set-theme

#!/usr/bin/env python3

import argparse
import fileinput
import os
import re
import sys
import textwrap

from pathlib import Path
from subprocess import run, PIPE


THEMES = {
  "gruvbox": {
    "dark": {
      "terminal": {
        "colorScheme": "Gruvbox Dark",
        "cursorColor": "#ffb261",
      },
      "tmux": {
        "status-style": "fg=colour244",
        "window-status-current-style": "fg=colour222",
        "pane-border-style": "fg=colour240",
        "pane-active-border-style": "fg=colour243"
      }
    },
    "light": {
      "terminal": {
        "colorScheme": "Gruvbox Light",
        "cursorColor": "#ffb261",
      },
      "tmux": {
        "status-style": "fg=colour179",
        "window-status-current-style": "fg=colour172",
        "pane-border-style": "fg=colour186",
        "pane-active-border-style": "fg=colour178"
      }
    }
  },
  "one": {
    "dark": {
      "terminal": {
        "colorScheme": "One Half Dark",
        "cursorColor": "#6de6f5",
      },
      "tmux": {
        "status-style": "fg=colour110",
        "window-status-current-style": "fg=colour39",
        "pane-border-style": "fg=colour240",
        "pane-active-border-style": "fg=colour243"
      }
    },
    "light": {
      "terminal": {
        "colorScheme": "One Half Light",
        "cursorColor": "#6de6f5",
      },
      "tmux": {
        "status-style": "fg=colour110",
        "window-status-current-style": "fg=colour39",
        "pane-border-style": "fg=colour253",
        "pane-active-border-style": "fg=colour250"
      }
    }
  }
}


def get_windows_user():
    result = run(['powershell.exe', '$env:UserName'],
                 stdout=PIPE,
                 universal_newlines=True)
    return result.stdout.rstrip()


HOME = str(Path.home())

TERMINAL_CONFIG = f'/c/Users/{get_windows_user()}/AppData/Local/Packages/Microsoft.WindowsTerminal_8wekyb3d8bbwe/LocalState/settings.json'  # noqa: E501
SHELL_CONFIG = f'{os.environ.get("XDG_CONFIG_HOME")}/zsh/.zshrc'
TMUX_CONFIG = f'{HOME}/.tmux.conf'
VIM_CONFIG = f'{HOME}/.vimrc'


def edit_inplace(file, preserve_symlinks=True):
    if preserve_symlinks:
        file = os.path.realpath(file)

    return fileinput.input(files=(file,), inplace=True)


def active_theme_and_background():
    with open(VIM_CONFIG, 'r') as f:
        for line in f:
            match = re.match('^set background=(.*)$', line)
            if match:
                bg = match.group(1)
                continue

            match = re.match('^colorscheme (.*$)$', line)
            if match:
                theme = match.group(1)
                continue
    try:
        return theme, bg
    except NameError:
        sys.exit('error: "set background" or "colorscheme" statement not found'
                 f' in {VIM_CONFIG}')


def change_terminal_theme(theme, bg):
    terminal_options = THEMES[theme][bg]['terminal']

    with edit_inplace(TERMINAL_CONFIG) as f:
        for line in f:
            for key, value in terminal_options.items():
                line = re.sub(rf'"{key}": ".*"', f'"{key}": "{value}"', line)
            sys.stdout.write(line)


def change_tmux_theme(theme, bg):
    tmux_options = THEMES[theme][bg]['tmux']

    with edit_inplace(TMUX_CONFIG) as f:
        for line in f:
            for key, value in tmux_options.items():
                line = re.sub(rf'^set -g {key} .*$', f'set -g {key} {value}',
                              line)
            sys.stdout.write(line)

    run(['tmux', 'source-file', TMUX_CONFIG])


def change_vim_theme(theme, bg):
    with edit_inplace(VIM_CONFIG) as f:
        for line in f:
            line = re.sub(r'^colorscheme .*$', f'colorscheme {theme}', line)
            line = re.sub(r'^set background=.*$', f'set background={bg}', line)
            sys.stdout.write(line)


def change_fzf_theme(bg):
    with edit_inplace(SHELL_CONFIG) as f:
        for line in f:
            re.sub(r'FZF_DEFAULT_OPTS="--color=.*"$',
                   f'FZF_DEFAULT_OPTS="--color={bg}"', line)
            sys.stdout.write(line)


def parseargs():
    parser = argparse.ArgumentParser(
        formatter_class=argparse.RawDescriptionHelpFormatter,
        description=textwrap.dedent('''\
        Set a theme along with optionally toggling dark and light backgrounds.
        '''))
    parser.add_argument('theme', choices=THEMES, nargs='?',
                        help='the theme name')
    parser.add_argument('--toggle-bg', action='store_true',
                        help='toggle the background between dark and light')
    args = parser.parse_args()

    if len(sys.argv) == 1:
        parser.error('at least one argument is required')

    return args


def main():
    args = parseargs()

    theme, bg = active_theme_and_background()

    if args.theme:
        theme = args.theme

    if args.toggle_bg:
        bg = 'light' if bg == 'dark' else 'dark'

    change_terminal_theme(theme, bg)
    change_tmux_theme(theme, bg)
    change_vim_theme(theme, bg)
    change_fzf_theme(bg)


if __name__ == '__main__':
    main()