'''Check that a workshop's index.html metadata is valid.  See the
docstrings on the checking functions for a summary of the checks.
'''


import sys
import os
import re
from datetime import date
from util import Reporter, split_metadata, load_yaml, check_unwanted_files

# Metadata field patterns.
EMAIL_PATTERN = r'[^@]+@[^@]+\.[^@]+'
HUMANTIME_PATTERN = r'((0?[1-9]|1[0-2]):[0-5]\d(am|pm)(-|to)(0?[1-9]|1[0-2]):[0-5]\d(am|pm))|((0?\d|1\d|2[0-3]):[0-5]\d(-|to)(0?\d|1\d|2[0-3]):[0-5]\d)'
EVENTBRITE_PATTERN = r'\d{9,10}'
URL_PATTERN = r'https?://.+'

# Defaults.
CARPENTRIES = ("dc", "swc", "lc", "cp")
DEFAULT_CONTACT_EMAIL = 'admin@software-carpentry.org'

USAGE = 'Usage: "workshop_check.py path/to/root/directory"'

# Country and language codes.  Note that codes mean different things: 'ar'
# is 'Arabic' as a language but 'Argentina' as a country.

ISO_COUNTRY = [
    'ad', 'ae', 'af', 'ag', 'ai', 'al', 'am', 'an', 'ao', 'aq', 'ar', 'as',
    'at', 'au', 'aw', 'ax', 'az', 'ba', 'bb', 'bd', 'be', 'bf', 'bg', 'bh',
    'bi', 'bj', 'bm', 'bn', 'bo', 'br', 'bs', 'bt', 'bv', 'bw', 'by', 'bz',
    'ca', 'cc', 'cd', 'cf', 'cg', 'ch', 'ci', 'ck', 'cl', 'cm', 'cn', 'co',
    'cr', 'cu', 'cv', 'cx', 'cy', 'cz', 'de', 'dj', 'dk', 'dm', 'do', 'dz',
    'ec', 'ee', 'eg', 'eh', 'er', 'es', 'et', 'eu', 'fi', 'fj', 'fk', 'fm',
    'fo', 'fr', 'ga', 'gb', 'gd', 'ge', 'gf', 'gg', 'gh', 'gi', 'gl', 'gm',
    'gn', 'gp', 'gq', 'gr', 'gs', 'gt', 'gu', 'gw', 'gy', 'hk', 'hm', 'hn',
    'hr', 'ht', 'hu', 'id', 'ie', 'il', 'im', 'in', 'io', 'iq', 'ir', 'is',
    'it', 'je', 'jm', 'jo', 'jp', 'ke', 'kg', 'kh', 'ki', 'km', 'kn', 'kp',
    'kr', 'kw', 'ky', 'kz', 'la', 'lb', 'lc', 'li', 'lk', 'lr', 'ls', 'lt',
    'lu', 'lv', 'ly', 'ma', 'mc', 'md', 'me', 'mg', 'mh', 'mk', 'ml', 'mm',
    'mn', 'mo', 'mp', 'mq', 'mr', 'ms', 'mt', 'mu', 'mv', 'mw', 'mx', 'my',
    'mz', 'na', 'nc', 'ne', 'nf', 'ng', 'ni', 'nl', 'no', 'np', 'nr', 'nu',
    'nz', 'om', 'pa', 'pe', 'pf', 'pg', 'ph', 'pk', 'pl', 'pm', 'pn', 'pr',
    'ps', 'pt', 'pw', 'py', 'qa', 're', 'ro', 'rs', 'ru', 'rw', 'sa', 'sb',
    'sc', 'sd', 'se', 'sg', 'sh', 'si', 'sj', 'sk', 'sl', 'sm', 'sn', 'so',
    'sr', 'st', 'sv', 'sy', 'sz', 'tc', 'td', 'tf', 'tg', 'th', 'tj', 'tk',
    'tl', 'tm', 'tn', 'to', 'tr', 'tt', 'tv', 'tw', 'tz', 'ua', 'ug', 'um',
    'us', 'uy', 'uz', 'va', 'vc', 've', 'vg', 'vi', 'vn', 'vu', 'wf', 'ws',
    'ye', 'yt', 'za', 'zm', 'zw'
]

ISO_LANGUAGE = [
    'aa', 'ab', 'ae', 'af', 'ak', 'am', 'an', 'ar', 'as', 'av', 'ay', 'az',
    'ba', 'be', 'bg', 'bh', 'bi', 'bm', 'bn', 'bo', 'br', 'bs', 'ca', 'ce',
    'ch', 'co', 'cr', 'cs', 'cu', 'cv', 'cy', 'da', 'de', 'dv', 'dz', 'ee',
    'el', 'en', 'eo', 'es', 'et', 'eu', 'fa', 'ff', 'fi', 'fj', 'fo', 'fr',
    'fy', 'ga', 'gd', 'gl', 'gn', 'gu', 'gv', 'ha', 'he', 'hi', 'ho', 'hr',
    'ht', 'hu', 'hy', 'hz', 'ia', 'id', 'ie', 'ig', 'ii', 'ik', 'io', 'is',
    'it', 'iu', 'ja', 'jv', 'ka', 'kg', 'ki', 'kj', 'kk', 'kl', 'km', 'kn',
    'ko', 'kr', 'ks', 'ku', 'kv', 'kw', 'ky', 'la', 'lb', 'lg', 'li', 'ln',
    'lo', 'lt', 'lu', 'lv', 'mg', 'mh', 'mi', 'mk', 'ml', 'mn', 'mr', 'ms',
    'mt', 'my', 'na', 'nb', 'nd', 'ne', 'ng', 'nl', 'nn', 'no', 'nr', 'nv',
    'ny', 'oc', 'oj', 'om', 'or', 'os', 'pa', 'pi', 'pl', 'ps', 'pt', 'qu',
    'rm', 'rn', 'ro', 'ru', 'rw', 'sa', 'sc', 'sd', 'se', 'sg', 'si', 'sk',
    'sl', 'sm', 'sn', 'so', 'sq', 'sr', 'ss', 'st', 'su', 'sv', 'sw', 'ta',
    'te', 'tg', 'th', 'ti', 'tk', 'tl', 'tn', 'to', 'tr', 'ts', 'tt', 'tw',
    'ty', 'ug', 'uk', 'ur', 'uz', 've', 'vi', 'vo', 'wa', 'wo', 'xh', 'yi',
    'yo', 'za', 'zh', 'zu'
]


def look_for_fixme(func):
    """Decorator to fail test if text argument starts with "FIXME"."""

    def inner(arg):
        if (arg is not None) and \
           isinstance(arg, str) and \
           arg.lstrip().startswith('FIXME'):
            return False
        return func(arg)
    return inner


@look_for_fixme
def check_layout(layout):
    '''"layout" in YAML header must be "workshop".'''

    return layout == 'workshop'


@look_for_fixme
def check_carpentry(layout):
    '''"carpentry" in YAML header must be "dc", "swc", "lc", or "cp".'''

    return layout in CARPENTRIES


@look_for_fixme
def check_country(country):
    '''"country" must be a lowercase ISO-3166 two-letter code.'''

    return country in ISO_COUNTRY


@look_for_fixme
def check_language(language):
    '''"language" must be a lowercase ISO-639 two-letter code.'''

    return language in ISO_LANGUAGE


@look_for_fixme
def check_humandate(date):
    """
    'humandate' must be a human-readable date with a 3-letter month
    and 4-digit year.  Examples include 'Feb 18-20, 2025' and 'Feb 18
    and 20, 2025'.  It may be in languages other than English, but the
    month name should be kept short to aid formatting of the main
    Carpentries web site.
    """

    if ',' not in date:
        return False

    month_dates, year = date.split(',')

    # The first three characters of month_dates are not empty
    month = month_dates[:3]
    if any(char == ' ' for char in month):
        return False

    # But the fourth character is empty ("February" is illegal)
    if month_dates[3] != ' ':
        return False

    # year contains *only* numbers
    try:
        int(year)
    except:
        return False

    return True


@look_for_fixme
def check_humantime(time):
    """
    'humantime' is a human-readable start and end time for the
    workshop, such as '09:00 - 16:00'.
    """

    return bool(re.match(HUMANTIME_PATTERN, time.replace(' ', '')))


def check_date(this_date):
    """
    'startdate' and 'enddate' are machine-readable start and end dates
    for the workshop, and must be in YYYY-MM-DD format, e.g.,
    '2015-07-01'.
    """

    # YAML automatically loads valid dates as datetime.date.
    return isinstance(this_date, date)


@look_for_fixme
def check_latitude_longitude(latlng):
    """
    'latlng' must be a valid latitude and longitude represented as two
    floating-point numbers separated by a comma.
    """

    try:
        lat, lng = latlng.split(',')
        lat = float(lat)
        lng = float(lng)
        return (-90.0 <= lat <= 90.0) and (-180.0 <= lng <= 180.0)
    except ValueError:
        return False


def check_instructors(instructors):
    """
    'instructor' must be a non-empty comma-separated list of quoted
    names, e.g. ['First name', 'Second name', ...'].  Do not use 'TBD'
    or other placeholders.
    """

    # YAML automatically loads list-like strings as lists.
    return isinstance(instructors, list) and len(instructors) > 0


def check_helpers(helpers):
    """
    'helper' must be a comma-separated list of quoted names,
    e.g. ['First name', 'Second name', ...'].  The list may be empty.
    Do not use 'TBD' or other placeholders.
    """

    # YAML automatically loads list-like strings as lists.
    return isinstance(helpers, list) and len(helpers) >= 0


@look_for_fixme
def check_emails(emails):
    """
    'emails' must be a comma-separated list of valid email addresses.
    The list may be empty. A valid email address consists of characters,
    an '@', and more characters.  It should not contain the default contact
    """

    # YAML automatically loads list-like strings as lists.
    if (isinstance(emails, list) and len(emails) >= 0):
        for email in emails:
            if ((not bool(re.match(EMAIL_PATTERN, email))) or (email == DEFAULT_CONTACT_EMAIL)):
                return False
    else:
        return False

    return True


def check_eventbrite(eventbrite):
    """
    'eventbrite' (the Eventbrite registration key) must be 9 or more
    digits.  It may appear as an integer or as a string.
    """

    if isinstance(eventbrite, int):
        return True
    else:
        return bool(re.match(EVENTBRITE_PATTERN, eventbrite))


@look_for_fixme
def check_collaborative_notes(collaborative_notes):
    """
    'collaborative_notes' must be a valid URL.
    """

    return bool(re.match(URL_PATTERN, collaborative_notes))


@look_for_fixme
def check_pass(value):
    """
    This test always passes (it is used for 'checking' things like the
    workshop address, for which no sensible validation is feasible).
    """

    return True


HANDLERS = {
    'layout':     (True, check_layout, 'layout isn\'t "workshop"'),

    'carpentry':  (True, check_carpentry, 'carpentry isn\'t in ' +
                   ', '.join(CARPENTRIES)),

    'country':    (True, check_country,
                   'country invalid: must use lowercase two-letter ISO code ' +
                   'from ' + ', '.join(ISO_COUNTRY)),

    'language':   (False,  check_language,
                   'language invalid: must use lowercase two-letter ISO code' +
                   ' from ' + ', '.join(ISO_LANGUAGE)),

    'humandate':  (True, check_humandate,
                   'humandate invalid. Please use three-letter months like ' +
                   '"Jan" and four-letter years like "2025"'),

    'humantime':  (True, check_humantime,
                   'humantime doesn\'t include numbers'),

    'startdate':  (True, check_date,
                   'startdate invalid. Must be of format year-month-day, ' +
                   'i.e., 2014-01-31'),

    'enddate':    (False, check_date,
                   'enddate invalid. Must be of format year-month-day, i.e.,' +
                   ' 2014-01-31'),

    'latlng':     (True, check_latitude_longitude,
                   'latlng invalid. Check that it is two floating point ' +
                   'numbers, separated by a comma'),

    'instructor': (True, check_instructors,
                   'instructor list isn\'t a valid list of format ' +
                   '["First instructor", "Second instructor",..]'),

    'helper':     (True, check_helpers,
                   'helper list isn\'t a valid list of format ' +
                   '["First helper", "Second helper",..]'),

    'email':    (True, check_emails,
                 'contact email list isn\'t a valid list of format ' +
                 '["me@example.org", "you@example.org",..] or contains incorrectly formatted email addresses or ' +
                 '"{0}".'.format(DEFAULT_CONTACT_EMAIL)),

    'eventbrite': (False, check_eventbrite, 'Eventbrite key appears invalid'),

    'collaborative_notes':   (False, check_collaborative_notes, 'Collaborative Notes URL appears invalid'),

    'venue':      (False, check_pass, 'venue name not specified'),

    'address':    (False, check_pass, 'address not specified')
}

# REQUIRED is all required categories.
REQUIRED = {k for k in HANDLERS if HANDLERS[k][0]}

# OPTIONAL is all optional categories.
OPTIONAL = {k for k in HANDLERS if not HANDLERS[k][0]}


def check_blank_lines(reporter, raw):
    """
    Blank lines are not allowed in category headers.
    """

    lines = [(i, x) for (i, x) in enumerate(
        raw.strip().split('\n')) if not x.strip()]
    reporter.check(not lines,
                   None,
                   'Blank line(s) in header: {0}',
                   ', '.join(["{0}: {1}".format(i, x.rstrip()) for (i, x) in lines]))


def check_categories(reporter, left, right, msg):
    """
    Report differences (if any) between two sets of categories.
    """

    diff = left - right
    reporter.check(len(diff) == 0,
                   None,
                   '{0}: offending entries {1}',
                   msg, sorted(list(diff)))


def check_file(reporter, path, data):
    """
    Get header from file, call all other functions, and check file for
    validity.
    """

    # Get metadata as text and as YAML.
    raw, header, body = split_metadata(path, data)

    # Do we have any blank lines in the header?
    check_blank_lines(reporter, raw)

    # Look through all header entries.  If the category is in the input
    # file and is either required or we have actual data (as opposed to
    # a commented-out entry), we check it.  If it *isn't* in the header
    # but is required, report an error.
    for category in HANDLERS:
        required, handler, message = HANDLERS[category]
        if category in header:
            if required or header[category]:
                reporter.check(handler(header[category]),
                               None,
                               '{0}\n    actual value "{1}"',
                               message, header[category])
        elif required:
            reporter.add(None,
                         'Missing mandatory key "{0}"',
                         category)

    # Check whether we have missing or too many categories
    seen_categories = set(header.keys())
    check_categories(reporter, REQUIRED, seen_categories,
                     'Missing categories')
    check_categories(reporter, seen_categories, REQUIRED.union(OPTIONAL),
                     'Superfluous categories')


def check_config(reporter, filename):
    """
    Check YAML configuration file.
    """

    config = load_yaml(filename)

    kind = config.get('kind', None)
    reporter.check(kind == 'workshop',
                   filename,
                   'Missing or unknown kind of event: {0}',
                   kind)

    carpentry = config.get('carpentry', None)
    reporter.check(carpentry in ('swc', 'dc', 'lc', 'cp'),
                   filename,
                   'Missing or unknown carpentry: {0}',
                   carpentry)


def main():
    '''Run as the main program.'''

    if len(sys.argv) != 2:
        print(USAGE, file=sys.stderr)
        sys.exit(1)

    root_dir = sys.argv[1]
    index_file = os.path.join(root_dir, 'index.html')
    config_file = os.path.join(root_dir, '_config.yml')

    reporter = Reporter()
    check_config(reporter, config_file)
    check_unwanted_files(root_dir, reporter)
    with open(index_file, encoding='utf-8') as reader:
        data = reader.read()
        check_file(reporter, index_file, data)
    reporter.report()


if __name__ == '__main__':
    main()