# ASCII graph log extension for Mercurial
#
# Copyright 2007 Joel Rosdahl <joel@rosdahl.net>
#
# This software may be used and distributed according to the terms of
# the GNU General Public License, incorporated herein by reference.
'''show revision graphs in terminal windows

This extension adds a --graph option to the incoming, outgoing and log
commands. When this options is given, an ascii representation of the
revision graph is also shown.
'''

import os
from mercurial.cmdutil import revrange, show_changeset
from mercurial.commands import templateopts
from mercurial.i18n import _
from mercurial.node import nullrev
from mercurial import bundlerepo, changegroup, cmdutil, commands, extensions
from mercurial import hg, url, util

def revisions(repo, start, stop):
    """cset DAG generator yielding (rev, node, [parents]) tuples

    This generator function walks through the revision history from revision
    start to revision stop (which must be less than or equal to start).
    """
    assert start >= stop
    cur = start
    while cur >= stop:
        ctx = repo[cur]
        parents = [p.rev() for p in ctx.parents() if p.rev() != nullrev]
        parents.sort()
        yield (ctx, parents)
        cur -= 1

def filerevs(repo, path, start, stop):
    """file cset DAG generator yielding (rev, node, [parents]) tuples

    This generator function walks through the revision history of a single
    file from revision start to revision stop (which must be less than or
    equal to start).
    """
    assert start >= stop
    filerev = len(repo.file(path)) - 1
    while filerev >= 0:
        fctx = repo.filectx(path, fileid=filerev)
        parents = [f.linkrev() for f in fctx.parents() if f.path() == path]
        parents.sort()
        if fctx.rev() <= start:
            yield (fctx, parents)
        if fctx.rev() <= stop:
            break
        filerev -= 1

def grapher(nodes):
    """grapher for asciigraph on a list of nodes and their parents

    nodes must generate tuples (node, parents, char, lines) where
     - parents must generate the parents of node, in sorted order,
       and max length 2,
     - char is the char to print as the node symbol, and
     - lines are the lines to display next to the node.
    """
    seen = []
    for node, parents, char, lines in nodes:
        if node not in seen:
            seen.append(node)
        nodeidx = seen.index(node)

        knownparents = []
        newparents = []
        for parent in parents:
            if parent in seen:
                knownparents.append(parent)
            else:
                newparents.append(parent)

        ncols = len(seen)
        nextseen = seen[:]
        nextseen[nodeidx:nodeidx + 1] = newparents
        edges = [(nodeidx, nextseen.index(p)) for p in knownparents]

        if len(newparents) > 0:
            edges.append((nodeidx, nodeidx))
        if len(newparents) > 1:
            edges.append((nodeidx, nodeidx + 1))
        nmorecols = len(nextseen) - ncols
        seen = nextseen
        yield (char, lines, nodeidx, edges, ncols, nmorecols)

def fix_long_right_edges(edges):
    for (i, (start, end)) in enumerate(edges):
        if end > start:
            edges[i] = (start, end + 1)

def get_nodeline_edges_tail(
        node_index, p_node_index, n_columns, n_columns_diff, p_diff, fix_tail):
    if fix_tail and n_columns_diff == p_diff and n_columns_diff != 0:
        # Still going in the same non-vertical direction.
        if n_columns_diff == -1:
            start = max(node_index + 1, p_node_index)
            tail = ["|", " "] * (start - node_index - 1)
            tail.extend(["/", " "] * (n_columns - start))
            return tail
        else:
            return ["\\", " "] * (n_columns - node_index - 1)
    else:
        return ["|", " "] * (n_columns - node_index - 1)

def draw_edges(edges, nodeline, interline):
    for (start, end) in edges:
        if start == end + 1:
            interline[2 * end + 1] = "/"
        elif start == end - 1:
            interline[2 * start + 1] = "\\"
        elif start == end:
            interline[2 * start] = "|"
        else:
            nodeline[2 * end] = "+"
            if start > end:
                (start, end) = (end,start)
            for i in range(2 * start + 1, 2 * end):
                if nodeline[i] != "+":
                    nodeline[i] = "-"

def get_padding_line(ni, n_columns, edges):
    line = []
    line.extend(["|", " "] * ni)
    if (ni, ni - 1) in edges or (ni, ni) in edges:
        # (ni, ni - 1)      (ni, ni)
        # | | | |           | | | |
        # +---o |           | o---+
        # | | c |           | c | |
        # | |/ /            | |/ /
        # | | |             | | |
        c = "|"
    else:
        c = " "
    line.extend([c, " "])
    line.extend(["|", " "] * (n_columns - ni - 1))
    return line

def ascii(ui, grapher):
    """prints an ASCII graph of the DAG returned by the grapher

    grapher is a generator that emits tuples with the following elements:

      - Character to use as node's symbol.
      - List of lines to display as the node's text.
      - Column of the current node in the set of ongoing edges.
      - Edges; a list of (col, next_col) indicating the edges between
        the current node and its parents.
      - Number of columns (ongoing edges) in the current revision.
      - The difference between the number of columns (ongoing edges)
        in the next revision and the number of columns (ongoing edges)
        in the current revision. That is: -1 means one column removed;
        0 means no columns added or removed; 1 means one column added.
    """
    prev_n_columns_diff = 0
    prev_node_index = 0
    for (node_ch, node_lines, node_index, edges, n_columns, n_columns_diff) in grapher:

        assert -2 < n_columns_diff < 2
        if n_columns_diff == -1:
            # Transform
            #
            #     | | |        | | |
            #     o | |  into  o---+
            #     |X /         |/ /
            #     | |          | |
            fix_long_right_edges(edges)

        # add_padding_line says whether to rewrite
        #
        #     | | | |        | | | |
        #     | o---+  into  | o---+
        #     |  / /         |   | |  # <--- padding line
        #     o | |          |  / /
        #                    o | |
        add_padding_line = (len(node_lines) > 2 and
                            n_columns_diff == -1 and
                            [x for (x, y) in edges if x + 1 < y])

        # fix_nodeline_tail says whether to rewrite
        #
        #     | | o | |        | | o | |
        #     | | |/ /         | | |/ /
        #     | o | |    into  | o / /   # <--- fixed nodeline tail
        #     | |/ /           | |/ /
        #     o | |            o | |
        fix_nodeline_tail = len(node_lines) <= 2 and not add_padding_line

        # nodeline is the line containing the node character (typically o)
        nodeline = ["|", " "] * node_index
        nodeline.extend([node_ch, " "])

        nodeline.extend(
            get_nodeline_edges_tail(
                node_index, prev_node_index, n_columns, n_columns_diff,
                prev_n_columns_diff, fix_nodeline_tail))

        # shift_interline is the line containing the non-vertical
        # edges between this entry and the next
        shift_interline = ["|", " "] * node_index
        if n_columns_diff == -1:
            n_spaces = 1
            edge_ch = "/"
        elif n_columns_diff == 0:
            n_spaces = 2
            edge_ch = "|"
        else:
            n_spaces = 3
            edge_ch = "\\"
        shift_interline.extend(n_spaces * [" "])
        shift_interline.extend([edge_ch, " "] * (n_columns - node_index - 1))

        # draw edges from the current node to its parents
        draw_edges(edges, nodeline, shift_interline)

        # lines is the list of all graph lines to print
        lines = [nodeline]
        if add_padding_line:
            lines.append(get_padding_line(node_index, n_columns, edges))
        lines.append(shift_interline)

        # make sure that there are as many graph lines as there are
        # log strings
        while len(node_lines) < len(lines):
            node_lines.append("")
        if len(lines) < len(node_lines):
            extra_interline = ["|", " "] * (n_columns + n_columns_diff)
            while len(lines) < len(node_lines):
                lines.append(extra_interline)

        # print lines
        indentation_level = max(n_columns, n_columns + n_columns_diff)
        for (line, logstr) in zip(lines, node_lines):
            ln = "%-*s %s" % (2 * indentation_level, "".join(line), logstr)
            ui.write(ln.rstrip() + '\n')

        # ... and start over
        prev_node_index = node_index
        prev_n_columns_diff = n_columns_diff

def get_revs(repo, rev_opt):
    if rev_opt:
        revs = revrange(repo, rev_opt)
        return (max(revs), min(revs))
    else:
        return (len(repo) - 1, 0)

def check_unsupported_flags(opts):
    for op in ["follow", "follow_first", "date", "copies", "keyword", "remove",
               "only_merges", "user", "only_branch", "prune", "newest_first",
               "no_merges", "include", "exclude"]:
        if op in opts and opts[op]:
            raise util.Abort(_("--graph option is incompatible with --%s") % op)

def graphlog(ui, repo, path=None, **opts):
    """show revision history alongside an ASCII revision graph

    Print a revision history alongside a revision graph drawn with
    ASCII characters.

    Nodes printed as an @ character are parents of the working
    directory.
    """

    check_unsupported_flags(opts)
    limit = cmdutil.loglimit(opts)
    start, stop = get_revs(repo, opts["rev"])
    stop = max(stop, start - limit + 1)
    if start == nullrev:
        return

    if path:
        path = util.canonpath(repo.root, os.getcwd(), path)
    if path: # could be reset in canonpath
        revdag = filerevs(repo, path, start, stop)
    else:
        revdag = revisions(repo, start, stop)

    graphdag = graphabledag(ui, repo, revdag, opts)
    ascii(ui, grapher(graphdag))

def graphrevs(repo, nodes, opts):
    nodes.reverse()
    include = set(nodes)
    limit = cmdutil.loglimit(opts)
    count = 0
    for node in nodes:
        if count >= limit:
            break
        ctx = repo[node]
        parents = [p.rev() for p in ctx.parents() if p.node() in include]
        parents.sort()
        yield (ctx, parents)
        count += 1

def graphabledag(ui, repo, revdag, opts):
    showparents = [ctx.node() for ctx in repo[None].parents()]
    displayer = show_changeset(ui, repo, opts, buffered=True)
    for (ctx, parents) in revdag:
        displayer.show(ctx)
        lines = displayer.hunk.pop(ctx.rev()).split('\n')[:-1]
        char = ctx.node() in showparents and '@' or 'o'
        yield (ctx.rev(), parents, char, lines)

def goutgoing(ui, repo, dest=None, **opts):
    """show the outgoing changesets alongside an ASCII revision graph

    Print the outgoing changesets alongside a revision graph drawn with
    ASCII characters.

    Nodes printed as an @ character are parents of the working
    directory.
    """

    check_unsupported_flags(opts)
    dest, revs, checkout = hg.parseurl(
        ui.expandpath(dest or 'default-push', dest or 'default'),
        opts.get('rev'))
    if revs:
        revs = [repo.lookup(rev) for rev in revs]
    other = hg.repository(cmdutil.remoteui(ui, opts), dest)
    ui.status(_('comparing with %s\n') % url.hidepassword(dest))
    o = repo.findoutgoing(other, force=opts.get('force'))
    if not o:
        ui.status(_("no changes found\n"))
        return

    o = repo.changelog.nodesbetween(o, revs)[0]
    revdag = graphrevs(repo, o, opts)
    graphdag = graphabledag(ui, repo, revdag, opts)
    ascii(ui, grapher(graphdag))

def gincoming(ui, repo, source="default", **opts):
    """show the incoming changesets alongside an ASCII revision graph

    Print the incoming changesets alongside a revision graph drawn with
    ASCII characters.

    Nodes printed as an @ character are parents of the working
    directory.
    """

    check_unsupported_flags(opts)
    source, revs, checkout = hg.parseurl(ui.expandpath(source), opts.get('rev'))
    other = hg.repository(cmdutil.remoteui(repo, opts), source)
    ui.status(_('comparing with %s\n') % url.hidepassword(source))
    if revs:
        revs = [other.lookup(rev) for rev in revs]
    incoming = repo.findincoming(other, heads=revs, force=opts["force"])
    if not incoming:
        try:
            os.unlink(opts["bundle"])
        except:
            pass
        ui.status(_("no changes found\n"))
        return

    cleanup = None
    try:

        fname = opts["bundle"]
        if fname or not other.local():
            # create a bundle (uncompressed if other repo is not local)
            if revs is None:
                cg = other.changegroup(incoming, "incoming")
            else:
                cg = other.changegroupsubset(incoming, revs, 'incoming')
            bundletype = other.local() and "HG10BZ" or "HG10UN"
            fname = cleanup = changegroup.writebundle(cg, fname, bundletype)
            # keep written bundle?
            if opts["bundle"]:
                cleanup = None
            if not other.local():
                # use the created uncompressed bundlerepo
                other = bundlerepo.bundlerepository(ui, repo.root, fname)

        chlist = other.changelog.nodesbetween(incoming, revs)[0]
        revdag = graphrevs(other, chlist, opts)
        graphdag = graphabledag(ui, repo, revdag, opts)
        ascii(ui, grapher(graphdag))

    finally:
        if hasattr(other, 'close'):
            other.close()
        if cleanup:
            os.unlink(cleanup)

def uisetup(ui):
    '''Initialize the extension.'''
    _wrapcmd(ui, 'log', commands.table, graphlog)
    _wrapcmd(ui, 'incoming', commands.table, gincoming)
    _wrapcmd(ui, 'outgoing', commands.table, goutgoing)

def _wrapcmd(ui, cmd, table, wrapfn):
    '''wrap the command'''
    def graph(orig, *args, **kwargs):
        if kwargs['graph']:
            return wrapfn(*args, **kwargs)
        return orig(*args, **kwargs)
    entry = extensions.wrapcommand(table, cmd, graph)
    entry[1].append(('G', 'graph', None, _("show the revision DAG")))

cmdtable = {
    "glog":
        (graphlog,
         [('l', 'limit', '', _('limit number of changes displayed')),
          ('p', 'patch', False, _('show patch')),
          ('r', 'rev', [], _('show the specified revision or range')),
         ] + templateopts,
         _('hg glog [OPTION]... [FILE]')),
}