#!/usr/bin/env python2

"""
Consistent formatting of rst section titles
"""

import re
import subprocess

spaces = [
    (0, 1), # we assume this is a over-and-underlined header
    (2, 1),
    (1, 1),
    (1, 0),
    (1, 0),
    ]

# match on a header line underlined with one of the valid characters
headermatch = re.compile(r'''\n*(.+)\n([][!"#$%&'()*+,./:;<=>?@\\^_`{|}~-])\2{2,}\n+''', flags=re.MULTILINE)


def main():
    for fn in subprocess.check_output(['hg', 'loc', 'set:**.rst+kallithea/i18n/how_to']).splitlines():
        print 'processing %s:' % fn
        s = file(fn).read()

        # find levels and their styles
        lastpos = 0
        styles = []
        for markup in headermatch.findall(s):
            style = markup[1]
            if style in styles:
                stylepos = styles.index(style)
                if stylepos > lastpos + 1:
                    print 'bad style %r with level %s - was at %s' % (style, stylepos, lastpos)
            else:
                stylepos = len(styles)
                if stylepos > lastpos + 1:
                    print 'bad new style %r - expected %r' % (style, styles[lastpos + 1])
                else:
                    styles.append(style)
            lastpos = stylepos

        # remove superfluous spacing (may however be restored by header spacing)
        s = re.sub(r'''(\n\n)\n*''', r'\1', s, flags=re.MULTILINE)

        # rewrite header markup with correct style, length and spacing
        def subf(m):
            title, style = m.groups()
            level = styles.index(style)
            before, after = spaces[level]
            return '\n' * (before + 1) + title + '\n' + style * len(title) + '\n' * (after + 1)
        s = headermatch.sub(subf, s)

        # remove superfluous spacing when headers are adjacent
        s = re.sub(r'''(\n.+\n([][!"#$%&'()*+,./:;<=>?@\\^_`{|}~-])\2{2,}\n\n\n)\n*''', r'\1', s, flags=re.MULTILINE)
        # fix trailing space and spacing before link sections
        s = s.strip() + '\n'
        s = re.sub(r'''\n+((?:\.\. _[^\n]*\n)+)$''', r'\n\n\n\1', s)

        file(fn, 'w').write(s)
        print subprocess.check_output(['hg', 'diff', fn])
        print

if __name__ == '__main__':
    main()