#!/usr/bin/python

## GPL by Peter Bengtsson, www.peterbe.com
## April 2005

__version__='1.5'


import sys
import re, os

def string_center(s, width, padding):
    # only python2.4 has 'hej'.center(80, '+')
    # python2.3 can only do 'hej'.center(80)
    try:
        return s.center(width, padding)
    except TypeError:
        pad_space = (width - len(s)) / 2
        return padding * pad_space + s + padding * pad_space

semicompiled_regex = re.compile("\.(py|cpy|vpy)c", re.I)
semicompiled = lambda line: semicompiled_regex.findall(line)

junk_regex = re.compile(r"\btags:", re.I)
isJunk = lambda line: junk_regex.findall(line)


backupfile_regex = re.compile("\.\w+~|\.bak:|\.bak\d:|\.svn|/\.#\w+", re.I)
backupfile = lambda line: backupfile_regex.findall(line)

result = sys.stdin.read()

try:
    LINES_EITHER_SIDE = open(os.path.expanduser('~/.Grepexpansion')).read()
    LINES_EITHER_SIDE = int(LINES_EITHER_SIDE.strip())
    assert LINES_EITHER_SIDE >= 0 and LINES_EITHER_SIDE < 100
    
except:    
    LINES_EITHER_SIDE = 0


try:
    arged_lines_either_side = int(sys.argv[1])
    assert arged_lines_either_side >0
    if arged_lines_either_side != LINES_EITHER_SIDE:
        try:
            f=open(os.path.expanduser('~/.Grepexpansion'), 'w')
            f.write(str(arged_lines_either_side))
            f.close()
        except:
            pass
    LINES_EITHER_SIDE = arged_lines_either_side
except IndexError:
    pass
except:
    print >>sys.stderr, "First argument must be a positive integer"

previous_filename = None    
for line in result.splitlines():
    if semicompiled(line):
        continue
    if backupfile(line):
        continue
    if isJunk(line):
        continue
    if line.startswith('Binary file'):
        continue
    _either_side = LINES_EITHER_SIDE + 1
    try:
        file, lineno = line.split(':')[:2]
    except:
        print line
        continue
    try:
        lineno = int(lineno)
    except ValueError:
        print >>sys.stderr, "Lineno not an int: %r" % lineno
        raise
    if previous_filename == file:
        print ""
    else:
        print string_center(" %s " % file, 80, '-')
    previous_filename = file
    content = open(file).read().splitlines()
    for i in range(max(lineno-_either_side,0)+1,
                   min(lineno+_either_side, len(content)-1),
                   1):
#        print i, lineno
        star = " "
        if i == lineno:
            star = "*"
        
        print "%s%s| %s" % (i, star, content[i-1])