#!/usr/bin/env python

"""Auto-generate PSEP 0 (PSEP index).

Generating the PSEP index is a multi-step process.  To begin, you must first

parse the PSEP files themselves, which in and of itself takes a couple of steps:

    1. Parse metadata.

    2. Validate metadata.

With the PSEP information collected, to create the index itself you must:

    1. Output static text.

    2. Format an entry for the PSEP.

    3. Output the PSEP (both by category and numerical index).

"""

from __future__ import absolute_import, with_statement

import sys

import os

import codecs

from operator import attrgetter

from psep0.output import write_psep0

from psep0.psep import PSEP, PSEPError

def main(argv):

    if not argv[1:]:

        path = '.'

    else:

        path = argv[1]

    pseps = []

    if os.path.isdir(path):

        for file_path in os.listdir(path):

            abs_file_path = os.path.join(path, file_path)

            if not os.path.isfile(abs_file_path):

                continue

            if file_path.startswith("psep-") and file_path.endswith(".txt"):

                with codecs.open(abs_file_path, 'r', encoding='UTF-8') as psep_file:

                    try:

                        pseps.append(PSEP(psep_file))

                    except PSEPError, e:

                        errmsg = "Error processing PSEP %s, excluding:" % \

                            (e.number,)

                        print >>sys.stderr, errmsg, e

                        sys.exit(1)

        pseps.sort(key=attrgetter('number'))

    elif os.path.isfile(path):

        with open(path, 'r') as psep_file:

            pseps.append(PSEP(psep_file))

    else:

        raise ValueError("argument must be a directory or file path")

    with codecs.open('psep-0000.txt', 'w', encoding='UTF-8') as psep0_file:

        write_psep0(pseps, psep0_file)

if __name__ == "__main__":

    main(sys.argv)