#!/usr/bin/env python
# encoding: utf-8
#
# Copyright (c) 2015 deanishe@deanishe.net
#
# MIT Licence. See http://opensource.org/licenses/MIT
#
# Created on 2015-11-26
#

# TODO: Exclude this module from test and code coverage in py2.6

"""
Post notifications via the OS X Notification Center. This feature
is only available on Mountain Lion (10.8) and later. It will
silently fail on older systems.

The main API is a single function, :func:`~workflow.notify.notify`.

It works by copying a simple application to your workflow's data
directory. It replaces the application's icon with your workflow's
icon and then calls the application to post notifications.
"""

from __future__ import print_function, unicode_literals

import os
import plistlib
import shutil
import subprocess
import sys
import tarfile
import tempfile
import uuid

import workflow


_wf = None
_log = None


#: Available system sounds from System Preferences > Sound > Sound Effects
SOUNDS = (
    'Basso',
    'Blow',
    'Bottle',
    'Frog',
    'Funk',
    'Glass',
    'Hero',
    'Morse',
    'Ping',
    'Pop',
    'Purr',
    'Sosumi',
    'Submarine',
    'Tink',
)


def wf():
    """Return `Workflow` object for this module.

    Returns:
        workflow.Workflow: `Workflow` object for current workflow.
    """
    global _wf
    if _wf is None:
        _wf = workflow.Workflow()
    return _wf


def log():
    """Return logger for this module.

    Returns:
        logging.Logger: Logger for this module.
    """
    global _log
    if _log is None:
        _log = wf().logger
    return _log


def notifier_program():
    """Return path to notifier applet executable.

    Returns:
        unicode: Path to Notify.app `applet` executable.
    """
    return wf().datafile('Notify.app/Contents/MacOS/applet')


def notifier_icon_path():
    """Return path to icon file in installed Notify.app.

    Returns:
        unicode: Path to `applet.icns` within the app bundle.
    """
    return wf().datafile('Notify.app/Contents/Resources/applet.icns')


def install_notifier():
    """Extract `Notify.app` from the workflow to data directory.

    Changes the bundle ID of the installed app and gives it the
    workflow's icon.
    """
    archive = os.path.join(os.path.dirname(__file__), 'Notify.tgz')
    destdir = wf().datadir
    app_path = os.path.join(destdir, 'Notify.app')
    n = notifier_program()
    log().debug("Installing Notify.app to %r ...", destdir)
    # z = zipfile.ZipFile(archive, 'r')
    # z.extractall(destdir)
    tgz = tarfile.open(archive, 'r:gz')
    tgz.extractall(destdir)
    assert os.path.exists(n), (
        "Notify.app could not be installed in {0!r}.".format(destdir))

    # Replace applet icon
    icon = notifier_icon_path()
    workflow_icon = wf().workflowfile('icon.png')
    if os.path.exists(icon):
        os.unlink(icon)

    png_to_icns(workflow_icon, icon)

    # Set file icon
    # PyObjC isn't available for 2.6, so this is 2.7 only. Actually,
    # none of this code will "work" on pre-10.8 systems. Let it run
    # until I figure out a better way of excluding this module
    # from coverage in py2.6.
    if sys.version_info >= (2, 7):  # pragma: no cover
        from AppKit import NSWorkspace, NSImage

        ws = NSWorkspace.sharedWorkspace()
        img = NSImage.alloc().init()
        img.initWithContentsOfFile_(icon)
        ws.setIcon_forFile_options_(img, app_path, 0)

    # Change bundle ID of installed app
    ip_path = os.path.join(app_path, 'Contents/Info.plist')
    bundle_id = '{0}.{1}'.format(wf().bundleid, uuid.uuid4().hex)
    data = plistlib.readPlist(ip_path)
    log().debug('Changing bundle ID to {0!r}'.format(bundle_id))
    data['CFBundleIdentifier'] = bundle_id
    plistlib.writePlist(data, ip_path)


def validate_sound(sound):
    """Coerce `sound` to valid sound name.

    Returns `None` for invalid sounds. Sound names can be found
    in `System Preferences > Sound > Sound Effects`.

    Args:
        sound (str): Name of system sound.

    Returns:
        str: Proper name of sound or `None`.
    """
    if not sound:
        return None

    # Case-insensitive comparison of `sound`
    if sound.lower() in [s.lower() for s in SOUNDS]:
        # Title-case is correct for all system sounds as of OS X 10.11
        return sound.title()
    return None


def notify(title='', text='', sound=None):
    """Post notification via Notify.app helper.

    Args:
        title (str, optional): Notification title.
        text (str, optional): Notification body text.
        sound (str, optional): Name of sound to play.

    Raises:
        ValueError: Raised if both `title` and `text` are empty.

    Returns:
        bool: `True` if notification was posted, else `False`.
    """
    if title == text == '':
        raise ValueError('Empty notification')

    sound = validate_sound(sound) or ''

    n = notifier_program()

    if not os.path.exists(n):
        install_notifier()

    env = os.environ.copy()
    enc = 'utf-8'
    env['NOTIFY_TITLE'] = title.encode(enc)
    env['NOTIFY_MESSAGE'] =  text.encode(enc)
    env['NOTIFY_SOUND'] = sound.encode(enc)
    cmd = [n]
    retcode = subprocess.call(cmd, env=env)
    if retcode == 0:
        return True

    log().error('Notify.app exited with status {0}.'.format(retcode))
    return False


def convert_image(inpath, outpath, size):
    """Convert an image file using `sips`.

    Args:
        inpath (str): Path of source file.
        outpath (str): Path to destination file.
        size (int): Width and height of destination image in pixels.

    Raises:
        RuntimeError: Raised if `sips` exits with non-zero status.
    """
    cmd = [
        b'sips',
        b'-z', b'{0}'.format(size), b'{0}'.format(size),
        inpath,
        b'--out', outpath]
    # log().debug(cmd)
    with open(os.devnull, 'w') as pipe:
        retcode = subprocess.call(cmd, stdout=pipe, stderr=subprocess.STDOUT)

    if retcode != 0:
        raise RuntimeError('sips exited with {0}'.format(retcode))


def png_to_icns(png_path, icns_path):
    """Convert PNG file to ICNS using `iconutil`.

    Create an iconset from the source PNG file. Generate PNG files
    in each size required by OS X, then call `iconutil` to turn
    them into a single ICNS file.

    Args:
        png_path (str): Path to source PNG file.
        icns_path (str): Path to destination ICNS file.

    Raises:
        RuntimeError: Raised if `iconutil` or `sips` fail.
    """
    tempdir = tempfile.mkdtemp(prefix='aw-', dir=wf().datadir)

    try:
        iconset = os.path.join(tempdir, 'Icon.iconset')

        assert not os.path.exists(iconset), (
            "Iconset path already exists : {0!r}".format(iconset))
        os.makedirs(iconset)

        # Copy source icon to icon set and generate all the other
        # sizes needed
        configs = []
        for i in (16, 32, 128, 256, 512):
            configs.append(('icon_{0}x{0}.png'.format(i), i))
            configs.append((('icon_{0}x{0}@2x.png'.format(i), i*2)))

        shutil.copy(png_path, os.path.join(iconset, 'icon_256x256.png'))
        shutil.copy(png_path, os.path.join(iconset, 'icon_128x128@2x.png'))

        for name, size in configs:
            outpath = os.path.join(iconset, name)
            if os.path.exists(outpath):
                continue
            convert_image(png_path, outpath, size)

        cmd = [
            b'iconutil',
            b'-c', b'icns',
            b'-o', icns_path,
            iconset]

        retcode = subprocess.call(cmd)
        if retcode != 0:
            raise RuntimeError("iconset exited with {0}".format(retcode))

        assert os.path.exists(icns_path), (
            "Generated ICNS file not found : {0!r}".format(icns_path))
    finally:
        try:
            shutil.rmtree(tempdir)
        except OSError:  # pragma: no cover
            pass


# def notify_native(title='', text='', sound=''):
#     """Post notification via the native API (via pyobjc).

#     At least one of `title` or `text` must be specified.

#     This method will *always* show the Python launcher icon (i.e. the
#     rocket with the snakes on it).

#     Args:
#         title (str, optional): Notification title.
#         text (str, optional): Notification body text.
#         sound (str, optional): Name of sound to play.

#     """

#     if title == text == '':
#         raise ValueError('Empty notification')

#     import Foundation

#     sound = sound or Foundation.NSUserNotificationDefaultSoundName

#     n = Foundation.NSUserNotification.alloc().init()
#     n.setTitle_(title)
#     n.setInformativeText_(text)
#     n.setSoundName_(sound)
#     nc = Foundation.NSUserNotificationCenter.defaultUserNotificationCenter()
#     nc.deliverNotification_(n)


if __name__ == '__main__':  # pragma: nocover
    # Simple command-line script to test module with
    # This won't work on 2.6, as `argparse` isn't available
    # by default.
    import argparse

    from unicodedata import normalize

    def uni(s):
        """Coerce `s` to normalised Unicode."""
        ustr = s.decode('utf-8')
        return normalize('NFD', ustr)

    p = argparse.ArgumentParser()
    p.add_argument('-p', '--png', help="PNG image to convert to ICNS.")
    p.add_argument('-l', '--list-sounds', help="Show available sounds.",
                   action='store_true')
    p.add_argument('-t', '--title',
                   help="Notification title.", type=uni,
                   default='')
    p.add_argument('-s', '--sound', type=uni,
                   help="Optional notification sound.", default='')
    p.add_argument('text', type=uni,
                   help="Notification body text.", default='', nargs='?')
    o = p.parse_args()

    # List available sounds
    if o.list_sounds:
        for sound in SOUNDS:
            print(sound)
        sys.exit(0)

    # Convert PNG to ICNS
    if o.png:
        icns = os.path.join(
            os.path.dirname(o.png),
            b'{0}{1}'.format(os.path.splitext(os.path.basename(o.png))[0],
                             '.icns'))

        print('Converting {0!r} to {1!r} ...'.format(o.png, icns),
              file=sys.stderr)

        assert not os.path.exists(icns), (
            "Destination file already exists : {0}".format(icns))

        png_to_icns(o.png, icns)
        sys.exit(0)

    # Post notification
    if o.title == o.text == '':
        print('ERROR: Empty notification.', file=sys.stderr)
        sys.exit(1)
    else:
        notify(o.title, o.text, o.sound)