"""

SoftLayer.CLI.columns

~~~~~~~~~~~~~~~~~~~~~~

Utilties for user-defined columns

:license: MIT, see LICENSE for more details.

"""

import click

from SoftLayer import utils

# pylint: disable=unused-argument

class Column(object):

"""Column desctribes an attribute and how to fetch/display it."""

def __init__(self, name, path, mask=None):

self.name = name

self.path = path

self.mask = mask

# If the mask is not set explicitly, infer it from the path

if self.mask is None and isinstance(path, (tuple, list)):

self.mask = '.'.join(path)

class ColumnFormatter(object):

"""Maps each column using a function"""

def __init__(self):

self.columns = []

self.column_funcs = []

self.mask_parts = set()

def add_column(self, column):

"""Add a new column along with a formatting function."""

self.columns.append(column.name)

self.column_funcs.append(column.path)

if column.mask is not None:

self.mask_parts.add(column.mask)

def row(self, data):

"""Return a formatted row for the given data."""

for column in self.column_funcs:

if callable(column):

yield column(data)

else:

yield utils.lookup(data, *column)

def mask(self):

"""Returns a SoftLayer mask to fetch data needed for each column."""

return ','.join(self.mask_parts)

def get_formatter(columns):

"""This function returns a callback to use with click options.

The returned function parses a comma-separated value and returns a new

ColumnFormatter.

:param columns: a list of Column instances

"""

column_map = dict((column.name, column) for column in columns)

def validate(ctx, param, value):

"""Click validation function."""

if value == '':

raise click.BadParameter('At least one column is required.')

formatter = ColumnFormatter()

for column in [col.strip() for col in value.split(',')]:

if column in column_map:

formatter.add_column(column_map[column])

else:

formatter.add_column(Column(column, column.split('.')))

return formatter

return validate