# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""
Validates a large collection of web-accessible VOTable files,
and generates a report as a directory tree of HTML files.
"""

# STDLIB
import os

# LOCAL
from astropy.utils.data import get_pkg_data_filename
from . import html
from . import result


__all__ = ['make_validation_report']


def get_srcdir():
    return os.path.dirname(__file__)


def get_urls(destdir, s):
    import gzip

    types = ['good', 'broken', 'incorrect']

    seen = set()
    urls = []
    for type in types:
        filename = get_pkg_data_filename(
            f'data/urls/cone.{type}.dat.gz')
        with gzip.open(filename, 'rb') as fd:
            for url in fd.readlines():
                next(s)
                url = url.strip()
                if url not in seen:
                    with result.Result(url, root=destdir) as r:
                        r['expected'] = type
                    urls.append(url)
                seen.add(url)

    return urls


def download(args):
    url, destdir = args
    with result.Result(url, root=destdir) as r:
        r.download_xml_content()


def validate_vo(args):
    url, destdir = args
    with result.Result(url, root=destdir) as r:
        r.validate_vo()


def votlint_validate(args):
    path_to_stilts_jar, url, destdir = args
    with result.Result(url, root=destdir) as r:
        if r['network_error'] is None:
            r.validate_with_votlint(path_to_stilts_jar)


def write_html_result(args):
    url, destdir = args
    with result.Result(url, root=destdir) as r:
        html.write_result(r)


def write_subindex(args):
    subset, destdir, total = args
    html.write_index_table(destdir, *subset, total=total)


def make_validation_report(
    urls=None, destdir='astropy.io.votable.validator.results',
    multiprocess=True, stilts=None):
    """
    Validates a large collection of web-accessible VOTable files.

    Generates a report as a directory tree of HTML files.

    Parameters
    ----------
    urls : list of str, optional
        If provided, is a list of HTTP urls to download VOTable files
        from.  If not provided, a built-in set of ~22,000 urls
        compiled by HEASARC will be used.

    destdir : path-like, optional
        The directory to write the report to.  By default, this is a
        directory called ``'results'`` in the current directory. If the
        directory does not exist, it will be created.

    multiprocess : bool, optional
        If `True` (default), perform validations in parallel using all
        of the cores on this machine.

    stilts : path-like, optional
        To perform validation with ``votlint`` from the the Java-based
        `STILTS <http://www.star.bris.ac.uk/~mbt/stilts/>`_ VOTable
        parser, in addition to `astropy.io.votable`, set this to the
        path of the ``'stilts.jar'`` file.  ``java`` on the system shell
        path will be used to run it.

    Notes
    -----
    Downloads of each given URL will be performed only once and cached
    locally in *destdir*.  To refresh the cache, remove *destdir*
    first.
    """
    from astropy.utils.console import (color_print, ProgressBar, Spinner)

    if stilts is not None:
        if not os.path.exists(stilts):
            raise ValueError(
                f'{stilts} does not exist.')

    destdir = os.path.abspath(destdir)

    if urls is None:
        with Spinner('Loading URLs', 'green') as s:
            urls = get_urls(destdir, s)
    else:
        color_print('Marking URLs', 'green')
        for url in ProgressBar.iterate(urls):
            with result.Result(url, root=destdir) as r:
                r['expected'] = type

    args = [(url, destdir) for url in urls]

    color_print('Downloading VO files', 'green')
    ProgressBar.map(
        download, args, multiprocess=multiprocess)

    color_print('Validating VO files', 'green')
    ProgressBar.map(
        validate_vo, args, multiprocess=multiprocess)

    if stilts is not None:
        color_print('Validating with votlint', 'green')
        votlint_args = [(stilts, x, destdir) for x in urls]
        ProgressBar.map(
            votlint_validate, votlint_args, multiprocess=multiprocess)

    color_print('Generating HTML files', 'green')
    ProgressBar.map(
        write_html_result, args, multiprocess=multiprocess)

    with Spinner('Grouping results', 'green') as s:
        subsets = result.get_result_subsets(urls, destdir, s)

    color_print('Generating index', 'green')
    html.write_index(subsets, urls, destdir)

    color_print('Generating subindices', 'green')
    subindex_args = [(subset, destdir, len(urls)) for subset in subsets]
    ProgressBar.map(
        write_subindex, subindex_args, multiprocess=multiprocess)