gpx.sample_gpx(points, dx, dt)

    cap = cv2.VideoCapture(video_file)
    image_files = []
    for p in key_points:
        dt = (p[0] - video_start_time).total_seconds()
        if dt > 0:
            CAP_PROP_POS_MSEC = (
                cv2.CAP_PROP_POS_MSEC
                if context.OPENCV3
                else cv2.cv.CV_CAP_PROP_POS_MSEC
            )
            cap.set(CAP_PROP_POS_MSEC, int(dt * 1000))
            ret, frame = cap.read()
            if ret:
                print("Grabbing frame for time {}".format(p[0]))
                filepath = os.path.join(
                    output_path, p[0].strftime("%Y_%m_%d_%H_%M_%S_%f")[:-3] + ".jpg"
                )
                cv2.imwrite(filepath, frame)
                geotag_from_gpx.add_exif_using_timestamp(
                    filepath, points, timestamp=p[0], orientation=orientation
                )

                # Display the resulting frame
                if visual:
                    # Display the resulting frame
                    max_display_size = 800
                    resize_ratio = float(max_display_size) / max(
                        frame.shape[0], frame.shape[1]
                    )
                    frame = cv2.resize(
                        frame, dsize=(0, 0), fx=resize_ratio, fy=resize_ratio
                    )
                    cv2.imshow("frame", frame)
                    if cv2.waitKey(1) & 0xFF == 27:
                        break
                image_files.append(filepath)
    # When everything done, release the capture
    cap.release()
    if visual:
        cv2.destroyAllWindows()
    return image_files
