# dagparser.py - parser and generator for concise description of DAGs

#

# Copyright 2010 Peter Arrenbrecht <peter@arrenbrecht.ch>

#

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

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

import re

import string

from .i18n import _

from . import (

    error,

    pycompat,

)

from .utils import stringutil

def parsedag(desc):

    '''parses a DAG from a concise textual description; generates events

    "+n" is a linear run of n nodes based on the current default parent

    "." is a single node based on the current default parent

    "$" resets the default parent to -1 (implied at the start);

        otherwise the default parent is always the last node created

    "<p" sets the default parent to the backref p

    "*p" is a fork at parent p, where p is a backref

    "*p1/p2/.../pn" is a merge of parents p1..pn, where the pi are backrefs

    "/p2/.../pn" is a merge of the preceding node and p2..pn

    ":name" defines a label for the preceding node; labels can be redefined

    "@text" emits an annotation event for text

    "!command" emits an action event for the current node

    "!!my command\n" is like "!", but to the end of the line

    "#...\n" is a comment up to the end of the line

    Whitespace between the above elements is ignored.

    A backref is either

     * a number n, which references the node curr-n, where curr is the current

       node, or

     * the name of a label you placed earlier using ":name", or

     * empty to denote the default parent.

    All string valued-elements are either strictly alphanumeric, or must

    be enclosed in double quotes ("..."), with "\" as escape character.

    Generates sequence of

      ('n', (id, [parentids])) for node creation

      ('l', (id, labelname)) for labels on nodes

      ('a', text) for annotations

      ('c', command) for actions (!)

      ('C', command) for line actions (!!)

    Examples

    --------

    Example of a complex graph (output not shown for brevity):

        >>> len(list(parsedag(b"""

        ...

        ... +3         # 3 nodes in linear run

        ... :forkhere  # a label for the last of the 3 nodes from above

        ... +5         # 5 more nodes on one branch

        ... :mergethis # label again

        ... <forkhere  # set default parent to labeled fork node

        ... +10        # 10 more nodes on a parallel branch

        ... @stable    # following nodes will be annotated as "stable"

        ... +5         # 5 nodes in stable

        ... !addfile   # custom command; could trigger new file in next node

        ... +2         # two more nodes

        ... /mergethis # merge last node with labeled node

        ... +4         # 4 more nodes descending from merge node

        ...

        ... """)))

        34

    Empty list:

        >>> list(parsedag(b""))

        []

    A simple linear run:

        >>> list(parsedag(b"+3"))

        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]

    Some non-standard ways to define such runs:

        >>> list(parsedag(b"+1+2"))

        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]

        >>> list(parsedag(b"+1*1*"))

        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]

        >>> list(parsedag(b"*"))

        [('n', (0, [-1]))]

        >>> list(parsedag(b"..."))

        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]

    A fork and a join, using numeric back references:

        >>> list(parsedag(b"+2*2*/2"))

        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))]

        >>> list(parsedag(b"+2<2+1/2"))

        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))]

    Placing a label:

        >>> list(parsedag(b"+1 :mylabel +1"))

        [('n', (0, [-1])), ('l', (0, 'mylabel')), ('n', (1, [0]))]

    An empty label (silly, really):

        >>> list(parsedag(b"+1:+1"))

        [('n', (0, [-1])), ('l', (0, '')), ('n', (1, [0]))]

    Fork and join, but with labels instead of numeric back references:

        >>> list(parsedag(b"+1:f +1:p2 *f */p2"))

        [('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])), ('l', (1, 'p2')),

         ('n', (2, [0])), ('n', (3, [2, 1]))]

        >>> list(parsedag(b"+1:f +1:p2 <f +1 /p2"))

        [('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])), ('l', (1, 'p2')),

         ('n', (2, [0])), ('n', (3, [2, 1]))]

    Restarting from the root:

        >>> list(parsedag(b"+1 $ +1"))

        [('n', (0, [-1])), ('n', (1, [-1]))]

    Annotations, which are meant to introduce sticky state for subsequent nodes:

        >>> list(parsedag(b"+1 @ann +1"))

        [('n', (0, [-1])), ('a', 'ann'), ('n', (1, [0]))]

        >>> list(parsedag(b'+1 @"my annotation" +1'))

        [('n', (0, [-1])), ('a', 'my annotation'), ('n', (1, [0]))]

    Commands, which are meant to operate on the most recently created node:

        >>> list(parsedag(b"+1 !cmd +1"))

        [('n', (0, [-1])), ('c', 'cmd'), ('n', (1, [0]))]

        >>> list(parsedag(b'+1 !"my command" +1'))

        [('n', (0, [-1])), ('c', 'my command'), ('n', (1, [0]))]

        >>> list(parsedag(b'+1 !!my command line\\n +1'))

        [('n', (0, [-1])), ('C', 'my command line'), ('n', (1, [0]))]

    Comments, which extend to the end of the line:

        >>> list(parsedag(b'+1 # comment\\n+1'))

        [('n', (0, [-1])), ('n', (1, [0]))]

    Error:

        >>> try: list(parsedag(b'+1 bad'))

        ... except Exception as e: print(pycompat.sysstr(bytes(e)))

        invalid character in dag description: bad...

    '''

    if not desc:

        return

    # pytype: disable=wrong-arg-types

    wordchars = pycompat.bytestr(string.ascii_letters + string.digits)

    # pytype: enable=wrong-arg-types

    labels = {}

    p1 = -1

    r = 0

    def resolve(ref):

        if not ref:

            return p1

        # pytype: disable=wrong-arg-types

        elif ref[0] in pycompat.bytestr(string.digits):

            # pytype: enable=wrong-arg-types

            return r - int(ref)

        else:

            return labels[ref]

    chiter = pycompat.iterbytestr(desc)

    def nextch():

        return next(chiter, b'\0')

    def nextrun(c, allow):

        s = b''

        while c in allow:

            s += c

            c = nextch()

        return c, s

    def nextdelimited(c, limit, escape):

        s = b''

        while c != limit:

            if c == escape:

                c = nextch()

            s += c

            c = nextch()

        return nextch(), s

    def nextstring(c):

        if c == b'"':

            return nextdelimited(nextch(), b'"', b'\\')

        else:

            return nextrun(c, wordchars)

    c = nextch()

    while c != b'\0':

        # pytype: disable=wrong-arg-types

        while c in pycompat.bytestr(string.whitespace):

            # pytype: enable=wrong-arg-types

            c = nextch()

        if c == b'.':

            yield b'n', (r, [p1])

            p1 = r

            r += 1

            c = nextch()

        elif c == b'+':

            # pytype: disable=wrong-arg-types

            c, digs = nextrun(nextch(), pycompat.bytestr(string.digits))

            # pytype: enable=wrong-arg-types

            n = int(digs)

            for i in range(0, n):

                yield b'n', (r, [p1])

                p1 = r

                r += 1

        elif c in b'*/':

            if c == b'*':

                c = nextch()

            c, pref = nextstring(c)

            prefs = [pref]

            while c == b'/':

                c, pref = nextstring(nextch())

                prefs.append(pref)

            ps = [resolve(ref) for ref in prefs]

            yield b'n', (r, ps)

            p1 = r

            r += 1

        elif c == b'<':

            c, ref = nextstring(nextch())

            p1 = resolve(ref)

        elif c == b':':

            c, name = nextstring(nextch())

            labels[name] = p1

            yield b'l', (p1, name)

        elif c == b'@':

            c, text = nextstring(nextch())

            yield b'a', text

        elif c == b'!':

            c = nextch()

            if c == b'!':

                cmd = b''

                c = nextch()

                while c not in b'\n\r\0':

                    cmd += c

                    c = nextch()

                yield b'C', cmd

            else:

                c, cmd = nextstring(c)

                yield b'c', cmd

        elif c == b'#':

            while c not in b'\n\r\0':

                c = nextch()

        elif c == b'$':

            p1 = -1

            c = nextch()

        elif c == b'\0':

            return  # in case it was preceded by whitespace

        else:

            s = b''

            i = 0

            while c != b'\0' and i < 10:

                s += c

                i += 1

                c = nextch()

            raise error.Abort(

                _(b'invalid character in dag description: %s...') % s

            )

def dagtextlines(

    events,

    addspaces=True,

    wraplabels=False,

    wrapannotations=False,

    wrapcommands=False,

    wrapnonlinear=False,

    usedots=False,

    maxlinewidth=70,

):

    '''generates single lines for dagtext()'''

    def wrapstring(text):

        if re.match(b"^[0-9a-z]*$", text):

            return text

        return b'"' + text.replace(b'\\', b'\\\\').replace(b'"', b'\"') + b'"'

    def gen():

        labels = {}

        run = 0

        wantr = 0

        needroot = False

        for kind, data in events:

            if kind == b'n':

                r, ps = data

                # sanity check

                if r != wantr:

                    raise error.Abort(_(b"expected id %i, got %i") % (wantr, r))

                if not ps:

                    ps = [-1]

                else:

                    for p in ps:

                        if p >= r:

                            raise error.Abort(

                                _(

                                    b"parent id %i is larger than "

                                    b"current id %i"

                                )

                                % (p, r)

                            )

                wantr += 1

                # new root?

                p1 = r - 1

                if len(ps) == 1 and ps[0] == -1:

                    if needroot:

                        if run:

                            yield b'+%d' % run

                            run = 0

                        if wrapnonlinear:

                            yield b'\n'

                        yield b'$'

                        p1 = -1

                    else:

                        needroot = True

                if len(ps) == 1 and ps[0] == p1:

                    if usedots:

                        yield b"."

                    else:

                        run += 1

                else:

                    if run:

                        yield b'+%d' % run

                        run = 0

                    if wrapnonlinear:

                        yield b'\n'

                    prefs = []

                    for p in ps:

                        if p == p1:

                            prefs.append(b'')

                        elif p in labels:

                            prefs.append(labels[p])

                        else:

                            prefs.append(b'%d' % (r - p))

                    yield b'*' + b'/'.join(prefs)

            else:

                if run:

                    yield b'+%d' % run

                    run = 0

                if kind == b'l':

                    rid, name = data

                    labels[rid] = name

                    yield b':' + name

                    if wraplabels:

                        yield b'\n'

                elif kind == b'c':

                    yield b'!' + wrapstring(data)

                    if wrapcommands:

                        yield b'\n'

                elif kind == b'C':

                    yield b'!!' + data

                    yield b'\n'

                elif kind == b'a':

                    if wrapannotations:

                        yield b'\n'

                    yield b'@' + wrapstring(data)

                elif kind == b'#':

                    yield b'#' + data

                    yield b'\n'

                else:

                    raise error.Abort(

                        _(b"invalid event type in dag: ('%s', '%s')")

                        % (

                            stringutil.escapestr(kind),

                            stringutil.escapestr(data),

                        )

                    )

        if run:

            yield b'+%d' % run

    line = b''

    for part in gen():

        if part == b'\n':

            if line:

                yield line

                line = b''

        else:

            if len(line) + len(part) >= maxlinewidth:

                yield line

                line = b''

            elif addspaces and line and part != b'.':

                line += b' '

            line += part

    if line:

        yield line

def dagtext(

    dag,

    addspaces=True,