# stack.py - code related to stack workflow

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

from mercurial.i18n import _

from mercurial import (

    destutil,

    error,

    node,

)

from .evolvebits import builddependencies, _orderrevs, _singlesuccessor

def getstack(repo, topic):

    # XXX need sorting

    trevs = repo.revs("topic(%s) - obsolete()", topic)

    return _orderrevs(repo, trevs)

def labelsgen(prefix, labelssuffix):

    """ Takes a label prefix and a list of suffixes. Returns a string of the prefix

    formatted with each suffix separated with a space.

    """

    return ' '.join(prefix % suffix for suffix in labelssuffix)

def showstack(ui, repo, topic, opts):

    fm = ui.formatter('topicstack', opts)

    prev = None

    entries = []

    idxmap = {}

    label = 'topic'

    if topic == repo.currenttopic:

        label = 'topic.active'

    data = stackdata(repo, topic)

    fm.plain(_('### topic: %s') % ui.label(topic, label),

             label='topic.stack.summary.topic')

    if 1 < data['headcount']:

        fm.plain(' (')

        fm.plain('%d heads' % data['headcount'],

                 label='topic.stack.summary.headcount.multiple')

        fm.plain(')')

    fm.plain('\n')

    fm.plain(_('### branch: %s')

             % '+'.join(data['branches']), # XXX handle multi branches

             label='topic.stack.summary.branches')

    if data['behindcount'] == -1:

        fm.plain(', ')

        fm.plain('ambigious rebase destination', label='topic.stack.summary.behinderror')

    elif data['behindcount']:

        fm.plain(', ')

        fm.plain('%d behind' % data['behindcount'], label='topic.stack.summary.behindcount')

    fm.plain('\n')

    for idx, r in enumerate(getstack(repo, topic), 1):

        ctx = repo[r]

        p1 = ctx.p1()

        if p1.obsolete():

            p1 = repo[_singlesuccessor(repo, p1)]

        if p1.rev() != prev and p1.node() != node.nullid:

            entries.append((idxmap.get(p1.rev()), False, p1))

        entries.append((idx, True, ctx))

        idxmap[ctx.rev()] = idx

        prev = r

    # super crude initial version

    for idx, isentry, ctx in entries[::-1]:

        states = []

        iscurrentrevision = repo.revs('%d and parents()', ctx.rev())

        if iscurrentrevision:

            states.append('current')

        if not isentry:

            symbol = '^'

            # "base" is kind of a "ghost" entry

            # skip other label for them (no current, no unstable)

            states = ['base']

        elif iscurrentrevision:

            symbol = '@'

        elif repo.revs('%d and unstable()', ctx.rev()):

            symbol = '$'

            states.append('unstable')

        else:

            symbol = ':'

            states.append('clean')

        fm.startitem()

        fm.data(isentry=isentry)

        if idx is None:

            fm.plain('  ')

        else:

            fm.write('topic.stack.index', 't%d', idx,

                     label='topic.stack.index ' + labelsgen('topic.stack.index.%s', states))

        fm.write('topic.stack.state.symbol', '%s', symbol,

                 label='topic.stack.state ' + labelsgen('topic.stack.state.%s', states))

        fm.plain(' ')

        fm.write('topic.stack.desc', '%s', ctx.description().splitlines()[0],

                 label='topic.stack.desc ' + labelsgen('topic.stack.desc.%s', states))

        fm.condwrite(states != ['clean'] and idx is not None, 'topic.stack.state',

                     ' (%s)', fm.formatlist(states, 'topic.stack.state'),

                     label='topic.stack.state ' + labelsgen('topic.stack.state.%s', states))

        fm.plain('\n')

    fm.end()

def stackdata(repo, topic):

    """get various data about a stack

    :changesetcount: number of non-obsolete changesets in the stack

    :troubledcount: number on troubled changesets

    :headcount: number of heads on the topic

    :behindcount: number of changeset on rebase destination

    """

    data = {}

    revs = repo.revs("topic(%s) - obsolete()", topic)

    data['changesetcount'] = len(revs)

    data['troubledcount'] = len([r for r in revs if repo[r].troubled()])

    deps, rdeps = builddependencies(repo, revs)

    data['headcount'] = len([r for r in revs if not rdeps[r]])

    data['behindcount'] = 0

    if revs:

        minroot = [min(r for r in revs if not deps[r])]

        try:

            dest = destutil.destmerge(repo, action='rebase',

                                      sourceset=minroot,

                                      onheadcheck=False)

            data['behindcount'] = len(repo.revs("only(%d, %ld)", dest,

                                                minroot))

        except error.NoMergeDestAbort:

            data['behindcount'] = 0

        except error.ManyMergeDestAbort:

            data['behindcount'] = -1

    data['branches'] = sorted(set(repo[r].branch() for r in revs))

    return data