dotfiles/install.py

#!/usr/bin/env python3

import argparse
from datetime import timedelta
import os
import shutil
import socket
import subprocess
import sys
from functools import partial
from pathlib import Path
from typing import List

import mako.lookup
import mako.template
import requests_cache
import toml
import yaml

http_session = requests_cache.CachedSession(expire_after=timedelta(days=1))

BASE16_TEMPLATES_URL = "https://raw.githubusercontent.com/chriskempson/base16-templates-source/master/list.yaml"
BASE16_TEMPLATES = yaml.safe_load(http_session.get(BASE16_TEMPLATES_URL).text)

# Pending https://github.com/chriskempson/base16-templates-source/pull/106
BASE16_TEMPLATES["wofi-colors"] = "https://github.com/agausmann/base16-wofi-colors"


def get_base16(scheme, app, template="default"):
    base_url = BASE16_TEMPLATES[app]
    if "github.com" in base_url:
        base_url = (
            base_url.replace("github.com", "raw.githubusercontent.com") + "/master/"
        )
    else:
        base_url += "/blob/master/"
    config = yaml.safe_load(http_session.get(base_url + "templates/config.yaml").text)
    output = config[template]["output"]
    extension = config[template]["extension"]
    return http_session.get(base_url + output + "/base16-" + scheme + extension).text


def is_outdated(src: List[Path], dst: Path) -> bool:
    if not dst.exists():
        return True

    dst_modified = dst.stat().st_mtime
    return any(a_src.stat().st_mtime > dst_modified for a_src in src if a_src.exists())


def main():
    parser = argparse.ArgumentParser(
        description="Generates and installs dotfiles for this host.",
        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
    )
    parser.add_argument(
        "-d",
        "--dotfiles",
        help="The base directory of the dotfiles repository.",
        type=Path,
        default=Path(sys.argv[0]).parent,
    )
    parser.add_argument(
        "-n",
        "--hostname",
        help="The hostname or other identifying name of this system that will"
        " be used to retrieve the host-specific configuration.",
        default=os.environ.get("HOSTNAME") or socket.gethostname(),
    )
    parser.add_argument(
        "-o",
        "--home",
        help="The home directory where generated dotfiles will be installed.",
        type=Path,
        default=os.environ.get("HOME") or Path.home(),
    )
    parser.add_argument(
        "-f",
        "--force",
        help="Force overwrite all files even if they are not considered outdated.",
        action="store_true",
    )
    args = parser.parse_args()

    raw_dir = args.dotfiles / "raw"
    templates_dir = args.dotfiles / "templates"
    include_dir = args.dotfiles / "include"
    default_host_filename = args.dotfiles / "hosts" / "default.toml"
    host_filename = args.dotfiles / "hosts" / "{}.toml".format(args.hostname)

    with open(default_host_filename) as host_file:
        host_config = toml.load(host_file)

    if host_filename.exists():
        with open(host_filename) as host_file:
            host_config.update(toml.load(host_file))

    host_config["name"] = args.hostname

    # Preprocess output configs for sway
    for input in host_config.get("inputs", []):
        # Generate config lines for sway template
        lines = []
        for key in input:
            if key == "match":
                continue
            if isinstance(input[key], list):
                val = " ".join(repr(elem) for elem in input[key])
            else:
                val = repr(input[key])
            lines.append(f"{key} {val}")

        input["sway-lines"] = lines

    for output in host_config["outputs"]:
        # Generate config lines for sway template
        lines = []
        for key in output:
            if key == "match":
                continue
            if isinstance(output[key], list):
                val = " ".join(repr(elem) for elem in output[key])
            else:
                val = repr(output[key])
            lines.append(f"{key} {val}")

        output["sway-lines"] = lines

        # Attempt to resolve device names for swaylock template
        # (Workaround https://github.com/swaywm/swaylock/issues/114)
        #
        # This will only work if this is run on the target host
        # and if sway is running, but that is usually the case...
        if output["match"] != "*":
            try:
                if "SWAYSOCK" in os.environ:
                    get_outputs = subprocess.check_output(
                        ["swaymsg", "-t", "get_outputs", "-p"],
                    ).decode("utf-8")
                    for line in get_outputs.splitlines():
                        # Line format: Output <device> '<match identifier>'
                        if line.startswith("Output") and output["match"] in line:
                            output["device"] = line.split()[1]
                            break

                elif "NIRI_SOCKET" in os.environ:
                    get_outputs = subprocess.check_output(
                        ["niri", "msg", "outputs"],
                    ).decode("utf-8")
                    for line in get_outputs.splitlines():
                        # Line format: Output "<match identifier>" (<device>)
                        if line.startswith("Output") and output["match"] in line:
                            output["device"] = (
                                line.split()[-1].removeprefix("(").removesuffix(")")
                            )
                            break
                else:
                    print(
                        "Could not find SWAYSOCK or NIRI_SOCKET, cannot retrieve output names."
                    )
                    print(
                        "Please re-run in sway or niri to finish configuring swaylock."
                    )

            except subprocess.CalledProcessError:
                print("Could not contact sway or niri to retrieve output names.")
                print("Please re-run in sway or niri to finish configuring swaylock.")

    lookup = mako.lookup.TemplateLookup(
        directories=[
            str(templates_dir),
            str(include_dir),
        ],
    )

    for raw_path in raw_dir.glob("**/*"):
        if not raw_path.is_file():
            continue
        rel_path = raw_path.relative_to(raw_dir)
        output_path = args.home / rel_path

        if args.force or is_outdated([raw_path], output_path):
            print(rel_path)
            output_path.parent.mkdir(parents=True, exist_ok=True)
            shutil.copy(raw_path, output_path)

    for template_path in templates_dir.glob("**/*"):
        if not template_path.is_file():
            continue
        rel_path = template_path.relative_to(templates_dir)
        output_path = args.home / template_path.relative_to(templates_dir)

        if args.force or is_outdated([template_path, host_filename], output_path):
            print(rel_path)
            template = mako.template.Template(
                filename=str(template_path),
                strict_undefined=True,
                lookup=lookup,
            )
            output = template.render(
                host=host_config,
                home=args.home,
                get_base16=partial(
                    get_base16, host_config.get("base16-scheme", "default-dark")
                ),
            )
            output_path.parent.mkdir(parents=True, exist_ok=True)
            with open(output_path, "w+") as output_file:
                output_file.write(output)

            # Copy permissions from original file
            output_path.chmod(template_path.stat().st_mode & 0o777)


if __name__ == "__main__":
    main()