#!/usr/bin/env python
# -*- python -*-

"""
NAME
	%(program)s - find a filename close to a given a SVN repository commit

SYNOPSIS
	%(program)s [OPTIONS] REPO REV NAME

DESCRIPTION
	Supposing we have a subversion repository containing a trunk and
        various branches.  Given the repository url and the revision number of
        a commit, what is the top of the branch?  $(program)s attempts to
        answer this by letting you search for a specific file name which is
        assumed to be unique within the branch and be situated at the top of
        the branch subtree.

%(options)s

AUTHOR
	Written by Henrik Levkowetz, <henrik@zinfandel.tools.ietf.org>

COPYRIGHT
	Copyright 2015 Henrik Levkowetz

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or (at
	your option) any later version. There is NO WARRANTY; not even the
	implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
	PURPOSE. See the GNU General Public License for more details.

"""

import sys, os.path, getopt, re

version = "0.13"
program = os.path.basename(sys.argv[0])
progdir = os.path.dirname(sys.argv[0])

# ----------------------------------------------------------------------
# Parse options

options = ""
for line in re.findall("\n +(if|elif) +opt in \[(.+)\]:\s+#(.+)\n", open(sys.argv[0]).read()):
    if not options:
        options += "OPTIONS\n"
    options += "        %-16s %s\n" % (line[1].replace('"', ''), line[2])
options = options.strip()

# with ' < 1:' on the next line, this is a no-op:
if len(sys.argv) <= 1:
    help()

try:
    opts, files = getopt.gnu_getopt(sys.argv[1:], "dfDhv", ["dirchange", "filechange", "dirpath", "help", "version",])
except Exception, e:
    print "%s: %s" % (program, e)
    sys.exit(1)

# ----------------------------------------------------------------------
# Handle options

# set default values, if any
opt_dirpath = False
opt_dirchange = False
opt_filechange = False
opt_verbose = False

# ----------------------------------------------------------------------
def help(msg=None, err=0):
    if msg:
        print(msg+'\n')
    print(__doc__ % globals())
    sys.exit(err)

# handle individual options
for opt, value in opts:
    if   opt in ["-h", "--help"]: # Output this help, then exit
        help()
    elif opt in ["-v", "--version"]: # Output version information, then exit
        print program, version
        sys.exit(0)
    elif opt in ["-d", "--dirchange"]: # Look only for directory changes
        opt_dirchange = True
    elif opt in ["-f", "--filechange"]: #Look only for file changes
        opt_filechange = True
    elif opt in ["-D", "--dirpath"]: # Output the directory path, not the file path 
        opt_dirpath = True

# if neither filechange nor dirchange have been specified, look for both
if not opt_filechange and not opt_dirchange:
    opt_filechange = True
    opt_dirchange = True

# ----------------------------------------------------------------------
def help(msg=None, err=0):
    if msg:
        print(msg+'\n')
    print(__doc__ % globals())
    sys.exit(err)

# ----------------------------------------------------------------------
def say(s):
    sys.stderr.write("%s\n" % (s))

# ----------------------------------------------------------------------
def note(s):
    if opt_verbose:
        sys.stderr.write("%s\n" % (s))

# ----------------------------------------------------------------------
def die(s, error=1):
    sys.stderr.write("\n%s: Error: %s\n\n" % (program, s))
    sys.exit(error)

# ----------------------------------------------------------------------
# Bad args

if len(files) < 3:
    help("Not enogh arguments\n\nExpected  %s REPO REV NAME" %program, 1)
    
# ----------------------------------------------------------------------
# The program itself

import pysvn
#import debug

repo, rev, name = files

changeset = pysvn.Transaction(repo, rev, True)
changed = changeset.changed()

# Each dictionary entry is a tuple, with elements as follows:
CHG_ACTION, CHG_KIND, CHG_TEXTMOD, CHG_PROPMOD = range(4)

node = None
for key in changed:
    if opt_dirchange and changed[key][CHG_KIND] == pysvn.node_kind.dir:
        node = key
        break
    if opt_filechange and changed[key][CHG_KIND] == pysvn.node_kind.file:
        node = '/'.join(key.split('/')[:-1])
        break

while node:
    #debug.show('node')
    list = changeset.list(node)
    if name in list:
        if opt_dirpath:
            print node
        else:
            sys.stdout.write(node)
            sys.stdout.write('/')
            sys.stdout.write(name)
            sys.stdout.write('\n')
        break
    node = '/'.join(node.split('/')[:-1])