# Copyright 2009-2010 Gregory P. Ward
# Copyright 2009-2010 Intelerad Medical Systems Incorporated
# Copyright 2010-2011 Fog Creek Software
# Copyright 2010-2011 Unity Technologies
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''High-level command functions: lfadd() et. al, plus the cmdtable.'''

import os
import shutil

from mercurial import util, match as match_, hg, node, context, error
from mercurial.i18n import _

import lfutil
import basestore

# -- Commands ----------------------------------------------------------

def lfconvert(ui, src, dest, *pats, **opts):
    '''Convert a normal repository to a largefiles repository

    Convert source repository creating an identical repository, except that all
    files that match the patterns given, or are over the given size will be
    added as largefiles. The size used to determine whether or not to track a
    file as a largefile is the size of the first version of the file. After
    running this command you will need to make sure that largefiles is enabled
    anywhere you intend to push the new repository.'''

    if opts['tonormal']:
        tolfile = False
    else:
        tolfile = True
        size = opts['size']
        if not size:
            size = ui.config(lfutil.longname, 'size', default=None)
            try:
                size = int(size)
            except ValueError:
                raise util.Abort(_('largefiles.size must be integer, was %s\n')
                                 % size)
            except TypeError:
                raise util.Abort(_('size must be specified'))

    try:
        rsrc = hg.repository(ui, src)
        if not rsrc.local():
            raise util.Abort(_('%s is not a local Mercurial repo') % src)
    except error.RepoError, err:
        ui.traceback()
        raise util.Abort(err.args[0])
    if os.path.exists(dest):
        if not os.path.isdir(dest):
            raise util.Abort(_('destination %s already exists') % dest)
        elif os.listdir(dest):
            raise util.Abort(_('destination %s is not empty') % dest)
    try:
        ui.status(_('initializing destination %s\n') % dest)
        rdst = hg.repository(ui, dest, create=True)
        if not rdst.local():
            raise util.Abort(_('%s is not a local Mercurial repo') % dest)
    except error.RepoError:
        ui.traceback()
        raise util.Abort(_('%s is not a repo') % dest)

    success = False
    try:
        # Lock destination to prevent modification while it is converted to.
        # Don't need to lock src because we are just reading from its history
        # which can't change.
        dst_lock = rdst.lock()

        # Get a list of all changesets in the source.  The easy way to do this
        # is to simply walk the changelog, using changelog.nodesbewteen().
        # Take a look at mercurial/revlog.py:639 for more details.
        # Use a generator instead of a list to decrease memory usage
        ctxs = (rsrc[ctx] for ctx in rsrc.changelog.nodesbetween(None,
            rsrc.heads())[0])
        revmap = {node.nullid: node.nullid}
        if tolfile:
            lfiles = set()
            normalfiles = set()
            if not pats:
                pats = ui.config(lfutil.longname, 'patterns', default=())
                if pats:
                    pats = pats.split(' ')
            if pats:
                matcher = match_.match(rsrc.root, '', list(pats))
            else:
                matcher = None

            lfiletohash = {}
            for ctx in ctxs:
                ui.progress(_('converting revisions'), ctx.rev(),
                    unit=_('revision'), total=rsrc['tip'].rev())
                _lfconvert_addchangeset(rsrc, rdst, ctx, revmap,
                    lfiles, normalfiles, matcher, size, lfiletohash)
            ui.progress(_('converting revisions'), None)

            if os.path.exists(rdst.wjoin(lfutil.shortname)):
                shutil.rmtree(rdst.wjoin(lfutil.shortname))

            for f in lfiletohash.keys():
                if os.path.isfile(rdst.wjoin(f)):
                    os.unlink(rdst.wjoin(f))
                try:
                    os.removedirs(os.path.dirname(rdst.wjoin(f)))
                except OSError:
                    pass

        else:
            for ctx in ctxs:
                ui.progress(_('converting revisions'), ctx.rev(),
                    unit=_('revision'), total=rsrc['tip'].rev())
                _addchangeset(ui, rsrc, rdst, ctx, revmap)

            ui.progress(_('converting revisions'), None)
        success = True
    finally:
        if not success:
            # we failed, remove the new directory
            shutil.rmtree(rdst.root)
        dst_lock.release()

def _addchangeset(ui, rsrc, rdst, ctx, revmap):
 # Convert src parents to dst parents
    parents = []
    for p in ctx.parents():
        parents.append(revmap[p.node()])
    while len(parents) < 2:
        parents.append(node.nullid)

    # Generate list of changed files
    files = set(ctx.files())
    if node.nullid not in parents:
        mc = ctx.manifest()
        mp1 = ctx.parents()[0].manifest()
        mp2 = ctx.parents()[1].manifest()
        files |= (set(mp1) | set(mp2)) - set(mc)
        for f in mc:
            if mc[f] != mp1.get(f, None) or mc[f] != mp2.get(f, None):
                files.add(f)

    def getfilectx(repo, memctx, f):
        if lfutil.standin(f) in files:
            # if the file isn't in the manifest then it was removed
            # or renamed, raise IOError to indicate this
            try:
                fctx = ctx.filectx(lfutil.standin(f))
            except error.LookupError:
                raise IOError()
            renamed = fctx.renamed()
            if renamed:
                renamed = lfutil.splitstandin(renamed[0])

            hash = fctx.data().strip()
            path = lfutil.findfile(rsrc, hash)
            ### TODO: What if the file is not cached?
            data = ''
            fd = None
            try:
                fd = open(path, 'rb')
                data = fd.read()
            finally:
                if fd:
                    fd.close()
            return context.memfilectx(f, data, 'l' in fctx.flags(),
                                      'x' in fctx.flags(), renamed)
        else:
            try:
                fctx = ctx.filectx(f)
            except error.LookupError:
                raise IOError()
            renamed = fctx.renamed()
            if renamed:
                renamed = renamed[0]
            data = fctx.data()
            if f == '.hgtags':
                newdata = []
                for line in data.splitlines():
                    id, name = line.split(' ', 1)
                    newdata.append('%s %s\n' % (node.hex(revmap[node.bin(id)]),
                        name))
                data = ''.join(newdata)
            return context.memfilectx(f, data, 'l' in fctx.flags(),
                                      'x' in fctx.flags(), renamed)

    dstfiles = []
    for file in files:
        if lfutil.isstandin(file):
            dstfiles.append(lfutil.splitstandin(file))
        else:
            dstfiles.append(file)
    # Commit
    mctx = context.memctx(rdst, parents, ctx.description(), dstfiles,
                          getfilectx, ctx.user(), ctx.date(), ctx.extra())
    ret = rdst.commitctx(mctx)
    rdst.dirstate.setparents(ret)
    revmap[ctx.node()] = rdst.changelog.tip()

def _lfconvert_addchangeset(rsrc, rdst, ctx, revmap, lfiles, normalfiles,
        matcher, size, lfiletohash):
    # Convert src parents to dst parents
    parents = []
    for p in ctx.parents():
        parents.append(revmap[p.node()])
    while len(parents) < 2:
        parents.append(node.nullid)

    # Generate list of changed files
    files = set(ctx.files())
    if node.nullid not in parents:
        mc = ctx.manifest()
        mp1 = ctx.parents()[0].manifest()
        mp2 = ctx.parents()[1].manifest()
        files |= (set(mp1) | set(mp2)) - set(mc)
        for f in mc:
            if mc[f] != mp1.get(f, None) or mc[f] != mp2.get(f, None):
                files.add(f)

    dstfiles = []
    for f in files:
        if f not in lfiles and f not in normalfiles:
            islfile = _islfile(f, ctx, matcher, size)
            # If this file was renamed or copied then copy
            # the lfileness of its predecessor
            if f in ctx.manifest():
                fctx = ctx.filectx(f)
                renamed = fctx.renamed()
                renamedlfile = renamed and renamed[0] in lfiles
                islfile |= renamedlfile
                if 'l' in fctx.flags():
                    if renamedlfile:
                        raise util.Abort(
                            _('Renamed/copied largefile %s becomes symlink')
                            % f)
                    islfile = False
            if islfile:
                lfiles.add(f)
            else:
                normalfiles.add(f)

        if f in lfiles:
            dstfiles.append(lfutil.standin(f))
            # lfile in manifest if it has not been removed/renamed
            if f in ctx.manifest():
                if 'l' in ctx.filectx(f).flags():
                    if renamed and renamed[0] in lfiles:
                        raise util.Abort(_('largefile %s becomes symlink') % f)

                # lfile was modified, update standins
                fullpath = rdst.wjoin(f)
                lfutil.createdir(os.path.dirname(fullpath))
                m = util.sha1('')
                m.update(ctx[f].data())
                hash = m.hexdigest()
                if f not in lfiletohash or lfiletohash[f] != hash:
                    try:
                        fd = open(fullpath, 'wb')
                        fd.write(ctx[f].data())
                    finally:
                        if fd:
                            fd.close()
                    executable = 'x' in ctx[f].flags()
                    os.chmod(fullpath, lfutil.getmode(executable))
                    lfutil.writestandin(rdst, lfutil.standin(f), hash,
                        executable)
                    lfiletohash[f] = hash
        else:
            # normal file
            dstfiles.append(f)

    def getfilectx(repo, memctx, f):
        if lfutil.isstandin(f):
            # if the file isn't in the manifest then it was removed
            # or renamed, raise IOError to indicate this
            srcfname = lfutil.splitstandin(f)
            try:
                fctx = ctx.filectx(srcfname)
            except error.LookupError:
                raise IOError()
            renamed = fctx.renamed()
            if renamed:
                # standin is always a lfile because lfileness
                # doesn't change after rename or copy
                renamed = lfutil.standin(renamed[0])

            return context.memfilectx(f, lfiletohash[srcfname], 'l' in
                fctx.flags(), 'x' in fctx.flags(), renamed)
        else:
            try:
                fctx = ctx.filectx(f)
            except error.LookupError:
                raise IOError()
            renamed = fctx.renamed()
            if renamed:
                renamed = renamed[0]

            data = fctx.data()
            if f == '.hgtags':
                newdata = []
                for line in data.splitlines():
                    id, name = line.split(' ', 1)
                    newdata.append('%s %s\n' % (node.hex(revmap[node.bin(id)]),
                        name))
                data = ''.join(newdata)
            return context.memfilectx(f, data, 'l' in fctx.flags(),
                                      'x' in fctx.flags(), renamed)

    # Commit
    mctx = context.memctx(rdst, parents, ctx.description(), dstfiles,
                          getfilectx, ctx.user(), ctx.date(), ctx.extra())
    ret = rdst.commitctx(mctx)
    rdst.dirstate.setparents(ret)
    revmap[ctx.node()] = rdst.changelog.tip()

def _islfile(file, ctx, matcher, size):
    '''
    A file is a lfile if it matches a pattern or is over
    the given size.
    '''
    # Never store hgtags or hgignore as lfiles
    if file == '.hgtags' or file == '.hgignore' or file == '.hgsigs':
        return False
    if matcher and matcher(file):
        return True
    try:
        return ctx.filectx(file).size() >= size * 1024 * 1024
    except error.LookupError:
        return False

def uploadlfiles(ui, rsrc, rdst, files):
    '''upload largefiles to the central store'''

    # Don't upload locally. All largefiles are in the system wide cache
    # so the other repo can just get them from there.
    if not files or rdst.local():
        return

    store = basestore._openstore(rsrc, rdst, put=True)

    at = 0
    files = filter(lambda h: not store.exists(h), files)
    for hash in files:
        ui.progress(_('uploading largefiles'), at, unit='largefile',
                    total=len(files))
        source = lfutil.findfile(rsrc, hash)
        if not source:
            raise util.Abort(_('Missing largefile %s needs to be uploaded')
                             % hash)
        # XXX check for errors here
        store.put(source, hash)
        at += 1
    ui.progress(_('uploading largefiles'), None)

def verifylfiles(ui, repo, all=False, contents=False):
    '''Verify that every big file revision in the current changeset
    exists in the central store.  With --contents, also verify that
    the contents of each big file revision are correct (SHA-1 hash
    matches the revision ID).  With --all, check every changeset in
    this repository.'''
    if all:
        # Pass a list to the function rather than an iterator because we know a
        # list will work.
        revs = range(len(repo))
    else:
        revs = ['.']

    store = basestore._openstore(repo)
    return store.verify(revs, contents=contents)

def cachelfiles(ui, repo, node):
    '''cachelfiles ensures that all largefiles needed by the specified revision
    are present in the repository's largefile cache.

    returns a tuple (cached, missing).  cached is the list of files downloaded
    by this operation; missing is the list of files that were needed but could
    not be found.'''
    lfiles = lfutil.listlfiles(repo, node)
    toget = []

    for lfile in lfiles:
        expectedhash = repo[node][lfutil.standin(lfile)].data().strip()
        # if it exists and its hash matches, it might have been locally
        # modified before updating and the user chose 'local'.  in this case,
        # it will not be in any store, so don't look for it.
        if (not os.path.exists(repo.wjoin(lfile)) \
                or expectedhash != lfutil.hashfile(repo.wjoin(lfile))) and \
                not lfutil.findfile(repo, expectedhash):
            toget.append((lfile, expectedhash))

    if toget:
        store = basestore._openstore(repo)
        ret = store.get(toget)
        return ret

    return ([], [])

def updatelfiles(ui, repo, filelist=None, printmessage=True):
    wlock = repo.wlock()
    try:
        lfdirstate = lfutil.openlfdirstate(ui, repo)
        lfiles = set(lfutil.listlfiles(repo)) | set(lfdirstate)

        if filelist is not None:
            lfiles = [f for f in lfiles if f in filelist]

        printed = False
        if printmessage and lfiles:
            ui.status(_('getting changed largefiles\n'))
            printed = True
            cachelfiles(ui, repo, '.')

        updated, removed = 0, 0
        for i in map(lambda f: _updatelfile(repo, lfdirstate, f), lfiles):
            # increment the appropriate counter according to _updatelfile's
            # return value
            updated += i > 0 and i or 0
            removed -= i < 0 and i or 0
            if printmessage and (removed or updated) and not printed:
                ui.status(_('getting changed largefiles\n'))
                printed = True

        lfdirstate.write()
        if printed and printmessage:
            ui.status(_('%d largefiles updated, %d removed\n') % (updated,
                removed))
    finally:
        wlock.release()

def _updatelfile(repo, lfdirstate, lfile):
    '''updates a single largefile and copies the state of its standin from
    the repository's dirstate to its state in the lfdirstate.

    returns 1 if the file was modified, -1 if the file was removed, 0 if the
    file was unchanged, and None if the needed largefile was missing from the
    cache.'''
    ret = 0
    abslfile = repo.wjoin(lfile)
    absstandin = repo.wjoin(lfutil.standin(lfile))
    if os.path.exists(absstandin):
        if os.path.exists(absstandin+'.orig'):
            shutil.copyfile(abslfile, abslfile+'.orig')
        expecthash = lfutil.readstandin(repo, lfile)
        if expecthash != '' and \
                (not os.path.exists(abslfile) or \
                expecthash != lfutil.hashfile(abslfile)):
            if not lfutil.copyfromcache(repo, expecthash, lfile):
                return None # don't try to set the mode or update the dirstate
            ret = 1
        mode = os.stat(absstandin).st_mode
        if mode != os.stat(abslfile).st_mode:
            os.chmod(abslfile, mode)
            ret = 1
    else:
        if os.path.exists(abslfile):
            os.unlink(abslfile)
            ret = -1
    state = repo.dirstate[lfutil.standin(lfile)]
    if state == 'n':
        lfdirstate.normal(lfile)
    elif state == 'r':
        lfdirstate.remove(lfile)
    elif state == 'a':
        lfdirstate.add(lfile)
    elif state == '?':
        try:
            # Mercurial >= 1.9
            lfdirstate.drop(lfile)
        except AttributeError:
            # Mercurial <= 1.8
            lfdirstate.forget(lfile)
    return ret

# -- hg commands declarations ------------------------------------------------


cmdtable = {
    'lfconvert': (lfconvert,
                  [('s', 'size', 0, 'All files over this size (in megabytes) '
                  'will be considered largefiles. This can also be specified '
                  'in your hgrc as [largefiles].size.'),
                  ('','tonormal',False,
                      'Convert from a largefiles repo to a normal repo')],
                  _('hg lfconvert SOURCE DEST [FILE ...]')),
    }