from __future__ import division
import sys
from cbook import iterable, flatten
from transforms import identity_transform

## Note, matplotlib artists use the doc strings for set and get
# methods to enable the introspection methods of set and get in the
# matlab interface Every set_ to be controlled by the set function
# method should have a docstring containing the line
#
# ACCEPTS: [ legal | values ]
#
# and aliases for setters and getters should have a docstring that
# starts with 'alias for ', as in 'alias for set_somemethod'
#
# You may wonder why we use so much boiler-plate manually defining the
# set_alias and get_alias functions, rather than using some clever
# python trick.  The answer is that I need to be able to manipulate
# the docstring, and there is no clever way to do that in python 2.2,
# as far as I can see - see
# http://groups.google.com/groups?hl=en&lr=&threadm=mailman.5090.1098044946.5135.python-list%40python.org&rnum=1&prev=/groups%3Fq%3D__doc__%2Bauthor%253Ajdhunter%2540ace.bsd.uchicago.edu%26hl%3Den%26btnG%3DGoogle%2BSearch


class Artist:
    """
    Abstract base class for someone who renders into a FigureCanvas
    """

    aname = 'Artist'
    zorder = 0
    def __init__(self):
        self.figure = None

        self._transform = identity_transform()
        self._transformSet = False
        self._visible = True
        self._alpha = 1.0
        self.clipbox = None
        self._clipon = False
        self._lod = False
        self._label = ''

        self.eventson = False  # fire events only if eventson
        self._oid = 0  # an observer id
        self._propobservers = {} # a dict from oids to funcs



    def add_callback(self, func):
        oid = self._oid
        self._propobservers[oid] = func
        self._oid += 1
        return oid

    def remove_callback(self, oid):        
        try: del self._propobservers[oid]
        except KeyError: pass

    def pchanged(self):
        'fire event when property changed'
        for oid, func in self._propobservers.items():
            func(self)
            
    def is_transform_set(self):
        'Artist has transform explicity let'                
        return self._transformSet

    def set_transform(self, t):
        """
set the Transformation instance used by this artist

ACCEPTS: a matplotlib.transform transformation instance
"""
        self._transform = t
        self._transformSet = True
        self.pchanged()
        
    def get_transform(self):
        'return the Transformation instance used by this artist'
        return self._transform

    def is_figure_set(self):
        return self.figure is not None

    def get_figure(self):
        'return the figure instance'
        return self.figure
    
    def set_figure(self, fig):
        """
Set the figure instance the artist belong to

ACCEPTS: a matplotlib.figure.Figure instance
        """
        self.figure = fig
        self.pchanged()
        
    def set_clip_box(self, clipbox):        
        """
Set the artist's clip Bbox

ACCEPTS: a matplotlib.transform.Bbox instance
        """
        self.clipbox = clipbox
        self._clipon = clipbox is not None
        self.pchanged()
        
    def get_alpha(self):
        """
Return the alpha value used for blending - not supported on all
backends
        """
        return self._alpha
    
    def get_visible(self):
        "return the artist's visiblity"
        return self._visible 

    def get_clip_on(self):
        'Return whether artist uses clipping'
        return self._clipon and self.clipbox is not None

    def get_clip_box(self):
        'Return artist clipbox'
        return self.clipbox

    def set_clip_on(self, b):
        """
Set  whether artist uses clipping

ACCEPTS: [True | False]
"""
        self._clipon = b
        if not b: self.clipbox = None
        self.pchanged()
    def draw(self, renderer, *args, **kwargs):
        'Derived classes drawing method'
        if not self.get_visible(): return 

    def set_alpha(self, alpha):
        """
Set the alpha value used for blending - not supported on
all backends

ACCEPTS: float
        """
        self._alpha = alpha
        self.pchanged()

    def set_lod(self, on):
        """
Set Level of Detail on or off.  If on, the artists may examine
things like the pixel width of the axes and draw a subset of
their contents accordingly

ACCEPTS: [True | False]
        """
        self._lod = on
        self.pchanged()
        
    def set_visible(self, b):
        """
set the artist's visiblity

ACCEPTS: [True | False]
"""
        self._visible = b
        self.pchanged()

    def update(self, props):
        store = self.eventson
        self.eventson = False
        changed = False
        for k,v in props.items():
            func = getattr(self, 'set_'+k, None)
            if func is None or not callable(func):
                raise AttributeError('Unknown property %s'%k)
            func(v)
            changed = True
        self.eventson = store
        if changed: self.pchanged()
        

    def get_label(self):
        return self._label

    def set_label(self, s):
        """
Set the line label to s for auto legend

ACCEPTS: any string
"""
        self._label = s
        self.pchanged()

    def get_zorder(self): return self.zorder

    def set_zorder(self, level):
        """
Set the zorder for the artist

ACCEPTS: any number
"""
        self.zorder = level
        self.pchanged()
    
    def update_from(self, other):
        'copy properties from other to self'
        self._transform = other._transform
        self._transformSet = other._transformSet
        self._visible = other._visible
        self._alpha = other._alpha
        self.clipbox = other.clipbox
        self._clipon = other._clipon
        self._lod = other._lod
        self._label = other._label
        self.pchanged()

class ArtistInspector:
    """
    A helper class to insect an Artist and return information about
    it's settable properties and their current values
    """
    def __init__(self, o):
        """
        Initialize the artist inspector with an artist or sequence of
        artists.  Id a sequence is used, we assume it is a homogeneous
        sequence (all Artists are of the same type) and it is your
        responsibility to make sure this is so.
        """
        if iterable(o): o = o[0]
        self.o = o
        self.aliasd = self.get_aliases()

    def get_aliases(self):
        """
        get a dict mapping fullname -> alias for each alias in o.
        Eg for lines: {'markerfacecolor': 'mfc',
                       'linewidth'      : 'lw',
                       }
        """
        names = [name for name in dir(self.o) if
                 (name.startswith('set_') or name.startswith('get_'))
                 and callable(getattr(self.o,name))]
        aliases = {}
        for name in names:
            func = getattr(self.o, name)
            if not self.is_alias(func): continue
            docstring = func.__doc__
            fullname = docstring[10:]
            aliases[fullname[4:]] = name[4:]
        return aliases

    def get_valid_values(self, attr):
        """
        get the legal arguments for the setter associated with attr

        This is done by querying the doc string of the function set_attr
        for a line that begins with ACCEPTS:

        Eg, for a line linestyle, return
        [ '-' | '--' | '-.' | ':' | 'steps' | 'None' ]
        """

        name = 'set_%s'%attr
        if not hasattr(self.o, name):
            raise AttributeError('%s has no function %s'%(self.o,name))
        func = getattr(self.o, name)

        docstring = func.__doc__
        if docstring is None: return 'unknown'

        if docstring.startswith('alias for '):
            return None
        for line in docstring.split('\n'):
            line = line.lstrip()
            if not line.startswith('ACCEPTS:'): continue
            return line[8:].strip()
        return 'unknown'

    def get_setters(self):
        """
        Get the attribute strings with setters for object h.  Eg, for a line,
        return ['markerfacecolor', 'linewidth', ....]
        """

        setters = []
        for name in dir(self.o):
            if not name.startswith('set_'): continue
            o = getattr(self.o,name)
            if not callable(o): continue
            func = o
            if self.is_alias(func): continue
            setters.append(name[4:])
        return setters

    def is_alias(self, o):
        'return true if method object o is an alias for another function'
        ds = o.__doc__
        if ds is None: return False
        return ds.startswith('alias for ')

    def aliased_name(self, s):
        """
        return 'PROPNAME or alias' if s has an alias, else return
        PROPNAME.

        Eg for the line markerfacecolor property, which has an alias,
        return 'markerfacecolor or mfc' and for the transform
        property, which does not, return 'transform'
        """
        if self.aliasd.has_key(s):
            return '%s or %s' % (s, self.aliasd[s])
        else: return s

    def pprint_setters(self, prop=None):
        """
        if prop is None, return a list of strings of all settable properies
        and their valid values

        if prop is not None, it is a valid property name and that
        property will be returned as a string of property : valid
        values
        """
        if prop is not None:
            accepts = self.get_valid_values(prop)
            return '    %s: %s' %(prop, accepts)

        attrs = self.get_setters()
        attrs.sort()
        lines = []

        for prop in attrs:
            accepts = self.get_valid_values(prop)
            name = self.aliased_name(prop)
            lines.append('    %s: %s' %(name, accepts))
        return lines

    def pprint_getters(self):
        """
        return the getters and actual values as list of strings'
        """
        getters = [name for name in dir(self.o)
                   if name.startswith('get_')
                   and callable(getattr(self.o, name))]
        getters.sort()
        lines = []
        for name in getters:
            func = getattr(self.o, name)
            if self.is_alias(func): continue
            try: val = func()
            except: continue
            if hasattr(val, 'shape') and len(val)>6:
                s = str(val[:6]) + '...'
            else:
                s = str(val)
            name = self.aliased_name(name[4:])
            lines.append('    %s = %s' %(name, s))
        return lines


def get(o, *args):
    """
    Return the value of handle property s

    h is an instance of a class, eg a Line2D or an Axes or Text.
    if s is 'somename', this function returns

      o.get_somename()

    get can be used to query all the gettable properties with get(o)
    Many properties have aliases for shorter typing, eg 'lw' is an
    alias for 'linewidth'.  In the output, aliases and full property
    names will be listed as

      property or  alias = value

    eg

      linewidth or lw = 2
    """

    insp = ArtistInspector(o)

    if len(args)==0:
        print '\n'.join(insp.pprint_getters())
        return

    name = args[0]
    func = getattr(o, 'get_' + name)
    return func()

def set(h, *args, **kwargs):
    """
    matlab(TM) and pylab allow you to use set and get to set and get
    object properties, as well as to do introspection on the object
    For example, to set the linestyle of a line to be dashed, you can do

      >>> line, = plot([1,2,3])
      >>> set(line, linestyle='--')

    If you want to know the valid types of arguments, you can provide the
    name of the property you want to set without a value

      >>> set(line, 'linestyle')
          linestyle: [ '-' | '--' | '-.' | ':' | 'steps' | 'None' ]

    If you want to see all the properties that can be set, and their
    possible values, you can do


      >>> set(line)
          ... long output listing omitted'

    set operates on a single instance or a list of instances.  If you are
    in quey mode introspecting the possible values, only the first
    instance in the sequnce is used.  When actually setting values, all
    the instances will be set.  Eg, suppose you have a list of two lines,
    the following will make both lines thicker and red

        >>> x = arange(0,1.0,0.01)
        >>> y1 = sin(2*pi*x)
        >>> y2 = sin(4*pi*x)
        >>> lines = plot(x, y1, x, y2)
        >>> set(lines, linewidth=2, color='r')

    Set works with the matlab(TM) style string/value pairs or with python
    kwargs.  For example, the following are equivalent

        >>> set(lines, 'linewidth', 2, 'color', r')  # matlab style
        >>> set(lines, linewidth=2, color='r')       # python style
    """

    insp = ArtistInspector(h)

    if len(kwargs)==0 and len(args)==0:
        print '\n'.join(insp.pprint_setters())
        return

    if len(kwargs)==0 and len(args)==1:
        print insp.pprint_setters(prop=args[0])
        return

    if not iterable(h): h = [h]
    else: h = flatten(h)


    if len(args)%2:
        raise ValueError('The set args must be string, value pairs')

    funcvals = []
    for i in range(0, len(args)-1, 2):
        funcvals.append((args[i], args[i+1]))
    funcvals.extend(kwargs.items())

    ret = []
    for o in h:
        for s, val in funcvals:
            s = s.lower()
            funcName = "set_%s"%s
            func = getattr(o,funcName)
            ret.extend( [func(val)] )
    return [x for x in flatten(ret)]


    
    
