screen-setup/core.ts

Setup screens position from saved profiles

import { array, int, object, optional, string } from 'cast.ts'
import { execSync } from 'child_process'
import { getLocalStorage } from '@beenotung/tslib/store.js'
import { storageDir } from './config.js'
import { compare } from '@beenotung/tslib/compare.js'

export type Configs = Config[]

export type Config = {
  profile_name: string
  screens: Screen[]
  last_applied?: number
}

export type Screen = {
  name: string
  w: number
  h: number
  x: number
  y: number
}

let screenParser = object({
  name: string({ nonEmpty: true }),
  w: int(),
  h: int(),
  x: int(),
  y: int(),
})

let configParser = object({
  profile_name: string({ nonEmpty: true }),
  screens: array(screenParser),
  last_applied: optional(int()),
})

let configsParser = array(configParser)

export function getCurrentConfig(): Config {
  let screens: Screen[] = []
  let text = execSync('xrandr').toString()
  let matches = text.matchAll(/\w+ connected (primary )?([\dx+]+)/g)

  for (let match of matches) {
    let name = match[0].match(/\w+/)?.[0]
    let [_, w, h, x, y] = match[0].match(/(\d+)x(\d+)\+(\d+)\+(\d+)/) || []
    let screen = screenParser.parse({ name, w, h, x, y })
    screens.push(screen)
  }
  return { profile_name: 'current', screens }
}

let storage = getLocalStorage(storageDir)

export function loadConfigs(): Configs {
  try {
    let configs = configsParser.parse(
      JSON.parse(storage.getItem('configs') || ''),
    )
    return configs.sort(
      (a, b) =>
        compare(b.last_applied || 0, a.last_applied || 0) ||
        compare(a.profile_name, b.profile_name),
    )
  } catch (error) {
    return []
  }
}

export function saveConfigs(configs: Configs) {
  let text = JSON.stringify(configsParser.parse(configs), null, 2)
  storage.setItem('configs', text)
}

export function applyConfig(config: Config) {
  config = configParser.parse(config)
  config.screens.forEach(({ name, w, h, x, y }) => {
    execSync(`xrandr --output ${name} --mode ${w}x${h} --pos ${x}x${y}`)
  })

  // update last_applied
  config.last_applied = Date.now()
  let configs = loadConfigs()
  let index = configs.findIndex(c => c.profile_name == config.profile_name)
  if (index == -1) {
    configs.push(config)
  } else {
    configs[index] = config
  }
  saveConfigs(configs)
}