# -*- coding: utf-8 -*-
# util functions
#
# Copyright (C) 2009-2012 Logilab. All rights reserved.
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.
"""
Several helper functions
"""
import os
import string
from mercurial import ui

from hgviewlib.hgpatches.scmutil import match
from hgviewlib.hgpatches import precursorsmarkers, successorsmarkers

def tounicode(string):
    """
    Tries to convert s into a unicode string
    """
    for encoding in ('utf-8', 'iso-8859-15', 'cp1252'):
        try:
            return unicode(string, encoding)
        except UnicodeDecodeError:
            pass
    return unicode(string, 'utf-8', 'replace')

def isexec(filectx):
    """
    Return True is the file at filectx revision is executable
    """
    if hasattr(filectx, "isexec"):
        return filectx.isexec()
    return "x" in filectx.flags()

def exec_flag_changed(filectx):
    """
    Return True if the file referenced by filectx has changed its exec
    flag
    """
    flag = isexec(filectx)
    parents = filectx.parents()
    if not parents:
        return ""

    pflag = isexec(parents[0])
    if flag != pflag:
        if flag:
            return "set"
        else:
            return "unset"
    return ""

def isbfile(filename):
    return filename and filename.startswith('.hgbfiles' + os.sep)

def bfilepath(filename):
    return filename and filename.replace('.hgbfiles' + os.sep, '')

def find_repository(path):
    """returns <path>'s mercurial repository

    None if <path> is not under hg control
    """
    path = os.path.abspath(path)
    while not os.path.isdir(os.path.join(path, ".hg")):
        oldpath = path
        path = os.path.dirname(path)
        if path == oldpath:
            return None
    return path

def rootpath(repo, rev, path):
    """return the path name of 'path' relative to repo's root at
    revision rev;
    path is relative to cwd
    """
    ctx = repo[rev]
    filenames = list(ctx.walk(match(ctx, [path], {})))
    if len(filenames) != 1 or filenames[0] not in ctx.manifest():
        return None
    else:
        return filenames[0]

# XXX what about functools.partial ?
class Curry(object):
    """Curryfication de fonction (http://fr.wikipedia.org/wiki/Curryfication)"""
    def __init__(self, function, *additional_args, **additional_kwargs):
        self.func = function
        self.additional_args = additional_args
        self.additional_kwargs = additional_kwargs

    def __call__(self, *args, **kwargs):
        args += self.additional_args
        kwarguments = self.additional_kwargs.copy()
        kwarguments.update(kwargs)
        return self.func(*args, **kwarguments)

# XXX duplicates logilab.mtconverter.__init__ code
CONTROL_CHARS = [chr(ci) for ci in range(32)]
TR_CONTROL_CHARS = [' '] * len(CONTROL_CHARS)
for c in ('\n', '\r', '\t'):
    TR_CONTROL_CHARS[ord(c)] = c
TR_CONTROL_CHARS[ord('\f')] = '\n'
TR_CONTROL_CHARS[ord('\v')] = '\n'
ESC_CAR_TABLE = string.maketrans(''.join(CONTROL_CHARS),
                                 ''.join(TR_CONTROL_CHARS))
ESC_UCAR_TABLE = unicode(ESC_CAR_TABLE, 'latin1')

def xml_escape(data):
    """escapes XML forbidden characters in attributes and PCDATA"""
    if isinstance(data, unicode):
        data = data.translate(ESC_UCAR_TABLE)
    else:
        data = data.translate(ESC_CAR_TABLE)
    return (data.replace('&','&amp;').replace('<','&lt;').replace('>','&gt;')
            .replace('"','&quot;').replace("'",'&#39;'))

def format_desc(desc, width):
    """ format a ctx description for oneliner
    representation (summary view) """
    udesc = tounicode(desc)
    udesc = xml_escape(udesc.split('\n', 1)[0])
    if len(udesc) > width:
        udesc = udesc[:width] + '...'
    return udesc


def first_known_precursors(ctx, excluded=()):
    obsstore = getattr(ctx._repo, 'obsstore', None)
    nm = ctx._repo.changelog.nodemap
    if obsstore is not None:
        markers = precursorsmarkers(obsstore, ctx.node())
        # consider all precursors
        candidates = set(mark[0] for mark in markers)
        seen = set(candidates)
        while candidates:
            current = candidates.pop()
            # is this changeset in the displayed set ?
            crev = nm.get(current)
            if crev is not None and crev not in excluded:
                yield ctx._repo[crev]
            else:
                for mark in precursorsmarkers(obsstore, current):
                    if mark[0] not in seen:
                        candidates.add(mark[0])
                        seen.add(mark[0])

def first_known_successors(ctx, excluded=()):
    obsstore = getattr(ctx._repo, 'obsstore', None)
    nm = ctx._repo.changelog.nodemap
    if obsstore is not None:
        markers = successorsmarkers(obsstore, ctx.node())
        # consider all precursors
        candidates = set()
        for mark in markers:
            candidates.update(mark[1])
        seen = set(candidates)
        while candidates:
            current = candidates.pop()
            # is this changeset in the displayed set ?
            crev = nm.get(current)
            if crev is not None and crev not in excluded:
                yield ctx._repo[crev]
            else:
                for mark in successorsmarkers(obsstore, current):
                    if mark[0] not in seen:
                        candidates.add(mark[0])
                        seen.add(mark[0])