#!/usr/bin/python3

"""Personal i3 companion."""

import argparse
import logging
import logging.handlers
import sys
import re
import asyncio
import shlex
import subprocess
import html
import functools

from i3ipc.aio import Connection
from i3ipc import Event
from systemd import journal
import ravel


logger = logging.getLogger("i3-companion")


def on(*events):
    """Tag events that should be provided to the function."""
    def decorator(fn):
        @functools.wraps(fn)
        def wrapper(*args, **kwargs):
            return fn(*args, **kwargs)
        on.functions = getattr(on, "functions", {})
        on.functions[fn] = events
        return wrapper
    return decorator


async def notify(i3, **kwargs):
    """Send a notification with notify-send."""
    peer = i3.session_bus["org.freedesktop.Notifications"]
    peer = peer["/org/freedesktop/Notifications"]
    interface = await peer.get_async_interface("org.freedesktop.Notifications")
    parameters = dict(
        app_name=logger.name,
        replaces_id=0,
        app_icon="dialog-information",
        summary="",
        actions=[],
        hints={},
        expire_timeout=5000)
    parameters.update(kwargs)
    return await interface.Notify(**parameters)


# See https://fontawesome.com/v5.15/icons
application_icons = {
    "chromium": "",
    "discord": "",
    "emacs": "",
    "firefox": "",
    "gimp": "",
    "gitg": "",
    "google-chrome": "",
    "inkscape": "",
    "libreoffice": "",
    "mpv": "",
    "pavucontrol": "",
    "signal": "",
    "snes9x-gtk": "",
    "spotify": "",
    "steam": "",
    "vbeterm": "",
    "zathura": "",
    "zoom": ""
}
application_icons_nomatch = ""
application_icons_alone = {
    application_icons[k] for k in {
        "vbeterm"
    }
}


@on(Event.WINDOW_MOVE, Event.WINDOW_NEW, Event.WINDOW_CLOSE)
async def workspace_rename(i3, event):
    """Rename workspaces using icons to match what's inside it."""
    tree = await i3.get_tree()
    workspaces = tree.workspaces()
    commands = []

    def application_icon(window):
        """Get application icon for a window."""
        for attr in ('window_instance',
                     'window_class'):
            name = getattr(window, attr, None)
            if name is None:
                continue
            for k, v in application_icons.items():
                if re.match(rf"^{k}\b", name, re.IGNORECASE):
                    logger.debug(f"in {attr}, found '{name}', matching {k}")
                    return v
        return application_icons_nomatch

    for workspace in workspaces:
        icons = set()
        for window in workspace.leaves():
            icon = application_icon(window)
            if icon is not None:
                icons.add(icon)
        if any([i not in application_icons_alone for i in icons]):
            icons -= application_icons_alone
        new_name = f"{workspace.num}:{'|'.join(icons)}".rstrip(":")
        if workspace.name != new_name:
            logger.debug(f"rename workspace {workspace.num}")
            command = f'rename workspace "{workspace.name}" to "{new_name}"'
            commands.append(command)
    await i3.command(';'.join(commands))


async def _new_workspace(i3):
    workspaces = await i3.get_workspaces()
    workspace_nums = {w.num for w in workspaces}
    max_num = max(workspace_nums)
    available = (set(range(1, max_num + 2)) - workspace_nums).pop()
    logger.info(f'create new workspace number {available}')
    await i3.command(f'workspace number "{available}"')
    return available


@on("new-workspace", "move-to-new-workspace")
async def new_workspace(i3, event):
    """Create a new workspace and optionally move a window to it."""
    # Get the currently focused window
    if event == "move-to-new-workspace":
        tree = await i3.get_tree()
        current = tree.find_focused()
        if not current:
            return

    num = await _new_workspace(i3)

    # Move the window to this workspace
    if event == "move-to-new-workspace":
        await current.command(f'move container to workspace '
                              f'number "{num}"')


exclusive_apps = {
    "emacs",
    "firefox"
}
intrusive_apps = {
    "vbeterm"
}


@on(Event.WINDOW_NEW)
async def worksplace_exclusive(i3, event):
    """Move new windows on a new workspace instead of sharing a workspace
    with an exclusive app."""
    w = event.container

    def can_intrude(w):
        """Can this new window intrude any workspace?"""
        if w.floating in {"auto_on", "user_on"}:
            return True
        if w.ipc_data['window_type'] not in {"normal", "splash", "unknown"}:
            return True
        if w.sticky:
            return True
        ids = {s is not None and s.lower() or None
               for s in {w.name, w.window_class, w.window_instance}}
        if ids.intersection(intrusive_apps):
            return True

    # Can the new window just intrude?
    if can_intrude(w):
        logger.debug("window {w.name} can intrude")
        return

    # Does the current workspace contains an exclusive app?
    tree = await i3.get_tree()
    workspace = tree.find_focused().workspace()
    if not workspace:
        return
    ids = {s is not None and s.lower() or None
           for ow in workspace.leaves()
           for s in {ow.name, ow.window_class, ow.window_instance}
           if w.id != ow.id}
    exclusives = ids.intersection(exclusive_apps)
    if not exclusives:
        logger.debug("no exclusive app, {w.name} can go there")
        return

    # Create a new workspace and move the window here
    num = await _new_workspace(i3)
    logger.info(f'move window {w.name} to workspace {num}')
    await w.command(f'move container to workspace number "{num}"')


@on("quake-console")
async def quake_console(i3, event):
    """Spawn a quake console or toggle an existing one."""
    try:
        _, term_exec, term_name, height = event.split(":")
        height = float(height)
    except Exception as exc:
        logger.warn(f"unable to parse payload {event}: {exc}")
        return

    tree = await i3.get_tree()
    term = tree.find_instanced(term_name)
    if not term:
        await i3.command(f'exec exec {term_exec} --name {term_name}')
        tries = 5
        while not term and tries:
            tree = await i3.get_tree()
            term = tree.find_instanced(term_name)
            await asyncio.sleep(0.2)
            tries -= 1
    if not term:
        raise RuntimeError("unable to spawn terminal")
    term = term[0]
    workspaces = await i3.get_workspaces()
    workspace = [ws for ws in workspaces if ws.focused][0]
    ws_x = workspace.rect.x
    ws_y = workspace.rect.y
    ws_width = workspace.rect.width
    ws_height = workspace.rect.height
    width = ws_width
    height = int(ws_height * height)
    posx = ws_x
    posy = ws_y
    command = (f'[instance={term_name}] '
               'border none,'
               f'resize set {width} px {height} px,'
               'scratchpad show,'
               f'move absolute position {posx}px {posy}px')
    logger.debug(f"QuakeConsole: {command}")
    await i3.command(command)


@on("container-info")
async def container_info(i3, event):
    """Show information about the focused container."""
    tree = await i3.get_tree()
    window = tree.find_focused()
    if not window:
        return
    logger.info(f"window raw information: {window.ipc_data}")
    summary = "About focused container"
    r = window.rect
    w = window
    info = {
        "name": w.name,
        "title": w.window_title,
        "class": w.window_class,
        "instance": w.window_instance,
        "role": w.window_role,
        "type": w.ipc_data['window_type'],
        "sticky": w.sticky,
        "floating": w.floating,
        "geometry": f"{r.width}×{r.height}+{r.x}+{r.y}",
        "layout": w.layout,
        "parcent": w.percent,
        "marks": ", ".join(w.marks) or "(none)"
    }
    body = "\n".join((f"<tt>{k:10}</tt> {html.escape(str(v))}"
                      for k, v in info.items()
                      if v is not None))
    result = await notify(i3,
                          app_icon="system-search",
                          expire_timeout=10000,
                          summary=summary,
                          body=body,
                          replaces_id=getattr(container_info, "last_id", 0))
    container_info.last_id = result[0]


@on("workspace-info")
async def workspace_info(i3, event):
    """Show information about the focused workspace."""
    workspaces = await i3.get_workspaces()
    focused = [w for w in workspaces if w.focused]
    if not focused:
        return
    workspace = focused[0]
    summary = f"Workspace {workspace.num} on {workspace.output}"
    tree = await i3.get_tree()
    workspace = [w for w in tree.workspaces()
                 if w.num == workspace.num]

    def format(container):
        if container.focused:
            style = 'foreground="#ffaf00"'
        elif not container.window:
            style = 'foreground="#6c98ee"'
        else:
            style = ''
        if container.window:
            content = (f"{(container.window_class or '???').lower()}: "
                       f"{(container.window_title or '???')}")
        elif container.type == 'workspace' and not container.nodes:
            # Empty workspaces use workspace_layout, but when default,
            # this is layout...
            layout = container.ipc_data['workspace_layout']
            if layout == "default":
                layout = container.layout
            content = f"({layout})"
        else:
            content = f"({container.layout})"
        root = (f"<span {style}>"
                f"{content.lower()}"
                "</span>")
        children = []
        for child in container.nodes:
            if child == container.nodes[-1]:
                first = "└─"
                others = "  "
            else:
                first = "├─"
                others = "│ "
            content = format(child).replace("\n", f"\n{others}")
            children.append(f"<tt>{first}</tt>{content}")
        children.insert(0, root)
        return "\n".join(children)

    body = format(workspace[0]).lstrip("\n")
    result = await notify(i3,
                          app_icon="system-search",
                          expire_timeout=20000,
                          summary=summary,
                          body=body,
                          replaces_id=getattr(workspace_info, "last_id", 0))
    workspace_info.last_id = result[0]


@on(Event.OUTPUT)
async def output_update(i3, event):
    """React to a XRandR change."""
    running = getattr(output_update, "running", None)
    if running is not None:
        running.cancel()
        output_update.running = None

    def output_update_now():
        """Execute actions to react to XRandR change."""
        output_update.running = None

        logger.info("XRandR change detected")
        cmds = (
            "systemctl --user reload --no-block xsettingsd.service",
            "systemctl --user start --no-block wallpaper.service",
        )
        for cmd in cmds:
            proc = subprocess.run(shlex.split(cmd))
            if proc.returncode != 0:
                logger.warning(f"{cmd} exited with {proc.returncode}")

    logger.debug("schedule XRandR change")
    output_update.running = asyncio.get_event_loop().call_later(
        2, output_update_now)


async def main(options):
    i3 = await Connection().connect()
    i3.session_bus = await ravel.session_bus_async()

    # Regular events
    for fn, events in on.functions.items():
        for event in events:
            if isinstance(event, Event):
                i3.on(event, fn)

    # React to some bindings
    async def binding_event(i3, event):
        """Process a binding event."""
        # We only processes it when it is a nop command and we use
        # this mechanism as an IPC mechanism. The alternative would be
        # to use ticks but we would need to spawn an i3-msg process
        # for that.
        cmd = event.binding.command
        if not cmd.startswith("nop "):
            return
        cmd = cmd[4:].strip('"\'')
        if not cmd:
            return
        kind = cmd.split(":")[0]
        for fn, events in on.functions.items():
            for e in events:
                if e == kind:
                    await fn(i3, cmd)
    i3.on(Event.BINDING, binding_event)

    await i3.main()


if __name__ == "__main__":
    # Parse
    description = sys.modules[__name__].__doc__
    for fn, events in on.functions.items():
        description += f" {fn.__doc__}"
    parser = argparse.ArgumentParser(description=description)
    parser.add_argument("--debug", "-d", action="store_true",
                        default=False,
                        help="enable debugging")
    options = parser.parse_args()

    # Logging
    root = logging.getLogger("")
    root.setLevel(logging.WARNING)
    logger.setLevel(options.debug and logging.DEBUG or logging.INFO)
    if sys.stdin.isatty():
        ch = logging.StreamHandler()
        ch.setFormatter(logging.Formatter("%(levelname)s: %(message)s"))
    else:
        root.addHandler(journal.JournalHandler(SYSLOG_IDENTIFIER=logger.name))

    try:
        asyncio.get_event_loop().run_until_complete(main(options))
    except Exception as e:
        logger.exception("%s", e)
        sys.exit(1)
    sys.exit(0)