Synnefo

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from datetime import datetime

from django.utils.timesince import timesince, timeuntil

from synnefo.util.text import uenc, udec

def parse_bool(value, strict=True):

    """Convert a string to boolen value.

    If string is True, then ValueError will be raised, if the string can not be

    converted to boolean. Otherwise the string will be returned as is.

    """

    if value.lower() in ("yes", "true", "t", "1"):

        return True

    if value.lower() in ("no", "false", "f", "0"):

        return False

    if strict:

        raise ValueError("Can convert '%s' to boolean value")

    else:

        return value

def format_bool(b):

    """Convert a boolean value to YES or NO."""

    return "YES" if b else "NO"

def format_date(d):

    if not d:

        return ""

    if d < datetime.now():

        return timesince(d) + " ago"

    else:

        return "in " + timeuntil(d)

def parse_filters(filter_by):

    """Parse a string into lookup parameters for QuerySet.filter(**kwargs).

    This functions converts a string of comma-separated key 'cond' val triples

    to two dictionaries, containing lookup parameters to be used for filter

    and exclude functions of QuerySet.

    e.g. filter_by="foo>=2, baz!=4" -> ({"foo__gte": "2"}, {"baz": "4"})

    """

    filter_dict = {}

    exclude_dict = {}

    filter_list = filter_by.split(",")

    def map_field_type(query):

        if "!=" in query:

            key, val = query.split("!=")

            exclude_dict[key] = parse_bool(val, strict=False)

            return

        OP_MAP = {

            ">=": "__gte",

            "=>": "__gte",

            ">":  "__gt",

            "<=": "__lte",

            "=<": "__lte",

            "<":  "__lt",

            "=":  "",

        }

        for op, new_op in OP_MAP.items():

            if op in query:

                key, val = query.split(op)

                filter_dict[key + new_op] = parse_bool(val, strict=False)

                return

    map(lambda x: map_field_type(x), filter_list)

    return (filter_dict, exclude_dict)

def pprint_table(out, table, headers=None, separator=None):

    """Print a pretty, aligned string representation of table.

    Works by finding out the max width of each column and padding to data

    to this value.

    """

    assert(isinstance(table, (list, tuple))), "Invalid table type"

    sep = separator if separator else "  "

    if headers:

        assert(isinstance(headers, (list, tuple))), "Invalid headers type"

        table.insert(0, headers)

    def strignify(obj):

        if isinstance(obj, (unicode, str)):

            return udec(obj)

        else:

            return str(obj)

    table = [map(strignify, row) for row in table]

    # Find out the max width of each column

    widths = [max(map(len, col)) for col in zip(*table)]

    t_length = sum(widths) + len(sep) * (len(widths) - 1)

    if headers:

        # pretty print the headers

        line = sep.join(uenc(v.rjust(w)) for v, w in zip(headers, widths))

        out.write(line + "\n")

        out.write("-" * t_length + "\n")

        # remove headers

        table = table[1:]

    # print the rest table

    for row in table:

        line = sep.join(uenc(v.rjust(w)) for v, w in zip(row, widths))

        out.write(line + "\n")