# Revision graph generator for Mercurial

#

# Copyright 2008 Dirkjan Ochtman <dirkjan@ochtman.nl>

# Copyright 2007 Joel Rosdahl <joel@rosdahl.net>

#

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

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

"""supports walking the history as DAGs suitable for graphical output

The most basic format we use is that of::

  (id, type, data, [parentids])

The node and parent ids are arbitrary integers which identify a node in the

context of the graph returned. Type is a constant specifying the node type.

Data depends on type.

"""

from mercurial.node import nullrev

import util

CHANGESET = 'C'

def dagwalker(repo, revs):

    """cset DAG generator yielding (id, CHANGESET, ctx, [parentids]) tuples

    This generator function walks through revisions (which should be ordered

    from bigger to lower). It returns a tuple for each node. The node and parent

    ids are arbitrary integers which identify a node in the context of the graph

    returned.

    """

    if not revs:

        return

    cl = repo.changelog

    lowestrev = min(revs)

    gpcache = {}

    knownrevs = set(revs)

    for rev in revs:

        ctx = repo[rev]

        parents = sorted(set([p.rev() for p in ctx.parents()

                              if p.rev() in knownrevs]))

        mpars = [p.rev() for p in ctx.parents() if

                 p.rev() != nullrev and p.rev() not in parents]

        for mpar in mpars:

            gp = gpcache.get(mpar)

            if gp is None:

                gp = gpcache[mpar] = grandparent(cl, lowestrev, revs, mpar)

            if not gp:

                parents.append(mpar)

            else:

                parents.extend(g for g in gp if g not in parents)

        yield (ctx.rev(), CHANGESET, ctx, parents)

def nodes(repo, nodes):

    """cset DAG generator yielding (id, CHANGESET, ctx, [parentids]) tuples

    This generator function walks the given nodes. It only returns parents

    that are in nodes, too.

    """

    include = set(nodes)

    for node in nodes:

        ctx = repo[node]

        parents = set([p.rev() for p in ctx.parents() if p.node() in include])

        yield (ctx.rev(), CHANGESET, ctx, sorted(parents))

def colored(dag, repo):

    """annotates a DAG with colored edge information

    For each DAG node this function emits tuples::

      (id, type, data, (col, color), [(col, nextcol, color)])

    with the following new elements:

      - Tuple (col, color) with column and color index for the current node

      - A list of tuples indicating the edges between the current node and its

        parents.

    """

    seen = []

    colors = {}

    newcolor = 1

    config = {}

    for key, val in repo.ui.configitems('graph'):

        if '.' in key:

            branch, setting = key.rsplit('.', 1)

            # Validation

            if setting == "width" and val.isdigit():

                config.setdefault(branch, {})[setting] = int(val)

            elif setting == "color" and val.isalnum():

                config.setdefault(branch, {})[setting] = val

    if config:

        getconf = util.lrucachefunc(

            lambda rev: config.get(repo[rev].branch(), {}))

    else:

        getconf = lambda rev: {}

    for (cur, type, data, parents) in dag:

        # Compute seen and next

        if cur not in seen:

            seen.append(cur) # new head

            colors[cur] = newcolor

            newcolor += 1

        col = seen.index(cur)

        color = colors.pop(cur)

        next = seen[:]

        # Add parents to next

        addparents = [p for p in parents if p not in next]

        next[col:col + 1] = addparents

        # Set colors for the parents

        for i, p in enumerate(addparents):

            if not i:

                colors[p] = color

            else:

                colors[p] = newcolor

                newcolor += 1

        # Add edges to the graph

        edges = []

        for ecol, eid in enumerate(seen):

            if eid in next:

                bconf = getconf(eid)

                edges.append((

                    ecol, next.index(eid), colors[eid],

                    bconf.get('width', -1),

                    bconf.get('color', '')))

            elif eid == cur:

                for p in parents:

                    bconf = getconf(p)

                    edges.append((

                        ecol, next.index(p), color,

                        bconf.get('width', -1),

                        bconf.get('color', '')))

        # Yield and move on

        yield (cur, type, data, (col, color), edges)

        seen = next

def grandparent(cl, lowestrev, roots, head):

    """Return all ancestors of head in roots which revision is

    greater or equal to lowestrev.

    """

    pending = set([head])

    seen = set()

    kept = set()

    llowestrev = max(nullrev, lowestrev)

    while pending:

        r = pending.pop()

        if r >= llowestrev and r not in seen:

            if r in roots:

                kept.add(r)

            else:

                pending.update([p for p in cl.parentrevs(r)])

            seen.add(r)

    return sorted(kept)

def asciiedges(type, char, lines, seen, rev, parents):

    """adds edge info to changelog DAG walk suitable for ascii()"""

    if rev not in seen:

        seen.append(rev)

    nodeidx = seen.index(rev)

    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 p != nullrev]

    while len(newparents) > 2:

        # ascii() only knows how to add or remove a single column between two

        # calls. Nodes with more than two parents break this constraint so we

        # introduce intermediate expansion lines to grow the active node list

        # slowly.

        edges.append((nodeidx, nodeidx))

        edges.append((nodeidx, nodeidx + 1))

        nmorecols = 1

        yield (type, char, lines, (nodeidx, edges, ncols, nmorecols))

        char = '\\'

        lines = []

        nodeidx += 1

        ncols += 1

        edges = []

        del newparents[0]

    if len(newparents) > 0:

        edges.append((nodeidx, nodeidx))

    if len(newparents) > 1:

        edges.append((nodeidx, nodeidx + 1))

    nmorecols = len(nextseen) - ncols

    seen[:] = nextseen

    yield (type, char, lines, (nodeidx, edges, ncols, nmorecols))

def _fixlongrightedges(edges):

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

        if end > start:

            edges[i] = (start, end + 1)

def _getnodelineedgestail(

        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 _drawedges(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:

            if 2 * end >= len(nodeline):

                continue

            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 _getpaddingline(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 asciistate():

    """returns the initial value for the "state" argument to ascii()"""

    return [0, 0]

def ascii(ui, state, type, char, text, coldata):

    """prints an ASCII graph of the DAG

    takes the following arguments (one call per node in the graph):

      - ui to write to

      - Somewhere to keep the needed state in (init to asciistate())

      - Column of the current node in the set of ongoing edges.

      - Type indicator of node data, usually 'C' for changesets.

      - Payload: (char, lines):

        - Character to use as node's symbol.

        - List of lines to display as the node's text.

      - 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.

    """

    idx, edges, ncols, coldiff = coldata

    assert -2 < coldiff < 2

    if coldiff == -1:

        # Transform

        #

        #     | | |        | | |

        #     o | |  into  o---+

        #     |X /         |/ /

        #     | |          | |

        _fixlongrightedges(edges)

    # add_padding_line says whether to rewrite

    #

    #     | | | |        | | | |

    #     | o---+  into  | o---+

    #     |  / /         |   | |  # <--- padding line

    #     o | |          |  / /

    #                    o | |

    add_padding_line = (len(text) > 2 and coldiff == -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(text) <= 2 and not add_padding_line

    # nodeline is the line containing the node character (typically o)

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

    nodeline.extend([char, " "])

    nodeline.extend(

        _getnodelineedgestail(idx, state[1], ncols, coldiff,

                              state[0], fix_nodeline_tail))

    # shift_interline is the line containing the non-vertical

    # edges between this entry and the next

    shift_interline = ["|", " "] * idx

    if coldiff == -1:

        n_spaces = 1

        edge_ch = "/"

    elif coldiff == 0:

        n_spaces = 2

        edge_ch = "|"

    else:

        n_spaces = 3

        edge_ch = "\\"

    shift_interline.extend(n_spaces * [" "])

    shift_interline.extend([edge_ch, " "] * (ncols - idx - 1))

    # draw edges from the current node to its parents

    _drawedges(edges, nodeline, shift_interline)

    # lines is the list of all graph lines to print

    lines = [nodeline]

    if add_padding_line:

        lines.append(_getpaddingline(idx, ncols, edges))

    lines.append(shift_interline)

    # make sure that there are as many graph lines as there are

    # log strings

    while len(text) < len(lines):

        text.append("")

    if len(lines) < len(text):

        extra_interline = ["|", " "] * (ncols + coldiff)

        while len(lines) < len(text):

            lines.append(extra_interline)

    # print lines

    indentation_level = max(ncols, ncols + coldiff)

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

        ln = "%-*s %s" % (2 * indentation_level, "".join(line), logstr)

        ui.write(ln.rstrip() + '\n')

    # ... and start over

    state[0] = coldiff

    state[1] = idx