# filemerge.py - file-level merge handling for Mercurial

#

# Copyright 2006, 2007, 2008 Matt Mackall <mpm@selenic.com>

#

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

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

from node import short

from i18n import _

import util, simplemerge, match, error, templater, templatekw

import os, tempfile, re, filecmp

import tagmerge

def _toolstr(ui, tool, part, default=""):

    return ui.config("merge-tools", tool + "." + part, default)

def _toolbool(ui, tool, part, default=False):

    return ui.configbool("merge-tools", tool + "." + part, default)

def _toollist(ui, tool, part, default=[]):

    return ui.configlist("merge-tools", tool + "." + part, default)

internals = {}

def internaltool(name, trymerge, onfailure=None):

    '''return a decorator for populating internal merge tool table'''

    def decorator(func):

        fullname = ':' + name

        func.__doc__ = "``%s``\n" % fullname + func.__doc__.strip()

        internals[fullname] = func

        internals['internal:' + name] = func

        func.trymerge = trymerge

        func.onfailure = onfailure

        return func

    return decorator

def _findtool(ui, tool):

    if tool in internals:

        return tool

    return findexternaltool(ui, tool)

def findexternaltool(ui, tool):

    for kn in ("regkey", "regkeyalt"):

        k = _toolstr(ui, tool, kn)

        if not k:

            continue

        p = util.lookupreg(k, _toolstr(ui, tool, "regname"))

        if p:

            p = util.findexe(p + _toolstr(ui, tool, "regappend"))

            if p:

                return p

    exe = _toolstr(ui, tool, "executable", tool)

    return util.findexe(util.expandpath(exe))

def _picktool(repo, ui, path, binary, symlink):

    def check(tool, pat, symlink, binary):

        tmsg = tool

        if pat:

            tmsg += " specified for " + pat

        if not _findtool(ui, tool):

            if pat: # explicitly requested tool deserves a warning

                ui.warn(_("couldn't find merge tool %s\n") % tmsg)

            else: # configured but non-existing tools are more silent

                ui.note(_("couldn't find merge tool %s\n") % tmsg)

        elif symlink and not _toolbool(ui, tool, "symlink"):

            ui.warn(_("tool %s can't handle symlinks\n") % tmsg)

        elif binary and not _toolbool(ui, tool, "binary"):

            ui.warn(_("tool %s can't handle binary\n") % tmsg)

        elif not util.gui() and _toolbool(ui, tool, "gui"):

            ui.warn(_("tool %s requires a GUI\n") % tmsg)

        else:

            return True

        return False

    # forcemerge comes from command line arguments, highest priority

    force = ui.config('ui', 'forcemerge')

    if force:

        toolpath = _findtool(ui, force)

        if toolpath:

            return (force, util.shellquote(toolpath))

        else:

            # mimic HGMERGE if given tool not found

            return (force, force)

    # HGMERGE takes next precedence

    hgmerge = os.environ.get("HGMERGE")

    if hgmerge:

        return (hgmerge, hgmerge)

    # then patterns

    for pat, tool in ui.configitems("merge-patterns"):

        mf = match.match(repo.root, '', [pat])

        if mf(path) and check(tool, pat, symlink, False):

            toolpath = _findtool(ui, tool)

            return (tool, util.shellquote(toolpath))

    # then merge tools

    tools = {}

    for k, v in ui.configitems("merge-tools"):

        t = k.split('.')[0]

        if t not in tools:

            tools[t] = int(_toolstr(ui, t, "priority", "0"))

    names = tools.keys()

    tools = sorted([(-p, t) for t, p in tools.items()])

    uimerge = ui.config("ui", "merge")

    if uimerge:

        if uimerge not in names:

            return (uimerge, uimerge)

        tools.insert(0, (None, uimerge)) # highest priority

    tools.append((None, "hgmerge")) # the old default, if found

    for p, t in tools:

        if check(t, None, symlink, binary):

            toolpath = _findtool(ui, t)

            return (t, util.shellquote(toolpath))

    # internal merge or prompt as last resort

    if symlink or binary:

        return ":prompt", None

    return ":merge", None

def _eoltype(data):

    "Guess the EOL type of a file"

    if '\0' in data: # binary

        return None

    if '\r\n' in data: # Windows

        return '\r\n'

    if '\r' in data: # Old Mac

        return '\r'

    if '\n' in data: # UNIX

        return '\n'

    return None # unknown

def _matcheol(file, origfile):

    "Convert EOL markers in a file to match origfile"

    tostyle = _eoltype(util.readfile(origfile))

    if tostyle:

        data = util.readfile(file)

        style = _eoltype(data)

        if style:

            newdata = data.replace(style, tostyle)

            if newdata != data:

                util.writefile(file, newdata)

@internaltool('prompt', False)

def _iprompt(repo, mynode, orig, fcd, fco, fca, toolconf):

    """Asks the user which of the local or the other version to keep as

    the merged version."""

    ui = repo.ui

    fd = fcd.path()

    if ui.promptchoice(_(" no tool found to merge %s\n"

                         "keep (l)ocal or take (o)ther?"

                         "$$ &Local $$ &Other") % fd, 0):

        return _iother(repo, mynode, orig, fcd, fco, fca, toolconf)

    else:

        return _ilocal(repo, mynode, orig, fcd, fco, fca, toolconf)

@internaltool('local', False)

def _ilocal(repo, mynode, orig, fcd, fco, fca, toolconf):

    """Uses the local version of files as the merged version."""

    return 0

@internaltool('other', False)

def _iother(repo, mynode, orig, fcd, fco, fca, toolconf):

    """Uses the other version of files as the merged version."""

    repo.wwrite(fcd.path(), fco.data(), fco.flags())

    return 0

@internaltool('fail', False)

def _ifail(repo, mynode, orig, fcd, fco, fca, toolconf):

    """

    Rather than attempting to merge files that were modified on both

    branches, it marks them as unresolved. The resolve command must be

    used to resolve these conflicts."""

    return 1

def _premerge(repo, toolconf, files, labels=None):

    tool, toolpath, binary, symlink = toolconf

    if symlink:

        return 1

    a, b, c, back = files

    ui = repo.ui

    validkeep = ['keep', 'keep-merge3']

    # do we attempt to simplemerge first?

    try:

        premerge = _toolbool(ui, tool, "premerge", not binary)

    except error.ConfigError:

        premerge = _toolstr(ui, tool, "premerge").lower()

        if premerge not in validkeep:

            _valid = ', '.join(["'" + v + "'" for v in validkeep])

            raise error.ConfigError(_("%s.premerge not valid "

                                      "('%s' is neither boolean nor %s)") %

                                    (tool, premerge, _valid))

    if premerge:

        if premerge == 'keep-merge3':

            if not labels:

                labels = _defaultconflictlabels

            if len(labels) < 3:

                labels.append('base')

        r = simplemerge.simplemerge(ui, a, b, c, quiet=True, label=labels)

        if not r:

            ui.debug(" premerge successful\n")

            return 0

        if premerge not in validkeep:

            util.copyfile(back, a) # restore from backup and try again

    return 1 # continue merging

@internaltool('merge', True,

              _("merging %s incomplete! "

                "(edit conflicts, then use 'hg resolve --mark')\n"))

def _imerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):

    """

    Uses the internal non-interactive simple merge algorithm for merging

    files. It will fail if there are any conflicts and leave markers in

    the partially merged file. Markers will have two sections, one for each side

    of merge."""

    tool, toolpath, binary, symlink = toolconf

    if symlink:

        repo.ui.warn(_('warning: internal :merge cannot merge symlinks '

                       'for %s\n') % fcd.path())

        return False, 1

    r = _premerge(repo, toolconf, files, labels=labels)

    if r:

        a, b, c, back = files

        ui = repo.ui

        r = simplemerge.simplemerge(ui, a, b, c, label=labels)

        return True, r

    return False, 0

@internaltool('merge3', True,

              _("merging %s incomplete! "

                "(edit conflicts, then use 'hg resolve --mark')\n"))

def _imerge3(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):

    """

    Uses the internal non-interactive simple merge algorithm for merging

    files. It will fail if there are any conflicts and leave markers in

    the partially merged file. Marker will have three sections, one from each

    side of the merge and one for the base content."""

    if not labels:

        labels = _defaultconflictlabels

    if len(labels) < 3:

        labels.append('base')

    return _imerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels)

@internaltool('tagmerge', True,

              _("automatic tag merging of %s failed! "

                "(use 'hg resolve --tool :merge' or another merge "

                "tool of your choice)\n"))

def _itagmerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):

    """

    Uses the internal tag merge algorithm (experimental).

    """

    return tagmerge.merge(repo, fcd, fco, fca)

@internaltool('dump', True)

def _idump(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):

    """

    Creates three versions of the files to merge, containing the

    contents of local, other and base. These files can then be used to

    perform a merge manually. If the file to be merged is named

    ``a.txt``, these files will accordingly be named ``a.txt.local``,

    ``a.txt.other`` and ``a.txt.base`` and they will be placed in the

    same directory as ``a.txt``."""

    r = _premerge(repo, toolconf, files, labels=labels)

    if r:

        a, b, c, back = files

        fd = fcd.path()

        util.copyfile(a, a + ".local")

        repo.wwrite(fd + ".other", fco.data(), fco.flags())

        repo.wwrite(fd + ".base", fca.data(), fca.flags())

    return False, r

def _xmerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):

    r = _premerge(repo, toolconf, files, labels=labels)

    if r:

        tool, toolpath, binary, symlink = toolconf

        a, b, c, back = files

        out = ""

        env = {'HG_FILE': fcd.path(),

               'HG_MY_NODE': short(mynode),

               'HG_OTHER_NODE': str(fco.changectx()),

               'HG_BASE_NODE': str(fca.changectx()),

               'HG_MY_ISLINK': 'l' in fcd.flags(),

               'HG_OTHER_ISLINK': 'l' in fco.flags(),

               'HG_BASE_ISLINK': 'l' in fca.flags(),

               }

        ui = repo.ui

        args = _toolstr(ui, tool, "args", '$local $base $other')

        if "$output" in args:

            out, a = a, back # read input from backup, write to original

        replace = {'local': a, 'base': b, 'other': c, 'output': out}

        args = util.interpolate(r'\$', replace, args,

                                lambda s: util.shellquote(util.localpath(s)))

        r = ui.system(toolpath + ' ' + args, cwd=repo.root, environ=env)

        return True, r

    return False, 0

def _formatconflictmarker(repo, ctx, template, label, pad):

    """Applies the given template to the ctx, prefixed by the label.

    Pad is the minimum width of the label prefix, so that multiple markers

    can have aligned templated parts.

    """

    if ctx.node() is None:

        ctx = ctx.p1()

    props = templatekw.keywords.copy()

    props['templ'] = template

    props['ctx'] = ctx

    props['repo'] = repo

    templateresult = template('conflictmarker', **props)

    label = ('%s:' % label).ljust(pad + 1)

    mark = '%s %s' % (label, templater.stringify(templateresult))

    if mark:

        mark = mark.splitlines()[0] # split for safety

    # 8 for the prefix of conflict marker lines (e.g. '<<<<<<< ')

    return util.ellipsis(mark, 80 - 8)

_defaultconflictmarker = ('{node|short} ' +

    '{ifeq(tags, "tip", "", "{tags} ")}' +

    '{if(bookmarks, "{bookmarks} ")}' +

    '{ifeq(branch, "default", "", "{branch} ")}' +

    '- {author|user}: {desc|firstline}')

_defaultconflictlabels = ['local', 'other']

def _formatlabels(repo, fcd, fco, fca, labels):

    """Formats the given labels using the conflict marker template.

    Returns a list of formatted labels.

    """

    cd = fcd.changectx()

    co = fco.changectx()

    ca = fca.changectx()

    ui = repo.ui

    template = ui.config('ui', 'mergemarkertemplate', _defaultconflictmarker)

    template = templater.parsestring(template, quoted=False)

    tmpl = templater.templater(None, cache={'conflictmarker': template})

    pad = max(len(l) for l in labels)