"""
This script reads from a YAML file and downloads data from CVAT.
"""

import os
import argparse
import subprocess 
import shutil
import yaml
from pathlib import Path
from cvat_dataset import CVATDataset
from merge_cocos import merge
from yolo_labels import get_yolo_labels

HOME = os.getenv("APP_HOME")
CVAT_TASKS = os.path.join(HOME, os.getenv("APP_CVAT_TASKS_YAML"))
PYPREPROCESS = os.getenv("APP_PYPREPROCESS")
import sys
sys.path.append(HOME)

if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument(
        'cvat_url', 
        type = str, 
        help = 'cvat url'
    )
    parser.add_argument(
        'cvat_org',
        type = str, 
        help = 'cvat organization'
    )
    parser.add_argument(
        '-odir', '--output_dir', 
        type = str, 
        help = "path to download directory",
        default = "/data"
    )
    args = parser.parse_args()

    with open(CVAT_TASKS, "r") as f:
        y = yaml.safe_load(f)
        TASK_IDS = y["task_ids"]
        NAMES = None
        if "names" in y:
            NAMES = y["names"]

    data_folder = Path(args.output_dir)
    data_folder.mkdir(parents=True, exist_ok=True)

    CVAT = CVATDataset(
        args.cvat_url,
        args.cvat_org,
        TASK_IDS,
        names = NAMES, 
        dest_folder = data_folder
    )
    CVAT.download_tasks()

    paths2imgs = []
    paths2json = []
    paths2dirs = []
    for dataset in data_folder.rglob("*.zip"):
        dir_name = dataset.parent / dataset.stem
        paths2dirs.append(dir_name)
        paths2imgs.append(dir_name / "images")
        paths2json.append(dir_name / "annotations" / "instances_default.json")
        if dir_name.exists():
            continue
        subprocess.call(['unzip', '-o', dataset, '-d', dir_name])
    
    if PYPREPROCESS == 'true':
        # looks for the py script called: trainer_files/preprocess.py
        # this script is characteristic to the project
        from trainer_files.preprocess import preprocess_cvat
        paths2json, paths2imgs = preprocess_cvat(paths2dirs)

    # TODO: add debugging / assert script to make sure preprocess is done correctly
    
    # merge everything into a single json file
    if len(paths2json) > 1:
        merge(
            paths2json, paths2imgs, data_folder / 'merged_cocos', 'merged', verbose=True
        )
    else:
        json_file = Path(paths2json[0])
        shutil.copy(
            json_file.as_posix(), 
            (json_file.parents[1] / 'merged.json').as_posix()
        )
        shutil.move(
            json_file.parents[1].as_posix(), 
            (data_folder / 'merged_cocos').as_posix()
        )

    # yolo format - labels
    path2json = data_folder / 'merged_cocos' / 'merged.json'
    get_yolo_labels(path2json, use_segment=False)