"""Ttk wrapper.

This module provides classes to allow using Tk themed widget set.

Ttk is based on a revised and enhanced version of
TIP #48 (http://tip.tcl.tk/48) specified style engine.

Its basic idea is to separate, to the extent possible, the code
implementing a widget's behavior from the code implementing its
appearance. Widget class bindings are primarily responsible for
maintaining the widget state and invoking callbacks, all aspects
of the widgets appearance lies at Themes.
"""

__version__ = "0.3.1"

__author__ = "Guilherme Polo <ggpolo@gmail.com>"

__all__ = ["Button", "Checkbutton", "Combobox", "Entry", "Frame", "Label",
           "Labelframe", "LabelFrame", "Menubutton", "Notebook", "Panedwindow",
           "PanedWindow", "Progressbar", "Radiobutton", "Scale", "Scrollbar",
           "Separator", "Sizegrip", "Spinbox", "Style", "Treeview",
           # Extensions
           "LabeledScale", "OptionMenu",
           # functions
           "tclobjs_to_py", "setup_master"]

import tkinter
from tkinter import _flatten, _join, _stringify, _splitdict

_sentinel = object()

# Verify if Tk is new enough to not need the Tile package
_REQUIRE_TILE = True if tkinter.TkVersion < 8.5 else False

def _load_tile(master):
    if _REQUIRE_TILE:
        import os
        tilelib = os.environ.get('TILE_LIBRARY')
        if tilelib:
            # append custom tile path to the list of directories that
            # Tcl uses when attempting to resolve packages with the package
            # command
            master.tk.eval(
                    'global auto_path; '
                    'lappend auto_path {%s}' % tilelib)

        master.tk.eval('package require tile') # TclError may be raised here
        master._tile_loaded = True

def _format_optvalue(value, script=False):
    """Internal function."""
    if script:
        # if caller passes a Tcl script to tk.call, all the values need to
        # be grouped into words (arguments to a command in Tcl dialect)
        value = _stringify(value)
    elif isinstance(value, (list, tuple)):
        value = _join(value)
    return value

def _format_optdict(optdict, script=False, ignore=None):
    """Formats optdict to a tuple to pass it to tk.call.

    E.g. (script=False):
      {'foreground': 'blue', 'padding': [1, 2, 3, 4]} returns:
      ('-foreground', 'blue', '-padding', '1 2 3 4')"""

    opts = []
    for opt, value in optdict.items():
        if not ignore or opt not in ignore:
            opts.append("-%s" % opt)
            if value is not None:
                opts.append(_format_optvalue(value, script))

    return _flatten(opts)

def _mapdict_values(items):
    # each value in mapdict is expected to be a sequence, where each item
    # is another sequence containing a state (or several) and a value
    # E.g. (script=False):
    #   [('active', 'selected', 'grey'), ('focus', [1, 2, 3, 4])]
    #   returns:
    #   ['active selected', 'grey', 'focus', [1, 2, 3, 4]]
    opt_val = []
    for *state, val in items:
        # hacks for backward compatibility
        state[0] # raise IndexError if empty
        if len(state) == 1:
            # if it is empty (something that evaluates to False), then
            # format it to Tcl code to denote the "normal" state
            state = state[0] or ''
        else:
            # group multiple states
            state = ' '.join(state) # raise TypeError if not str
        opt_val.append(state)
        if val is not None:
            opt_val.append(val)
    return opt_val

def _format_mapdict(mapdict, script=False):
    """Formats mapdict to pass it to tk.call.

    E.g. (script=False):
      {'expand': [('active', 'selected', 'grey'), ('focus', [1, 2, 3, 4])]}

      returns:

      ('-expand', '{active selected} grey focus {1, 2, 3, 4}')"""

    opts = []
    for opt, value in mapdict.items():
        opts.extend(("-%s" % opt,
                     _format_optvalue(_mapdict_values(value), script)))

    return _flatten(opts)

def _format_elemcreate(etype, script=False, *args, **kw):
    """Formats args and kw according to the given element factory etype."""
    spec = None
    opts = ()
    if etype in ("image", "vsapi"):
        if etype == "image": # define an element based on an image
            # first arg should be the default image name
            iname = args[0]
            # next args, if any, are statespec/value pairs which is almost
            # a mapdict, but we just need the value
            imagespec = _join(_mapdict_values(args[1:]))
            spec = "%s %s" % (iname, imagespec)

        else:
            # define an element whose visual appearance is drawn using the
            # Microsoft Visual Styles API which is responsible for the
            # themed styles on Windows XP and Vista.
            # Availability: Tk 8.6, Windows XP and Vista.
            class_name, part_id = args[:2]
            statemap = _join(_mapdict_values(args[2:]))
            spec = "%s %s %s" % (class_name, part_id, statemap)

        opts = _format_optdict(kw, script)

    elif etype == "from": # clone an element
        # it expects a themename and optionally an element to clone from,
        # otherwise it will clone {} (empty element)
        spec = args[0] # theme name
        if len(args) > 1: # elementfrom specified
            opts = (_format_optvalue(args[1], script),)

    if script:
        spec = '{%s}' % spec
        opts = ' '.join(opts)

    return spec, opts

def _format_layoutlist(layout, indent=0, indent_size=2):
    """Formats a layout list so we can pass the result to ttk::style
    layout and ttk::style settings. Note that the layout doesn't have to
    be a list necessarily.

    E.g.:
      [("Menubutton.background", None),
       ("Menubutton.button", {"children":
           [("Menubutton.focus", {"children":
               [("Menubutton.padding", {"children":
                [("Menubutton.label", {"side": "left", "expand": 1})]
               })]
           })]
       }),
       ("Menubutton.indicator", {"side": "right"})
      ]

      returns:

      Menubutton.background
      Menubutton.button -children {
        Menubutton.focus -children {
          Menubutton.padding -children {
            Menubutton.label -side left -expand 1
          }
        }
      }
      Menubutton.indicator -side right"""
    script = []

    for layout_elem in layout:
        elem, opts = layout_elem
        opts = opts or {}
        fopts = ' '.join(_format_optdict(opts, True, ("children",)))
        head = "%s%s%s" % (' ' * indent, elem, (" %s" % fopts) if fopts else '')

        if "children" in opts:
            script.append(head + " -children {")
            indent += indent_size
            newscript, indent = _format_layoutlist(opts['children'], indent,
                indent_size)
            script.append(newscript)
            indent -= indent_size
            script.append('%s}' % (' ' * indent))
        else:
            script.append(head)

    return '\n'.join(script), indent

def _script_from_settings(settings):
    """Returns an appropriate script, based on settings, according to
    theme_settings definition to be used by theme_settings and
    theme_create."""
    script = []
    # a script will be generated according to settings passed, which
    # will then be evaluated by Tcl
    for name, opts in settings.items():
        # will format specific keys according to Tcl code
        if opts.get('configure'): # format 'configure'
            s = ' '.join(_format_optdict(opts['configure'], True))
            script.append("ttk::style configure %s %s;" % (name, s))

        if opts.get('map'): # format 'map'
            s = ' '.join(_format_mapdict(opts['map'], True))
            script.append("ttk::style map %s %s;" % (name, s))

        if 'layout' in opts: # format 'layout' which may be empty
            if not opts['layout']:
                s = 'null' # could be any other word, but this one makes sense
            else:
                s, _ = _format_layoutlist(opts['layout'])
            script.append("ttk::style layout %s {\n%s\n}" % (name, s))

        if opts.get('element create'): # format 'element create'
            eopts = opts['element create']
            etype = eopts[0]

            # find where args end, and where kwargs start
            argc = 1 # etype was the first one
            while argc < len(eopts) and not hasattr(eopts[argc], 'items'):
                argc += 1

            elemargs = eopts[1:argc]
            elemkw = eopts[argc] if argc < len(eopts) and eopts[argc] else {}
            spec, opts = _format_elemcreate(etype, True, *elemargs, **elemkw)

            script.append("ttk::style element create %s %s %s %s" % (
                name, etype, spec, opts))

    return '\n'.join(script)

def _list_from_statespec(stuple):
    """Construct a list from the given statespec tuple according to the
    accepted statespec accepted by _format_mapdict."""
    nval = []
    for val in stuple:
        typename = getattr(val, 'typename', None)
        if typename is None:
            nval.append(val)
        else: # this is a Tcl object
            val = str(val)
            if typename == 'StateSpec':
                val = val.split()
            nval.append(val)

    it = iter(nval)
    return [_flatten(spec) for spec in zip(it, it)]

def _list_from_layouttuple(tk, ltuple):
    """Construct a list from the tuple returned by ttk::layout, this is
    somewhat the reverse of _format_layoutlist."""
    ltuple = tk.splitlist(ltuple)
    res = []

    indx = 0
    while indx < len(ltuple):
        name = ltuple[indx]
        opts = {}
        res.append((name, opts))
        indx += 1

        while indx < len(ltuple): # grab name's options
            opt, val = ltuple[indx:indx + 2]
            if not opt.startswith('-'): # found next name
                break

            opt = opt[1:] # remove the '-' from the option
            indx += 2

            if opt == 'children':
                val = _list_from_layouttuple(tk, val)

            opts[opt] = val

    return res

def _val_or_dict(tk, options, *args):
    """Format options then call Tk command with args and options and return
    the appropriate result.

    If no option is specified, a dict is returned. If an option is
    specified with the None value, the value for that option is returned.
    Otherwise, the function just sets the passed options and the caller
    shouldn't be expecting a return value anyway."""
    options = _format_optdict(options)
    res = tk.call(*(args + options))

    if len(options) % 2: # option specified without a value, return its value
        return res

    return _splitdict(tk, res, conv=_tclobj_to_py)

def _convert_stringval(value):
    """Converts a value to, hopefully, a more appropriate Python object."""
    value = str(value)
    try:
        value = int(value)
    except (ValueError, TypeError):
        pass

    return value

def _to_number(x):
    if isinstance(x, str):
        if '.' in x:
            x = float(x)
        else:
            x = int(x)
    return x

def _tclobj_to_py(val):
    """Return value converted from Tcl object to Python object."""
    if val and hasattr(val, '__len__') and not isinstance(val, str):
        if getattr(val[0], 'typename', None) == 'StateSpec':
            val = _list_from_statespec(val)
        else:
            val = list(map(_convert_stringval, val))

    elif hasattr(val, 'typename'): # some other (single) Tcl object
        val = _convert_stringval(val)

    return val

def tclobjs_to_py(adict):
    """Returns adict with its values converted from Tcl objects to Python
    objects."""
    for opt, val in adict.items():
        adict[opt] = _tclobj_to_py(val)

    return adict

def setup_master(master=None):