#!/usr/bin/env python

# Josh's SVN wrapper script
#
# Recommend putting in path as 'jsvn' or something other than 'svn' and
# making an alias svn='jsvn'
#
# The script detects if you have colorsvn and colordiff and uses them for
# appropriate subcommands if so.
#
# Implemented subcommands:
#  branch[es] <branch_name>
#   - with no arguments, list branches with '*' by the current one
#   - with an argument, create a new branch from the current one
#  tags
#   - list tags
#  switch <short_name>
#   - switch to 'trunk', branch name, or tag name without having to specify
#     the full URL
#   - falls back to Subversion "switch" if <short_name> doesn't exist

import sys
import os
import re
from subprocess import *

PATH = os.environ['PATH'].split(os.pathsep)

def findInPath(cmd):
    for p in PATH:
        full_path = os.path.join(p, cmd)
        if os.path.exists(full_path):
            return full_path
    return ''

def getSVNURL(svn):
    for line in Popen([svn, 'info'], stdout=PIPE).communicate()[0].split('\n'):
        m = re.match('^URL:\s*(.*?)\s*$', line)
        if m is not None:
            return m.group(1)
    return ''

def getSVNRoot(svn):
    url = getSVNURL(svn)
    parts = url.split('/')
    for i in range(0, len(parts)):
        if parts[i] in ('trunk', 'tags', 'branches'):
            return '/'.join(parts[:i])
    return ''

def getSVNRelPath(svn):
    url = getSVNURL(svn)
    parts = url.split('/')
    for i in range(0, len(parts) - 1):
        if parts[i] == 'trunk' or i > 0 and parts[i-1] in ('tags', 'branches'):
            return '/' + '/'.join(parts[i+1:])
    return '/'

def getSVNTopLevel(svn):
    url = getSVNURL(svn)
    parts = url.split('/')
    for i in range(0, len(parts)):
        if parts[i] == 'trunk' or i > 0 and parts[i-1] in ('tags', 'branches'):
            return '/'.join(parts[:i+1])
    return ''

def getSVNBranchList(svn):
    colist = []
    root = getSVNRoot(svn)
    lines = Popen([svn, 'ls', root + '/branches'],
                stdout=PIPE).communicate()[0].split('\n')
    for line in lines:
        if re.match(r'^\s*$', line) is None:
            colist.append(re.sub(r'/$', '', line))
    return colist

def getSVNTagList(svn):
    colist = []
    root = getSVNRoot(svn)
    lines = Popen([svn, 'ls', root + '/tags'],
                stdout=PIPE).communicate()[0].split('\n')
    for line in lines:
        if re.match(r'^\s*$', line) is None:
            colist.append(re.sub(r'/$', '', line))
    return colist

def branch(argv, svn):
    if len(argv) < 2:
        bl = ['trunk'] + getSVNBranchList(svn)
        current = getSVNTopLevel(svn).split('/')[-1]
        for b in bl:
            sys.stdout.write('*' if b == current else ' ')
            sys.stdout.write(b + '\n')
        return 0
    branch_name = argv[1]
    origin = getSVNTopLevel(svn)
    root = getSVNRoot(svn)
    if origin == '' or root == '':
        sys.stderr.write("Could not determine origin/root URL\n")
        return 1
    comment = "Created '%s' branch" % branch_name
    branch_path = root + '/branches/' + branch_name
    Popen([svn, 'copy', origin, branch_path, '-m', comment]).wait()
    return 0

def tags(argv, svn):
    tl = getSVNTagList(svn)
    for t in tl:
        sys.stdout.write(t + '\n')
    return 0

def switch(argv, svn, colorsvn):
    if len(argv) < 2:
        return -1
    root = getSVNRoot(svn)
    path = getSVNRelPath(svn)
    if argv[1] == 'trunk':
        Popen([svn, 'switch', root + '/trunk' + path]).wait()
        return 0
    bl = getSVNBranchList(svn)
    if argv[1] in bl:
        Popen([svn, 'switch', root + '/branches/' + argv[1] + path]).wait()
        return 0
    tl = getSVNTagList(svn)
    if argv[1] in tl:
        Popen([svn, 'switch', root + '/tags/' + argv[1] + path]).wait()
        return 0
    return -2

def main(argv):
    realsvn = findInPath('svn')
    colorsvn = findInPath('colorsvn')
    colordiff = findInPath('colordiff')

    if realsvn == '':
        sys.stderr.write("Error: 'svn' not found in path\n")
        return 1

    if len(argv) >= 1:
        if argv[0] == "branch" or argv[0] == "branches":
            return branch(argv, realsvn)

        if argv[0] == "switch":
            r = switch(argv, realsvn, colorsvn)
            if r >= 0:
                return r

        if argv[0] == "tags":
            return tags(argv, realsvn)

        if argv[0] == "diff" and colordiff != '':
            diff_out = Popen([realsvn] + argv, stdout=PIPE).stdout
            Popen([colordiff], stdin=diff_out).wait()
            return 0

    if colorsvn != '':
        Popen([colorsvn] + argv).wait()
        return 0

    Popen([realsvn] + argv).wait()
    return 0

if __name__ == "__main__":
    sys.exit(main(sys.argv[1:]))