"""Variant on standard library's cmd with extra features:

Searchable command history
Multi-line commands
Case-insensitive commands
Special-character shortcut commands
Load commands from file
Settable environment parameters

still to do:
edit
>
"""
import cmd, re, os

class Cmd(cmd.Cmd):
    caseInsensitive = True
    multilineCommands = []
    continuationPrompt = '> '    
    shortcuts = {'?': 'help', '!': 'shell', '@': 'load'}   
    excludeFromHistory = '''run r list l history hi ed li eof'''.split()   
    defaultExtension = 'txt'
    defaultFileName = 'command.txt'
    editor = os.environ.get('EDITOR') or ''
    settable = ['prompt', 'continuationPrompt', 'defaultFileName', 'editor']
    terminators = ';\n'
    def do_cmdenvironment(self, args):
	self.stdout.write("""
	Commands are %(casesensitive)scase-sensitive.
	Commands may be terminated with: %(terminators)s
	Settable parameters: %(settable)s
	""" % 
        { 'casesensitive': 'not ' if self.caseInsensitive else '',
	  'terminators': ' '.join(self.terminators),
	  'settable': ' '.join(self.settable)
	})
	
    def __init__(self, *args, **kwargs):	
        cmd.Cmd.__init__(self, *args, **kwargs)
        self.history = History()
	
    def precmd(self, line):
        """Hook method executed just before the command line is
        interpreted, but after the input prompt is generated and issued.
        
        Makes commands case-insensitive (but unfortunately does not alter command completion).
        """
        try:
            (command, args) = line.split(None,1)
	except ValueError:
	    (command, args) = line, ''
	if self.caseInsensitive:
	    command = command.lower()
	statement = ' '.join([command, args])
	if (not self.multilineCommands) or (command not in self.multilineCommands):
	    return statement
	return self.finishStatement(statement)

    def postcmd(self, stop, line):
        """Hook method executed just after a command dispatch is finished."""
	try:
	    command = line.split(None,1)[0].lower()
	    if command not in self.excludeFromHistory:
		self.history.append(line)
	finally:
	    return stop
	
    def finishStatement(self, firstline):
	statement = firstline
	while not self.statementHasEnded(statement):
	    statement = '%s\n%s' % (statement, self.pseudo_raw_input(self.continuationPrompt))
	return statement
	# assembling a list of lines and joining them at the end would be faster, 
	# but statementHasEnded needs a string arg; anyway, we're getting
	# user input and users are slow.
	
    def pseudo_raw_input(self, prompt):
	"""copied from cmd's cmdloop; like raw_input, but accounts for changed stdin, stdout"""
	
	if self.use_rawinput:
	    try:
		line = raw_input(prompt)
	    except EOFError:
		line = 'EOF'
	else:
	    self.stdout.write(prompt)
	    self.stdout.flush()
	    line = self.stdin.readline()
	    if not len(line):
		line = 'EOF'
	    else:
		line = line[:-1] # chop \n
	return line
			    
    def do_EOF(self, arg):
	return True
    do_eof = do_EOF
    
    statementEndPattern = re.compile(r'[%s]\s*$' % terminators)	
    def statementHasEnded(self, lines):
	return bool(self.statementEndPattern.search(lines))
	       
    def clean(self, s):
	"""cleans up a string"""
	if self.caseInsensitive:
	    return s.strip().lower()
	return s.strip()
    
    def parseline(self, line):
        """Parse the line into a command name and a string containing
        the arguments.  Returns a tuple containing (command, args, line).
        'command' and 'args' may be None if the line couldn't be parsed.
        """
        line = line.strip()
        if not line:
            return None, None, line
	shortcut = self.shortcuts.get(line[0])
	if shortcut and hasattr(self, 'do_%s' % shortcut):
	    line = '%s %s' % (shortcut, line[1:])
        i, n = 0, len(line)
        while i < n and line[i] in self.identchars: i = i+1
        cmd, arg = line[:i], line[i:].strip().strip(self.terminators)
        return cmd, arg, line
    
    def showParam(self, param):
        param = self.clean(param)
        if param in self.settable:
            val = getattr(self, param)
            self.stdout.write('%s: %s\n' % (param, str(getattr(self, param))))

    def do_show(self, arg):
        'Shows value of a parameter'
        if arg.strip():
            self.showParam(arg)
        else:
            for param in self.settable:
                self.showParam(param)
    
    def do_set(self, arg):
        'Sets a parameter'        
        try:
            paramName, val = arg.split(None, 1)
	    paramName = self.clean(paramName)
	    if paramName not in self.settable:
		raise NotSettableError	    		
	    currentVal = getattr(self, paramName)
	    val = cast(currentVal, val.strip(self.terminators))
	    setattr(self, paramName, val)
	    self.stdout.write('%s - was: %s\nnow: %s\n' % (paramName, currentVal, val))
        except (ValueError, AttributeError, NotSettableError):
            self.do_show(arg)
		
    def do_shell(self, arg):
        'execute a command as if at the OS prompt.'
        os.system(arg)
	
    def do_history(self, arg):
        """history [arg]: lists past commands issued
        
        no arg -> list all
        arg is integer -> list one history item, by index
        arg is string -> string search
        arg is /enclosed in forward-slashes/ -> regular expression search
        """
        if arg:
            history = self.history.get(arg)
        else:
            history = self.history
        for hi in history:
            self.stdout.write(hi.pr())
    def last_matching(self, arg):
        try:
            if arg:
                return self.history.get(arg)[-1]
            else:
                return self.history[-1]
        except:
            return None        
    def do_list(self, arg):
        """list [arg]: lists last command issued
        
        no arg -> list absolute last
        arg is integer -> list one history item, by index
        - arg, arg - (integer) -> list up to or after #arg
        arg is string -> list last command matching string search
        arg is /enclosed in forward-slashes/ -> regular expression search
        """
        try:
            self.stdout.write(self.last_matching(arg).pr())
        except:
            pass
    do_hi = do_history
    do_l = do_list
    do_li = do_list
	
    def do_ed(self, arg):
        'ed [N]: brings up SQL from N commands ago in text editor, and puts result in SQL buffer.'
	if not self.editor:
	    self.do_show('editor')
	    return
        buffer = self.last_matching(arg)
        if not buffer:
            print 'Nothing appropriate in buffer to edit.'
            return
        f = open(self.defaultFileName, 'w')
        f.write(buffer)
        f.close()
	os.system('%s %s' % (self.editor, self.defaultFileName))
        self.load(self.defaultFileName)
    do_edit = do_ed
    
    def do_save(self, fname=None):
	"""Saves most recent command to a file."""
	
	if fname is None:
	    fname = self.defaultFileName
        try:
            f = open(fname, 'w')
            f.write(self.history[-1])
            f.close()
        except Exception, e:
            print 'Error saving %s: %s' % (fname, str(e))
	    
    def do_load(self, fname=None):
        """Runs command(s) from a file."""
	if fname is None:
	    fname = self.defaultFileName	
	keepstate = Statekeeper(self, ('stdin','use_rawinput','prompt','continuationPrompt'))
	try:
	    self.stdin = open(fname, 'r')
        except IOError, e:
            try:
                self.stdin = open('%s.%s' % (fname, self.defaultExtension), 'r')
		self.use_rawinput = False
		self.prompt = self.continuationPrompt = ''
		self.cmdloop()
		self.stdin.close()
		self.lastcmd = ''		
            except IOError:
                print 'Problem opening file %s: \n%s' % (fname, e)
        finally:	
	    keepstate.restore()
	    
class HistoryItem(str):
    def __init__(self, instr):
        str.__init__(self, instr)
        self.lowercase = self.lower()
        self.idx = None
    def pr(self):
	return '-------------------------[%d]\n%s\n' % (self.idx, str(self))
        
class History(list):
    rangeFrom = re.compile(r'^([\d])+\s*\-$')
    def append(self, new):
        new = HistoryItem(new)
        list.append(self, new)
        new.idx = len(self)
    def extend(self, new):
        for n in new:
            self.append(n)
    def get(self, getme):
        try:
            getme = int(getme)
            if getme < 0:
                return self[:(-1 * getme)]
            else:
                return [self[getme-1]]
        except IndexError:
            return []
        except (ValueError, TypeError):
            getme = getme.strip()
            mtch = self.rangeFrom.search(getme)
            if mtch:
                return self[(int(mtch.group(1))-1):]
            if getme.startswith(r'/') and getme.endswith(r'/'):
                finder = re.compile(getme[1:-1], re.DOTALL | re.MULTILINE | re.IGNORECASE)
                def isin(hi):
                    return finder.search(hi)
            else:
                def isin(hi):
                    return (getme.lower() in hi.lowercase)
            return [itm for itm in self if isin(itm)]

class NotSettableError(Exception):
    None    
	
def cast(current, new):
    """Tries to force a new value into the same type as the current."""
    typ = type(current)
    print type(new)
    if typ == bool:
	new = new.lower()    
	print new
	try:
	    print new == 'on'
	    if (new=='on') or (new[0] in ('y','t')):
		return True
	    try:
		return bool(int(new))
	    except ValueError:
		pass
	    return False
	except TypeError:
	    pass
    try:
	return typ(new)
    except:
	print "Problem setting parameter (now %s) to %s; incorrect type?" % (current, new)
	return current
	
class Statekeeper(object):
    def __init__(self, obj, attribs):
	self.obj = obj
	self.attribs = attribs
	self.save()
    def save(self):
	for attrib in self.attribs:
	    setattr(self, attrib, getattr(self.obj, attrib))
    def restore(self):
	for attrib in self.attribs:
	    setattr(self.obj, attrib, getattr(self, attrib))