import os
import numpy as np
import urllib
import tarfile, zipfile
from pathlib import Path
from tqdm import tqdm


def unpack(path):
    if path.endswith("tar.gz"):
        with tarfile.open(path, "r:gz") as tar:
            tar.extractall(path=os.path.split(path)[0])
    elif path.endswith("tar"):
        with tarfile.open(path, "r:") as tar:
            tar.extractall(path=os.path.split(path)[0])
    elif path.endswith("zip"):
        with zipfile.ZipFile(path, "r") as f:
            f.extractall(path=os.path.split(path)[0])
    else:
        raise NotImplementedError(
            "Unknown file extension: {}".format(os.path.splitext(path)[1])
        )


def reporthook(bar):
    """tqdm progress bar for downloads."""

    def hook(b=1, bsize=1, tsize=None):
        if tsize is not None:
            bar.total = tsize
        bar.update(b * bsize - bar.n)

    return hook


def get_root(name):
    base = "data/"
    root = os.path.join(base, name)
    os.makedirs(root, exist_ok=True)
    return root


def is_prepared(root):
    return Path(root).joinpath(".ready").exists()


def mark_prepared(root):
    Path(root).joinpath(".ready").touch()


def prompt_download(file_, source, target_dir, content_dir=None):
    targetpath = os.path.join(target_dir, file_)
    while not os.path.exists(targetpath):
        if content_dir is not None and os.path.exists(
            os.path.join(target_dir, content_dir)
        ):
            break
        print(
            "Please download '{}' from '{}' to '{}'.".format(file_, source, targetpath)
        )
        if content_dir is not None:
            print(
                "Or place its content into '{}'.".format(
                    os.path.join(target_dir, content_dir)
                )
            )
        input("Press Enter when done...")
    return targetpath


def download_url(file_, url, target_dir):
    targetpath = os.path.join(target_dir, file_)
    os.makedirs(target_dir, exist_ok=True)
    with tqdm(
        unit="B", unit_scale=True, unit_divisor=1024, miniters=1, desc=file_
    ) as bar:
        urllib.request.urlretrieve(url, targetpath, reporthook=reporthook(bar))
    return targetpath


def download_urls(urls, target_dir):
    paths = dict()
    for fname, url in urls.items():
        outpath = download_url(fname, url, target_dir)
        paths[fname] = outpath
    return paths


def quadratic_crop(x, bbox, alpha=1.0):
    """bbox is xmin, ymin, xmax, ymax"""
    im_h, im_w = x.shape[:2]
    bbox = np.array(bbox, dtype=np.float32)
    bbox = np.clip(bbox, 0, max(im_h, im_w))
    center = 0.5 * (bbox[0] + bbox[2]), 0.5 * (bbox[1] + bbox[3])
    w = bbox[2] - bbox[0]
    h = bbox[3] - bbox[1]
    l = int(alpha * max(w, h))
    l = max(l, 2)

    required_padding = -1 * min(
        center[0] - l, center[1] - l, im_w - (center[0] + l), im_h - (center[1] + l)
    )
    required_padding = int(np.ceil(required_padding))
    if required_padding > 0:
        padding = [
            [required_padding, required_padding],
            [required_padding, required_padding],
        ]
        padding += [[0, 0]] * (len(x.shape) - 2)
        x = np.pad(x, padding, "reflect")
        center = center[0] + required_padding, center[1] + required_padding
    xmin = int(center[0] - l / 2)
    ymin = int(center[1] - l / 2)
    return np.array(x[ymin : ymin + l, xmin : xmin + l, ...])