# 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 .node import nullrev

from .thirdparty import attr

from . import (

    dagop,

    smartset,

    util,

)

CHANGESET = b'C'

PARENT = b'P'

GRANDPARENT = b'G'

MISSINGPARENT = b'M'

# Style of line to draw. None signals a line that ends and is removed at this

# point. A number prefix means only the last N characters of the current block

# will use that style, the rest will use the PARENT style. Add a - sign

# (so making N negative) and all but the first N characters use that style.

EDGES = {PARENT: b'|', GRANDPARENT: b':', MISSINGPARENT: None}

def dagwalker(repo, revs):

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

    This generator function walks through revisions (which should be ordered

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

    Each parentinfo entry is a tuple with (edgetype, parentid), where edgetype

    is one of PARENT, GRANDPARENT or MISSINGPARENT. The node and parent ids

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

    returned.

    """

    gpcache = {}

    for rev in revs:

        ctx = repo[rev]

        # partition into parents in the rev set and missing parents, then

        # augment the lists with markers, to inform graph drawing code about

        # what kind of edge to draw between nodes.

        pset = {p.rev() for p in ctx.parents() if p.rev() in revs}

        mpars = [

            p.rev()

            for p in ctx.parents()

            if p.rev() != nullrev and p.rev() not in pset

        ]

        parents = [(PARENT, p) for p in sorted(pset)]

        for mpar in mpars:

            gp = gpcache.get(mpar)

            if gp is None:

                # precompute slow query as we know reachableroots() goes

                # through all revs (issue4782)

                if not isinstance(revs, smartset.baseset):

                    revs = smartset.baseset(revs)

                gp = gpcache[mpar] = sorted(

                    set(dagop.reachableroots(repo, revs, [mpar]))

                )

            if not gp:

                parents.append((MISSINGPARENT, mpar))

                pset.add(mpar)

            else:

                parents.extend((GRANDPARENT, g) for g in gp if g not in pset)

                pset.update(gp)

        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 = {

            (PARENT, 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(b'graph'):

        if b'.' in key:

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

            # Validation

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

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

            elif setting == b"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 pt, 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(b'width', -1),

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

                    )

                )

            elif eid == cur:

                for ptype, p in parents:

                    bconf = getconf(p)

                    edges.append(

                        (

                            ecol,

                            next.index(p),

                            color,

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

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

                        )

                    )

        # Yield and move on

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

        seen = next

def asciiedges(type, char, state, rev, parents):

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

    seen = state.seen

    if rev not in seen:

        seen.append(rev)

    nodeidx = seen.index(rev)

    knownparents = []

    newparents = []

    for ptype, parent in parents:

        if parent == rev:

            # self reference (should only be seen in null rev)

            continue

        if parent in seen:

            knownparents.append(parent)

        else:

            newparents.append(parent)

            state.edges[parent] = state.styles.get(ptype, b'|')

    ncols = len(seen)

    width = 1 + ncols * 2

    nextseen = seen[:]

    nextseen[nodeidx : nodeidx + 1] = newparents

    edges = [(nodeidx, nextseen.index(p)) for p in knownparents]

    seen[:] = nextseen

    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

        width += 2

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

        char = b'\\'

        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

    if nmorecols > 0:

        width += 2

    # remove current node from edge characters, no longer needed

    state.edges.pop(rev, None)

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

def _fixlongrightedges(edges):

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

        if end > start:

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

def _getnodelineedgestail(echars, idx, pidx, ncols, coldiff, pdiff, fix_tail):

    if fix_tail and coldiff == pdiff and coldiff != 0:

        # Still going in the same non-vertical direction.

        if coldiff == -1:

            start = max(idx + 1, pidx)

            tail = echars[idx * 2 : (start - 1) * 2]

            tail.extend([b"/", b" "] * (ncols - start))

            return tail

        else:

            return [b"\\", b" "] * (ncols - idx - 1)

    else:

        remainder = ncols - idx - 1

        return echars[-(remainder * 2) :] if remainder > 0 else []

def _drawedges(echars, edges, nodeline, interline):

    for (start, end) in edges:

        if start == end + 1:

            interline[2 * end + 1] = b"/"

        elif start == end - 1:

            interline[2 * start + 1] = b"\\"

        elif start == end:

            interline[2 * start] = echars[2 * start]

        else:

            if 2 * end >= len(nodeline):

                continue

            nodeline[2 * end] = b"+"

            if start > end:

                (start, end) = (end, start)

            for i in range(2 * start + 1, 2 * end):

                if nodeline[i] != b"+":

                    nodeline[i] = b"-"

def _getpaddingline(echars, idx, ncols, edges):

    # all edges up to the current node

    line = echars[: idx * 2]

    # an edge for the current node, if there is one

    if (idx, idx - 1) in edges or (idx, idx) in edges:

        # (idx, idx - 1)      (idx, idx)

        # | | | |           | | | |

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

        # | | X |           | X | |

        # | |/ /            | |/ /

        # | | |             | | |

        line.extend(echars[idx * 2 : (idx + 1) * 2])

    else:

        line.extend([b' ', b' '])

    # all edges to the right of the current node

    remainder = ncols - idx - 1

    if remainder > 0:

        line.extend(echars[-(remainder * 2) :])

    return line

def _drawendinglines(lines, extra, edgemap, seen, state):

    """Draw ending lines for missing parent edges

    None indicates an edge that ends at between this node and the next

    Replace with a short line ending in ~ and add / lines to any edges to

    the right.

    """

    if None not in edgemap.values():

        return

    # Check for more edges to the right of our ending edges.

    # We need enough space to draw adjustment lines for these.

    edgechars = extra[::2]

    while edgechars and edgechars[-1] is None:

        edgechars.pop()

    shift_size = max((edgechars.count(None) * 2) - 1, 0)

    minlines = 3 if not state.graphshorten else 2

    while len(lines) < minlines + shift_size:

        lines.append(extra[:])

    if shift_size:

        empties = []

        toshift = []

        first_empty = extra.index(None)

        for i, c in enumerate(extra[first_empty::2], first_empty // 2):

            if c is None:

                empties.append(i * 2)

            else:

                toshift.append(i * 2)

        targets = list(range(first_empty, first_empty + len(toshift) * 2, 2))

        positions = toshift[:]

        for line in lines[-shift_size:]:

            line[first_empty:] = [b' '] * (len(line) - first_empty)

            for i in range(len(positions)):

                pos = positions[i] - 1

                positions[i] = max(pos, targets[i])

                line[pos] = b'/' if pos > targets[i] else extra[toshift[i]]

    map = {1: b'|', 2: b'~'} if not state.graphshorten else {1: b'~'}

    for i, line in enumerate(lines):

        if None not in line:

            continue

        line[:] = [c or map.get(i, b' ') for c in line]

    # remove edges that ended

    remove = [p for p, c in edgemap.items() if c is None]

    for parent in remove:

        del edgemap[parent]

        seen.remove(parent)

@attr.s

class asciistate:

    """State of ascii() graph rendering"""

    seen = attr.ib(init=False, default=attr.Factory(list))

    edges = attr.ib(init=False, default=attr.Factory(dict))

    lastcoldiff = attr.ib(init=False, default=0)

    lastindex = attr.ib(init=False, default=0)

    styles = attr.ib(init=False, default=attr.Factory(EDGES.copy))

    graphshorten = attr.ib(init=False, default=False)