#!/bin/python3
"""A simple windowswitcher for sway"""
# switch_window, get_windows and extract_nodes_iterative is derived from 
# https://github.com/tobiaspc/wofi-scripts Copyright (c) 2020 Tobi which
# is covered by the MIT License. However this program is licenced under
# the GPLv3+ Copyright (c) 2020 Micke Nordin. See LICENSE file for details.

import json
import math
import subprocess

import wx


class SwaySwitch(wx.Frame):  # pylint: disable=no-member
    """Frame for the swayswitcher"""
    def __init__(self, *args, **kw):  # pylint: disable=unused-argument
        """Constructor"""
        wx.Frame.__init__(self, None, title="", style=wx.STAY_ON_TOP)  # pylint: disable=no-member
        # create a panel in the frame
        self.pnl = wx.Panel(self)  # pylint: disable=no-member
        # get windows from sway
        windows = get_windows()
        label_len = 20

        # and create a sizer to manage the layout of child widgets
        x_and_y = int(math.sqrt(len(windows)) + 0.5)
        sizer = wx.GridSizer(x_and_y)  # pylint: disable=no-member
        self.pnl.SetSizer(sizer)
        for window in windows:
            try:
                label = window['window_properties']['class']
            except KeyError:
                try:
                    label = window['app_id']
                    if len(label) < label_len:
                        label = label + ':' + window['name'][:label_len -
                                                             len(label)]
                except KeyError:
                    label = window['name']
                if len(label) > label_len:
                    label = label[:label_len]
            winid = window['id']
            size = wx.Window.GetFont(self).GetPointSize() * label_len  # pylint: disable=no-member
            btn = wx.Button(  # pylint: disable=no-member
                parent=self.pnl,
                id=winid,
                label=label,
                size=wx.Size(size, size))  # pylint: disable=no-member
            btn.Bind(
                wx.EVT_BUTTON,
                lambda event, mwinid=winid: self.switch_window(event, mwinid))
            sizer.Add(btn, 0, wx.ALIGN_CENTER)  # pylint: disable=no-member
            # Set up esc keybinding
            self.Bind(wx.EVT_CHAR_HOOK, lambda event: self.on_key_press(event))  # pylint: disable=unnecessary-lambda
        sizer.Fit(self)
        sizer.Layout()

    def on_key_press(self, event):
        """Intercept esc key press"""
        keycode = event.GetUnicodeKey()
        if keycode == wx.WXK_ESCAPE:  # pylint: disable=no-member
            self.Close(True)
        else:
            event.Skip(True)

    def switch_window(self, event, winid):  # pylint: disable=unused-argument
        """Switches the focus to the given id"""
        command = "swaymsg [con_id={}] focus".format(winid)
        subprocess.Popen(command, shell=True, stdout=subprocess.PIPE)
        self.Close(True)


def get_windows():
    """Returns a list of all json window objects"""
    command = "swaymsg -t get_tree"
    process = subprocess.Popen(command,
                               shell=True,
                               stdout=subprocess.PIPE,
                               stderr=subprocess.PIPE)
    data = json.loads(process.communicate()[0])

    # Select outputs that are active
    windows = []
    for output in data['nodes']:

        # The scratchpad (under __i3) is not supported
        if output.get('name') != '__i3' and output.get('type') == 'output':
            workspaces = output.get('nodes')
            for workspace in workspaces:
                if workspace.get('type') == 'workspace':
                    windows += extract_nodes_iterative(workspace)
    return windows


def extract_nodes_iterative(workspace):
    """Extracts all windows from a sway workspace json object"""
    all_nodes = []

    floating_nodes = workspace.get('floating_nodes')

    for floating_node in floating_nodes:
        all_nodes.append(floating_node)

    nodes = workspace.get('nodes')

    for node in nodes:

        # Leaf node
        if len(node.get('nodes')) == 0:
            all_nodes.append(node)
        # Nested node, handled iterative
        else:
            for inner_node in node.get('nodes'):
                nodes.append(inner_node)

    return all_nodes


# Entry point
if __name__ == "__main__":
    # When this module is run (not imported) then create the app, the
    # frame, show it, and start the event loop.
    app = wx.App()
    frm = SwaySwitch(None, title="")
    frm.Show()
    app.MainLoop()