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# Revision $Id: loader.py 14270 2011-07-12 21:36:39Z kwc $

"""
General routines and representations for loading roslaunch model.
"""

from __future__ import with_statement

import os
import sys
from copy import deepcopy

from roslaunch.core import Param, RosbinExecutable, Node, Test, Machine, \
    RLException, PHASE_SETUP

try:
    from roslib.names import make_global_ns, ns_join, PRIV_NAME, load_mappings, is_legal_name, canonicalize_name
except ImportError:
    raise ImportError('Cannot import new roslib libraries.\nThis is probably due to incompatible "roslib" directories on your PYTHONPATH.\nPlease check your PYTHONPATH and try again')


#lazy-import global for yaml and rosparam
yaml = None
rosparam = None

class LoadException(RLException):
    """Error loading data as specified (e.g. cannot find included files, etc...)"""
    pass

#TODO: lists, maps(?)
def convert_value(value, type_):
    """
    Convert a value from a string representation into the specified
    type
    
    @param value: string representation of value
    @type  value: str
    @param type_: int, double, string, bool, or auto
    @type  type_: str
    @raise ValueError: if parameters are invalid
    """
    type_ = type_.lower()
    # currently don't support XML-RPC date, dateTime, maps, or list
    # types
    if type_ == 'auto':
        #attempt numeric conversion
        try:
            if '.' in value:
                return float(value)
            else:
                return int(value)
        except ValueError, e:
            pass
        #bool
        lval = value.lower()
        if lval == 'true' or lval == 'false':
            return convert_value(value, 'bool')
        #string
        return value
    elif type_ == 'str' or type_ == 'string':
        return value
    elif type_ == 'int':
        return int(value)
    elif type_ == 'double':
        return float(value)
    elif type_ == 'bool' or type_ == 'boolean':
        value = value.lower()
        if value == 'true' or value == '1':
            return True
        elif value == 'false' or value == '0':
            return False
        raise ValueError("%s is not a '%s' type"%(value, type_))
    else:
        raise ValueError("Unknown type '%s'"%type_)        

def process_include_args(context):
    """
    Processes arg declarations in context and makes sure that they are
    properly declared for passing into an included file. Also will
    correctly setup the context for passing to the included file.
    """

    # make sure all arguments have values. arg_names and resolve_dict
    # are cleared when the context was initially created.
    arg_dict = context.include_resolve_dict.get('arg', {})
    for arg in context.arg_names:
        if not arg in arg_dict:
            raise LoadException("include args must have declared values")
        
    # save args that were passed so we can check for unused args in post-processing
    context.args_passed = arg_dict.keys()[:]
    # clear arg declarations so included file can re-declare
    context.arg_names = []

    # swap in new resolve dict for passing
    context.resolve_dict = context.include_resolve_dict
    context.include_resolve_dict = None
    
def post_process_include_args(context):
    bad = [a for a in context.args_passed if a not in context.arg_names]
    if bad:
        raise LoadException("unused args [%s] for include of [%s]"%(', '.join(bad), context.filename))

def load_sysargs_into_context(context, argv):
    """
    Load in ROS remapping arguments as arg assignments for context.

    @param context: context to load into. context's resolve_dict for 'arg' will be reinitialized with values.
    @type  context: L{LoaderContext{
    @param argv: command-line arguments
    @type  argv: [str]
    """
    # we use same command-line spec as ROS nodes
    mappings = load_mappings(argv)
    context.resolve_dict['arg'] = mappings

class LoaderContext(object):
    """
    Container for storing current loader context (e.g. namespace,
    local parameter state, remapping state).
    """
    
    def __init__(self, ns, filename, parent=None, params=None, env_args=None, \
                     resolve_dict=None, include_resolve_dict=None, arg_names=None):
        """
        @param ns: namespace
        @type  ns: str
        @param filename: name of file this is being loaded from
        @type  filename: str
        @param resolve_dict: (optional) resolution dictionary for substitution args
        @type  resolve_dict: dict
        @param include_resolve_dict: special resolution dictionary for
        <include> tags. Must be None if this is not an <include>
        context.
        @type include_resolve_dict: dict
        @param arg_names: name of args that have been declared in this context
        @type  arg_names: [str]
        """
        self.parent = parent
        self.ns = make_global_ns(ns or '/')
        self._remap_args = []
        self.params = params or []
        self.env_args = env_args or []
        self.filename = filename
        # for substitution args
        self.resolve_dict = resolve_dict or {}
        # arg names. Args that have been declared in this context
        self.arg_names = arg_names or []
        # special scoped resolve dict for processing in <include> tag
        self.include_resolve_dict = include_resolve_dict or None

    def add_param(self, p):
        """
        Add a ~param to the context. ~params are evaluated by any node
        declarations that occur later in the same context.

        @param p: parameter
        @type  p: L{Param}
        """
        
        # override any params already set
        matches = [m for m in self.params if m.key == p.key]
        for m in matches:
            self.params.remove(m)
        self.params.append(p)
        
    def add_remap(self, remap):
        """
        Add a new remap setting to the context. if a remap already
        exists with the same from key, it will be removed
        
        @param remap: remap setting
        @type  remap: (str, str)
        """
        remap = [canonicalize_name(x) for x in remap]
        if not remap[0] or not remap[1]:
            raise RLException("remap from/to attributes cannot be empty")
        if not is_legal_name(remap[0]):
            raise RLException("remap from [%s] is not a valid ROS name"%remap[0])
        if not is_legal_name(remap[1]):
            raise RLException("remap to [%s] is not a valid ROS name"%remap[1])
        
        matches = [r for r in self._remap_args if r[0] == remap[0]]
        for m in matches:
            self._remap_args.remove(m)
        self._remap_args.append(remap)
        
    def add_arg(self, name, default=None, value=None):
        """
        Add 'arg' to existing context. Args are only valid for their immediate context.
        """
        if name in self.arg_names:
            raise LoadException("arg '%s' has already been declared"%name)
        self.arg_names.append(name)

        resolve_dict = self.resolve_dict if self.include_resolve_dict is None else self.include_resolve_dict

        if not 'arg' in resolve_dict:
            resolve_dict['arg'] = {}
        arg_dict = resolve_dict['arg']

        # args can only be declared once. they must also have one and
        # only value at the time that they are declared.
        if value is not None:
            # value is set, error if declared in our arg dict as args
            # with set values are constant/grounded.
            if name in arg_dict:
                raise LoadException("cannot override arg '%s', which has already been set"%name)
            arg_dict[name] = value
        elif default is not None:
            # assign value if not in context
            if name not in arg_dict:
                arg_dict[name] = default
        else:
            # no value or default: appending to arg_names is all we
            # need to do as it declares the existence of the arg.
            pass
        
    def remap_args(self):
        """
        @return: copy of the current remap arguments
        @rtype: [(str, str)]
        """
        if self.parent:
            args = []
            # filter out any parent remap args that have the same from key
            for pr in self.parent.remap_args():
                if not [r for r in self._remap_args if r[0] == pr[0]]:
                    args.append(pr)
            args.extend(self._remap_args)
            return args
        return self._remap_args[:]
    
    def include_child(self, ns, filename):
        """
        Create child namespace based on include inheritance rules
        @param ns: sub-namespace of child context, or None if the
           child context shares the same namespace
        @type  ns: str
        @param filename: name of include file
        @type  filename: str        
        @return: A child xml context that inherits from this context
        @rtype: L{LoaderContext}jj
        """
        ctx = self.child(ns)
        # arg declarations are reset across include boundaries
        ctx.arg_names = []
        ctx.filename = filename
        # keep the resolve_dict for now, we will do all new assignments into include_resolve_dict
        ctx.include_resolve_dict = {}
        #del ctx.resolve_dict['arg']
        return ctx

    def child(self, ns):
        """
        @param ns: sub-namespace of child context, or None if the
           child context shares the same namespace
        @type  ns: str
        @return: A child xml context that inherits from this context
        @rtype: L{LoaderContext}
        """
        if ns:
            if ns[0] == '/': # global (discouraged)
                child_ns = ns
            elif ns == PRIV_NAME: # ~name
                # private names can only be scoped privately or globally
                child_ns = PRIV_NAME
            else:
                child_ns = ns_join(self.ns, ns)
        else:
            child_ns = self.ns
        return LoaderContext(child_ns, self.filename, parent=self,
                             params=self.params, env_args=self.env_args[:],
                             resolve_dict=deepcopy(self.resolve_dict),
                             arg_names=self.arg_names[:], include_resolve_dict=self.include_resolve_dict)
        
#TODO: in-progress refactorization. I'm slowly separating out
#non-XML-specific logic from xmlloader and moving into Loader. Soon
#this will mean that it will be easier to write coverage tests for
#lower-level logic.
        
class Loader(object):
    """
    Lower-level library for loading ROS launch model. It provides an
    abstraction between the representation (e.g. XML) and the
    validation of the property values.
    """

    def add_param(self, ros_config, param_name, param_value, verbose=True):
        """
        Add L{Param} instances to launch config. Dictionary values are
        unrolled into individual parameters.

        @param ros_config: launch configuration
        @type  ros_config: L{ROSLaunchConfig}
        @param param_name: name of parameter namespace to load values
            into. If param_name is '/', param_value must be a dictionary
        @type  param_name: str
        @param param_value: value to assign to param_name. If
            param_value is a dictionary, it's values will be unrolled
            into individual parameters.
        @type  param_value: str
        @raise ValueError: if parameters cannot be processed into valid Params
        """

        # shouldn't ever happen
        if not param_name:
            raise ValueError("no parameter name specified")
        
        if param_name == '/' and type(param_value) != dict:
            raise ValueError("Cannot load non-dictionary types into global namespace '/'")

        if type(param_value) == dict:
            # unroll params
            for k, v in param_value.iteritems():
                self.add_param(ros_config, ns_join(param_name, k), v, verbose=verbose)
        else:
            ros_config.add_param(Param(param_name, param_value), verbose=verbose)
        
    def load_rosparam(self, context, ros_config, cmd, param, file_, text, verbose=True):
        """
        Load rosparam setting
        
        @param context: Loader context
        @type  context: L{LoaderContext}
        @param ros_config: launch configuration
        @type  ros_config: L{ROSLaunchConfig}
        @param cmd: 'load', 'dump', or 'delete'
        @type  cmd: str
        @param file_: filename for rosparam to use or None
        @type  file_: str
        @param text: text for rosparam to load. Ignored if file_ is set.
        @type  text: str
        @raise ValueError: if parameters cannot be processed into valid rosparam setting
        """
        if not cmd in ('load', 'dump', 'delete'):
            raise ValueError("command must be 'load', 'dump', or 'delete'")
        if file_ is not None:
            if cmd == 'load' and not os.path.isfile(file_):
                raise ValueError("file does not exist [%s]"%file_)
            if cmd == 'delete':
                raise ValueError("'file' attribute is invalid with 'delete' command.")

        full_param = ns_join(context.ns, param) if param else context.ns

        if cmd == 'dump':
            ros_config.add_executable(RosbinExecutable('rosparam', (cmd, file_, full_param), PHASE_SETUP))
        elif cmd == 'delete':
            ros_config.add_executable(RosbinExecutable('rosparam', (cmd, full_param), PHASE_SETUP))
        elif cmd == 'load':
            # load YAML text
            if file_:
                with open(file_, 'r') as f:
                    text = f.read()
                    
            # parse YAML text
            # - lazy import
            global yaml
            if yaml is None:
                import yaml
            # - lazy import: we have to import rosparam in oder to to configure the YAML constructors
            global rosparam
            if rosparam is None:
                import rosparam
            try:
                data = yaml.load(text)
                # #3162: if there is no YAML, load() will return an
                # empty string.  We want an empty dictionary instead
                # for our representation of empty.
                if data is None:
                    data = {}
            except yaml.MarkedYAMLError, e:
                if not file_: 
                    raise ValueError("Error within YAML block:\n\t%s\n\nYAML is:\n%s"%(str(e), text))
                else:
                    raise ValueError("file %s contains invalid YAML:\n%s"%(file_, str(e)))
            except Exception, e:
                if not file_:
                    raise ValueError("invalid YAML: %s\n\nYAML is:\n%s"%(str(e), text))
                else:
                    raise ValueError("file %s contains invalid YAML:\n%s"%(file_, str(e)))

            # 'param' attribute is required for non-dictionary types
            if not param and type(data) != dict:
                raise ValueError("'param' attribute must be set for non-dictionary values")

            self.add_param(ros_config, full_param, data, verbose=verbose)

        else:
            raise ValueError("unknown command %s"%cmd)


    def load_env(self, context, ros_config, name, value):
        """
        Load environment variable setting

        @param context: Loader context
        @type  context: L{LoaderContext}
        @param ros_config: launch configuration
        @type  ros_config: L{ROSLaunchConfig}
        @param name: environment variable name
        @type  name: str
        @param value: environment variable value
        @type  value: str
        """
        if not name:
            raise ValueError("'name' attribute must be non-empty")
        context.env_args.append((name, value))


    def param_value(self, verbose, name, ptype, value, textfile, binfile, command):
        """
        Parse text representation of param spec into Python value
        @param name: param name, for error message use only
        @type  name: str
        @param verbose: print verbose output
        @type  verbose: bool
        @param textfile: name of text file to load from, or None
        @type  textfile: str        
        @param binfile: name of binary file to load from, or None
        @type  binfile: str        
        @param command: command to execute for parameter value, or None
        @type  command: str
        @raise ValueError: if parameters are invalid
        """
        if value is not None:
            return convert_value(value.strip(), ptype)
        elif textfile is not None:
            with open(textfile, 'r') as f:
                return f.read()
        elif binfile is not None:
            import xmlrpclib
            with open(binfile, 'rb') as f:
                return xmlrpclib.Binary(f.read())
        elif command is not None:
            if type(command) == unicode:
                command = command.encode('UTF-8') #attempt to force to string for shlex/subprocess
            if verbose:
                print "... executing command param [%s]"%command
            import subprocess, shlex #shlex rocks
            try:
                p = subprocess.Popen(shlex.split(command), stdout=subprocess.PIPE)
                c_value = p.communicate()[0]
                if p.returncode != 0:
                    raise ValueError("Cannot load command parameter [%s]: command [%s] returned with code [%s]"%(name, command, p.returncode))
            except OSError, (errno, strerr):
                if errno == 2:
                    raise ValueError("Cannot load command parameter [%s]: no such command [%s]"%(name, command))
                raise
            if c_value is None:
                raise ValueError("parameter: unable to get output of command [%s]"%command)
            return c_value
        else: #_param_tag prevalidates, so this should not be reachable
            raise ValueError("unable to determine parameter value")

