#!/usr/bin/env python3
from argparse import ArgumentParser, Namespace
from pathlib import Path
from natsort import natsorted
import numpy as np
import pandas as pd
from vre import VRE
from vre.utils import FFmpegVideo, FakeVideo, image_read, abs_path
from vre.representations import build_representations_from_cfg, add_external_representations
from vre.logger import vre_logger as logger
from omegaconf import OmegaConf

import imp

def get_args() -> Namespace:
    """cli args"""
    parser = ArgumentParser()
    parser.add_argument("video_path", help="Path to the scene video we are processing", type=abs_path)
    parser.add_argument("--output_path", "-o", required=True, type=abs_path,
                        help="Path to the output directory where representations are stored")
    parser.add_argument("--config_path", required=True, help="Path to global YAML cfg file", type=abs_path)
    parser.add_argument("--representations", nargs="+", help="Subset of representations to run VRE for")
    # run parameters
    group = parser.add_mutually_exclusive_group()
    group.add_argument("--frames", type=int, nargs="+", help="The list of frames to be exported from the video")
    group.add_argument("--start_frame", type=int, help="The first frame index. If not set, defaults to 0.")
    parser.add_argument("--end_frame", type=int, help="The end frame index. If not set, defaults to length of video")
    parser.add_argument("--output_dir_exists_mode", choices=["overwrite", "skip_computed", "raise"], default="raise")
    parser.add_argument("--n_threads_data_storer", type=int, default=0)
    parser.add_argument("--external_representations", "-I", nargs="+", default=[],
                        help="Path to external reprs. Format: /path/to/file.py:fn_name. fn -> {str: Representation}")
    # collage parameters (calls vre_collage)
    parser.add_argument("--make_video_collage", action="store_true", help="if set, calls vre_collage on the output")
    parser.add_argument("--collage_fps", type=float, help="Required by --make_video_collage for the collage output")

    args = parser.parse_args()
    if args.make_video_collage:
        assert args.collage_fps is not None and args.collage_fps > 0, args.collage_fps
    return args

def main(args: Namespace):
    """Za main function"""
    cfg = OmegaConf.to_container(OmegaConf.load(args.config_path), resolve=True)
    if args.representations is not None:
        assert (d := set(args.representations).difference(r := cfg["representations"].keys())) == set(), f"\n-{d}\n-{r}"
        logger.info(f"Keeping only {args.representations} from the config")
        cfg["representations"] = {k: v for k, v in cfg["representations"].items() if k in args.representations}

    if args.video_path.is_dir():
        all_files = natsorted([f for f in args.video_path.iterdir() if f.is_file()], key=lambda p: p.name)
        suffixes = set(p.suffix for p in all_files)
        assert len(suffixes) == 1, f"Expected a single type of files in '{args.video_path}' found {suffixes}"
        frames = [int(x.stem) for x in all_files]
        fn = {".png": image_read, ".npz": lambda p: np.load(p)["arr_0"], ".npy": np.load}[next(iter(suffixes))]
        raw_data = [fn(f) for f in all_files]
        assert all(x.shape == raw_data[0].shape for x in raw_data), f"Images shape differ in '{args.video_path}'"
        logger.info(f"--video_path is a directory. Assuming a directory of images. Found {len(raw_data)} images.")
        video = FakeVideo(np.array(raw_data, dtype=np.uint8), fps=1, frames=frames)
    else:
        video = FFmpegVideo(args.video_path)

    frames = args.frames
    if args.start_frame is not None:
        frames = range(args.start_frame, args.end_frame or len(video))

    representations = build_representations_from_cfg(cfg=cfg)
    if len(args.external_representations) > 0:
        for external_path in args.external_representations:
            representations = add_external_representations(representations, external_path, cfg)

    vre = VRE(video, representations)
    vre_metadata = vre.run(args.output_path, frames=frames, output_dir_exists_mode=args.output_dir_exists_mode,
                           n_threads_data_storer=args.n_threads_data_storer)
    vre_run_stats = pd.DataFrame(vre_metadata["run_stats"], index=vre_metadata["runtime_args"]["frames"])
    print(vre_run_stats if len(vre_run_stats) > 1 else vre_run_stats.T)

    if args.make_video_collage:
        vre_collage = imp.load_source("vre_collage", (Path(__file__).parent / "vre_collage").__str__())
        vre_collage.main(Namespace(vre_export_dir=args.output_path, output_path=args.output_path / "collage",
                                   video=True, fps=args.collage_fps, output_resolution=None))

if __name__ == "__main__":
    main(get_args())
