#@+leo-ver=4
#@+node:@file read_only_nodes.py
"""Inhibit changes to @read-only nodes"""

# Contributed by Davide Salomoni <dsalomoni@yahoo.com>

from leoPlugins import *
from leoGlobals import *

import ftplib, urllib, urlparse, os, cStringIO
from formatter import AbstractFormatter, DumbWriter
from htmllib import HTMLParser

try:
	import tkFileDialog
except ImportError:
	tkFileDialog = None

if tkFileDialog: # Register the handlers...

	#@	@+others
	#@+node:documentation for @read-only nodes
	#@+at 
	#@nonl
	# Dear Leo users,
	# 
	# Here's my first attempt at customizing leo. I wanted to have the ability 
	# to
	# import files in "read-only" mode, that is, in a mode where files could 
	# only
	# be read by leo (not tangled), and also kept in sync with the content on 
	# the
	# drive.
	# 
	# The reason for this is for example that I have external programs that 
	# generate
	# resource files. I want these files to be part of a leo outline, but I 
	# don't
	# want leo to tangle or in any way modify them. At the same time, I want 
	# them
	# to be up-to-date in the leo outline.
	# 
	# So I coded the directive plugin. It has the following characteristics:
	# 
	# - It reads the specified file and puts it into the node content.
	# 
	# - If the @read-only directive was in the leo outline already, and the 
	# file content
	# on disk has changed from what is stored in the outline, it marks the 
	# node as
	# changed and prints a "changed" message to the log window; if, on the 
	# other hand,
	# the file content has _not_ changed, the file is simply read and the node 
	# is
	# not marked as changed.
	# 
	# - When you write a @read-only directive, the file content is added to 
	# the node
	# immediately, i.e. as soon as you press Enter (no need to call a menu
	# entry to import the content).
	# 
	# - If you want to refresh/update the content of the file, just edit the 
	# headline
	# and press Enter. The file is reloaded, and if in the meantime it has 
	# changed,
	# a "change" message is sent to the log window.
	# 
	# - The body text of a @read-only file cannot be modified in leo.
	# 
	# Davide Salomoni
	#@-at
	#@-node:documentation for @read-only nodes
	#@+node:ftp/http access
	#@+at 
	#@nonl
	# The syntax to access files in @read-only via ftp/http is the following:
	# 
	# @read-only http://www.ietf.org/rfc/rfc0791.txt
	# @read-only ftp://ftp.someserver.org/filepath
	# 
	# If FTP authentication (username/password) is required, it can be 
	# specified as follows:
	# 
	# @read-only ftp://username:password@ftp.someserver.org/filepath
	# 
	# For more details, see the doc string for the class FTPurl.
	#@-at
	#@-node:ftp/http access
	#@+node:class FTPurl
	class FTPurl:
		"""An FTP wrapper class to store/retrieve files using an FTP URL.
	
	    To create a connection, call the class with the constructor:
	
	        FTPurl(url[, mode])
	
	    The url should have the following syntax:
	    
	        ftp://[username:password@]remotehost/filename
	    
	    If username and password are left out, the connection is made using
	    username=anonymous and password=realuser@host (for more information,
	    see the documentation of module ftplib).
	    
	    The mode can be '' (default, for ASCII mode) or 'b' (for binary mode).
		This class raises an IOError exception if something goes wrong.
		"""
		
		#@	@+others
		#@+node:__init__
		def __init__(self, ftpURL, mode=''):
			parse = urlparse.urlparse(ftpURL)
			if parse[0] != 'ftp':
				raise IOError, "error reading %s: malformed ftp URL" % ftpURL
		
			# ftp URL; syntax: ftp://[username:password@]hostname/filename
			self.mode = mode
			authIndex = parse[1].find('@')
			if authIndex == -1:
				auth = None
				ftphost = parse[1]
			else:
				auth = parse[1][:authIndex]
				ftphost = parse[1][authIndex+1:]
			self.ftp = ftplib.FTP(ftphost)
			if auth == None:
				self.ftp.login()
			else:
				# the URL has username/password
				pwdIndex = auth.find(':')
				if pwdIndex == -1:
					raise IOError, "error reading %s: malformed ftp URL" % ftpURL
				user = auth[:pwdIndex]
				password = auth[pwdIndex+1:]
				self.ftp.login(user, password)
			self.path = parse[2][1:]
			self.filename = os.path.basename(self.path)
			self.dirname = os.path.dirname(self.path)
			self.isConnectionOpen = 1
			self.currentLine = 0
		#@-node:__init__
		#@+node:read
		def read(self):
			"""Read the filename specified in the constructor and return it as a string.
		    If the constructor specifies no filename, or if the URL ends with '/',
		    return the list of files in the URL directory.
			"""
			self.checkParams()
			if self.filename=='' or self.path[-1]=='/':
				return self.dir()
		
			try:
				if self.mode == '':  # mode='': ASCII mode
					slist = []
					self.ftp.retrlines('RETR %s' % self.path, slist.append)
					s = '\n'.join(slist)
				else: # mode='b': binary mode
					file = cStringIO.StringIO()
					self.ftp.retrbinary('RETR %s' % self.path, file.write)
					s = file.getvalue()
					file.close()
				return s
			except:
				exception, msg, tb = sys.exc_info()
				raise IOError, msg
		
		#@-node:read
		#@+node:readline
		def readline(self):
			"""Read one entire line from the remote file."""
			try:
				self.lst
			except AttributeError:
				self.lst = self.read().splitlines(1)
			
			if self.currentLine < len(self.lst):
				s = self.lst[self.currentLine]
				self.currentLine = self.currentLine + 1
				return s
			else:
				return ''
		#@-node:readline
		#@+node:write
		def write(self, s):
			"""write(s) stores the string s to the filename specified in the
		    constructor."""
			self.checkParams()
			if self.filename == '':
				raise IOError, 'filename not specified'
			
			try:
				file = cStringIO.StringIO(s)
				if self.mode == '':  # mode='': ASCII mode
					self.ftp.storlines('STOR %s' % self.path, file)
				else: # mode='b': binary mode
					self.ftp.storbinary('STOR %s' % self.path, file)
				file.close()
			except:
				exception, msg, tb = sys.exc_info()
				raise IOError, msg
		#@-node:write
		#@+node:seek
		def seek(offset=0):
			self.currentLine = 0  # we don't support fancy seeking via FTP
		#@-node:seek
		#@+node:flush
		def flush():
			pass # no fancy stuff here.
		#@nonl
		#@-node:flush
		#@+node:dir
		def dir(self, path=None):
			"""Issue a LIST command passing the specified argument and return output as a string."""
			s = []
		
			if path == None:
				path = self.dirname
			try:
				listcmd = 'LIST %s' % path
				self.ftp.retrlines(listcmd.rstrip(), s.append)
				return '\n'.join(s)
			except:
				exception, msg, tb = sys.exc_info()
				raise IOError, msg
		#@-node:dir
		#@+node:exists
		def exists(self, path=None):
			"""Return 1 if the specified path exists. If path is omitted, the current file name is tried."""
			if path == None:
				path = self.filename
		
			s = self.dir(path)
			if s.lower().find('no such file') == -1:
				return 1
			else:
				return 0
		#@-node:exists
		#@+node:checkParams
		def checkParams(self):
			if self.mode not in ('','b'):
				raise IOError, 'invalid mode: %s' % self.mode
			if not self.isConnectionOpen:
				raise IOError, 'ftp connection closed'
		#@-node:checkParams
		#@+node:close
		def close(self):
			"""Close an existing FTPurl connection."""
			try:
				self.ftp.quit()
			except:
				self.ftp.close()
			del self.ftp
			self.isConnectionOpen = 0
		#@nonl
		#@-node:close
		#@-others
	#@-node:class FTPurl
	#@+node:enable/disable_body
	# Alas, these do not seem to work on XP:
	# disabling the body text _permanently_ stops the cursor from blinking.
	
	def enable_body(body):
		global insertOnTime,insertOffTime
		if body.cget("state") == "disabled":
			try:
				es("enable")
				print insertOffTime,insertOnTime
				body.configure(state="normal")
				body.configure(insertontime=insertOnTime,insertofftime=insertOffTime)
			except: es_exception()
				
	def disable_body(body):
		global insertOnTime,insertOffTime
		if body.cget("state") == "normal":
			try:
				es("disable")
				insertOnTime = body.cget("insertontime")
				insertOffTime = body.cget("insertofftime")
				print insertOffTime,insertOnTime
				body.configure(state="disabled")
			except: es_exception()
	#@-node:enable/disable_body
	#@+node:insert_read_only_node (FTP version)
	# Sets v's body text from the file with the given name.
	# Returns true if the body text changed.
	def insert_read_only_node (c,v,name):
		if name=="":
			name = tkFileDialog.askopenfilename(
				title="Open",
				filetypes=[("All files", "*")]
				)
			c.beginUpdate()
			v.setHeadString("@read-only %s" % name)
			c.endUpdate()
		parse = urlparse.urlparse(name)
		try:
			if parse[0] == 'ftp':
				file = FTPurl(name)  # FTP URL
			elif parse[0] == 'http':
				file = urllib.urlopen(name)  # HTTP URL
			else:
				file = open(name,"r")  # local file
			# es("..." + name)
			new = file.read()
			file.close()
		except IOError,msg:
			# es("error reading %s: %s" % (name, msg))
			# es("...not found: " + name)
			v.setBodyStringOrPane("") # Clear the body text.
			return true # Mark the node as changed.
		else:
			ext = os.path.splitext(parse[2])[1]
			if ext.lower() in ['.htm', '.html']:
				#@			<< convert HTML to text >>
				#@+node:<< convert HTML to text >>
				fh = cStringIO.StringIO()
				fmt = AbstractFormatter(DumbWriter(fh))
				# the parser stores parsed data into fh (file-like handle)
				parser = HTMLParser(fmt)
				
				# send the HTML text to the parser
				parser.feed(new)
				parser.close()
				
				# now replace the old string with the parsed text
				new = fh.getvalue()
				fh.close()
				
				# finally, get the list of hyperlinks and append to the end of the text
				hyperlinks = parser.anchorlist
				numlinks = len(hyperlinks)
				if numlinks > 0:
					hyperlist = ['\n\n--Hyperlink list follows--']
					for i in xrange(numlinks):
						hyperlist.append("\n[%d]: %s" % (i+1,hyperlinks[i])) # 3/26/03: was i.
					new = new + ''.join(hyperlist)
				#@nonl
				#@-node:<< convert HTML to text >>
				#@nl
			previous = v.t.bodyString
			v.setBodyStringOrPane(new)
			changed = (toUnicode(new,'ascii') != toUnicode(previous,'ascii'))
			if changed and previous != "":
				es("changed: %s" % name) # A real change.
			return changed
	#@nonl
	#@-node:insert_read_only_node (FTP version)
	#@+node:on_open2
	#  scan the outline and process @read-only nodes.
	def on_open2 (tag,keywords):
		
		
		if tag == "start2":
			c = top()
		else:
			c = keywords.get("new_c")
	
		v = c.rootVnode()
		es("scanning for @read-only nodes...",color="blue")
		c.beginUpdate()
		while v:
			h = v.headString()
			if match_word(h,0,"@read-only"):
				changed = insert_read_only_node(c,v,h[11:])
				es("changing %s" % v.headString(),color="red")
				if changed:
					if not v.isDirty():
						v.setDirty()
					if not c.isChanged():
						c.setChanged(changed)
			v = v.threadNext()
		c.endUpdate()
	#@-node:on_open2
	#@+node:on_bodykey1
	# override the body key handler if we are in an @read-only node.
	
	def on_bodykey1 (tag,keywords):
	
		c = keywords.get("c")
		v = keywords.get("v")
		h = v.headString()
		if match_word(h,0,"@read-only"):
			# The following code causes problems with scrolling and syntax coloring.
			# Its advantage is that it makes clear that the text can't be changed,
			# but perhaps that is obvious anyway...
			if 0: # Davide Salomoni requests that this code be eliminated.
				# An @read-only node: do not change its text.
				body = c.frame.body.bodyCtrl
				body.delete("1.0","end")
				body.insert("1.0",v.bodyString())
			return 1 # Override the body key event handler.
	#@nonl
	#@-node:on_bodykey1
	#@+node:on_headkey2
	# update the body text when we press enter
	
	def on_headkey2 (tag,keywords):
	
		c = keywords.get("c")
		v = keywords.get("v")
		h = v.headString()
		ch = keywords.get("ch")
		if ch == '\r' and match_word(h,0,"@read-only"):
			# on-the-fly update of @read-only directives
			changed = insert_read_only_node(c,v,h[11:])
			c.setChanged(changed)
	#@nonl
	#@-node:on_headkey2
	#@+node:on_select1
	def on_select1 (tag,keywords):
	
		# Doesn't work: the cursor doesn't start blinking.
		# Enable the body text so select will work properly.
		c = keywords.get("c")
		enable_body(c.frame.body)
	#@-node:on_select1
	#@+node:on_select2
	def on_select2 (tag,keywords):
	
		c = keywords.get("c")
		v = c.currentVnode()
		h = v.headString()
		if match_word(h,0,"@read-only"):
			disable_body(c.frame.body)
		else:
			enable_body(c.frame.body)
	#@-node:on_select2
	#@-others

	if app.gui is None:
		app().createTkGui(__file__)

	if app.gui.guiName() == "tkinter":

		registerHandler(("start2","open2"), on_open2)
		registerHandler("bodykey1", on_bodykey1)
		registerHandler("headkey2", on_headkey2)
		if 0: # doesn't work: the cursor stops blinking.
			registerHandler("select1", on_select1)
			registerHandler("select2", on_select2)
	
		__version__ = "1.5" # Set version for the plugin handler.
		plugin_signon(__name__)

#@-node:@file read_only_nodes.py
#@-leo
