#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Part of the PsychoPy library
# Copyright (C) 2002-2018 Jonathan Peirce (C) 2019 Open Science Tools Ltd.
# Distributed under the terms of the GNU General Public License (GPL).

"""Experiment classes:
    Experiment, Flow, Routine, Param, Loop*, *Handlers, and NameSpace

The code that writes out a *_lastrun.py experiment file is (in order):
    experiment.Experiment.writeScript() - starts things off, calls other parts
    settings.SettingsComponent.writeStartCode()
    experiment.Flow.writeBody()
        which will call the .writeBody() methods from each component
    settings.SettingsComponent.writeEndCode()
"""

from __future__ import absolute_import, print_function

import io
import keyword
import re

from builtins import object
from builtins import str
# from future import standard_library

import psychopy
from psychopy import constants
from psychopy.constants import PY3
from psychopy.localization import _translate
from .components.settings import _numpyImports, _numpyRandomImports
from .utils import nonalphanumeric_re, valid_var_re

# standard_library.install_aliases()

# predefine some regex's; deepcopy complains if do in NameSpace.__init__()


class IndentingBuffer(io.StringIO):

    def __init__(self, *args, **kwargs):
        io.StringIO.__init__(self, *args, **kwargs)
        self.oneIndent = "    "
        self.indentLevel = 0
        self._writtenOnce = []

    def writeIndented(self, text):
        """Write to the StringIO buffer, but add the current indent.
        Use write() if you don't want the indent.

        To test if the prev character was a newline use::
            self.getvalue()[-1]=='\n'

        """
        self.write(self.oneIndent * self.indentLevel + text)

    def writeIndentedLines(self, text):
        """As writeIndented(text) except that each line in text gets
        the indent level rather than the first line only.
        """
        for line in text.splitlines():
            self.write(self.oneIndent * self.indentLevel + line + '\n')

    def writeOnceIndentedLines(self, text):
        """Add code to the experiment that is only run exactly once,
        (typically this is used to write the writeOnceInit sections after
        all `import`s were done but before Window creation).

        Parameters
        ----------
        text : str
            The code to run. May include newline characters to write several
            lines of code at once.

        Notes
        -----
        For running an `import`, use meth:~`Experiment.requireImport` or
        :meth:~`Experiment.requirePsychopyLibs` instead.

        See also
        --------
        :meth:~`Experiment.requireImport`,
        :meth:~`Experiment.requirePsychopyLibs`
        """
        if text not in self._writtenOnce:
            self.writeIndentedLines(text)
            self._writtenOnce.append(text)

    def setIndentLevel(self, newLevel, relative=False):
        """Change the indent level for the buffer to a new value.

        Set relative to True to increment or decrement the current value.
        """
        if relative:
            self.indentLevel += newLevel
        else:
            self.indentLevel = newLevel

    def write(self, text):
        if PY3:
            io.StringIO.write(self, "{}".format(text))
        else:
            io.StringIO.write(self, u"{}".format(text))


# noinspection PyUnresolvedReferences
class NameSpace(object):
    """class for managing variable names in builder-constructed experiments.

    The aim is to help detect and avoid name-space collisions from
    user-entered variable names.
    Track four groups of variables:
        numpy =    part of numpy or numpy.random
        psychopy = part of psychopy, such as event or data; include os here
        builder =  used internally by the builder when constructing an expt
        user =     used 'externally' by a user when programming an experiment
    Some vars, like core, are part of both psychopy and numpy, so the order of
    operations can matter

    Notes for development:
    are these all of the ways to get into the namespace?
    - import statements at top of file: numpy, psychopy, os, etc
    - a handful of things that always spring up automatically, like t and win
    - routines: user-entered var name = routine['name'].val, plus sundry
        helper vars, like theseKeys
    - flow elements: user-entered = flowElement['name'].val
    - routine & flow from either GUI or .psyexp file
    - each routine and flow element potentially has a ._clockName,
        loops have thisName, albeit thisNam (missing end character)
    - column headers in condition files
    - abbreviating parameter names (e.g. rgb=thisTrial.rgb)

    :Author:
        2011 Jeremy Gray
    """

    def __init__(self, exp):
        """Set-up an experiment's namespace: reserved words and user space
        """
        super(NameSpace, self).__init__()
        self.exp = exp
        # deepcopy fails if you pre-compile regular expressions and stash here

        self.numpy = _numpyImports + _numpyRandomImports + ['np']
        # noinspection PyUnresolvedReferences
        self.keywords = keyword.kwlist + dir(__builtins__)
        # these are based on a partial test, known to be incomplete:
        self.psychopy = psychopy.__all__ + ['psychopy', 'os'] + dir(constants)
        self.builder = ['KeyResponse', 'keyboard', 'buttons',
                        'continueRoutine', 'expInfo', 'expName', 'thisExp',
                        'filename', 'logFile', 'paramName',
                        't', 'frameN', 'currentLoop', 'dlg', '_thisDir',
                        'endExpNow',
                        'globalClock', 'routineTimer', 'frameDur',
                        'theseKeys', 'win', 'x', 'y', 'level', 'component',
                        'thisComponent']
        # user-entered, from Builder dialog or conditions file:
        self.user = []
        self.nonUserBuilder = self.numpy + self.keywords + self.psychopy

        # strings used as codes, separate function from display value:
        # need the actual strings to be inside _translate for poedit discovery
        toTranslate = [
            "one of your Components, Routines, or condition parameters",
            " Avoid `this`, `these`, `continue`, `Clock`, or `component` in name",
            "Builder variable",
            "Psychopy module",
            "numpy function",
            "python keyword"
        ]
        self._localized = {None: ''}  # start with this so None=""
        for transStr in toTranslate:
            self._localized[transStr] = _translate(transStr)

    def __str__(self, numpy_count_only=True):
        varibs = self.user + self.builder + self.psychopy
        if numpy_count_only:
            return "%s + [%d numpy]" % (str(varibs), len(self.numpy))
        return str(varibs + self.numpy)

    def getDerived(self, basename):
        """ buggy
        idea: return variations on name, based on its type, to flag name that
        will come to exist at run-time;
        more specific than is_possibly-derivable()
        if basename is a routine, return continueBasename and basenameClock,
        if basename is a loop, return makeLoopIndex(name)
        """
        derived_names = []
        for flowElement in self.exp.flow:
            if flowElement.getType() in ('LoopInitiator', 'LoopTerminator'):
                flowElement = flowElement.loop  # we want the loop itself
                # basename can be <type 'instance'>
                derived_names += [self.makeLoopIndex(basename)]
            if (basename == str(flowElement.params['name']) and
                    basename + 'Clock' not in derived_names):
                derived_names += [basename + 'Clock',
                                  'continue' + basename.capitalize()]
        # other derived_names?
        #
        return derived_names

    def getCollisions(self):
        """return None, or a list of names in .user that are also in
        one of the other spaces
        """
        standard = set(self.builder + self.psychopy + self.numpy)
        duplicates = list(set(self.user).intersection(standard))
        su = sorted(self.user)
        duplicates += [var for i, var in enumerate(su)
                       if i < len(su) - 1 and su[i + 1] == var]
        return duplicates or None

    def isValid(self, name):
        """var-name compatible? return True if string name is
        alphanumeric + underscore only, with non-digit first
        """
        return bool(valid_var_re.match(name))

    def isPossiblyDerivable(self, name):
        """catch all possible derived-names, regardless of whether currently
        """
        derivable = (name.startswith('this') or
                     name.startswith('these') or
                     name.startswith('continue') or
                     name.endswith('Clock') or
                     name.lower().find('component') > -1)
        if derivable:
            return (" Avoid `this`, `these`, `continue`, `Clock`,"
                    " or `component` in name")
        return None

    def exists(self, name):
        """returns None, or a message indicating where the name is in use.
        cannot guarantee that a name will be conflict-free.
        does not check whether the string is a valid variable name.

        >>> exists('t')
        Builder variable
        """
        try:
            name = str(name)  # convert from unicode if possible
        except Exception:
            pass

        # check getDerived:

        # check in this order: return a key from NameSpace._localized.keys(),
        # not a localized value
        if name in self.user:
            return "one of your Components, Routines, or condition parameters"
        if name in self.builder:
            return "Builder variable"
        if name in self.psychopy:
            return "Psychopy module"
        if name in self.numpy:
            return "numpy function"
        if name in self.keywords:
            return "python keyword"

        return  # None, meaning does not exist already

    def add(self, name, sublist='default'):
        """add name to namespace by appending a name or list of names to a
        sublist, eg, self.user
        """
        if name is None:
            return
        if sublist == 'default':
            sublist = self.user
        if not isinstance(name, list):
            sublist.append(name)
        else:
            sublist += name

    def remove(self, name, sublist='default'):
        """remove name from the specified sublist (and hence from the
        name-space), eg, self.user
        """
        if name is None:
            return
        if sublist == 'default':
            sublist = self.user
        if not isinstance(name, list):
            name = [name]
        for n in list(name):
            if n in sublist:
                del sublist[sublist.index(n)]

    def rename(self, name, newName, sublist='default'):
        if name is None:
            return
        if sublist == 'default':
            sublist = self.user
        if not isinstance(name, list):
            name = [name]
        for n in list(name):
            if n in sublist:
                sublist[sublist.index(n)] = newName

    def makeValid(self, name, prefix='var'):
        """given a string, return a valid and unique variable name.
        replace bad characters with underscore, add an integer suffix until
        its unique

        >>> makeValid('Z Z Z')
        'Z_Z_Z'
        >>> makeValid('a')
        'a'
        >>> makeValid('a')
        'a_2'
        >>> makeValid('123')
        'var_123'
        """

        # make it legal:
        try:
            # convert from unicode, flag as uni if can't convert
            name = str(name)
        except Exception:
            prefix = 'uni'
        if not name:
            name = prefix + '_1'
        if name[0].isdigit():
            name = prefix + '_' + name
        # replace all bad chars with _
        name = nonalphanumeric_re.sub('_', name)

        # try to make it unique; success depends on accuracy of self.exists():
        i = 2  # skip _1: user can rename the first one to be _1 if desired
        # maybe it already has _\d+? if so, increment from there
        if self.exists(name) and '_' in name:
            basename, count = name.rsplit('_', 1)
            try:
                i = int(count) + 1
                name = basename
            except Exception:
                pass
        nameStem = name + '_'
        while self.exists(name):  # brute-force a unique name
            name = nameStem + str(i)
            i += 1
        return name

    def makeLoopIndex(self, name):
        """return a valid, readable loop-index name:
            'this' + (plural->singular).capitalize() [+ (_\d+)]
        """
        try:
            newName = str(name)
        except Exception:
            newName = name
        prefix = 'this'
        irregular = {'stimuli': 'stimulus',
                     'mice': 'mouse', 'people': 'person'}
        for plural, singular in list(irregular.items()):
            nn = re.compile(plural, re.IGNORECASE)
            newName = nn.sub(singular, newName)
        if newName.endswith('s') and newName.lower() not in list(irregular.values()):
            newName = newName[:-1]  # trim last 's'
        else:  # might end in s_2, so delete that s; leave S
            match = re.match(r"^(.*)s(_\d+)$", newName)
            if match:
                newName = match.group(1) + match.group(2)
        # retain CamelCase:
        newName = prefix + newName[0].capitalize() + newName[1:]
        newName = self.makeValid(newName)
        return newName
