# -*-python-*-
#
# Copyright (C) 1999-2023 The ViewCVS Group. All Rights Reserved.
#
# By using this file, you agree to the terms and conditions set forth in
# the LICENSE.html file which can be found at the top level of the ViewVC
# distribution or at http://viewvc.org/license-1.html.
#
# For more information, visit http://viewvc.org/
#
# -----------------------------------------------------------------------

"Version Control lib driver for locally accessible cvs-repositories."

import vclib
import os
import os.path
import sys
import stat
import re
import calendar
import subprocess
import vclib.ccvs
from operator import attrgetter


def enc_decode(s, encoding="utf-8"):
    if s is None:
        return None
    return s.decode(encoding, "surrogateescape")


def _path_join(path_parts):
    return "/".join(path_parts)


class BaseCVSRepository(vclib.Repository):
    def __init__(self, name, rootpath, authorizer, utilities,
                 content_encoding, path_encoding):
        if not os.path.isdir(vclib._getfspath(rootpath, path_encoding)):
            raise vclib.ReposNotFound(name)

        self.name = name
        self.rootpath = rootpath
        self.auth = authorizer
        self.utilities = utilities
        self.content_encoding = content_encoding
        self.path_encoding = path_encoding

        # See if this repository is even viewable, authz-wise.
        if not vclib.check_root_access(self):
            raise vclib.ReposNotFound(name)

    def open(self):
        # See if a universal read access determination can be made.
        if self.auth and self.auth.check_universal_access(self.name) == 1:
            self.auth = None

    def rootname(self):
        return self.name

    def roottype(self):
        return vclib.CVS

    def authorizer(self):
        return self.auth

    def itemtype(self, path_parts, rev):
        basepath = self._getpath(path_parts)
        kind = None
        if os.path.isdir(self._getfspath(basepath)):
            kind = vclib.DIR
        elif os.path.isfile(self._getfspath(basepath + ",v")):
            kind = vclib.FILE
        else:
            atticpath = self._getpath(self._atticpath(path_parts))
            if os.path.isfile(self._getfspath(atticpath + ",v")):
                kind = vclib.FILE
        if not kind:
            raise vclib.ItemNotFound(path_parts)
        if not vclib.check_path_access(self, path_parts, kind, rev):
            raise vclib.ItemNotFound(path_parts)
        return kind

    def itemprops(self, path_parts, rev):
        self.itemtype(path_parts, rev)  # does auth-check
        return {}  # CVS doesn't support properties

    def listdir(self, path_parts, rev, options):
        if self.itemtype(path_parts, rev) != vclib.DIR:  # does auth-check
            raise vclib.Error("Path '%s' is not a directory." % (_path_join(path_parts)))

        # Only RCS files (*,v) and subdirs are returned.
        data = []
        full_name = self._getpath(path_parts)
        for file in vclib.os_listdir(full_name, self.path_encoding):
            name = None
            kind, errors = _check_path(os.path.join(full_name, file),
                                       self.path_encoding)
            if kind == vclib.FILE:
                if file[-2:] == ",v":
                    name = file[:-2]
            elif kind == vclib.DIR:
                if file != "Attic" and file != "CVS":  # CVS directory is for fileattr
                    name = file
            else:
                name = file
            if not name:
                continue
            if vclib.check_path_access(self, path_parts + [name], kind, rev):
                data.append(CVSDirEntry(name, kind, errors, 0))

        full_name = os.path.join(full_name, "Attic")
        if os.path.isdir(self._getfspath(full_name)):
            for file in vclib.os_listdir(full_name, self.path_encoding):
                name = None
                kind, errors = _check_path(os.path.join(full_name, file),
                                           self.path_encoding)
                if kind == vclib.FILE:
                    if file[-2:] == ",v":
                        name = file[:-2]
                elif kind != vclib.DIR:
                    name = file
                if not name:
                    continue
                if vclib.check_path_access(self, path_parts + [name], kind, rev):
                    data.append(CVSDirEntry(name, kind, errors, 1))

        return data

    def _getpath(self, path_parts):
        return os.path.join(*((self.rootpath,) + tuple(path_parts)))

    def _getfspath(self, path):
        """Get path on local file system.

        PATH should be a path represented in str. On system using posix path,
        it returns a path represented in bytes. On Windows, returns PATH
        itself."""

        return vclib._getfspath(path, self.path_encoding)

    def _atticpath(self, path_parts):
        return path_parts[:-1] + ["Attic"] + path_parts[-1:]

    def rcsfile(self, path_parts, root=0, v=1):
        "Return path to RCS file"

        ret_parts = path_parts
        ret_file = self._getpath(ret_parts)
        if not os.path.isfile(self._getfspath(ret_file + ",v")):
            ret_parts = self._atticpath(path_parts)
            ret_file = self._getpath(ret_parts)
            if not os.path.isfile(self._getfspath(ret_file + ",v")):
                raise vclib.ItemNotFound(path_parts)
        if root:
            ret = ret_file
        else:
            ret = _path_join(ret_parts)
        if v:
            ret = ret + ",v"
        return ret

    def isexecutable(self, path_parts, rev):
        if self.itemtype(path_parts, rev) != vclib.FILE:  # does auth-check
            raise vclib.Error("Path '%s' is not a file." % (_path_join(path_parts)))
        rcsfile = self.rcsfile(path_parts, 1)
        return os.access(self._getfspath(rcsfile), os.X_OK)

    def filesize(self, path_parts, rev):
        if self.itemtype(path_parts, rev) != vclib.FILE:  # does auth-check
            raise vclib.Error("Path '%s' is not a file." % (_path_join(path_parts)))
        return -1

    def cvsgraph_popen(self, cvsgraph_args, is_text=False, capture_err=True):
        """Run cvsgraph, with appropriate transcode of args. Unlike
        rcs_popen, this uses always UTF-8 in text mode encoding"""

        cmd = self.utilities.cvsgraph or "cvsgraph"
        if sys.platform != "win32":
            cmd = os.fsencode(cmd)
            cvsgraph_args = [self._getfspath(arg) for arg in cvsgraph_args]
        stderr = subprocess.STDOUT if capture_err else subprocess.DEVNULL
        if is_text:
            proc = subprocess.Popen(
                [cmd] + list(cvsgraph_args),
                bufsize=-1,
                stdout=subprocess.PIPE,
                stderr=stderr,
                encoding="utf-8",
                errors="surrogateescape",
                close_fds=(sys.platform != "win32"),
            )
        else:
            proc = subprocess.Popen(
                [cmd] + list(cvsgraph_args),
                bufsize=-1,
                stdout=subprocess.PIPE,
                stderr=stderr,
                close_fds=(sys.platform != "win32"),
            )
        return proc.stdout


class BinCVSRepository(BaseCVSRepository):
    def _get_tip_revision(self, rcs_file, rev=None):
        """Get the (basically) youngest revision (filtered by REV)."""
        args = (rcs_file,)
        fp = self.rcs_popen("rlog", args, True, False)
        filename, default_branch, tags, lockinfo, msg, eof = _parse_log_header(fp)
        revs = []
        while not eof:
            revision, eof = _parse_log_entry(fp)
            if revision:
                revs.append(revision)
        revs = _file_log(revs, tags, lockinfo, default_branch, rev)
        if revs:
            return revs[-1]
        return None

    def openfile(self, path_parts, rev, options):
        """see vclib.Repository.openfile docstring

        Option values recognized by this implementation:

          cvs_oldkeywords
            boolean. true to use the original keyword substitution values.
        """
        if self.itemtype(path_parts, rev) != vclib.FILE:  # does auth-check
            raise vclib.Error("Path '%s' is not a file." % (_path_join(path_parts)))
        if not rev or rev == "HEAD" or rev == "MAIN":
            rev_flag = "-p"
        else:
            rev_flag = "-p" + rev
        if options.get("cvs_oldkeywords", 0):
            kv_flag = "-ko"
        else:
            kv_flag = "-kkv"
        full_name = self.rcsfile(path_parts, root=1, v=0)
        used_rlog = 0
        tip_rev = None  # used only if we have to fallback to using rlog
        fp = self.rcs_popen("co", (kv_flag, rev_flag, full_name))
        try:
            filename, revision = _parse_co_header(fp, self.content_encoding)
        except COMissingRevision:
            # We got a "revision X.Y.Z absent" error from co.  This could be
            # because we were asked to find a tip of a branch, which co
            # doesn't seem to handle.  So we do rlog-gy stuff to figure out
            # which revision the tip of the branch currently maps to.
            #
            # TODO: Only do this when 'rev' is a branch symbol name?
            if not used_rlog:
                tip_rev = self._get_tip_revision(full_name + ",v", rev)
                used_rlog = 1
            if not tip_rev:
                raise vclib.Error("Unable to find valid revision")
            fp = self.rcs_popen("co", ("-p" + tip_rev.string, full_name))
            filename, revision = _parse_co_header(fp, self.content_encoding)

        if filename is None:
            # CVSNT's co exits without any output if a dead revision is requested.
            # Bug at http://www.cvsnt.org/cgi-bin/bugzilla/show_bug.cgi?id=190
            # As a workaround, we invoke rlog to find the first non-dead revision
            # that precedes it and check out that revision instead.  Of course,
            # if we've already invoked rlog above, we just reuse its output.
            if not used_rlog:
                tip_rev = self._get_tip_revision(full_name + ",v", rev)
                used_rlog = 1
            if not (tip_rev and tip_rev.undead):
                raise vclib.Error('Could not find non-dead revision preceding "%s"' % rev)
            fp = self.rcs_popen("co", ("-p" + tip_rev.undead.string, full_name))
            filename, revision = _parse_co_header(fp, self.content_encoding)

        if filename is None:
            raise vclib.Error('Missing output from co (filename = "%s")' % full_name)

        if not _paths_eq(filename, full_name):
            raise vclib.Error(
                'The filename from co ("%s") did not match (expected "%s")' % (filename, full_name)
            )

        return fp, revision

    def dirlogs(self, path_parts, rev, entries, options):
        """see vclib.Repository.dirlogs docstring

        rev can be a tag name or None. if set only information from revisions
        matching the tag will be retrieved

        Option values recognized by this implementation:

          cvs_subdirs
            boolean. true to fetch logs of the most recently modified file in each
            subdirectory

        Option values returned by this implementation:

          cvs_tags, cvs_branches
            lists of tag and branch names encountered in the directory
        """
        if self.itemtype(path_parts, rev) != vclib.DIR:  # does auth-check
            raise vclib.Error("Path '%s' is not a directory." % (_path_join(path_parts)))

        subdirs = options.get("cvs_subdirs", 0)
        entries_to_fetch = []
        for entry in entries:
            if vclib.check_path_access(self, path_parts + [entry.name], None, rev):
                entries_to_fetch.append(entry)
        alltags = _get_logs(self, path_parts, entries_to_fetch, rev, subdirs)
        branches = options["cvs_branches"] = []
        tags = options["cvs_tags"] = []
        for name, rev in alltags.items():
            if Tag(None, rev).is_branch:
                branches.append(name)
            else:
                tags.append(name)

    def itemlog(self, path_parts, rev, sortby, first, limit, options):
        """see vclib.Repository.itemlog docstring

        rev parameter can be a revision number, a branch number, a tag name,
        or None. If None, will return information about all revisions, otherwise,
        will only return information about the specified revision or branch.

        Option values recognized by this implementation:

          cvs_pass_rev
            boolean, default false. set to true to pass rev parameter as -r
            argument to rlog, this is more efficient but causes less
            information to be returned

        Option values returned by this implementation:

          cvs_tags
            dictionary of Tag objects for all tags encountered
        """

        if self.itemtype(path_parts, rev) != vclib.FILE:  # does auth-check
            raise vclib.Error("Path '%s' is not a file." % (_path_join(path_parts)))

        # Invoke rlog
        rcsfile = self.rcsfile(path_parts, 1)
        if rev and options.get("cvs_pass_rev", 0):
            args = "-r" + rev, rcsfile
        else:
            args = (rcsfile,)

        fp = self.rcs_popen("rlog", args, True, False)
        filename, default_branch, tags, lockinfo, msg, eof = _parse_log_header(fp)

        # Retrieve revision objects
        revs = []
        while not eof:
            revision, eof = _parse_log_entry(fp)
            if revision:
                revs.append(revision)

        filtered_revs = _file_log(revs, tags, lockinfo, default_branch, rev)

        options["cvs_tags"] = tags
        # Both of Revision.date and Revision.number are sortable, not None
        if sortby == vclib.SORTBY_DATE:
            filtered_revs.sort(key=attrgetter('date', 'number'), reverse=True)
        elif sortby == vclib.SORTBY_REV:
            filtered_revs.sort(key=attrgetter('number'), reverse=True)

        if len(filtered_revs) < first:
            return []
        if limit:
            return filtered_revs[first : (first + limit)]
        return filtered_revs

    def rcs_popen(self, rcs_cmd, rcs_args, is_text=False, capture_err=True):
        # as we use this function as "r" mode only, we don't care stdin
        # to communicate child process.
        if self.utilities.cvsnt:
            cmd = self.utilities.cvsnt
            args = ["rcsfile", rcs_cmd]
            args.extend(list(rcs_args))
        else:
            cmd = os.path.join(self.utilities.rcs_dir, rcs_cmd)
            args = rcs_args
        if sys.platform != "win32":
            cmd = os.fsencode(cmd)
            args = [self._getfspath(arg) for arg in args]
        stderr = subprocess.STDOUT if capture_err else subprocess.DEVNULL
        if is_text:
            proc = subprocess.Popen(
                [cmd] + list(args),
                bufsize=-1,
                stdout=subprocess.PIPE,
                stderr=stderr,
                encoding=self.content_encoding,
                errors="surrogateescape",
                close_fds=(sys.platform != "win32"),
            )
        else:
            proc = subprocess.Popen(
                [cmd] + list(args),
                bufsize=-1,
                stdout=subprocess.PIPE,
                stderr=stderr,
                close_fds=(sys.platform != "win32"),
            )
        return proc.stdout

    def annotate(self, path_parts, rev=None, include_text=False):
        if self.itemtype(path_parts, rev) != vclib.FILE:  # does auth-check
            raise vclib.Error("Path '%s' is not a file." % (_path_join(path_parts)))

        from vclib.ccvs import blame

        source = blame.BlameSource(self._getfspath(self.rcsfile(path_parts, 1)),
                                   rev, include_text, self.content_encoding)
        return source, source.revision

    def revinfo(self, rev):
        raise vclib.UnsupportedFeature

    def rawdiff(self, path_parts1, rev1, path_parts2, rev2, diff_type,
                options={}, is_text=True):
        """see vclib.Repository.rawdiff docstring

        Option values recognized by this implementation:

          ignore_keyword_subst - boolean, ignore keyword substitution
        """
        if self.itemtype(path_parts1, rev1) != vclib.FILE:  # does auth-check
            raise vclib.Error("Path '%s' is not a file." % (_path_join(path_parts1)))
        if self.itemtype(path_parts2, rev2) != vclib.FILE:  # does auth-check
            raise vclib.Error("Path '%s' is not a file." % (_path_join(path_parts2)))

        args = vclib._diff_args(diff_type, options)
        if options.get("ignore_keyword_subst", 0):
            args.append("-kk")

        rcsfile = self.rcsfile(path_parts1, 1)
        if path_parts1 != path_parts2:
            raise NotImplementedError("cannot diff across paths in cvs")
        args.extend(["-r" + rev1, "-r" + rev2, rcsfile])

        fp = self.rcs_popen("rcsdiff", args, is_text)

        # Eat up the non-GNU-diff-y headers.
        while 1:
            line = fp.readline()
            if not line or line[0:5] in ("diff ", b"diff "):
                break
        return fp


class CVSDirEntry(vclib.DirEntry):
    def __init__(self, name, kind, errors, in_attic, absent=0):
        vclib.DirEntry.__init__(self, name, kind, errors)
        self.in_attic = in_attic
        self.absent = absent  # meaning, no revisions found on requested tag


class Revision(vclib.Revision):
    def __init__(self, revstr, date=None, author=None, dead=None, changed=None, log=None):
        vclib.Revision.__init__(
            self, _revision_tuple(revstr), revstr, date, author, changed, log, None, None
        )
        self.dead = dead


class Tag:
    def __init__(self, name, revstr):
        self.name = name
        self.number = _tag_tuple(revstr)
        self.is_branch = len(self.number) % 2 == 1 or not self.number


# ======================================================================
# Functions for dealing with Revision and Tag objects


def _match_revs_tags(revlist, taglist):
    """Match up a list of Revision objects with a list of Tag objects

    Sets the following properties on each Revision in revlist:
      "tags"
        list of non-branch tags which refer to this revision
        example: if revision is 1.2.3.4, tags is a list of all 1.2.3.4 tags

      "branches"
        list of branch tags which refer to this revision's branch
        example: if revision is 1.2.3.4, branches is a list of all 1.2.3 tags

      "branch_points"
        list of branch tags which branch off of this revision
        example: if revision is 1.2, it's a list of tags like 1.2.3 and 1.2.4

      "prev"
        reference to the previous revision, possibly None
        example: if revision is 1.2.3.4, prev is 1.2.3.3

      "next"
        reference to next revision, possibly None
        example: if revision is 1.2.3.4, next is 1.2.3.5

      "parent"
        reference to revision this one branches off of, possibly None
        example: if revision is 1.2.3.4, parent is 1.2

      "undead"
        If the revision is dead, then this is a reference to the first
        previous revision which isn't dead, otherwise it's a reference
        to itself. If all the previous revisions are dead it's None.

      "branch_number"
        tuple representing branch number or empty tuple if on trunk
        example: if revision is 1.2.3.4, branch_number is (1, 2, 3)

    Each tag in taglist gets these properties set:
      "co_rev"
        reference to revision that would be retrieved if tag were checked out

      "branch_rev"
        reference to revision branched off of, only set for branch tags
        example: if tag is 1.2.3, branch_rev points to 1.2 revision

      "aliases"
        list of tags that have the same number
    """

    # map of branch numbers to lists of corresponding branch Tags
    branch_dict = {}

    # map of revision numbers to lists of non-branch Tags
    tag_dict = {}

    # map of revision numbers to lists of branch Tags
    branch_point_dict = {}

    # toss tags into "branch_dict", "tag_dict", and "branch_point_dict"
    # set "aliases" property and default "co_rev" and "branch_rev" values
    for tag in taglist:
        tag.co_rev = None
        if tag.is_branch:
            tag.branch_rev = None
            _dict_list_add(branch_point_dict, tag.number[:-1], tag)
            tag.aliases = _dict_list_add(branch_dict, tag.number, tag)
        else:
            tag.aliases = _dict_list_add(tag_dict, tag.number, tag)

    # sort the revisions so the loop below can work properly
    revlist.sort()

    # array of the most recently encountered revision objects indexed by depth
    history = []

    # loop through revisions, setting properties and storing state in "history"
    for rev in revlist:
        depth = len(rev.number) // 2 - 1

        # set "prev" and "next" properties
        rev.prev = rev.next = None
        if depth < len(history):
            prev = history[depth]
            if prev and (depth == 0 or rev.number[:-1] == prev.number[:-1]):
                rev.prev = prev
                prev.next = rev

        # set "parent"
        rev.parent = None
        if depth and depth <= len(history):
            parent = history[depth - 1]
            if parent and parent.number == rev.number[:-2]:
                rev.parent = history[depth - 1]

        # set "undead"
        if rev.dead:
            prev = rev.prev or rev.parent
            rev.undead = prev and prev.undead
        else:
            rev.undead = rev

        # set "tags" and "branch_points"
        rev.tags = tag_dict.get(rev.number, [])
        rev.branch_points = branch_point_dict.get(rev.number, [])

        # set "branches" and "branch_number"
        if rev.prev:
            rev.branches = rev.prev.branches
            rev.branch_number = rev.prev.branch_number
        else:
            rev.branch_number = depth and rev.number[:-1] or ()
            try:
                rev.branches = branch_dict[rev.branch_number]
            except KeyError:
                rev.branches = []

        # set "co_rev" and "branch_rev"
        for tag in rev.tags:
            tag.co_rev = rev

        for tag in rev.branch_points:
            tag.co_rev = rev
            tag.branch_rev = rev

        # This loop only needs to be run for revisions at the heads of branches,
        # but for the simplicity's sake, it actually runs for every revision on
        # a branch. The later revisions overwrite values set by the earlier ones.
        for branch in rev.branches:
            branch.co_rev = rev

        # end of outer loop, store most recent revision in "history" array
        while len(history) <= depth:
            history.append(None)
        history[depth] = rev


def _add_tag(tag_name, revision):
    """Create a new tag object and associate it with a revision"""
    if revision:
        tag = Tag(tag_name, revision.string)
        tag.aliases = revision.tags
        revision.tags.append(tag)
    else:
        tag = Tag(tag_name, None)
        tag.aliases = []
    tag.co_rev = revision
    tag.is_branch = 0
    return tag


def _remove_tag(tag):
    """Remove a tag's associations"""
    tag.aliases.remove(tag)
    if tag.is_branch and tag.branch_rev:
        tag.branch_rev.branch_points.remove(tag)


def _revision_tuple(revision_string):
    """convert a revision number into a tuple of integers"""
    t = tuple(map(int, revision_string.split(".")))
    if len(t) % 2 == 0:
        return t
    raise ValueError


def _tag_tuple(revision_string):
    """convert a revision number or branch number into a tuple of integers"""
    if revision_string:
        t = [int(x) for x in revision_string.split(".")]
        t_len = len(t)
        if t_len == 1:
            return ()
        if t_len > 2 and t[-2] == 0 and t_len % 2 == 0:
            del t[-2]
        return tuple(t)
    return ()


def _dict_list_add(dict, idx, elem):
    try:
        list = dict[idx]
    except KeyError:
        list = dict[idx] = [elem]
    else:
        list.append(elem)
    return list


# ======================================================================
# Functions for parsing output from RCS utilities


class COMalformedOutput(vclib.Error):
    pass


class COMissingRevision(vclib.Error):
    pass


# TODO: suck up other warnings in _re_co_warning?
_re_co_filename = re.compile(br"^(.*),v\s+-->\s+" br"(?:(?:standard output)|(?:stdout))\s*\n?$")
_re_co_warning = re.compile(br"^.*co: .*,v: " br"warning: Unknown phrases like .*\n$")
_re_co_missing_rev = re.compile(br"^.*co: .*,v: revision.*absent\n$")
_re_co_side_branches = re.compile(br"^.*co: .*,v: " br"no side branches present for [\d\.]+\n$")
_re_co_revision = re.compile(br"^revision\s+([\d\.]+)\s*\n$")


def _parse_co_header(fp, encoding="utf-8"):
    """Parse RCS co header.

    fp is a file (pipe) opened for reading the co standard error stream.

    Returns: (filename, revision) or (None, None) if output is empty
    """

    # Python 3: in this context, fp is raw mode.

    # header from co:
    #
    #    /home/cvsroot/mod_dav/dav_shared_stub.c,v  -->  standard output
    #    revision 1.1
    #
    # Sometimes, the following line might occur at line 2:
    #
    #    co: INSTALL,v: warning: Unknown phrases like `permissions ...;' are
    #    present.

    # parse the output header
    filename = None

    # look for a filename in the first line (if there is a first line).
    line = fp.readline()
    if not line:
        return None, None
    match = _re_co_filename.match(line)
    if not match:
        raise COMalformedOutput("Unable to find filename in co output stream")
    filename = match.group(1)

    # look through subsequent lines for a revision.  we might encounter
    # some ignorable or problematic lines along the way.
    while 1:
        line = fp.readline()
        if not line:
            break
        # look for a revision.
        match = _re_co_revision.match(line)
        if match:
            return (enc_decode(filename, encoding), enc_decode(match.group(1), encoding))
        elif _re_co_missing_rev.match(line) or _re_co_side_branches.match(line):
            raise COMissingRevision("Got missing revision error from co output stream")
        elif _re_co_warning.match(line):
            pass
        else:
            break

    raise COMalformedOutput("Unable to find revision in co output stream")


# if your rlog doesn't use 77 '=' characters, then this must change
LOG_END_MARKER = "=" * 77 + "\n"
ENTRY_END_MARKER = "-" * 28 + "\n"

_EOF_FILE = "end of file entries"  # no more entries for this RCS file
_EOF_LOG = "end of log"  # hit the true EOF on the pipe
_EOF_ERROR = "error message found"  # rlog issued an error

# rlog error messages look like
#
#   rlog: filename/goes/here,v: error message
#   rlog: filename/goes/here,v:123: error message
#
# so we should be able to match them with a regex like
#
#   ^rlog\: (.*)(?:\:\d+)?\: (.*)$
#
# But for some reason the windows version of rlog omits the "rlog: " prefix
# for the first error message when the standard error stream has been
# redirected to a file or pipe. (the prefix is present in subsequent errors
# and when rlog is run from the console). So the expression below is more
# complicated
_re_log_error = re.compile(r"^(?:rlog\: )*(.*,v)(?:\:\d+)?\: (.*)$")

# CVSNT error messages look like:
# cvs rcsfile: `C:/path/to/file,v' does not appear to be a valid rcs file
# cvs [rcsfile aborted]: C:/path/to/file,v: No such file or directory
# cvs [rcsfile aborted]: cannot open C:/path/to/file,v: Permission denied
_re_cvsnt_error = re.compile(
    r"^(?:cvs rcsfile\: |cvs \[rcsfile aborted\]: )"
    r"(?:\`(.*,v)\' |"
    r"cannot open (.*,v)\: |(.*,v)\: |)"
    r"(.*)$"
)


def _parse_log_header(fp):
    """Parse and RCS/CVS log header.

    fp is a file (pipe) opened for reading the log information.

    On entry, fp should point to the start of a log entry.
    On exit, fp will have consumed the separator line between the header and
    the first revision log.

    If there is no revision information (e.g. the "-h" switch was passed to
    rlog), then fp will consumed the file separator line on exit.

    Returns: filename, default branch, tag dictionary, lock dictionary,
    rlog error message, and eof flag
    """

    filename = branch = msg = ""
    taginfo = {}  # tag name => number
    lockinfo = {}  # revision => locker
    state = 0  # 0 = base, 1 = parsing symbols, 2 = parsing locks
    eof = None

    while 1:
        line = fp.readline()
        if not line:
            # the true end-of-file
            eof = _EOF_LOG
            break

        if state == 1:
            if line[0] == "\t":
                [tag, rev] = [x.strip() for x in line.split(":")]
                taginfo[tag] = rev
            else:
                # oops. this line isn't tag info. stop parsing tags.
                state = 0

        if state == 2:
            if line[0] == "\t":
                [locker, rev] = [x.strip() for x in line.split(":")]
                lockinfo[rev] = locker
            else:
                # oops. this line isn't lock info. stop parsing tags.
                state = 0

        if state == 0:
            if line[:9] == "RCS file:":
                filename = line[10:-1]
            elif line[:5] == "head:":
                # head = line[6:-1]
                pass
            elif line[:7] == "branch:":
                branch = line[8:-1]
            elif line[:6] == "locks:":
                # start parsing the lock information
                state = 2
            elif line[:14] == "symbolic names":
                # start parsing the tag information
                state = 1
            elif line == ENTRY_END_MARKER:
                # end of the headers
                break
            elif line == LOG_END_MARKER:
                # end of this file's log information
                eof = _EOF_FILE
                break
            else:
                error = _re_cvsnt_error.match(line)
                if error:
                    p1, p2, p3, msg = error.groups()
                    filename = p1 or p2 or p3
                    if not filename:
                        raise vclib.Error("Could not get filename from CVSNT error:\n%s" % line)
                    eof = _EOF_ERROR
                    break

                error = _re_log_error.match(line)
                if error:
                    filename, msg = error.groups()
                    if msg[:30] == "warning: Unknown phrases like ":
                        # don't worry about this warning. it can happen with some RCS
                        # files that have unknown fields in them (e.g. "permissions 644;"
                        continue
                    eof = _EOF_ERROR
                    break

    return filename, branch, taginfo, lockinfo, msg, eof


_re_log_info = re.compile(
    r"^date:\s+([^;]+);"
    r"\s+author:\s+([^;]+);"
    r"\s+state:\s+([^;]+);"
    r"(\s+lines:\s+([0-9\s+-]+);?)?"
    r"(\s+commitid:\s+([a-zA-Z0-9]+))?\n$"
)

# TODO: _re_rev should be updated to extract the "locked" flag
_re_rev = re.compile(r"^revision\s+([0-9.]+).*")


def _parse_log_entry(fp):
    """Parse a single log entry.

    On entry, fp should point to the first line of the entry (the "revision"
    line).
    On exit, fp will have consumed the log separator line (dashes) or the
    end-of-file marker (equals).

    Returns: Revision object and eof flag (see _EOF_*)
    """
    rev = None
    line = fp.readline()
    if not line:
        return None, _EOF_LOG
    if line == LOG_END_MARKER:
        # Needed because some versions of RCS precede LOG_END_MARKER
        # with ENTRY_END_MARKER
        return None, _EOF_FILE
    if line[:8] == "revision":
        match = _re_rev.match(line)
        if not match:
            return None, _EOF_LOG
        rev = match.group(1)

        line = fp.readline()
        if not line:
            return None, _EOF_LOG
        match = _re_log_info.match(line)

    eof = None
    log = ""
    while 1:
        line = fp.readline()
        if not line:
            # true end-of-file
            eof = _EOF_LOG
            break
        if line[:9] == "branches:":
            continue
        if line == ENTRY_END_MARKER:
            break
        if line == LOG_END_MARKER:
            # end of this file's log information
            eof = _EOF_FILE
            break

        log = log + line

    if not rev or not match:
        # there was a parsing error
        return None, eof

    # parse out a time tuple for the local time
    tm = vclib.ccvs.cvs_strptime(match.group(1))

    # rlog seems to assume that two-digit years are 1900-based (so, "04"
    # comes out as "1904", not "2004").
    EPOCH = 1970
    if tm[0] < EPOCH:
        tm = list(tm)
        if (tm[0] - 1900) < 70:
            tm[0] = tm[0] + 100
        if tm[0] < EPOCH:
            raise ValueError("invalid year")
    date = calendar.timegm(tm)

    return (
        Revision(
            rev,
            date,
            # author, state, lines changed
            match.group(2),
            match.group(3) == "dead",
            match.group(5),
            log,
        ),
        eof,
    )


def _skip_file(fp):
    "Skip the rest of a file's log information."
    while 1:
        line = fp.readline()
        if not line:
            break
        if line == LOG_END_MARKER:
            break


def _paths_eq(path1, path2):
    "See if two path strings are the same"
    # This function is neccessary because CVSNT (since version 2.0.29)
    # converts paths passed as arguments to use upper case drive
    # letter and forward slashes
    return os.path.normcase(path1) == os.path.normcase(path2)


# ======================================================================
# Functions for interpreting and manipulating log information


def _file_log(revs, taginfo, lockinfo, cur_branch, filter):
    """Augment list of Revisions and a dictionary of Tags"""

    # Add artificial ViewVC tag MAIN. If the file has a default branch, then
    # MAIN acts like a branch tag pointing to that branch. Otherwise MAIN acts
    # like a branch tag that points to the trunk. (Note: A default branch is
    # just a branch number specified in an RCS file that tells CVS and RCS
    # what branch to use for checkout and update operations by default, when
    # there's no revision argument or sticky branch to override it. Default
    # branches get set by "cvs import" to point to newly created vendor
    # branches. Sometimes they are also set manually with "cvs admin -b")
    taginfo["MAIN"] = cur_branch

    # Create tag objects
    for name, num in taginfo.items():
        taginfo[name] = Tag(name, num)
    tags = list(taginfo.values())

    # Set view_tag to a Tag object in order to filter results. We can filter by
    # revision number or branch number
    if filter:
        try:
            view_tag = Tag(None, filter)
        except ValueError:
            view_tag = None
        else:
            tags.append(view_tag)

    # Match up tags and revisions
    _match_revs_tags(revs, tags)

    # Match up lockinfo and revision
    for rev in revs:
        rev.lockinfo = lockinfo.get(rev.string)

    # Add artificial ViewVC tag HEAD, which acts like a non-branch tag pointing
    # at the latest revision on the MAIN branch. The HEAD revision doesn't have
    # anything to do with the "head" revision number specified in the RCS file
    # and in rlog output. HEAD refers to the revision that the CVS and RCS co
    # commands will check out by default, whereas the "head" field just refers
    # to the highest revision on the trunk.
    taginfo["HEAD"] = _add_tag("HEAD", taginfo["MAIN"].co_rev)

    # Determine what revisions to return
    if filter:
        # If view_tag isn't set, it means filter is not a valid revision or
        # branch number. Check taginfo to see if filter is set to a valid tag
        # name. If so, filter by that tag, otherwise raise an error.
        if not view_tag:
            try:
                view_tag = taginfo[filter]
            except KeyError:
                raise vclib.Error('Invalid tag or revision number "%s"' % filter)
        filtered_revs = []

        # only include revisions on the tag branch or it's parent branches
        if view_tag.is_branch:
            branch = view_tag.number
        elif len(view_tag.number) > 2:
            branch = view_tag.number[:-1]
        else:
            branch = ()

        # for a normal tag, include all tag revision and all preceding revisions.
        # for a branch tag, include revisions on branch, branch point revision,
        # and all preceding revisions
        for rev in revs:
            if (
                rev.number == view_tag.number
                or rev.branch_number == view_tag.number
                or (
                    rev.number < view_tag.number
                    and rev.branch_number == branch[: len(rev.branch_number)]
                )
            ):
                filtered_revs.append(rev)

        # get rid of the view_tag if it was only created for filtering
        if view_tag.name is None:
            _remove_tag(view_tag)
    else:
        filtered_revs = revs

    return filtered_revs


def _get_logs(repos, dir_path_parts, entries, view_tag, get_dirs):
    alltags = {"MAIN": "", "HEAD": "1.1"}  # all the tags seen in the files of this dir

    entries_idx = 0
    entries_len = len(entries)
    max_args = 100

    while 1:
        chunk = []

        while len(chunk) < max_args and entries_idx < entries_len:
            entry = entries[entries_idx]
            path = _log_path(entry, repos._getpath(dir_path_parts), get_dirs,
                             repos.path_encoding)
            if path:
                entry.path = path
                entry.idx = entries_idx
                chunk.append(entry)

            # set properties even if we don't retrieve logs
            entry.rev = entry.date = entry.author = None
            entry.dead = entry.log = entry.lockinfo = None

            entries_idx = entries_idx + 1

        if not chunk:
            return alltags

        args = []
        if not view_tag:
            # NOTE: can't pass tag on command line since a tag may contain "-"
            #       we'll search the output for the appropriate revision
            # fetch the latest revision on the default branch
            args.append("-r")
        args.extend([x.path for x in chunk])
        rlog = repos.rcs_popen("rlog", args, True)

        # consume each file found in the resulting log
        chunk_idx = 0
        while chunk_idx < len(chunk):
            file = chunk[chunk_idx]
            filename, default_branch, taginfo, lockinfo, msg, eof = _parse_log_header(rlog)

            if eof == _EOF_LOG:
                # the rlog output ended early. this can happen on errors that rlog
                # thinks are so serious that it stops parsing the current file and
                # refuses to parse any of the files that come after it. one of the
                # errors that triggers this obnoxious behavior looks like:
                #
                # rlog: c:\cvsroot\dir\file,v:8: unknown expand mode u
                # rlog aborted

                # if current file has errors, restart on the next one
                if file.errors:
                    chunk_idx = chunk_idx + 1
                    if chunk_idx < len(chunk):
                        entries_idx = chunk[chunk_idx].idx
                    break

                # otherwise just error out
                raise vclib.Error('Rlog output ended early. Expected RCS file "%s"' % file.path)

            # if rlog filename doesn't match current file and we already have an
            # error message about this file, move on to the next file
            while not (file and _paths_eq(file.path, filename)):
                if file and file.errors:
                    chunk_idx = chunk_idx + 1
                    file = chunk_idx < len(chunk) and chunk[chunk_idx] or None
                    continue

                raise vclib.Error(
                    "Error parsing rlog output. Expected RCS file %s"
                    ", found %s" % (file and file.path, filename)
                )

            # if we get an rlog error message, restart loop without advancing
            # chunk_idx cause there might be more output about the same file
            if eof == _EOF_ERROR:
                file.errors.append("rlog error: %s" % msg)
                continue

            tag = None
            if view_tag == "MAIN" or view_tag == "HEAD":
                tag = Tag(None, default_branch)
            elif view_tag in taginfo:
                tag = Tag(None, taginfo[view_tag])
            elif view_tag and (eof != _EOF_FILE):
                # the tag wasn't found, so skip this file (unless we already
                # know there's nothing left of it to read)
                _skip_file(rlog)
                eof = _EOF_FILE

            # we don't care about the specific values -- just the keys and whether
            # the values point to branches or revisions. this the fastest way to
            # merge the set of keys and keep values that allow us to make the
            # distinction between branch tags and normal tags
            alltags.update(taginfo)

            # read all of the log entries until we find the revision we want
            wanted_entry = None
            while not eof:

                # fetch one of the log entries
                entry, eof = _parse_log_entry(rlog)

                if not entry:
                    # parsing error
                    break

                # A perfect match is a revision on the branch being viewed or
                # a revision having the tag being viewed or any revision
                # when nothing is being viewed. When there's a perfect match
                # we set the wanted_entry value and break out of the loop.
                # An imperfect match is a revision at the branch point of a
                # branch being viewed. When there's an imperfect match we
                # also set the wanted_entry value but keep looping in case
                # something better comes along.
                perfect = (
                    not tag
                    or entry.number == tag.number
                    or (len(entry.number) == 2 and not tag.number)
                    or entry.number[:-1] == tag.number
                )
                if perfect or entry.number == tag.number[:-1]:
                    wanted_entry = entry
                    if perfect:
                        break

            if wanted_entry:
                file.rev = wanted_entry.string
                file.date = wanted_entry.date
                file.author = wanted_entry.author
                file.dead = file.kind == vclib.FILE and wanted_entry.dead
                file.absent = 0
                file.log = wanted_entry.log
                file.lockinfo = lockinfo.get(file.rev)
                # suppress rlog errors if we find a usable revision in the end
                del file.errors[:]
            elif file.kind == vclib.FILE:
                file.dead = 0
                file.absent = 1

            # done with this file now, skip the rest of this file's revisions
            if not eof:
                _skip_file(rlog)

            # end of while loop, advance index
            chunk_idx = chunk_idx + 1

        rlog.close()


def _log_path(entry, dirpath, getdirs, encoding):
    path = name = None
    if not entry.errors:
        if entry.kind == vclib.FILE:
            path = entry.in_attic and "Attic" or ""
            name = entry.name
        elif entry.kind == vclib.DIR and getdirs:
            entry.newest_file = _newest_file(os.path.join(dirpath, entry.name),
                                             encoding)
            if entry.newest_file:
                path = entry.name
                name = entry.newest_file

    if name:
        return os.path.join(dirpath, path, name + ",v")
    return None


# ======================================================================
# Functions for dealing with the filesystem

if sys.platform == "win32":
    def _check_path(path, encoding):
        kind = None
        errors = []

        if os.path.isfile(path):
            kind = vclib.FILE
        elif os.path.isdir(path):
            kind = vclib.DIR
        else:
            errors.append("error: path is not a file or directory")

        if not os.access(path, os.R_OK):
            errors.append("error: path is not accessible")

        return kind, errors


else:
    _uid = os.getuid()
    _gid = os.getgid()

    def _check_path(pathname, encoding):
        try:
            info = os.stat(vclib._getfspath(pathname, encoding))
        except os.error as e:
            return None, ["stat error: %s" % e]

        kind = None
        errors = []

        mode = info[stat.ST_MODE]
        isdir = stat.S_ISDIR(mode)
        isreg = stat.S_ISREG(mode)
        if isreg or isdir:
            #
            # Quick version of access() where we use existing stat() data.
            #
            # This might not be perfect -- the OS may return slightly different
            # results for some bizarre reason. However, we make a good show of
            # "can I read this file/dir?" by checking the various perm bits.
            #
            # NOTE: if the UID matches, then we must match the user bits -- we
            # cannot defer to group or other bits. Similarly, if the GID
            # matches, then we must have read access in the group bits.
            #
            # If the UID or GID don't match, we need to check the
            # results of an os.access() call, in case the web server process
            # is in the group that owns the directory.
            #
            if isdir:
                mask = stat.S_IROTH | stat.S_IXOTH
            else:
                mask = stat.S_IROTH

            if info[stat.ST_UID] == _uid:
                if ((mode >> 6) & mask) != mask:
                    errors.append("error: path is not accessible to user %i" % _uid)
            elif info[stat.ST_GID] == _gid:
                if ((mode >> 3) & mask) != mask:
                    errors.append("error: path is not accessible to group %i" % _gid)
            # If the process running the web server is a member of
            # the group stat.ST_GID access may be granted.
            # so the fall back to os.access is needed to figure this out.
            elif (mode & mask) != mask:
                if not os.access(vclib._getfspath(pathname, encoding),
                                 isdir and (os.R_OK | os.X_OK) or os.R_OK):
                    errors.append("error: path is not accessible")

            if isdir:
                kind = vclib.DIR
            else:
                kind = vclib.FILE

        else:
            errors.append("error: path is not a file or directory")

        return kind, errors


def _newest_file(dirpath, encoding):
    """Find the last modified RCS file in a directory"""
    newest_file = None
    newest_time = 0

    # FIXME:  This sucker is leaking unauthorized paths!

    for subfile in vclib.os_listdir(dirpath, encoding):
        # TODO: filter CVS locks? stale NFS handles?
        if subfile[-2:] != ",v":
            continue
        path = os.path.join(dirpath, subfile)
        info = os.stat(vclib._getfspath(path, encoding))
        if not stat.S_ISREG(info[stat.ST_MODE]):
            continue
        if info[stat.ST_MTIME] > newest_time:
            kind, verboten = _check_path(path, encoding)
            if kind == vclib.FILE and not verboten:
                newest_file = subfile[:-2]
                newest_time = info[stat.ST_MTIME]

    return newest_file
