# -*- coding: utf-8 -*-

import os
import os.path as osp
import socket
import time
import atexit
import random

# Local imports
from spyderlib.cli_options import get_options
from spyderlib.baseconfig import get_conf_path, running_in_mac_app
from spyderlib.config import CONF
from spyderlib.baseconfig import DEV, TEST
from spyderlib.utils.external import lockfile
from spyderlib.py3compat import is_unicode


def send_args_to_spyder(args):
    """
    Simple socket client used to send the args passed to the Spyder 
    executable to an already running instance.

    Args can be Python scripts or files with these extensions: .spydata, .mat,
    .npy, or .h5, which can be imported by the Variable Explorer.
    """
    port = CONF.get('main', 'open_files_port')

    # Wait ~50 secs for the server to be up
    # Taken from http://stackoverflow.com/a/4766598/438386
    for _x in range(200):
        try:
            for arg in args:
                client = socket.socket(socket.AF_INET, socket.SOCK_STREAM,
                                       socket.IPPROTO_TCP)
                client.connect(("127.0.0.1", port))
                if is_unicode(arg):
                    arg = arg.encode('utf-8')
                client.send(osp.abspath(arg))
                client.close()
        except socket.error:
            time.sleep(0.25)
            continue
        break


def main():
    """
    Start Spyder application.

    If single instance mode is turned on (default behavior) and an instance of
    Spyder is already running, this will just parse and send command line
    options to the application.
    """
    # Renaming old configuration files (the '.' prefix has been removed)
    # (except for .spyder.ini --> spyder.ini, which is done in userconfig.py)
    if DEV is None:
        cpath = get_conf_path()
        for fname in os.listdir(cpath):
            if fname.startswith('.'):
                old, new = osp.join(cpath, fname), osp.join(cpath, fname[1:])
                try:
                    os.rename(old, new)
                except OSError:
                    pass

    # Parse command line options
    options, args = get_options()

    if CONF.get('main', 'single_instance') and not options.new_instance \
      and not running_in_mac_app():
        # Minimal delay (0.1-0.2 secs) to avoid that several
        # instances started at the same time step in their
        # own foots while trying to create the lock file
        time.sleep(random.randrange(1000, 2000, 90)/10000.)

        # Lock file creation
        lock_file = get_conf_path('spyder.lock')
        lock = lockfile.FilesystemLock(lock_file)

        # Try to lock spyder.lock. If it's *possible* to do it, then
        # there is no previous instance running and we can start a
        # new one. If *not*, then there is an instance already
        # running, which is locking that file
        try:
            lock_created = lock.lock()
        except:
            # If locking fails because of errors in the lockfile
            # module, try to remove a possibly stale spyder.lock.
            # This is reported to solve all problems with
            # lockfile (See issue 2363)
            try:
                if os.name == 'nt':
                    if osp.isdir(lock_file):
                        import shutil
                        shutil.rmtree(lock_file, ignore_errors=True)
                else:
                    if osp.islink(lock_file):
                        os.unlink(lock_file)
            except:
                pass

            # Then start Spyder as usual and *don't* continue
            # executing this script because it doesn't make
            # sense
            from spyderlib import spyder
            spyder.main()
            return

        if lock_created:
            # Start a new instance
            if TEST is None:
                atexit.register(lock.unlock)
            from spyderlib import spyder
            spyder.main()
        else:
            # Pass args to Spyder or print an informative
            # message
            if args:
                send_args_to_spyder(args)
            else:
                print("Spyder is already running. If you want to open a new \n"
                      "instance, please pass to it the --new-instance option")
    else:
        from spyderlib import spyder
        spyder.main()


if __name__ == "__main__":
    main()