#!/usr/bin/env python3

"""
csvtomd 0.2.1
tsvtomd 0.2.1, just changed the default delimiter. Ville Rantanen

# The MIT License (MIT)

Copyright (c) 2014 Matthew Lewis

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

Convert your CSV files into Markdown tables.

More info: http://github.com/mplewis/csvtomd
"""

import argparse
import csv
import sys


DEFAULT_PADDING = 2


def check_negative(value):
    try:
        ivalue = int(value)
    except ValueError:
        raise argparse.ArgumentTypeError(
            '"%s" must be an integer' % value)
    if ivalue < 0:
        raise argparse.ArgumentTypeError(
            '"%s" must not be a negative value' % value)
    return ivalue


def pad_to(unpadded, target_len):
    """
    Pad a string to the target length in characters, or return the original
    string if it's longer than the target length.
    """
    under = target_len - len(unpadded)
    if under <= 0:
        return unpadded
    return unpadded + (' ' * under)


def normalize_cols(table):
    """
    Pad short rows to the length of the longest row to help render "jagged"
    CSV files
    """
    longest_row_len = max([len(row) for row in table])
    for row in table:
        while len(row) < longest_row_len:
            row.append('')
    return table


def pad_cells(table):
    """Pad each cell to the size of the largest cell in its column."""
    col_sizes = [max(map(len, col)) for col in zip(*table)]
    for row in table:
        for cell_num, cell in enumerate(row):
            row[cell_num] = pad_to(cell, col_sizes[cell_num])
    return table


def horiz_div(col_widths, horiz, vert, padding):
    """
    Create the column dividers for a table with given column widths.

    col_widths: list of column widths
    horiz: the character to use for a horizontal divider
    vert: the character to use for a vertical divider
    padding: amount of padding to add to each side of a column
    """
    horizs = [horiz * w for w in col_widths]
    div = ''.join([padding * horiz, vert, padding * horiz])
    return div.join(horizs)


def add_dividers(row, divider, padding):
    """Add dividers and padding to a row of cells and return a string."""
    div = ''.join([padding * ' ', divider, padding * ' '])
    return div.join(row)


def md_table(table, *, padding=DEFAULT_PADDING, divider='|', header_div='-'):
    """
    Convert a 2D array of items into a Markdown table.

    padding: the number of padding spaces on either side of each divider
    divider: the vertical divider to place between columns
    header_div: the horizontal divider to place between the header row and
        body cells
    """
    table = normalize_cols(table)
    table = pad_cells(table)
    header = table[0]
    body = table[1:]

    col_widths = [len(cell) for cell in header]
    horiz = horiz_div(col_widths, header_div, divider, padding)

    header = add_dividers(header, divider, padding)
    body = [add_dividers(row, divider, padding) for row in body]

    table = [header, horiz]
    table.extend(body)
    table = [row.rstrip() for row in table]
    return '\n'.join(table)


def csv_to_table(file, delimiter):
    return list(csv.reader(file, delimiter=delimiter))


def main():
    parser = argparse.ArgumentParser(
        description='Read one or more CSV files and output their contents in '
                    'the form of Markdown tables.')
    parser.add_argument('files', metavar='csv_file', type=str, nargs='*',
                        default=['-'],
                        help="One or more CSV files to be converted. "
                        "Use - for stdin.")
    parser.add_argument('-n', '--no-filenames', action='store_false',
                        dest='show_filenames',
                        help="Don't display filenames when outputting "
                             "multiple Markdown tables.")
    parser.add_argument('-p', '--padding', type=check_negative,
                        default=DEFAULT_PADDING,
                        help="The number of spaces to add between table cells "
                             "and column dividers. Default is 2 spaces.")
    parser.add_argument('-d', '--delimiter', default='\t',
                        help='The delimiter to use when parsing CSV data. '
                             'Default is "%(default)s"')

    args = parser.parse_args()
    first = True

    if '-' in args.files and len(args.files) > 1:
        print('Standard input can only be used alone.', file=sys.stderr)
        exit(1)
    for file_num, filename in enumerate(args.files):
        # Print space between consecutive tables
        if not first:
            print('')
        else:
            first = False
        # Read the CSV files
        if filename == '-':
            table = csv_to_table(sys.stdin, args.delimiter)
        else:
            with open(filename, 'rU') as f:
                table = csv_to_table(f, args.delimiter)
        # Print filename for each table if --no-filenames wasn't passed and
        # more than one CSV was provided
        file_count = len(args.files)
        if args.show_filenames and file_count > 1:
            print(filename + '\n')
        # Generate and print Markdown table
        print(md_table(table, padding=args.padding))


if __name__ == '__main__':
    main()