#!/bin/sh
"""": # -*-python-*-
bup_python="$(dirname "$0")/bup-python" || exit $?
exec "$bup_python" "$0" ${1+"$@"}
"""
# end of bup preamble

from errno import EACCES
from io import BytesIO
import os, sys, stat, time, math

from bup import hashsplit, git, options, index, client, metadata, hlinkdb
from bup.hashsplit import GIT_MODE_TREE, GIT_MODE_FILE, GIT_MODE_SYMLINK
from bup.helpers import (add_error, grafted_path_components, handle_ctrl_c,
                         hostname, istty2, log, parse_date_or_fatal, parse_num,
                         path_components, progress, qprogress, resolve_parent,
                         saved_errors, stripped_path_components,
                         userfullname, username, valid_save_name)


optspec = """
bup save [-tc] [-n name] <filenames...>
--
r,remote=  hostname:/path/to/repo of remote repository
t,tree     output a tree id
c,commit   output a commit id
n,name=    name of backup set to update (if any)
d,date=    date for the commit (seconds since the epoch)
v,verbose  increase log output (can be used more than once)
q,quiet    don't show progress meter
smaller=   only back up files smaller than n bytes
bwlimit=   maximum bytes/sec to transmit to server
f,indexfile=  the name of the index file (normally BUP_DIR/bupindex)
strip      strips the path to every filename given
strip-path= path-prefix to be stripped when saving
graft=     a graft point *old_path*=*new_path* (can be used more than once)
#,compress=  set compression level to # (0-9, 9 is highest) [1]
"""
o = options.Options(optspec)
(opt, flags, extra) = o.parse(sys.argv[1:])

git.check_repo_or_die()
if not (opt.tree or opt.commit or opt.name):
    o.fatal("use one or more of -t, -c, -n")
if not extra:
    o.fatal("no filenames given")

opt.progress = (istty2 and not opt.quiet)
opt.smaller = parse_num(opt.smaller or 0)
if opt.bwlimit:
    client.bwlimit = parse_num(opt.bwlimit)

if opt.date:
    date = parse_date_or_fatal(opt.date, o.fatal)
else:
    date = time.time()

if opt.strip and opt.strip_path:
    o.fatal("--strip is incompatible with --strip-path")

graft_points = []
if opt.graft:
    if opt.strip:
        o.fatal("--strip is incompatible with --graft")

    if opt.strip_path:
        o.fatal("--strip-path is incompatible with --graft")

    for (option, parameter) in flags:
        if option == "--graft":
            splitted_parameter = parameter.split('=')
            if len(splitted_parameter) != 2:
                o.fatal("a graft point must be of the form old_path=new_path")
            old_path, new_path = splitted_parameter
            if not (old_path and new_path):
                o.fatal("a graft point cannot be empty")
            graft_points.append((resolve_parent(old_path),
                                 resolve_parent(new_path)))

is_reverse = os.environ.get('BUP_SERVER_REVERSE')
if is_reverse and opt.remote:
    o.fatal("don't use -r in reverse mode; it's automatic")

if opt.name and not valid_save_name(opt.name):
    o.fatal("'%s' is not a valid branch name" % opt.name)
refname = opt.name and 'refs/heads/%s' % opt.name or None
if opt.remote or is_reverse:
    try:
        cli = client.Client(opt.remote)
    except client.ClientError as e:
        log('error: %s' % e)
        sys.exit(1)
    oldref = refname and cli.read_ref(refname) or None
    w = cli.new_packwriter(compression_level=opt.compress)
else:
    cli = None
    oldref = refname and git.read_ref(refname) or None
    w = git.PackWriter(compression_level=opt.compress)

handle_ctrl_c()


def eatslash(dir):
    if dir.endswith('/'):
        return dir[:-1]
    else:
        return dir


# Metadata is stored in a file named .bupm in each directory.  The
# first metadata entry will be the metadata for the current directory.
# The remaining entries will be for each of the other directory
# elements, in the order they're listed in the index.
#
# Since the git tree elements are sorted according to
# git.shalist_item_sort_key, the metalist items are accumulated as
# (sort_key, metadata) tuples, and then sorted when the .bupm file is
# created.  The sort_key must be computed using the element's real
# name and mode rather than the git mode and (possibly mangled) name.

# Maintain a stack of information representing the current location in
# the archive being constructed.  The current path is recorded in
# parts, which will be something like ['', 'home', 'someuser'], and
# the accumulated content and metadata for of the dirs in parts is
# stored in parallel stacks in shalists and metalists.

parts = [] # Current archive position (stack of dir names).
shalists = [] # Hashes for each dir in paths.
metalists = [] # Metadata for each dir in paths.


def _push(part, metadata):
    # Enter a new archive directory -- make it the current directory.
    parts.append(part)
    shalists.append([])
    metalists.append([('', metadata)]) # This dir's metadata (no name).


def _pop(force_tree, dir_metadata=None):
    # Leave the current archive directory and add its tree to its parent.
    assert(len(parts) >= 1)
    part = parts.pop()
    shalist = shalists.pop()
    metalist = metalists.pop()
    if metalist and not force_tree:
        if dir_metadata: # Override the original metadata pushed for this dir.
            metalist = [('', dir_metadata)] + metalist[1:]
        sorted_metalist = sorted(metalist, key = lambda x : x[0])
        metadata = ''.join([m[1].encode() for m in sorted_metalist])
        metadata_f = BytesIO(metadata)
        mode, id = hashsplit.split_to_blob_or_tree(w.new_blob, w.new_tree,
                                                   [metadata_f],
                                                   keep_boundaries=False)
        shalist.append((mode, '.bupm', id))
    # FIXME: only test if collision is possible (i.e. given --strip, etc.)?
    if force_tree:
        tree = force_tree
    else:
        names_seen = set()
        clean_list = []
        for x in shalist:
            name = x[1]
            if name in names_seen:
                parent_path = '/'.join(parts) + '/'
                add_error('error: ignoring duplicate path %r in %r'
                          % (name, parent_path))
            else:
                names_seen.add(name)
                clean_list.append(x)
        tree = w.new_tree(clean_list)
    if shalists:
        shalists[-1].append((GIT_MODE_TREE,
                             git.mangle_name(part,
                                             GIT_MODE_TREE, GIT_MODE_TREE),
                             tree))
    return tree


lastremain = None
def progress_report(n):
    global count, subcount, lastremain
    subcount += n
    cc = count + subcount
    pct = total and (cc*100.0/total) or 0
    now = time.time()
    elapsed = now - tstart
    kps = elapsed and int(cc/1024./elapsed)
    kps_frac = 10 ** int(math.log(kps+1, 10) - 1)
    kps = int(kps/kps_frac)*kps_frac
    if cc:
        remain = elapsed*1.0/cc * (total-cc)
    else:
        remain = 0.0
    if (lastremain and (remain > lastremain)
          and ((remain - lastremain)/lastremain < 0.05)):
        remain = lastremain
    else:
        lastremain = remain
    hours = int(remain/60/60)
    mins = int(remain/60 - hours*60)
    secs = int(remain - hours*60*60 - mins*60)
    if elapsed < 30:
        remainstr = ''
        kpsstr = ''
    else:
        kpsstr = '%dk/s' % kps
        if hours:
            remainstr = '%dh%dm' % (hours, mins)
        elif mins:
            remainstr = '%dm%d' % (mins, secs)
        else:
            remainstr = '%ds' % secs
    qprogress('Saving: %.2f%% (%d/%dk, %d/%d files) %s %s\r'
              % (pct, cc/1024, total/1024, fcount, ftotal,
                 remainstr, kpsstr))


indexfile = opt.indexfile or git.repo('bupindex')
r = index.Reader(indexfile)
try:
    msr = index.MetaStoreReader(indexfile + '.meta')
except IOError as ex:
    if ex.errno != EACCES:
        raise
    log('error: cannot access %r; have you run bup index?' % indexfile)
    sys.exit(1)
hlink_db = hlinkdb.HLinkDB(indexfile + '.hlink')

def already_saved(ent):
    return ent.is_valid() and w.exists(ent.sha) and ent.sha

def wantrecurse_pre(ent):
    return not already_saved(ent)

def wantrecurse_during(ent):
    return not already_saved(ent) or ent.sha_missing()

def find_hardlink_target(hlink_db, ent):
    if hlink_db and not stat.S_ISDIR(ent.mode) and ent.nlink > 1:
        link_paths = hlink_db.node_paths(ent.dev, ent.ino)
        if link_paths:
            return link_paths[0]

total = ftotal = 0
if opt.progress:
    for (transname,ent) in r.filter(extra, wantrecurse=wantrecurse_pre):
        if not (ftotal % 10024):
            qprogress('Reading index: %d\r' % ftotal)
        exists = ent.exists()
        hashvalid = already_saved(ent)
        ent.set_sha_missing(not hashvalid)
        if not opt.smaller or ent.size < opt.smaller:
            if exists and not hashvalid:
                total += ent.size
        ftotal += 1
    progress('Reading index: %d, done.\n' % ftotal)
    hashsplit.progress_callback = progress_report

# Root collisions occur when strip or graft options map more than one
# path to the same directory (paths which originally had separate
# parents).  When that situation is detected, use empty metadata for
# the parent.  Otherwise, use the metadata for the common parent.
# Collision example: "bup save ... --strip /foo /foo/bar /bar".

# FIXME: Add collision tests, or handle collisions some other way.

# FIXME: Detect/handle strip/graft name collisions (other than root),
# i.e. if '/foo/bar' and '/bar' both map to '/'.

first_root = None
root_collision = None
tstart = time.time()
count = subcount = fcount = 0
lastskip_name = None
lastdir = ''
for (transname,ent) in r.filter(extra, wantrecurse=wantrecurse_during):
    (dir, file) = os.path.split(ent.name)
    exists = (ent.flags & index.IX_EXISTS)
    hashvalid = already_saved(ent)
    wasmissing = ent.sha_missing()
    oldsize = ent.size
    if opt.verbose:
        if not exists:
            status = 'D'
        elif not hashvalid:
            if ent.sha == index.EMPTY_SHA:
                status = 'A'
            else:
                status = 'M'
        else:
            status = ' '
        if opt.verbose >= 2:
            log('%s %-70s\n' % (status, ent.name))
        elif not stat.S_ISDIR(ent.mode) and lastdir != dir:
            if not lastdir.startswith(dir):
                log('%s %-70s\n' % (status, os.path.join(dir, '')))
            lastdir = dir

    if opt.progress:
        progress_report(0)
    fcount += 1
    
    if not exists:
        continue
    if opt.smaller and ent.size >= opt.smaller:
        if exists and not hashvalid:
            if opt.verbose:
                log('skipping large file "%s"\n' % ent.name)
            lastskip_name = ent.name
        continue

    assert(dir.startswith('/'))
    if opt.strip:
        dirp = stripped_path_components(dir, extra)
    elif opt.strip_path:
        dirp = stripped_path_components(dir, [opt.strip_path])
    elif graft_points:
        dirp = grafted_path_components(graft_points, dir)
    else:
        dirp = path_components(dir)

    # At this point, dirp contains a representation of the archive
    # path that looks like [(archive_dir_name, real_fs_path), ...].
    # So given "bup save ... --strip /foo/bar /foo/bar/baz", dirp
    # might look like this at some point:
    #   [('', '/foo/bar'), ('baz', '/foo/bar/baz'), ...].

    # This dual representation supports stripping/grafting, where the
    # archive path may not have a direct correspondence with the
    # filesystem.  The root directory is represented by an initial
    # component named '', and any component that doesn't have a
    # corresponding filesystem directory (due to grafting, for
    # example) will have a real_fs_path of None, i.e. [('', None),
    # ...].

    if first_root == None:
        first_root = dirp[0]
    elif first_root != dirp[0]:
        root_collision = True

    # If switching to a new sub-tree, finish the current sub-tree.
    while parts > [x[0] for x in dirp]:
        _pop(force_tree = None)

    # If switching to a new sub-tree, start a new sub-tree.
    for path_component in dirp[len(parts):]:
        dir_name, fs_path = path_component
        # Not indexed, so just grab the FS metadata or use empty metadata.
        try:
           meta = metadata.from_path(fs_path) if fs_path else metadata.Metadata()
        except (OSError, IOError) as e:
            add_error(e)
            lastskip_name = dir_name
            meta = metadata.Metadata()
        _push(dir_name, meta)

    if not file:
        if len(parts) == 1:
            continue # We're at the top level -- keep the current root dir
        # Since there's no filename, this is a subdir -- finish it.
        oldtree = already_saved(ent) # may be None
        newtree = _pop(force_tree = oldtree)
        if not oldtree:
            if lastskip_name and lastskip_name.startswith(ent.name):
                ent.invalidate()
            else:
                ent.validate(GIT_MODE_TREE, newtree)
            ent.repack()
        if exists and wasmissing:
            count += oldsize
        continue

    # it's not a directory
    id = None
    if hashvalid:
        id = ent.sha
        git_name = git.mangle_name(file, ent.mode, ent.gitmode)
        git_info = (ent.gitmode, git_name, id)
        shalists[-1].append(git_info)
        sort_key = git.shalist_item_sort_key((ent.mode, file, id))
        meta = msr.metadata_at(ent.meta_ofs)
        meta.hardlink_target = find_hardlink_target(hlink_db, ent)
        # Restore the times that were cleared to 0 in the metastore.
        (meta.atime, meta.mtime, meta.ctime) = (ent.atime, ent.mtime, ent.ctime)
        metalists[-1].append((sort_key, meta))
    else:
        if stat.S_ISREG(ent.mode):
            try:
                f = hashsplit.open_noatime(ent.name)
            except (IOError, OSError) as e:
                add_error(e)
                lastskip_name = ent.name
            else:
                try:
                    (mode, id) = hashsplit.split_to_blob_or_tree(
                                            w.new_blob, w.new_tree, [f],
                                            keep_boundaries=False)
                except (IOError, OSError) as e:
                    add_error('%s: %s' % (ent.name, e))
                    lastskip_name = ent.name
        else:
            if stat.S_ISDIR(ent.mode):
                assert(0)  # handled above
            elif stat.S_ISLNK(ent.mode):
                try:
                    rl = os.readlink(ent.name)
                except (OSError, IOError) as e:
                    add_error(e)
                    lastskip_name = ent.name
                else:
                    (mode, id) = (GIT_MODE_SYMLINK, w.new_blob(rl))
            else:
                # Everything else should be fully described by its
                # metadata, so just record an empty blob, so the paths
                # in the tree and .bupm will match up.
                (mode, id) = (GIT_MODE_FILE, w.new_blob(""))

        if id:
            ent.validate(mode, id)
            ent.repack()
            git_name = git.mangle_name(file, ent.mode, ent.gitmode)
            git_info = (mode, git_name, id)
            shalists[-1].append(git_info)
            sort_key = git.shalist_item_sort_key((ent.mode, file, id))
            hlink = find_hardlink_target(hlink_db, ent)
            try:
                meta = metadata.from_path(ent.name, hardlink_target=hlink)
            except (OSError, IOError) as e:
                add_error(e)
                lastskip_name = ent.name
            else:
                metalists[-1].append((sort_key, meta))

    if exists and wasmissing:
        count += oldsize
        subcount = 0


if opt.progress:
    pct = total and count*100.0/total or 100
    progress('Saving: %.2f%% (%d/%dk, %d/%d files), done.    \n'
             % (pct, count/1024, total/1024, fcount, ftotal))

while len(parts) > 1: # _pop() all the parts above the root
    _pop(force_tree = None)
assert(len(shalists) == 1)
assert(len(metalists) == 1)

# Finish the root directory.
tree = _pop(force_tree = None,
            # When there's a collision, use empty metadata for the root.
            dir_metadata = metadata.Metadata() if root_collision else None)

if opt.tree:
    print tree.encode('hex')
if opt.commit or opt.name:
    msg = 'bup save\n\nGenerated by command:\n%r\n' % sys.argv
    userline = '%s <%s@%s>' % (userfullname(), username(), hostname())
    commit = w.new_commit(tree, oldref, userline, date, None,
                          userline, date, None, msg)
    if opt.commit:
        print commit.encode('hex')

msr.close()
w.close()  # must close before we can update the ref
        
if opt.name:
    if cli:
        cli.update_ref(refname, commit, oldref)
    else:
        git.update_ref(refname, commit, oldref)

if cli:
    cli.close()

if saved_errors:
    log('WARNING: %d errors encountered while saving.\n' % len(saved_errors))
    sys.exit(1)
