# 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'''

import os

import sys

from mercurial.cmdutil import revrange, show_changeset

from mercurial.commands import templateopts

from mercurial.i18n import _

from mercurial.node import nullrev

from mercurial.util import Abort, canonpath

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 = sorted(p.rev() for p in ctx.parents() if p.rev() != nullrev)

        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.filerev() 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

    """

    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_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 (len(repo) - 1, 0)

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.

    """

    limit = get_limit(opts["limit"])

    start, stop = get_revs(repo, opts["rev"])

    stop = max(stop, start - limit + 1)

    if start == nullrev:

        return

    if path:

        path = 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)

    repo_parents = repo.dirstate.parents()

    displayer = show_changeset(ui, repo, opts, buffered=True)

    def graphabledag():

        for (ctx, parents) in revdag:

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

            # the graph.

            displayer.show(ctx)

            lines = displayer.hunk.pop(ctx.rev()).split("\n")[:-1]

            char = ctx.node() in repo_parents and '@' or 'o'

            yield (ctx.rev(), parents, char, lines)

    ascii(ui, grapher(graphabledag()))

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]')),

}