import re

LETTER = set('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')
VALID = set('_0123456789') | LETTER


def cleanName(name):
    clean = ''.join(c if c in VALID else '_' for c in name)
    if clean == '' or not clean[0] in LETTER:
        clean = 'x' + clean
    return clean


def isClean(name):
    if name is None or len(name) == 0 or name[0] not in LETTER:
        return False
    return all(c in VALID for c in name[1:])


def expandDir(dirName, paths):
    if dirName.startswith('~'):
        dirName = dirName.replace('~', paths['home'], 1)
    elif dirName.startswith('..'):
        dirName = dirName.replace('..', paths['up'], 1)
    elif dirName.startswith('.'):
        dirName = dirName.replace('.', paths['cur'], 1)
    return dirName


def setFromSpec(spec):
    covered = set()
    for r_str in spec.split(','):
        bounds = r_str.split('-')
        if len(bounds) == 1:
            covered.add(int(r_str))
        else:
            b = int(bounds[0])
            e = int(bounds[1])
            if (e < b):
                (b, e) = (e, b)
            for n in range(b, e + 1):
                covered.add(n)
    return covered


def rangesFromSet(nodeSet):
    ranges = []
    curstart = None
    curend = None
    for n in sorted(nodeSet):
        if curstart is None:
            curstart = n
            curend = n
        elif n == curend + 1:
            curend = n
        else:
            ranges.append((curstart, curend))
            curstart = n
            curend = n
    if curstart is not None:
        ranges.append((curstart, curend))
    return ranges


def rangesFromList(nodeList):  # the list must be sorted
    ranges = []
    curstart = None
    curend = None
    for n in nodeList:
        if curstart is None:
            curstart = n
            curend = n
        elif n == curend + 1:
            curend = n
        else:
            ranges.append((curstart, curend))
            curstart = n
            curend = n
    if curstart is not None:
        ranges.append((curstart, curend))
    return ranges


def specFromRanges(ranges):  # ranges must be normalized
    return ','.join(
        '{}'.format(r[0]) if r[0] == r[1] else '{}-{}'.format(*r)
        for r in ranges
    )


def valueFromTf(tf):
    return '\\'.join(
        x.replace('\\t', '\t').replace('\\n', '\n') for x in tf.split('\\\\')
    )


def tfFromValue(val):
    return str(val) if type(val) is int else val.replace('\\', '\\\\').replace(
        '\t', '\\t'
    ).replace('\n', '\\n')


def makeInverse(data):
    inverse = {}
    for n in data:
        for m in data[n]:
            inverse.setdefault(m, set()).add(n)
    return inverse


def makeInverseVal(data):
    inverse = {}
    for n in data:
        for (m, val) in data[n].items():
            inverse.setdefault(m, {})[n] = val
    return inverse


def nbytes(by):
    units = ['B', 'KB', 'MB', 'GB', 'TB']
    for i in range(len(units)):
        if by < 1024 or i == len(units) - 1:
            fmt = '{:>5}{}' if i == 0 else '{:>5.1f}{}'
            return fmt.format(by, units[i])
        by /= 1024


def collectFormats(config):
    varPattern = re.compile(r'\{([^}]+)\}')
    featureSet = set()

    def collectFormat(tpl):
        features = []

        def varReplace(match):
            varText = match.group(1)
            fts = tuple(varText.split('/'))
            features.append(fts)
            for ft in fts:
                featureSet.add(ft)
            return '{}'

        rtpl = varPattern.sub(varReplace, tpl)
        return (rtpl, tuple(features))

    formats = {}
    for (fmt, tpl) in sorted(config.items()):
        if fmt.startswith('fmt:'):
            formats[fmt[4:]] = collectFormat(tpl)
    return (formats, sorted(featureSet))


def compileFormats(cformats, features):
    xformats = {}
    for (fmt, (rtpl, feats)) in sorted(cformats.items()):
        tpl = rtpl.replace('\\n', '\n').replace('\\t', '\t')
        xformats[fmt] = compileFormat(tpl, feats, features)
    return xformats


def compileFormat(rtpl, feats, features):
    replaceFuncs = []
    for feat in feats:
        replaceFuncs.append(makeFunc(feat, features))

    def g(n):
        values = tuple(replaceFunc(n) for replaceFunc in replaceFuncs)
        return rtpl.format(*values)

    return g


def makeFunc(feat, features):
    if len(feat) == 1:
        ft = feat[0]
        f = features[ft].data
        return (lambda n: f.get(n, ''))
    elif len(feat) == 2:
        (ft1, ft2) = feat
        f1 = features[ft1].data
        f2 = features[ft2].data
        return (lambda n: (f1.get(n, f2.get(n, ''))))


def itemize(string, sep=None):
    if not string:
        return []
    if not sep:
        return string.strip().split()
    return string.strip().split(sep)