# 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.

import sys

from mercurial.cmdutil import revrange, show_changeset

from mercurial.i18n import _

from mercurial.node import nullid, nullrev

from mercurial.util import Abort

def revision_grapher(repo, start_rev, stop_rev):

    """incremental revision grapher

    This generator function walks through the revision history from

    revision start_rev to revision stop_rev (which must be less than

    or equal to start_rev) and for each revision emits tuples with the

    following elements:

      - Current revision.

      - Current node.

      - 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.

    """

    assert start_rev >= stop_rev

    curr_rev = start_rev

    revs = []

    while curr_rev >= stop_rev:

        node = repo.changelog.node(curr_rev)

        # Compute revs and next_revs.

        if curr_rev not in revs:

            # New head.

            revs.append(curr_rev)

        rev_index = revs.index(curr_rev)

        next_revs = revs[:]

        # Add parents to next_revs.

        parents = get_rev_parents(repo, curr_rev)

        parents_to_add = []

        for parent in parents:

            if parent not in next_revs:

                parents_to_add.append(parent)

        parents_to_add.sort()

        next_revs[rev_index:rev_index + 1] = parents_to_add

        edges = []

        for parent in parents:

            edges.append((rev_index, next_revs.index(parent)))

        n_columns_diff = len(next_revs) - len(revs)

        yield (curr_rev, node, rev_index, edges, len(revs), n_columns_diff)

        revs = next_revs

        curr_rev -= 1

def get_rev_parents(repo, rev):

    return [x for x in repo.changelog.parentrevs(rev) if x != nullrev]

def fix_long_right_edges(edges):

    for (i, (start, end)) in enumerate(edges):

        if end > start:

            edges[i] = (start, end + 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 format_line(line, level, logstr):

    text = "%-*s %s" % (2 * level, "".join(line), logstr)

    return "%s\n" % text.rstrip()

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 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 get_limit(limit_opt):

    if limit_opt:

        try:

            limit = int(limit_opt)

        except ValueError:

            raise Abort(_("limit must be a positive integer"))

        if limit <= 0:

            raise Abort(_("limit must be positive"))

    else:

        limit = sys.maxint

    return limit

def get_revs(repo, rev_opt):

    if rev_opt:

        revs = revrange(repo, rev_opt)

        return (max(revs), min(revs))

    else:

        return (repo.changelog.count() - 1, 0)

def graphlog(ui, repo, **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.

    """

    limit = get_limit(opts["limit"])

    (start_rev, stop_rev) = get_revs(repo, opts["rev"])

    stop_rev = max(stop_rev, start_rev - limit + 1)

    if start_rev == nullrev:

        return

    cs_printer = show_changeset(ui, repo, opts)

    grapher = revision_grapher(repo, start_rev, stop_rev)

    repo_parents = repo.dirstate.parents()

    prev_n_columns_diff = 0

    prev_node_index = 0

    for (rev, node, node_index, edges, n_columns, n_columns_diff) in grapher:

        # log_strings is the list of all log strings to draw alongside

        # the graph.

        ui.pushbuffer()

        cs_printer.show(rev, node)

        log_strings = ui.popbuffer().split("\n")[:-1]

        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(log_strings) > 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(log_strings) <= 2 and not add_padding_line

        # nodeline is the line containing the node character (@ or o).

        nodeline = ["|", " "] * node_index

        if node in repo_parents:

            node_ch = "@"

        else:

            node_ch = "o"

        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(log_strings) < len(lines):

            log_strings.append("")

        if len(lines) < len(log_strings):

            extra_interline = ["|", " "] * (n_columns + n_columns_diff)

            while len(lines) < len(log_strings):

                lines.append(extra_interline)

        # Print lines.

        indentation_level = max(n_columns, n_columns + n_columns_diff)

        for (line, logstr) in zip(lines, log_strings):

            ui.write(format_line(line, indentation_level, logstr))

        # ...and start over.

        prev_node_index = node_index

        prev_n_columns_diff = n_columns_diff

cmdtable = {

    "glog":

        (graphlog,

         [('l', 'limit', '', _('limit number of changes displayed')),

          ('p', 'patch', False, _('show patch')),

          ('r', 'rev', [], _('show the specified revision or range')),

          ('', 'style', '', _('display using template map file')),

          ('', 'template', '', _('display with template'))],

         _('hg glog [OPTION]...')),

}