#!/usr/bin/env python

import git, os, sys, time, pyinotify, netrc
from optparse import OptionParser
from twisted.words.protocols import irc
from twisted.internet import reactor, protocol
from twisted.internet.task import LoopingCall

have_bitly = False
try:
	import bitly
	have_bitly = True
except:
	pass

parser = OptionParser()
parser.add_option('-s', '--host')
parser.add_option('-n', '--nick', default = 'git')
parser.add_option('-d', '--dir')
parser.add_option('-c', '--channel')
parser.add_option('-i', '--interval', type = 'int', default = 10)
parser.add_option('-u', '--url')

(options, args) = parser.parse_args()

if not options.host or not options.dir or not options.channel or not options.nick:
	parser.print_help()
	sys.exit(1)

if have_bitly and not netrc.netrc().authenticators('bitly'):
	have_bitly = False

root = options.dir

if root[-1] == '/':
	root = root[:-1]

repos = None

def repo_commit_msg(repo, branch, commits):
	reponame = os.path.splitext(os.path.basename(repo.working_dir))[0]

	deletions = insertions = 0
	files = []

	for c in commits:
		deletions += c.stats.total['deletions']
		insertions += c.stats.total['insertions']
		files.extend((f for f in c.stats.files.iterkeys() if not f in files))

	stat = '%d files,' % len(files)
	if len(commits) > 1:
		stat = '%d commits, %s' % (len(commits), stat)
	stat += ' \00305--%d\017' % deletions
	stat += ' \00303++%d\017' % insertions

	commit = commits[-1]
	msg = '\002%s%s\002 pushed to \002%s\002 by \002%s\002 (%s) %s' % (
		reponame,
		('/'+branch) if branch else '',
		commit.sha[:7],
		commit.committer.name if commit.author.name == commit.committer.name else '%s/%s' % (commit.committer.name, commit.author.name),
		stat,
		commit.summary
	)

	if options.url:
		msg += ' | '
		url = options.url % {'repo': reponame, 'commit': commit.sha}
		if have_bitly:
			short_url = None
			try:
				bitly_auth = netrc.netrc().authenticators('bitly')
				bitly_api = bitly.Api(login = bitly_auth[0], apikey = bitly_auth[2])
				short_url = bitly_api.shorten(url)
			except:
				short_url = None

			if short_url:
				url = short_url
		msg += url

	return msg

class ReposNotifyEvent(pyinotify.ProcessEvent):
	def new_repo(self, event):
		flags = pyinotify.EventsCodes.ALL_FLAGS
		heads = '%s/refs/heads' % event.pathname

		i = 0
		# Wait max 10 seconds for refs/heads/ to appear.
		while not os.access(heads, os.F_OK) and i < 10:
			time.sleep(1)
			i += 1
		if not os.access(heads, os.F_OK):
			self.bot.gitmsg('Repo %s was found but couldn''t locate refs/heads/ (repo NOT added).' % os.path.splitext(event.name)[0])
			return

		wdd = self.bot.wm.add_watch(heads, flags['IN_MODIFY'] | flags['IN_CREATE'])
		repos[event.pathname] = [None, None, wdd]
		self.bot.gitmsg('New repo: %s' % os.path.splitext(event.name)[0])

	def updated_repo(self, event):
		pathname = event.pathname
		while len(pathname) > 1 and not pathname in repos:
			pathname = os.path.dirname(pathname)
		if len(pathname) == 1 or not pathname in repos:
			return
		l = repos[pathname]
		if not l[0]:
			l[0] = git.Repo(pathname)
		repo = l[0]
		if not repo.heads: # No branches
			return
		if not l[1]:
			l[1] = dict([(h.name, h.commit.sha) for h in repo.heads])
		for h in repo.heads:
			last = l[1][h.name] if h.name in l[1] else None
			if h.commit.sha != last:
				commits = list(repo.iter_commits('%s..%s' % (last, h.name)))
				if not len(commits): # No commits
					continue
				msg = repo_commit_msg(repo, h.name, commits)
				self.bot.gitmsg(msg)
				l[1][h.name] = h.commit.sha

	def process_IN_CREATE(self, event):
		if os.path.dirname(event.pathname) == root:
			self.new_repo(event)
		else:
			self.updated_repo(event)

	def process_IN_DELETE(self, event):
		if event.pathname in repos:
			self.bot.wm.rm_watch(repos[event.pathname][2].values())
			del repos[event.pathname]
			self.bot.gitmsg('Removed repo: %s' % os.path.splitext(event.name)[0])

	def process_IN_MODIFY(self, event):
		self.updated_repo(event)

def check_notifies(bot):
	bot.notifier.process_events()
	while bot.notifier.check_events():
		bot.notifier.read_events()
		bot.notifier.process_events()

class Bot(irc.IRCClient):
	nickname = options.nick

	def initial_add(self):
		global repos
		if not repos:
			repos = {}
			for path in (x for x in os.listdir(root) if x.endswith('.git')):
				try:
					r = git.Repo('%s/%s' % (root, path))
				except:
					continue
				flags = pyinotify.EventsCodes.ALL_FLAGS
				wdd = self.wm.add_watch('%s/%s/refs/heads' % (root, path), flags['IN_MODIFY'] | flags['IN_CREATE'])
				repos['%s/%s' % (root, path)] = [r, dict([(h.name, h.commit.sha) for h in r.heads]), wdd]

	def gitmsg(self, msg):
		self.say(options.channel, msg)

	def signedOn(self):
		self.join(options.channel)
		self.wm = pyinotify.WatchManager()
		flags = pyinotify.EventsCodes.ALL_FLAGS
		self.wm.add_watch(root, flags['IN_DELETE'] | flags['IN_CREATE'] | flags['IN_ONLYDIR'])
		self.rne = ReposNotifyEvent()
		self.rne.bot = self
		self.notifier = pyinotify.Notifier(self.wm, self.rne, timeout = options.interval)

		self.initial_add()

		self.repeater = LoopingCall(check_notifies, self)
		self.repeater.start(options.interval)

	def get_repo(self, name, target):
		repo = [(k, v) for k, v in repos.iteritems() if os.path.basename(k).startswith(name)]
		if len(repo) == 1:
			path = repo[0][0]
			repo = repo[0][1]
			r = repo[0] or git.Repo(path)
			return r
		elif len(repo) == 0:
			self.msg(target, 'No repo found.')
		else:
			self.msg(target, 'Ambiguous name: %s' % (', '.join([os.path.basename(x[0]) for x in repo])))

		return None

	def get_commits(self, repo, name):
		try:
			if '..' in name:
				frm, to = name.split('..')
				commits = list(repo.iter_commits('%s..%s' % (frm, to)))
			else:
				commits = [repo.commit(name)]
		except ValueError:
			return []
		except git.errors.GitCommandError:
			return []

		return commits

	def get_branch(self, repo, branch, target):
		heads = sorted((h for h in repo.heads if h.name.startswith(branch)), cmp = lambda a, b: cmp(a.name, b.name))

		if not len(heads):
			self.msg(target, 'No branches matches "%s".' % branch)

		if heads[0].name == branch:
			return heads[0]

		heads = [h for h in repo.heads if h.name.startswith(branch)]

		if not len(heads):
			self.msg(target, 'No branches matches "%s".' % branch)
		elif len(heads) > 1:
			self.msg(target, 'Ambiguous name: %s' % (', '.join([h.name for h in heads])))
		else:
			return heads[0]

	def privmsg(self, user, channel, message):
		private = channel == self.nickname
		nick = user.split('!')[0]
		target = nick if private else channel
		messagelist = message.split()
		if len(messagelist) < 2:
			return
		if messagelist[0].startswith(self.nickname):
			cmd = messagelist[1].lower()
			if cmd == 'list':
				s = 'Repos: %s' % ', '.join([os.path.splitext(os.path.basename(x))[0] for x in repos.keys()])
				self.msg(target, s)
			elif cmd == 'last':
				if not len(messagelist) >= 3:
					self.msg(target, 'Usage: %s last REPO [BRANCH]' % self.nickname)
					return

				repo = self.get_repo(messagelist[2].lower(), target)
				if not repo:
					return

				branch = self.get_branch(repo, messagelist[3] if len(messagelist) == 4 else 'master', target)
				if not branch:
					return

				msg = repo_commit_msg(repo, branch.name, [branch.commit]) if repo.heads else ('No commits found for %s' % os.path.splitext(os.path.basename(repo.working_dir))[0])
				self.msg(target, msg)
			elif cmd == 'show':
				if not len(messagelist) == 4:
					self.msg(target, 'Usage: %s show REPO COMMIT' % self.nickname)
					return

				repo = self.get_repo(messagelist[2].lower(), target)
				if not repo:
					return

				commits = self.get_commits(repo, messagelist[3])
				if not commits:
					self.msg(target, 'No commits found.')
					return

				msg = repo_commit_msg(repo, None, commits)
				self.msg(target, msg)
			elif cmd == 'branches':
				if not len(messagelist) == 3:
					self.msg(target, 'Usage: %s branches REPO')
					return

				repo = self.get_repo(messagelist[2].lower(), target)
				if not repo:
					return

				reponame = os.path.splitext(os.path.basename(repo.working_dir))[0]
				self.msg(target, '\002%s\002 has branches %s' % (reponame, ', '.join(['\002%s\002' % h.name for h in repo.heads])))

class BotFactory(protocol.ReconnectingClientFactory):
	protocol = Bot

if __name__ == '__main__':
	f = BotFactory()
	reactor.connectTCP(options.host, 6667, f)
	reactor.run()