#!/usr/bin/env python

from arvados.fuse import *
import arvados
import subprocess
import argparse
import daemon

if __name__ == '__main__':
    # Handle command line parameters
    parser = argparse.ArgumentParser(
        description='''Mount Keep data under the local filesystem.  By default, if neither
        --collection or --tags is specified, this mounts as a virtual directory
        under which all Keep collections are available as subdirectories named
        with the Keep locator; however directories will not be visible to 'ls'
        until a program tries to access them.''',
        epilog="""
Note: When using the --exec feature, you must either specify the
mountpoint before --exec, or mark the end of your --exec arguments
with "--".
""")
    parser.add_argument('mountpoint', type=str, help="""Mount point.""")
    parser.add_argument('--allow-other', action='store_true',
                        help="""Let other users read the mount""")
    parser.add_argument('--collection', type=str, help="""Mount only the specified collection at the mount point.""")
    parser.add_argument('--tags', action='store_true', help="""Mount as a virtual directory consisting of subdirectories representing tagged
collections on the server.""")
    parser.add_argument('--groups', action='store_true', help="""Mount as a virtual directory consisting of subdirectories representing groups on the server.""")
    parser.add_argument('--debug', action='store_true', help="""Debug mode""")
    parser.add_argument('--foreground', action='store_true', help="""Run in foreground (default is to daemonize unless --exec specified)""", default=False)
    parser.add_argument('--exec', type=str, nargs=argparse.REMAINDER,
                        dest="exec_args", metavar=('command', 'args', '...', '--'),
                        help="""Mount, run a command, then unmount and exit""")

    args = parser.parse_args()

    # Create the request handler
    operations = Operations(os.getuid(), os.getgid())

    if args.groups:
        api = arvados.api('v1')
        e = operations.inodes.add_entry(GroupsDirectory(llfuse.ROOT_INODE, operations.inodes, api))
    elif args.tags:
        api = arvados.api('v1')
        e = operations.inodes.add_entry(TagsDirectory(llfuse.ROOT_INODE, operations.inodes, api))
    elif args.collection != None:
        # Set up the request handler with the collection at the root
        e = operations.inodes.add_entry(CollectionDirectory(llfuse.ROOT_INODE, operations.inodes, args.collection))
    else:
        # Set up the request handler with the 'magic directory' at the root
        operations.inodes.add_entry(MagicDirectory(llfuse.ROOT_INODE, operations.inodes))

    # FUSE options, see mount.fuse(8)
    opts = [optname for optname in ['allow_other', 'debug']
            if getattr(args, optname)]

    if args.exec_args:
        # Initialize the fuse connection
        llfuse.init(operations, args.mountpoint, opts)

        t = threading.Thread(None, lambda: llfuse.main())
        t.start()

        # wait until the driver is finished initializing
        operations.initlock.wait()

        rc = 255
        try:
            rc = subprocess.call(args.exec_args, shell=False)
        except OSError as e:
            sys.stderr.write('arv-mount: %s -- exec %s\n' % (str(e), args.exec_args))
            rc = e.errno
        except Exception as e:
            sys.stderr.write('arv-mount: %s\n' % str(e))
        finally:
            subprocess.call(["fusermount", "-u", "-z", args.mountpoint])

        exit(rc)
    else:
        if args.foreground:
            # Initialize the fuse connection
            llfuse.init(operations, args.mountpoint, opts)
            llfuse.main()
        else:
            with daemon.DaemonContext():
                # Initialize the fuse connection
                llfuse.init(operations, args.mountpoint, opts)
                llfuse.main()