""" Mercurial phases support code

    ---

    Copyright 2011 Pierre-Yves David <pierre-yves.david@ens-lyon.org>

                   Logilab SA        <contact@logilab.fr>

                   Augie Fackler     <durin42@gmail.com>

    This software may be used and distributed according to the terms

    of the GNU General Public License version 2 or any later version.

    ---

This module implements most phase logic in mercurial.

Basic Concept

=============

A 'changeset phase' is an indicator that tells us how a changeset is

manipulated and communicated. The details of each phase is described

below, here we describe the properties they have in common.

Like bookmarks, phases are not stored in history and thus are not

permanent and leave no audit trail.

First, no changeset can be in two phases at once. Phases are ordered,

so they can be considered from lowest to highest. The default, lowest

phase is 'public' - this is the normal phase of existing changesets. A

child changeset can not be in a lower phase than its parents.

These phases share a hierarchy of traits:

            immutable shared

    public:     X        X

    draft:               X

    secret:

Local commits are draft by default.

Phase Movement and Exchange

===========================

Phase data is exchanged by pushkey on pull and push. Some servers have

a publish option set, we call such a server a "publishing server".

Pushing a draft changeset to a publishing server changes the phase to

public.

A small list of fact/rules define the exchange of phase:

* old client never changes server states

* pull never changes server states

* publish and old server changesets are seen as public by client

* any secret changeset seen in another repository is lowered to at

  least draft

Here is the final table summing up the 49 possible use cases of phase

exchange:

                           server

                  old     publish      non-publish

                 N   X    N   D   P    N   D   P

    old client

    pull

     N           -   X/X  -   X/D X/P  -   X/D X/P

     X           -   X/X  -   X/D X/P  -   X/D X/P

    push

     X           X/X X/X  X/P X/P X/P  X/D X/D X/P

    new client

    pull

     N           -   P/X  -   P/D P/P  -   D/D P/P

     D           -   P/X  -   P/D P/P  -   D/D P/P

     P           -   P/X  -   P/D P/P  -   P/D P/P

    push

     D           P/X P/X  P/P P/P P/P  D/D D/D P/P

     P           P/X P/X  P/P P/P P/P  P/P P/P P/P

Legend:

    A/B = final state on client / state on server

    * N = new/not present,

    * P = public,

    * D = draft,

    * X = not tracked (i.e., the old client or server has no internal

          way of recording the phase.)

    passive = only pushes

    A cell here can be read like this:

    "When a new client pushes a draft changeset (D) to a publishing

    server where it's not present (N), it's marked public on both

    sides (P/P)."

Note: old client behave as a publishing server with draft only content

- other people see it as public

- content is pushed as draft

"""

from __future__ import absolute_import

import errno

import struct

from .i18n import _

from .node import (

    bin,

    hex,

    nullid,

    nullrev,

    short,

    wdirrev,

)

from .pycompat import (

    getattr,

    setattr,

)

from . import (

    error,

    pycompat,

    smartset,

    txnutil,

    util,

)

_fphasesentry = struct.Struct(b'>i20s')

INTERNAL_FLAG = 64  # Phases for mercurial internal usage only

HIDEABLE_FLAG = 32  # Phases that are hideable

# record phase index

public, draft, secret = range(3)

internal = INTERNAL_FLAG | HIDEABLE_FLAG

archived = HIDEABLE_FLAG

allphases = list(range(internal + 1))

trackedphases = allphases[1:]

# record phase names

cmdphasenames = [b'public', b'draft', b'secret']  # known to `hg phase` command

phasenames = [None] * len(allphases)

phasenames[: len(cmdphasenames)] = cmdphasenames

phasenames[archived] = b'archived'

phasenames[internal] = b'internal'

# record phase property

mutablephases = tuple(allphases[1:])

remotehiddenphases = tuple(allphases[2:])

localhiddenphases = tuple(p for p in allphases if p & HIDEABLE_FLAG)

def supportinternal(repo):

    """True if the internal phase can be used on a repository"""

    return b'internal-phase' in repo.requirements

def _readroots(repo, phasedefaults=None):

    """Read phase roots from disk

    phasedefaults is a list of fn(repo, roots) callable, which are

    executed if the phase roots file does not exist. When phases are

    being initialized on an existing repository, this could be used to

    set selected changesets phase to something else than public.

    Return (roots, dirty) where dirty is true if roots differ from

    what is being stored.

    """

    repo = repo.unfiltered()

    dirty = False

    roots = [set() for i in allphases]

    try:

        f, pending = txnutil.trypending(repo.root, repo.svfs, b'phaseroots')

        try:

            for line in f:

                phase, nh = line.split()

                roots[int(phase)].add(bin(nh))

        finally:

            f.close()

    except IOError as inst:

        if inst.errno != errno.ENOENT:

            raise

        if phasedefaults:

            for f in phasedefaults:

                roots = f(repo, roots)

        dirty = True

    return roots, dirty

def binaryencode(phasemapping):

    """encode a 'phase -> nodes' mapping into a binary stream

    Since phases are integer the mapping is actually a python list:

    [[PUBLIC_HEADS], [DRAFTS_HEADS], [SECRET_HEADS]]

    """

    binarydata = []

    for phase, nodes in enumerate(phasemapping):

        for head in nodes:

            binarydata.append(_fphasesentry.pack(phase, head))

    return b''.join(binarydata)

def binarydecode(stream):

    """decode a binary stream into a 'phase -> nodes' mapping

    Since phases are integer the mapping is actually a python list."""

    headsbyphase = [[] for i in allphases]

    entrysize = _fphasesentry.size

    while True:

        entry = stream.read(entrysize)

        if len(entry) < entrysize:

            if entry:

                raise error.Abort(_(b'bad phase-heads stream'))

            break

        phase, node = _fphasesentry.unpack(entry)

        headsbyphase[phase].append(node)

    return headsbyphase

def _sortedrange_insert(data, idx, rev, t):

    merge_before = False

    if idx:

        r1, t1 = data[idx - 1]

        merge_before = r1[-1] + 1 == rev and t1 == t

    merge_after = False

    if idx < len(data):

        r2, t2 = data[idx]

        merge_after = r2[0] == rev + 1 and t2 == t

    if merge_before and merge_after:

        data[idx - 1] = (pycompat.xrange(r1[0], r2[-1] + 1), t)

        data.pop(idx)

    elif merge_before:

        data[idx - 1] = (pycompat.xrange(r1[0], rev + 1), t)

    elif merge_after:

        data[idx] = (pycompat.xrange(rev, r2[-1] + 1), t)

    else:

        data.insert(idx, (pycompat.xrange(rev, rev + 1), t))

def _sortedrange_split(data, idx, rev, t):

    r1, t1 = data[idx]

    if t == t1:

        return

    t = (t1[0], t[1])

    if len(r1) == 1:

        data.pop(idx)

        _sortedrange_insert(data, idx, rev, t)

    elif r1[0] == rev:

        data[idx] = (pycompat.xrange(rev + 1, r1[-1] + 1), t1)

        _sortedrange_insert(data, idx, rev, t)

    elif r1[-1] == rev:

        data[idx] = (pycompat.xrange(r1[0], rev), t1)

        _sortedrange_insert(data, idx + 1, rev, t)

    else:

        data[idx : idx + 1] = [

            (pycompat.xrange(r1[0], rev), t1),

            (pycompat.xrange(rev, rev + 1), t),

            (pycompat.xrange(rev + 1, r1[-1] + 1), t1),

        ]

def _trackphasechange(data, rev, old, new):

    """add a phase move to the <data> list of ranges

    If data is None, nothing happens.

    """

    if data is None:

        return

    # If data is empty, create a one-revision range and done

    if not data:

        data.insert(0, (pycompat.xrange(rev, rev + 1), (old, new)))

        return

    low = 0

    high = len(data)

    t = (old, new)

    while low < high:

        mid = (low + high) // 2

        revs = data[mid][0]

        if rev in revs:

            _sortedrange_split(data, mid, rev, t)

            return

        if revs[0] == rev + 1:

            if mid and data[mid - 1][0][-1] == rev:

                _sortedrange_split(data, mid - 1, rev, t)

            else:

                _sortedrange_insert(data, mid, rev, t)

            return

        if revs[-1] == rev - 1:

            if mid + 1 < len(data) and data[mid + 1][0][0] == rev:

                _sortedrange_split(data, mid + 1, rev, t)

            else:

                _sortedrange_insert(data, mid + 1, rev, t)

            return

        if revs[0] > rev:

            high = mid

        else:

            low = mid + 1

    if low == len(data):

        data.append((pycompat.xrange(rev, rev + 1), t))

        return

    r1, t1 = data[low]

    if r1[0] > rev:

        data.insert(low, (pycompat.xrange(rev, rev + 1), t))

    else:

        data.insert(low + 1, (pycompat.xrange(rev, rev + 1), t))

class phasecache(object):

    def __init__(self, repo, phasedefaults, _load=True):

        if _load:

            # Cheap trick to allow shallow-copy without copy module

            self.phaseroots, self.dirty = _readroots(repo, phasedefaults)

            self._loadedrevslen = 0

            self._phasesets = None

            self.filterunknown(repo)

            self.opener = repo.svfs

    def hasnonpublicphases(self, repo):

        """detect if there are revisions with non-public phase"""

        repo = repo.unfiltered()

        cl = repo.changelog

        if len(cl) >= self._loadedrevslen:

            self.invalidate()

            self.loadphaserevs(repo)

        return any(self.phaseroots[1:])

    def nonpublicphaseroots(self, repo):

        """returns the roots of all non-public phases

        The roots are not minimized, so if the secret revisions are

        descendants of draft revisions, their roots will still be present.

        """

        repo = repo.unfiltered()

        cl = repo.changelog

        if len(cl) >= self._loadedrevslen:

            self.invalidate()

            self.loadphaserevs(repo)

        return set().union(*[roots for roots in self.phaseroots[1:] if roots])

    def getrevset(self, repo, phases, subset=None):

        """return a smartset for the given phases"""

        self.loadphaserevs(repo)  # ensure phase's sets are loaded

        phases = set(phases)

        publicphase = public in phases

        if publicphase:

            # In this case, phases keeps all the *other* phases.

            phases = set(allphases).difference(phases)

            if not phases:

                return smartset.fullreposet(repo)

        # fast path: _phasesets contains the interesting sets,

        # might only need a union and post-filtering.

        revsneedscopy = False

        if len(phases) == 1:

            [p] = phases

            revs = self._phasesets[p]

            revsneedscopy = True  # Don't modify _phasesets

        else:

            # revs has the revisions in all *other* phases.

            revs = set.union(*[self._phasesets[p] for p in phases])

        def _addwdir(wdirsubset, wdirrevs):

            if wdirrev in wdirsubset and repo[None].phase() in phases:

                if revsneedscopy:

                    wdirrevs = wdirrevs.copy()

                # The working dir would never be in the # cache, but it was in

                # the subset being filtered for its phase (or filtered out,

                # depending on publicphase), so add it to the output to be

                # included (or filtered out).

                wdirrevs.add(wdirrev)

            return wdirrevs

        if not publicphase:

            if repo.changelog.filteredrevs:

                revs = revs - repo.changelog.filteredrevs

            if subset is None:

                return smartset.baseset(revs)

            else:

                revs = _addwdir(subset, revs)