#!/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 on both sway and i3 window managers.

Inspired by https://github.com/olemartinorg/i3-alternating-layout

Copyright: 2019-2021 Piotr Miller & Contributors
e-mail: nwg.piotr@gmail.com
Project: https://github.com/nwg-piotr/autotiling
License: GPL3

Dependencies: python-i3ipc>=2.0.1 (i3ipc-python)
"""
import argparse
import os
import sys
from functools import partial

from i3ipc import Connection, Event

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


def temp_dir():
    if os.getenv("TMPDIR"):
        return os.getenv("TMPDIR")
    elif os.getenv("TEMP"):
        return os.getenv("TEMP")
    elif os.getenv("TMP"):
        return os.getenv("TMP")

    return "/tmp"


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


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

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


def switch_splitting(i3, e, debug, outputs, workspaces, depth_limit):
    try:
        con = i3.get_tree().find_focused()
        output = output_name(con)
        # Stop, if outputs is set and current output is not in the selection
        if outputs and output not in outputs:
            if debug:
                print(
                    "Debug: Autotiling turned off on output {}".format(output),
                    file=sys.stderr,
                )
            return

        if con and not workspaces or (str(con.workspace().num) in 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"

            if 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 < 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")
                    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, )

        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 main():
    parser = argparse.ArgumentParser()
    parser.add_argument("-d",
                        "--debug",
                        action="store_true",
                        help="print debug messages to stderr")
    parser.add_argument("-v",
                        "--version",
                        action="version",
                        version="%(prog)s {}, Python {}".format(__version__, sys.version),
                        help="display version information", )
    parser.add_argument("-o",
                        "--outputs",
                        help="restricts autotiling to certain output; "
                        "example: autotiling --output  DP-1 HDMI-0",
                        nargs="*",
                        type=str,
                        default=[], )
    parser.add_argument("-w",
                        "--workspaces",
                        help="restricts autotiling to certain workspaces; example: autotiling --workspaces 8 9",
                        nargs="*",
                        type=str,
                        default=[], )
    parser.add_argument("-l",
                        "--limit",
                        help='limit how often autotiling will split a container; '
                        'try "2", if you like master-stack layouts; default: 0 (no limit)',
                        type=int,
                        default=0, )
    """
    Changing event subscription has already been the objective of several pull request. To avoid doing this again
    and again, let's allow to specify them in the `--events` argument.
    """
    parser.add_argument("-e",
                        "--events",
                        help="list of events to trigger switching split orientation; default: WINDOW MODE",
                        nargs="*",
                        type=str,
                        default=["WINDOW", "MODE"])

    args = parser.parse_args()

    if args.debug and args.outputs:
        print("autotiling is only active on outputs:", ",".join(args.outputs))

    if args.debug and args.workspaces:
        print("autotiling is only active on workspaces:", ','.join(args.workspaces))

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

    if not args.events:
        print("No events specified", file=sys.stderr)
        sys.exit(1)

    handler = partial(
        switch_splitting,
        debug=args.debug,
        outputs=args.outputs,
        workspaces=args.workspaces,
        depth_limit=args.limit,
    )
    i3 = Connection()
    for e in args.events:
        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__":
    # execute only if run as a script
    main()