#!/usr/bin/env python
"""
metashell.py - Meta Shell
Author: Sean B. Palmer, inamidst.com
"""

import sys, os, re
from code import metagen
metagen.meta = '../meta'

def PS1(path): 
   return 'sbp@metashell:%s$ ' % path

def makepath(path): 
   path = os.path.dirname(path)
   if not os.path.isdir(path): 
      os.makedirs(path)

def barf(msg): 
   print >> sys.stderr, msg
   sys.exit(1)

def join(here, there): 
   if there.startswith('~') or there.startswith('/'): 
      return os.path.normpath(there)
   elif here.startswith('~'): 
      here = here.lstrip('~')
      if not here.startswith('/'): 
         here = '/' + here
      return os.path.normpath('~' + os.path.join(here, there))
   return os.path.normpath(os.path.join(here, there))

def cd(keyword): 
   newpath = join(main.path, keyword)
   if newpath.startswith('/'): 
      dirname = os.path.join(metagen.meta, newpath.lstrip('/'))
      if not os.path.exists(dirname): 
         raise OSError("Directory does not exist: %s" % dirname)
   elif newpath.startswith('~/'): 
      if not metagen.bykeyword(newpath[2:]): 
         raise OSError("No files have this keyword: %s" % newpath[2:])
   elif newpath != '~': raise ValueError("Unknown path: %s" % newpath)
   main.path = newpath

def ls(keyword=None): 
   if keyword is None: 
      keyword = main.path
   else: keyword = join(main.path, keyword)

   if not keyword: 
      for keyword in metagen.bykeyword(): 
         print '~/' + keyword
   elif keyword in ('~', '~/'): 
      for filename in metagen.bykeyword(): 
         print '~/' + filename
   elif keyword.startswith('~'): 
      # @@@@@@@@@@ empty keyword?
      keyword = keyword.lstrip('~/')
      for (path, metafn, metadata) in metagen.bykeyword(keyword): 
         print path, '-', metadata.get('title') or '[untitled]'
   else: 
      keyword = keyword.lstrip('/')
      dirname = os.path.join(metagen.meta, keyword)
      for fn in sorted(os.listdir(dirname)): 
         filename = os.path.join(keyword, fn)
         if os.path.isdir(os.path.join(dirname, filename)): 
            print '/' + filename + '/'
         else: print '/' + filename

def make(path): 
   path = join(main.path, path)
   if not path.startswith('/'): 
      raise OSError("Path %s doesn't start with /" % path)
   if path.endswith('/'): 
      path += 'index'

   if not os.path.isdir(metagen.meta): 
      barf("Error: There is no meta directory")
   metafn = os.path.join(metagen.meta, '.' + path)
   metafn = os.path.normpath(metafn)

   if os.path.exists(metafn): 
      barf("Error: file <%s> already exists" % metafn)
   makepath(metafn)

   title = raw_input("Title: ")
   desc = raw_input("Description: ")
   keywords = raw_input("Keywords: ")

   if not (title or desc or keywords): 
      barf("Error: Must enter title or desc or keywords")

   # print "Opening %s for writing..." % metafn
   f = open(metafn, 'w')
   if title: print >> f, 'title:', title
   if desc: print >> f, 'description:', desc
   if keywords: 
      keywords = sorted(keywords.split(' '))
      print >> f, 'keywords:', ' '.join(keywords)
   f.close()

   print "Created %s successfully" % path

def edit(path): 
   path = join(main.path, path)
   if not path.startswith('/'): 
      raise OSError("Path %s doesn't start with /" % path)
   if path.endswith('/'): 
      path += 'index'

   filepath = os.path.join(metagen.meta, '.' + path)
   filepath = os.path.normpath(filepath)

   replacement = []
   f = open(filepath)
   for line in f: 
      line = line.rstrip('\r\n')
      if (not line.startswith('#')) and line: 
         print 'Current:', line
         input = raw_input('Replacement Value: ')
         key, value = line.split(': ', 1)
         if not input.strip(): 
            replacement.append(key + ': ' + value)
         elif input.startswith('/') or input.startswith('!'): 
            sep = input[0]
            here, there = input[1:-1].split(sep, 1)
            try: r_regexp = re.compile(here)
            except: newvalue = value.replace(here, there)
            else: newvalue = r_regexp.sub(there, value)
            replacement.append(key + ': ' + newvalue)
         else: replacement.append(key + ': ' + input.rstrip('\r\n'))
   f.close()
   if replacement: 
      f = open(filepath, 'w')
      for line in replacement: 
         print >> f, line
      f.close()

def cat(path): 
   path = join(main.path, path)
   if not path.startswith('/'): 
      raise OSError("Path %s doesn't start with /" % path)
   if path.endswith('/'): 
      path += 'index'

   filepath = os.path.join(metagen.meta, '.' + path)
   filepath = os.path.normpath(filepath)
   if not os.path.exists(filepath): 
      barf("Path doesn't exist: %s" % filepath)
   f = open(filepath)
   for line in f: 
      print line.rstrip('\r\n')
   f.close()

def exit(): 
   print 
   sys.exit()

def run(func, args): 
   assert func.isalpha()
   try: eval(func)(*args)
   except Exception, e: 
      if isinstance(e, SystemExit): 
         raise e
      else: print 'Error:', e   

def main(): 
   main.path = '~'
   while True: 
      try: command = raw_input(PS1(main.path))
      except EOFError: command = 'exit'
      if ' ' in command: 
         prog, args = command.split(' ', 1)
         run(prog, args.split(' '))
      else: run(command, tuple())

if __name__=="__main__": 
   main()