#!/usr/bin/env python3

"""
This script uses the i3ipc python module to switch the layout splith / splitv
for the currently focused window, depending on its dimensions.
It works both on sway and i3 window managers.
Inspired by https://github.com/olemartinorg/i3-alternating-layout
Copyright: 2019-2022 Piotr Miller & Contributors
e-mail: nwg.piotr@gmail.com
Project: https://github.com/nwg-piotr/nwg-shell
License: MIT
Dependencies: python-i3ipc>=2.0.1 (i3ipc-python), python-psutil

This code is a version of the 'autotiling` script (https://github.com/nwg-piotr/nwg-shell),
modified for use with nwg-shell. I wanted to avoid adding the shell-specific stuff to the original script,
as it's quite widely used outside the project. All the arguments remain the same. One more dependency (psutil).

Additions:
- killing existing *autotiling* process instances on startup;
- gentle SIGINT & SIGTERM handler.
"""
import argparse
import os
import signal
import sys

from functools import partial
from psutil import process_iter
from i3ipc import Connection, Event

try:
    from .__about__ import __version__
except ImportError:
    __version__ = "unknown"

from nwg_shell_config.tools import temp_dir, get_data_dir, load_json, check_key

settings = load_json(os.path.join(get_data_dir(), "settings"))
check_key(settings, "autotiling-workspaces", "")
check_key(settings, "autotiling-output-limits", {})
check_key(settings, "autotiling-output-splitwidths", {})
check_key(settings, "autotiling-output-splitheights", {})


def save_string(string, file):
    try:
        file = open(file, "wt")
        file.write(string)
        file.close()
    except Exception as e:
        print(e)


def find_output_name(con):
    if con.type == "root":
        return None

    p = con.parent
    if p:
        if p.type == "output":
            return p.name
        else:
            return find_output_name(p)


def switch_splitting(i3, e, debug):
    try:
        con = i3.get_tree().find_focused()
        if con and not settings["autotiling-workspaces"] or (
                str(con.workspace().num) in settings["autotiling-workspaces"]):
            if con.floating:
                # We're on i3: on sway it would be None
                # May be 'auto_on' or 'user_on'
                is_floating = "_on" in con.floating
            else:
                # We are on sway
                is_floating = con.type == "floating_con"

            # Depth_limit contributed by @Syphdias to original autotiling script
            output_name = find_output_name(con)
            if settings["autotiling-output-limits"]:
                output_depth_limit = settings["autotiling-output-limits"][output_name] if output_name in settings[
                    "autotiling-output-limits"] else 0

                if output_depth_limit:
                    # Assume we reached the depth limit, unless we can find a workspace
                    depth_limit_reached = True
                    current_con = con
                    current_depth = 0
                    while current_depth < output_depth_limit:
                        # Check if we found the workspace of the current container
                        if current_con.type == "workspace":
                            # Found the workspace within the depth limitation
                            depth_limit_reached = False
                            break

                        # Look at the parent for next iteration
                        current_con = current_con.parent

                        # Only count up the depth, if the container has more than one container as child
                        if len(current_con.nodes) > 1:
                            current_depth += 1

                    if depth_limit_reached:
                        if debug:
                            print("Debug: Depth limit reached", file=sys.stderr)
                        return

            is_full_screen = con.fullscreen_mode == 1
            is_stacked = con.parent.layout == "stacked"
            is_tabbed = con.parent.layout == "tabbed"

            # Exclude floating containers, stacked layouts, tabbed layouts and full screen mode
            if (not is_floating
                    and not is_stacked
                    and not is_tabbed
                    and not is_full_screen):

                new_layout = "splitv" if con.rect.height > con.rect.width else "splith"

                if new_layout != con.parent.layout:
                    result = i3.command(new_layout)
                    if result[0].success and debug:
                        print("Debug: Switched to {}".format(new_layout), file=sys.stderr)
                    elif debug:
                        print("Error: Switch failed with err {}".format(result[0].error), file=sys.stderr, )

                # splitwidth & splitheight contributed by @JoseConseco to original autotiling script
                if e.change in ["new", "move"] and con.percent:
                    if con.parent.layout == "splitv":  # top / bottom
                        if output_name in settings["autotiling-output-splitheights"] and \
                                settings["autotiling-output-splitheights"][output_name] != 1.0:
                            i3.command("resize set height {} ppt".format(
                                int(con.percent * settings["autotiling-output-splitheights"][output_name] * 100)))
                            if debug:
                                print("Debug: Scaling height x {}".format(
                                    settings["autotiling-output-splitheights"][output_name]), file=sys.stderr)
                    else:  # left / right
                        if output_name in settings["autotiling-output-splitwidths"] and \
                                settings["autotiling-output-splitwidths"][output_name] != 1.0:
                            i3.command("resize set width {} ppt".format(
                                int(con.percent * settings["autotiling-output-splitwidths"][output_name] * 100)))
                            if debug:
                                print("Debug: Scaling width x {}".format(
                                    settings["autotiling-output-splitwidths"][output_name]), file=sys.stderr)

        elif debug:
            print("Debug: No focused container found or autotiling on the workspace turned off", file=sys.stderr)

    except Exception as e:
        print("Error: {}".format(e), file=sys.stderr)


def signal_handler(sig, frame):
    desc = {2: "SIGINT", 15: "SIGTERM"}
    if sig in [2, 15]:
        print("Terminated with {}".format(desc[sig]))
        sys.exit(0)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("-d",
                        "--debug",
                        action="store_true",
                        help="print debug messages to stderr")

    args = parser.parse_args()

    own_pid = os.getpid()

    for proc in process_iter():
        if "autotiling" in proc.name():
            pid = proc.pid
            if not pid == own_pid:
                print("Killing '{}', pid {}".format(proc.name(), pid))
                os.kill(pid, signal.SIGINT)

    catchable_sigs = set(signal.Signals) - {signal.SIGKILL, signal.SIGSTOP}
    for sig in catchable_sigs:
        signal.signal(sig, signal_handler)

    if args.debug:
        if settings["autotiling-workspaces"]:
            print("Debug: autotiling is only active on workspaces:", settings["autotiling-workspaces"], file=sys.stderr)
        if settings["autotiling-output-limits"]:
            print("Debug: per-output limits: {}".format(settings["autotiling-output-limits"]), file=sys.stderr)
        if settings["autotiling-output-splitwidths"]:
            print("Debug: per-output split widths: {}".format(settings["autotiling-output-splitwidths"]), file=sys.stderr)
        if settings["autotiling-output-splitheights"]:
            print("Debug: per-output split heights: {}".format(settings["autotiling-output-splitheights"]), file=sys.stderr)

    # For use w/ nwg-panel
    ws_file = os.path.join(temp_dir(), "autotiling")
    if settings["autotiling-workspaces"]:
        save_string(settings["autotiling-workspaces"], ws_file)
    else:
        if os.path.isfile(ws_file):
            os.remove(ws_file)

    handler = partial(switch_splitting, debug=args.debug)
    i3 = Connection()
    for e in ["WINDOW", "MODE"]:
        try:
            i3.on(Event[e], handler)
            print("{} subscribed".format(Event[e]))
        except KeyError:
            print("'{}' is not a valid event".format(e), file=sys.stderr)

    i3.main()


if __name__ == "__main__":
    main()
