import os
from ranger.shared import FileManagerAware
from ranger.gui.widgets import console_mode as cmode
from ranger.ext.command_parser import LazyParser as parse

class Command(FileManagerAware):
	"""Abstract command class"""
	name = None
	def __init__(self, line, mode):
		self.line = line
		self.mode = mode

	def execute(self):
		"""Override this"""

	def tab(self):
		"""Override this"""

	def quick_open(self):
		"""Override this"""

	def _tab_only_directories(self):
		from os.path import dirname, basename, expanduser, join, isdir

		line = parse(self.line)
		pwd = self.fm.env.pwd.path

		try:
			rel_dest = line.rest(1)
		except IndexError:
			rel_dest = ''

		# expand the tilde into the user directory
		if rel_dest.startswith('~'):
			return line + expanduser(rel_dest) + '/'

		# define some shortcuts
		abs_dest = join(pwd, rel_dest)
		abs_dirname = dirname(abs_dest)
		rel_basename = basename(rel_dest)
		rel_dirname = dirname(rel_dest)
		
		try:
			# are we after a directory?
			if rel_dest.endswith('/') or rel_dest == '':
				_, dirnames, _ = os.walk(abs_dest).next()

			# are we in the middle of the filename?
			else:
				_, dirnames, _ = os.walk(abs_dirname).next()
				dirnames = [dn for dn in dirnames \
						if dn.startswith(rel_basename)]
		except (OSError, StopIteration):
			# os.walk found nothing
			pass
		else:
			dirnames.sort()

			# no results, return None
			if len(dirnames) == 0:
				return

			# one result. since it must be a directory, append a slash.
			if len(dirnames) == 1:
				return line + join(rel_dirname, dirnames[0]) + '/'

			# more than one result. append no slash, so the user can
			# manually type in the slash to advance into that directory
			return (line + join(rel_dirname, dirname) for dirname in dirnames)
	
	def _tab_directory_content(self):
		from os.path import dirname, basename, expanduser, join, isdir

		line = parse(self.line)
		pwd = self.fm.env.pwd.path

		try:
			rel_dest = line.rest(1)
		except IndexError:
			rel_dest = ''

		# expand the tilde into the user directory
		if rel_dest.startswith('~'):
			return line + expanduser(rel_dest) + '/'

		# define some shortcuts
		abs_dest = join(pwd, rel_dest)
		abs_dirname = dirname(abs_dest)
		rel_basename = basename(rel_dest)
		rel_dirname = dirname(rel_dest)
		
		try:
			# are we after a directory?
			if rel_dest.endswith('/') or rel_dest == '':
				_, dirnames, filenames = os.walk(abs_dest).next()
				names = dirnames + filenames

			# are we in the middle of the filename?
			else:
				_, dirnames, filenames = os.walk(abs_dirname).next()
				names = [name for name in (dirnames + filenames) \
						if name.startswith(rel_basename)]
		except (OSError, StopIteration):
			# os.walk found nothing
			pass
		else:
			names.sort()

			# no results, return None
			if len(names) == 0:
				return

			# one result. since it must be a directory, append a slash.
			if len(names) == 1:
				return line + join(rel_dirname, names[0]) + '/'

			# more than one result. append no slash, so the user can
			# manually type in the slash to advance into that directory
			return (line + join(rel_dirname, name) for name in names)


# -------------------------------- definitions

class cd(Command):
	"""
	:cd <dirname>
	
	The cd command changes the directory.
	The command 'cd -' is equivalent to typing ``.

	In the quick console, the directory will be entered without the
	need to press enter, as soon as there is one unambiguous match.
	"""

	def execute(self):
		line = parse(self.line)
		try:
			destination = line.rest(1)
		except IndexError:
			destination = '~'

		if destination == '-':
			self.fm.enter_bookmark('`')
		else:
			self.fm.enter_dir(destination)

	def tab(self):
		return self._tab_only_directories()
	
	def quick_open(self):
		from os.path import isdir, join, normpath
		line = parse(self.line)
		pwd = self.fm.env.pwd.path

		try:
			rel_dest = line.rest(1)
		except IndexError:
			return False

		abs_dest = normpath(join(pwd, rel_dest))
		return rel_dest != '.' and isdir(abs_dest)

class find(Command):
	"""
	:find <string>

	The find command will attempt to find a partial, case insensitive
	match in the filenames of the current directory.

	In the quick command console, once there is one unambiguous match,
	the file will be run automatically.
	"""
	count = 0
	def execute(self):
		if self.mode != cmode.COMMAND_QUICK:
			self._search()

		import re
		search = parse(self.line).rest(1)
		search = re.escape(search)
		self.fm.env.last_search = re.compile(search, re.IGNORECASE)

	def quick_open(self):
		self._search()
		if self.count == 1:
			self.fm.move_right()
			self.fm.block_input(0.5)
			return True

	def tab(self):
		return self._tab_directory_content()

	def _search(self):
		self.count = 0
		line = parse(self.line)
		pwd = self.fm.env.pwd
		try:
			arg = line.rest(1)
		except IndexError:
			return False
		
		length = len(pwd.files)
		for i in range(length):
			actual_index = (pwd.pointer + i) % length
			filename = pwd.files[actual_index].basename_lower
			if arg in filename:
				self.count += 1
				if self.count == 1:
					pwd.move(absolute=actual_index)
					self.fm.env.cf = pwd.pointed_obj
			if self.count > 1:
				return False

		return self.count == 1


class quit(Command):
	"""
	:quit
	
	Quits the program immediately.
	"""
	def execute(self):
		raise SystemExit


class delete(Command):
	"""
	:delete

	Tries to delete the selection.

	"Selection" is defined as all the "marked files" (by default, you
	can mark files with space or v). If there are no marked files,
	use the "current file" (where the cursor is)
	"""
	def execute(self):
		self.fm.delete()


class mkdir(Command):
	"""
	:mkdir <dirname>

	Creates a directory with the name <dirname>.
	"""
	def execute(self):
		line = parse(self.line)
		try:
			self.fm.mkdir(line.rest(1))
		except IndexError:
			pass


class rename(Command):
	"""
	:rename <newname>

	Changes the name of the currently highlighted file to <newname>
	"""
	def execute(self):
		line = parse(self.line)
		self.fm.rename(self.fm.env.cf, line.rest(1))

	def tab(self):
		return self._tab_directory_content()


class filter(Command):
	"""
	:filter <string>

	Displays only the files which contain <string> in their basename.
	"""
	def execute(self):
		line = parse(self.line)
		self.fm.set_filter(line.rest(1))
	

# -------------------------------- rest

by_name = {}
for varname, var in vars().copy().items():
	try:
		if issubclass(var, Command) and var != Command:
			by_name[var.name or varname] = var
	except TypeError:
		pass
del varname
del var

def alias(**kw):
	for key, value in kw.items():
		by_name[key] = value

alias(q=quit)

def command_generator(start):
	return (cmd + ' ' for cmd in by_name if cmd.startswith(start))