import contextlib

import errno

import os

from mercurial.node import sha1nodeconstants

from mercurial import (

    error,

    extensions,

    match as matchmod,

    pycompat,

    scmutil,

    util,

)

from mercurial.interfaces import (

    dirstate as intdirstate,

    util as interfaceutil,

)

from . import gitutil

pygit2 = gitutil.get_pygit2()

def readpatternfile(orig, filepath, warn, sourceinfo=False):

    if not (b'info/exclude' in filepath or filepath.endswith(b'.gitignore')):

        return orig(filepath, warn, sourceinfo=False)

    result = []

    warnings = []

    with open(filepath, b'rb') as fp:

        for l in fp:

            l = l.strip()

            if not l or l.startswith(b'#'):

                continue

            if l.startswith(b'!'):

                warnings.append(b'unsupported ignore pattern %s' % l)

                continue

            if l.startswith(b'/'):

                result.append(b'rootglob:' + l[1:])

            else:

                result.append(b'relglob:' + l)

    return result, warnings

extensions.wrapfunction(matchmod, b'readpatternfile', readpatternfile)

_STATUS_MAP = {}

if pygit2:

    _STATUS_MAP = {

        pygit2.GIT_STATUS_CONFLICTED: b'm',

        pygit2.GIT_STATUS_CURRENT: b'n',

        pygit2.GIT_STATUS_IGNORED: b'?',

        pygit2.GIT_STATUS_INDEX_DELETED: b'r',

        pygit2.GIT_STATUS_INDEX_MODIFIED: b'n',

        pygit2.GIT_STATUS_INDEX_NEW: b'a',

        pygit2.GIT_STATUS_INDEX_RENAMED: b'a',

        pygit2.GIT_STATUS_INDEX_TYPECHANGE: b'n',

        pygit2.GIT_STATUS_WT_DELETED: b'r',

        pygit2.GIT_STATUS_WT_MODIFIED: b'n',

        pygit2.GIT_STATUS_WT_NEW: b'?',

        pygit2.GIT_STATUS_WT_RENAMED: b'a',

        pygit2.GIT_STATUS_WT_TYPECHANGE: b'n',

        pygit2.GIT_STATUS_WT_UNREADABLE: b'?',

        pygit2.GIT_STATUS_INDEX_MODIFIED | pygit2.GIT_STATUS_WT_MODIFIED: b'm',

    }

@interfaceutil.implementer(intdirstate.idirstate)

class gitdirstate:

        self._ui = ui

        self.git = gitrepo

        self._plchangecallbacks = {}

        # TODO: context.poststatusfixup is bad and uses this attribute

        self._dirty = False

    def p1(self):

        try:

            return self.git.head.peel().id.raw

        except pygit2.GitError:

            # Typically happens when peeling HEAD fails, as in an

            # empty repository.

            return sha1nodeconstants.nullid

    def p2(self):

        # TODO: MERGE_HEAD? something like that, right?

        return sha1nodeconstants.nullid

    def setparents(self, p1, p2=None):

        if p2 is None:

            p2 = sha1nodeconstants.nullid

        assert p2 == sha1nodeconstants.nullid, b'TODO merging support'

        self.git.head.set_target(gitutil.togitnode(p1))

    @util.propertycache

    def identity(self):

        return util.filestat.frompath(

            os.path.join(self._root, b'.git', b'index')

        )

    def branch(self):

        return b'default'

    def parents(self):

        # TODO how on earth do we find p2 if a merge is in flight?

        return self.p1(), sha1nodeconstants.nullid

    def __iter__(self):

        return (pycompat.fsencode(f.path) for f in self.git.index)

    def items(self):

        for ie in self.git.index:

            yield ie.path, None  # value should be a DirstateItem

    # py2,3 compat forward

    iteritems = items

    def __getitem__(self, filename):

        try:

            gs = self.git.status_file(filename)

        except KeyError:

            return b'?'

        return _STATUS_MAP[gs]

    def __contains__(self, filename):

        try:

            gs = self.git.status_file(filename)

            return _STATUS_MAP[gs] != b'?'

        except KeyError:

            return False

    def status(self, match, subrepos, ignored, clean, unknown):

        listclean = clean

        # TODO handling of clean files - can we get that from git.status()?

        modified, added, removed, deleted, unknown, ignored, clean = (

            [],

            [],

            [],

            [],

            [],

            [],

            [],

        )

        gstatus = self.git.status()

        for path, status in gstatus.items():

            path = pycompat.fsencode(path)

            if not match(path):

                continue

            if status == pygit2.GIT_STATUS_IGNORED:

                if path.endswith(b'/'):

                    continue

                ignored.append(path)

            elif status in (

                pygit2.GIT_STATUS_WT_MODIFIED,

                pygit2.GIT_STATUS_INDEX_MODIFIED,

                pygit2.GIT_STATUS_WT_MODIFIED

                | pygit2.GIT_STATUS_INDEX_MODIFIED,

            ):

                modified.append(path)

            elif status == pygit2.GIT_STATUS_INDEX_NEW:

                added.append(path)

            elif status == pygit2.GIT_STATUS_WT_NEW:

                unknown.append(path)

            elif status == pygit2.GIT_STATUS_WT_DELETED:

                deleted.append(path)

            elif status == pygit2.GIT_STATUS_INDEX_DELETED:

                removed.append(path)

            else:

                raise error.Abort(

                    b'unhandled case: status for %r is %r' % (path, status)

                )

        if listclean:

            observed = set(

                modified + added + removed + deleted + unknown + ignored

            )

            index = self.git.index

            index.read()

            for entry in index:

                path = pycompat.fsencode(entry.path)

                if not match(path):

                    continue

                if path in observed:

                    continue  # already in some other set

                if path[-1] == b'/':

                    continue  # directory

                clean.append(path)

        # TODO are we really always sure of status here?

        return (

            False,

            scmutil.status(

                modified, added, removed, deleted, unknown, ignored, clean

            ),

        )

    def flagfunc(self, buildfallback):

        # TODO we can do better

        return buildfallback()

    def getcwd(self):

        # TODO is this a good way to do this?

        return os.path.dirname(

            os.path.dirname(pycompat.fsencode(self.git.path))

        )

    def normalize(self, path):

        normed = util.normcase(path)

        assert normed == path, b"TODO handling of case folding: %s != %s" % (

            normed,

            path,

        )

        return path

    @property

    def _checklink(self):

        return util.checklink(os.path.dirname(pycompat.fsencode(self.git.path)))

    def copies(self):

        # TODO support copies?

        return {}

    # # TODO what the heck is this

    _filecache = set()

    def pendingparentchange(self):

        # TODO: we need to implement the context manager bits and

        # correctly stage/revert index edits.

        return False

    def write(self, tr):

        # TODO: call parent change callbacks

        if tr:

            def writeinner(category):

                self.git.index.write()

            tr.addpending(b'gitdirstate', writeinner)

        else:

            self.git.index.write()

    def pathto(self, f, cwd=None):

        if cwd is None:

            cwd = self.getcwd()

        # TODO core dirstate does something about slashes here

        assert isinstance(f, bytes)

        r = util.pathto(self._root, cwd, f)

        return r

    def matches(self, match):

        for x in self.git.index:

            p = pycompat.fsencode(x.path)

            if match(p):

                yield p

    def set_clean(self, f, parentfiledata):

        """Mark a file normal and clean."""

        # TODO: for now we just let libgit2 re-stat the file. We can

        # clearly do better.

    def set_possibly_dirty(self, f):

        """Mark a file normal, but possibly dirty."""

        # TODO: for now we just let libgit2 re-stat the file. We can

        # clearly do better.

    def walk(self, match, subrepos, unknown, ignored, full=True):

        # TODO: we need to use .status() and not iterate the index,

        # because the index doesn't force a re-walk and so `hg add` of

        # a new file without an intervening call to status will

        # silently do nothing.

        r = {}

        cwd = self.getcwd()

        for path, status in self.git.status().items():

            if path.startswith('.hg/'):

                continue

            path = pycompat.fsencode(path)

            if not match(path):

                continue

            # TODO construct the stat info from the status object?

            try:

                s = os.stat(os.path.join(cwd, path))

            except OSError as e:

                if e.errno != errno.ENOENT:

                    raise

                continue

            r[path] = s

        return r

    def savebackup(self, tr, backupname):

        # TODO: figure out a strategy for saving index backups.

        pass

    def restorebackup(self, tr, backupname):

        # TODO: figure out a strategy for saving index backups.

        pass

    def set_tracked(self, f):

        uf = pycompat.fsdecode(f)

        if uf in self.git.index:

            return False

        index = self.git.index

        index.read()

        index.add(uf)

        index.write()

        return True

    def add(self, f):

        index = self.git.index

        index.read()

        index.add(pycompat.fsdecode(f))

        index.write()

    def drop(self, f):

        index = self.git.index

        index.read()

        fs = pycompat.fsdecode(f)

        if fs in index:

            index.remove(fs)

            index.write()

    def set_untracked(self, f):

        index = self.git.index

        index.read()

        fs = pycompat.fsdecode(f)

        if fs in index:

            index.remove(fs)

            index.write()

            return True

        return False

    def remove(self, f):

        index = self.git.index

        index.read()

        index.remove(pycompat.fsdecode(f))

        index.write()

    def copied(self, path):

        # TODO: track copies?

        return None

    def prefetch_parents(self):

        # TODO

        pass

    def update_file(self, *args, **kwargs):

        # TODO

        pass

    @contextlib.contextmanager

    def parentchange(self):

        # TODO: track this maybe?

        yield

    def addparentchangecallback(self, category, callback):

        # TODO: should this be added to the dirstate interface?

        self._plchangecallbacks[category] = callback

    def clearbackup(self, tr, backupname):

        # TODO

        pass

    def setbranch(self, branch):