"""
corecommands.py - Implements core PyLink commands.
"""

import gc
import sys
import importlib

from . import control
from pylinkirc import utils, world
from pylinkirc.log import log

# Essential, core commands go here so that the "commands" plugin with less-important,
# but still generic functions can be reloaded.

@utils.add_cmd
def identify(irc, source, args):
    """<username> <password>

    Logs in to PyLink using the configured administrator account."""
    if utils.isChannel(irc.called_by):
        irc.reply('Error: This command must be sent in private. '
                '(Would you really type a password inside a channel?)')
        return
    try:
        username, password = args[0], args[1]
    except IndexError:
        irc.msg(source, 'Error: Not enough arguments.')
        return
    # Usernames are case-insensitive, passwords are NOT.
    if username.lower() == irc.conf['login']['user'].lower() and password == irc.conf['login']['password']:
        realuser = irc.conf['login']['user']
        irc.users[source].identified = realuser
        irc.msg(source, 'Successfully logged in as %s.' % realuser)
        log.info("(%s) Successful login to %r by %s",
                 irc.name, username, irc.getHostmask(source))
    else:
        irc.msg(source, 'Error: Incorrect credentials.')
        u = irc.users[source]
        log.warning("(%s) Failed login to %r from %s",
                    irc.name, username, irc.getHostmask(source))

@utils.add_cmd
def shutdown(irc, source, args):
    """takes no arguments.

    Exits PyLink by disconnecting all networks."""
    irc.checkAuthenticated(source, allowOper=False)
    u = irc.users[source]

    log.info('(%s) SHUTDOWN requested by "%s!%s@%s", exiting...', irc.name, u.nick,
             u.ident, u.host)

    control._shutdown(irc)

@utils.add_cmd
def load(irc, source, args):
    """<plugin name>.

    Loads a plugin from the plugin folder."""
    irc.checkAuthenticated(source, allowOper=False)
    try:
        name = args[0]
    except IndexError:
        irc.reply("Error: Not enough arguments. Needs 1: plugin name.")
        return
    if name in world.plugins:
        irc.reply("Error: %r is already loaded." % name)
        return
    log.info('(%s) Loading plugin %r for %s', irc.name, name, irc.getHostmask(source))
    try:
        world.plugins[name] = pl = utils.loadPlugin(name)
    except ImportError as e:
        if str(e) == ('No module named %r' % name):
            log.exception('Failed to load plugin %r: The plugin could not be found.', name)
        else:
            log.exception('Failed to load plugin %r: ImportError.', name)
        raise
    else:
        importlib.reload(pl)
        if hasattr(pl, 'main'):
            log.debug('Calling main() function of plugin %r', pl)
            pl.main(irc)
    irc.reply("Loaded plugin %r." % name)

@utils.add_cmd
def unload(irc, source, args):
    """<plugin name>.

    Unloads a currently loaded plugin."""
    irc.checkAuthenticated(source, allowOper=False)
    try:
        name = args[0]
    except IndexError:
        irc.reply("Error: Not enough arguments. Needs 1: plugin name.")
        return
    if name in world.plugins:
        log.info('(%s) Unloading plugin %r for %s', irc.name, name, irc.getHostmask(source))
        pl = world.plugins[name]
        log.debug('sys.getrefcount of plugin %s is %s', pl, sys.getrefcount(pl))

        # Remove any command functions defined by the plugin.
        for cmdname, cmdfuncs in world.services['pylink'].commands.copy().items():
            log.debug('cmdname=%s, cmdfuncs=%s', cmdname, cmdfuncs)

            for cmdfunc in cmdfuncs:
                log.debug('__module__ of cmdfunc %s is %s', cmdfunc, cmdfunc.__module__)
                if cmdfunc.__module__ == name:
                    log.debug("Removing %s from world.services['pylink'].commands[%s]", cmdfunc, cmdname)
                    world.services['pylink'].commands[cmdname].remove(cmdfunc)

                    # If the cmdfunc list is empty, remove it.
                    if not cmdfuncs:
                        log.debug("Removing world.services['pylink'].commands[%s] (it's empty now)", cmdname)
                        del world.services['pylink'].commands[cmdname]

        # Remove any command hooks set by the plugin.
        for hookname, hookfuncs in world.hooks.copy().items():
            for hookfunc in hookfuncs:
                if hookfunc.__module__ == name:
                    world.hooks[hookname].remove(hookfunc)
                    # If the hookfuncs list is empty, remove it.
                    if not hookfuncs:
                        del world.hooks[hookname]

        # Call the die() function in the plugin, if present.
        if hasattr(pl, 'die'):
            try:
                pl.die(irc)
            except:  # But don't allow it to crash the server.
                log.exception('(%s) Error occurred in die() of plugin %s, skipping...', irc.name, pl)

        # Delete it from memory (hopefully).
        del world.plugins[name]
        if name in sys.modules:
            del sys.modules[name]
        if name in globals():
            del globals()[name]

        # Garbage collect.
        gc.collect()

        irc.reply("Unloaded plugin %r." % name)
        return True  # We succeeded, make it clear (this status is used by reload() below)
    else:
        irc.reply("Unknown plugin %r." % name)

@utils.add_cmd
def reload(irc, source, args):
    """<plugin name>.

    Loads a plugin from the plugin folder."""
    try:
        name = args[0]
    except IndexError:
        irc.reply("Error: Not enough arguments. Needs 1: plugin name.")
        return
    if unload(irc, source, args):
        load(irc, source, args)

@utils.add_cmd
def rehash(irc, source, args):
    """takes no arguments.

    Reloads the configuration file for PyLink, (dis)connecting added/removed networks.
    Plugins must be manually reloaded."""
    irc.checkAuthenticated(source, allowOper=False)
    try:
        control._rehash()
    except Exception as e:  # Something went wrong, abort.
        log.exception("Error REHASHing config: ")
        irc.reply("Error loading configuration file: %s: %s" % (type(e).__name__, e))
        return
    else:
        irc.reply("Done.")