"""Status line.

Provides space for some buttons (typically navigation buttons),
information about the current viewport, and a status line.

Part of the tagit module.
A copy of the license is provided with the project.
Author: Matthias Baumgartner, 2022
"""
# standard imports
import os
import logging

# kivy imports
from kivy.clock import mainthread
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
import kivy.properties as kp

# tagit imports
from tagit import config, dialogues, logger

# inner-module imports
from .browser import BrowserAwareMixin
from .session import ConfigAwareMixin

# exports
__all__ = ('Status', )


## code ##

# load kv
Builder.load_file(os.path.join(os.path.dirname(__file__), 'status.kv'))

# classes
class Status(BoxLayout, BrowserAwareMixin, ConfigAwareMixin):
    """Status line."""
    # root reference
    root = kp.ObjectProperty(None)
    # log history
    history = kp.ListProperty()
    # log handlers
    handler_history = None
    handler_status = None

    # events

    __events__ = ('on_status', )

    def on_status(sender, status):
        """Event prototype"""
        pass


    # bindings to others

    def on_root(self, wx, root):
        """Bind events."""
        # bind to browser and config
        BrowserAwareMixin.on_root(self, wx, root)
        ConfigAwareMixin.on_root(self, wx, root)
        # bind to status update event
        self.bind(on_status=self.status_from_event)

    def on_browser(self, wx, browser):
        """Bind to current browser properties."""
        # remove old binding
        if self.browser is not None:
            self.browser.unbind(page_size=self.on_navigation)
            self.browser.unbind(items=self.on_navigation)
            self.browser.unbind(offset=self.on_navigation)
        # add new binding
        self.browser = browser
        if self.browser is not None:
            self.browser.bind(page_size=self.on_navigation)
            self.browser.bind(items=self.on_navigation)
            self.browser.bind(offset=self.on_navigation)
        self.on_navigation(browser, browser.offset)

    def on_config_changed(self, session, key, value):
        if key in (('ui', 'standalone', 'logging', 'status'),
                   ('ui', 'standalone', 'logging', 'console')):
            self.on_cfg(session, session.cfg)

    def on_cfg(self, wx, cfg):
        """Register handlers according to config."""
        if self.handler_status is not None:
            logging.getLogger().root.removeHandler(self.handler_status)
        if self.handler_history is not None:
            logging.getLogger().root.removeHandler(self.handler_history)

        # status log event
        self.handler_status = logger.logger_config(
            logger.CallbackHandler(self.status_from_log),
            logger.ColorsMarkup,
            cfg('ui', 'standalone', 'logging', 'status').to_tree(defaults=True))
        logging.getLogger().root.addHandler(self.handler_status)

        # history (console)
        self.handler_history = logger.logger_config(
            logger.CallbackHandler(self.update_history),
            logger.ColorsMarkup,
            cfg('ui', 'standalone', 'logging', 'console').to_tree(defaults=True))
        logging.getLogger().root.addHandler(self.handler_history)

    def __del__(self):
        if self.browser is not None:
            self.browser.unbind(page_size=self.on_navigation)
            self.browser.unbind(items=self.on_navigation)
            self.browser.unbind(offset=self.on_navigation)
            self.browser = None

        if self.handler_status is not None:
            logging.getLogger().root.removeHandler(self.handler_status)
            self.handler_status = None

        if self.handler_history is not None:
            logging.getLogger().root.removeHandler(self.handler_history)
            self.handler_history = None


    # console

    def on_touch_down(self, touch):
        """Open console dialogue when clicked on the status label."""
        if self.status_label.collide_point(*touch.pos):
            self.console() # show console
            return True
        elif self.navigation_label.collide_point(*touch.pos):
            self.root.trigger('JumpToPage') # show page dialogue
            return True
        return super(Status, self).on_touch_down(touch)

    def console(self):
        """Open console dialogue."""
        dlg = dialogues.Console()
        self.bind(history=dlg.update)
        dlg.update(self, self.history)
        dlg.open()


    # content updates

    def on_navigation(self, browser, value):
        """Update the navigation label if the browser changes."""
        first = browser.offset + 1 # first on page
        last = min(browser.offset + browser.page_size, browser.n_items) # last on page
        total = browser.n_items # total results
        self.navigation = f'{first} - {last} of {total}'

    @mainthread
    def update_history(self, fmt, record):
        """Update the history from the logger."""
        self.history.append(fmt(record))

    def status_from_event(self, wx, status):
        """Update the status line from the status event."""
        self.status = status

    @mainthread
    def status_from_log(self, fmt, record):
        """Update the status line from the logger."""
        self.status = fmt(record)


## config ##

# status
config.declare(('ui', 'standalone', 'logging', 'status', 'level'),
    config.Enum('debug', 'info', 'warn', 'error', 'critical'), 'info',
    __name__, 'Log level', 'Maximal log level for which messages are shown. The order is: critical > error > warning > info > volatile > debug')

config.declare(('ui', 'standalone', 'logging', 'status', 'filter'),
    config.List(config.String()), ['tagit'],
    __name__, 'Module filter', 'Module name for which log messages are accepted.')

config.declare(('ui', 'standalone', 'logging', 'status', 'fmt'), config.String(), '{title}{message}',
    __name__, 'Log format', 'Log message formatting. The formatting follows the typical python format string where each item is enclosed in curly braces (e.g. "{message}"). For printable items see the `logging attributes <https://docs.python.org/3.6/library/logging.html#logrecord-attributes>`_.  In addition to those, the item "title" is available, which is a placeholder for the formatted title (if present).')

config.declare(('ui', 'standalone', 'logging', 'status', 'title'), config.String(), '{title}: ',
    __name__, 'Title format', 'Title formatting.')

config.declare(('ui', 'standalone', 'logging', 'status', 'maxlen'), config.Unsigned(), 40,
    __name__, 'Maximal line length', 'Maximal line length (e.g. console width). Use Infinity to set no line length limit.')

# console
config.declare(('ui', 'standalone', 'logging', 'console', 'level'),
    config.Enum('debug', 'info', 'warn', 'error', 'critical'), 'info',
    __name__, 'Log level', 'Maximal log level for which messages are shown. The order is: critical > error > warning > info > volatile > debug')

config.declare(('ui', 'standalone', 'logging', 'console', 'filter'),
    config.List(config.String()), ['tagit'],
    __name__, 'Module filter', 'Module name for which log messages are accepted.')

config.declare(('ui', 'standalone', 'logging', 'console', 'fmt'),
    config.String(), '[{levelname}] {title}{message}',
    __name__, 'Log format', 'Log message formatting. The formatting follows the typical python format string where each item is enclosed in curly braces (e.g. "{message}"). For printable items see the `logging attributes <https://docs.python.org/3.6/library/logging.html#logrecord-attributes>`_.  In addition to those, the item "title" is available, which is a placeholder for the formatted title (if present).')

config.declare(('ui', 'standalone', 'logging', 'console', 'title'), config.String(), '[{title}]',
    __name__, 'Title format', 'Title formatting.')

config.declare(('ui', 'standalone', 'logging', 'console', 'maxlen'), config.Unsigned(), 0,
    __name__, 'Maximal line length', 'Maximal line length (e.g. console width). Use zero or infinity to set no line length limit.')

## EOF ##