#!/usr/bin/env python3
from collections import defaultdict
import os
import subprocess

import click
import yaml


class FynnWacom:
    def __init__(self, config, verbose=False):
        self.config = config
        self.verbose = verbose
        self.validate_config()

    def validate_config(self):
        try:
            self.usbid = self.config['device']['usbid'].lower()
            self.device_name = self.config['device']['name']
            self.profile_file = os.path.expanduser(self.config['device']['profile_file'])

            # check default profile
            default_profile = self.config['device']['default_profile']
            if default_profile not in self.config['mappings']:
                raise click.ClickException("Profile {} missing from mappigns".format(default_profile))

            # check mappings
            for name, mapping in self.config['mappings'].items():
                # does the baseprofile exist?
                if 'base_profile' in mapping and mapping['base_profile'] not in self.config['mappings']:
                    raise click.ClickException("Base profile {} not found for profile {}"
                                               "".format(mapping['base_profile'], name))

                for key in mapping:
                    if key in ('base_profile',):
                        continue

                    pass

                # check recursion
                pass
        except KeyError as e:
            raise click.ClickException("Key missing in config: {}".format(e))

    def get_current_profile(self):
        try:
            with open(self.profile_file) as pf:
                return pf.read().strip()
        except IOError:
            return self.config['device']['default_profile']

    @property
    def wheel_state(self):
        """Read the wacom tablet wheel status from /sys, int in [0, 3]"""
        basepath = '/sys/bus/hid/drivers/wacom/'
        wacom_dirs = [d for d in os.listdir(basepath) if self.usbid in d.lower()]
        if not wacom_dirs:
            raise click.ClickException("Could not find usbid {} in {}".format(self.usbid, basepath))

        ledpath = os.path.join(basepath, sorted(wacom_dirs)[0], 'wacom_led/status_led0_select')

        with open(ledpath) as ledfile:
            return int(ledfile.read())

    @staticmethod
    def _call(cmd):
        # print(" >> Calling: ", " ".join(cmd))
        return subprocess.check_output(cmd, encoding='utf-8')

    def guess_devices(self, subname):
        found = False
        for device in self._call(["xinput", "list", "--name-only"]).split("\n"):
            if not device.startswith(self.device_name):
                continue
            rest = device.replace(self.device_name, "")
            if subname.lower() in rest.lower():
                yield device
                found = True

        if not found:
            raise click.ClickException("Subdevice {} for {} not found".format(subname, self.device_name))

    def build_mapping(self, profile, wheel_state):
        conf = self.config['mappings'][profile]
        mapping = defaultdict(dict)
        if 'base_profile' in conf:
            mapping = self.build_mapping(conf['base_profile'], wheel_state)

        # copy mappings into mapping dict
        for key, keymap in conf.items():
            if key in ('base_profile', 'wheel'):
                continue
            mapping[key].update(keymap)

        # handle wheel, if present and in wheel_state range
        if 'wheel' in conf and len(conf['wheel']) > wheel_state and conf['wheel'][wheel_state]:
            for device, key_mapping in conf['wheel'][wheel_state].items():
                mapping[device].update(key_mapping)

        return mapping

    def configure(self, profile):
        if profile not in self.config['mappings']:
            raise click.ClickException("Profile {} does not exist".format(profile))

        mapping = self.build_mapping(profile, self.wheel_state)

        if self.verbose:
            print("Current mapping for profile {}: {}".format(profile, mapping))

        for subdevice, keymap in mapping.items():
            for button, keysym in keymap.items():
                if len(keysym) == 1:
                    keysym = "key {}".format(keysym)
                try:
                    btn = ["Button", str(int(button))]
                except ValueError:
                    btn = [button]

                for device in self.guess_devices(subdevice):
                    cmd = ["xsetwacom", "set", device] + btn + [keysym]
                    if self.verbose:
                        print(" >> xsetwacom set '{}' '{}' '{}'".format(device, btn, keysym))
                    self._call(cmd)

        with open(self.profile_file, 'w') as f:
            f.write(profile + "\n")


@click.command()
@click.option('-c', '--config', default='~/.config/fynncom/fynncom.yaml',
              help='Path to config file')
@click.option('-p', '--profile', default=None,
              help='Profile to switch to')
@click.option('-v', '--verbose', is_flag=True, default=False,
              help='Be more verbose')
def cli(config, profile, verbose):
    # check for xinput / xsetwacom
    for cmd in ('xinput', 'xsetwacom'):
        if subprocess.call(["which", cmd], stdout=subprocess.DEVNULL) != 0:
            raise click.ClickException("Could not find `{}`, please install it".format(cmd))

    # load config
    try:
        with open(os.path.expanduser(config)) as f:
            config = yaml.safe_load(f)
    except IOError as e:
        raise click.ClickException("Could not load config: {}".format(e))

    fynncom = FynnWacom(config, verbose)
    profile = profile or fynncom.get_current_profile()
    fynncom.configure(profile)

    print("Switched to profile {} with weel-state {}".format(profile, fynncom.wheel_state))


if __name__ == '__main__':
    cli()