#!/usr/bin/env python3

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

from attrs import define, field
import cattrs
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())


class BackgroundMode(Enum):
    Fill = "fill"

    @property
    def sway_value(self) -> str:
        match self:
            case self.Fill:
                return "fill"

    @property
    def wpaperd_value(self) -> str:
        match self:
            case self.Fill:
                return "center"


@define
class InputConfig:
    match: str
    tap: bool | None = None

    @property
    def sway_lines(self) -> str:
        lines = []
        if self.tap is not None:
            lines.append(f"    tap {'enabled' if self.tap else 'disabled'}")

        return "\n".join(lines)


@define
class OutputConfig:
    match: str
    position: list | None = None
    mode: str | None = None
    scale: float | None = None
    background_path: str | None = None
    background_mode: BackgroundMode = BackgroundMode.Fill
    port: str | None = None

    @property
    def sway_lines(self) -> str:
        lines = []
        if self.position:
            lines.append(f"    position {' '.join(map(str, self.position))}")
        if self.mode:
            lines.append(f"    mode '{self.mode}'")
        if self.background_path:
            lines.append(
                f"    background '{self.background_path}' {self.background_mode.sway_value}"
            )

        return "\n".join(lines)

    @property
    def swaylock_image_line(self) -> str | None:
        if (self.match != "*" and self.port is None) or self.background_path is None:
            return None

        if self.match == "*":
            return f"image={self.background_path}"
        return f"image={self.port}:{self.background_path}"

    @property
    def niri_lines(self) -> str:
        lines = []
        if self.position:
            lines.append(f"    position x={self.position[0]} y={self.position[1]}")
        if self.mode:
            lines.append(f"    mode \"{self.mode.removesuffix('Hz')}\"")
        if self.scale:
            lines.append(f"    scale {self.scale}")

        return "\n".join(lines)

    @property
    def wpaperd_config_fragment(self) -> dict:
        if self.background_path is None:
            return {}

        key = self.match
        if self.match == "*":
            key = "any"

        return {
            key: {
                "path": self.background_path,
                "mode": self.background_mode.wpaperd_value,
            }
        }


@define
class NiriConfig:
    default_column_width: float = 0.5


@define
class HostConfig:
    name: str
    is_virtual: bool = False
    base16_scheme: str = "seti"
    wireless: list[str] = field(factory=list)
    ethernet: list[str] = field(factory=list)
    auto_ethernet: bool = True
    disks: list[str] = field(factory=lambda: ["/"])
    has_battery: bool = False
    system_font: str = "Fira Sans"
    system_mono_font: str = "Fira Mono"
    temperature_path: str | None = None
    terminal: str = "alacritty"
    lock_cmd: str = "swaylock -c 000000"
    display_on_cmd: str = "wlopm --on *"
    display_off_cmd: str = "wlopm --off *"
    use_jump_host: bool = False
    inputs: list[InputConfig] = field(factory=list)
    outputs: list[OutputConfig] = field(factory=list)
    niri: NiriConfig = field(factory=NiriConfig)

    @property
    def swaylock_images(self) -> str:
        return "\n".join(
            line for output in self.outputs if (line := output.swaylock_image_line)
        )

    @property
    def wpaperd_config(self) -> str:
        config = {}

        for output in self.outputs:
            config.update(output.wpaperd_config_fragment)

        return toml.dumps(config)


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()

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

    host_toml = {
        "name": args.hostname,
    }
    if host_filename.exists():
        with open(host_filename) as host_file:
            host_toml.update(toml.load(host_file))

    host_config = cattrs.structure(host_toml, HostConfig)

    for output in host_config.outputs:
        # Attempt to resolve port 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 or niri is running, but that is usually the case...
        if output.match == "*":
            continue

        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 <port> '<match identifier>'
                    if line.startswith("Output") and output.match in line:
                        output.port = 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>" (<port>)
                    if line.startswith("Output") and output.match in line:
                        output.port = (
                            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),
        ],
    )

    changed_paths = set()

    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)
            changed_paths.update(map(str, rel_path.parents))

    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.base16_scheme),
            )
            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)
            changed_paths.update(map(str, rel_path.parents))

    # Post-install hooks
    if ".config/waybar" in changed_paths:
        subprocess.call(["killall", "-USR2", "waybar"])


if __name__ == "__main__":
    main()