local utils = require 'utils'
local silo = require 'silo'
local log = require 'log'
local path = require 'path'

local exports = {}

local shasum = utils.ext_piped "shasum"
local ha_checksum = ""

local homenix = path.join { silo.dirs.config, "home-manager/home.nix" }

if path.exists(homenix) then
  ha_checksum = (shasum {homenix}).stdout
  log.debug(ha_checksum)
end

local function clear_invalid_links()
  utils.nu [[
       ( glob /home/jri/.local/share/applications/*.desktop
       | each { ls -l $in }
       | flatten
       | where target? != null
       | par-each {|entry| get target
         | open $in
         | parse -r '\nTryExec\s?=\s?(?<bin>[^\n]+)'
         | get -i 0
         | default {}
         | merge $entry }
       | where bin? != null
       | where {|e| which $e.bin | is-empty }
       | each {|e| rm $e.name; print $"Cleared ($e.name)" }
       )
      ]]
end

local function link_apps()
  utils.nu [[
      ( glob ~/.nix-profile/share/applications/*.desktop
      | par-each { try { ln -s $in ~/.local/share/applications/; print $"Linked ($in)" } } )
    ]]
end

exports.after_apply_all = function()
  if utils.which "home-manager" == nil and (shasum {homenix}).stdout ~= ha_checksum then
    local hm = utils.ext "home-manager"

    log.info("Applying home-manager config")
    hm { "switch" }

    log.info "Expiring old home manager configurations"
    hm { "expire-generations", "-1 days" }

    log.info "Clear invalid links"
    clear_invalid_links()

    log.info "Linking applications"
    link_apps()
  else
    log.info "Home manager does not need to be updated"
  end
end

return exports