-- Copyright (c) 2024 Florian Fischer. All rights reserved.
--
-- vis-lockfiles is free software: you can redistribute it and/or modify it under
-- the terms of the GNU General Public License as published by the Free Software
-- Foundation, either version 3 of the License, or (at your option) any later
-- version.
--
-- vis-lockfiles is distributed in the hope that it will be useful, but WITHOUT
-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
-- FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License along with
-- vis-lockfiles found in the LICENSE file.
-- If not, see <https://www.gnu.org/licenses/>.
local source_str = debug.getinfo(1, 'S').source:sub(2)
local script_path = source_str:match('(.*/)')

local lockfiles = dofile(script_path .. 'lockfiles.lua')

local M = {}
M.directory = '${XDG_STATE_HOME:-${HOME}/.local/state}/vis/locks'
M.directory_expanded = nil

local function get_lock_dir()
  if M.directory_expanded ~= M.directory then
    M.directory = lockfiles.capture_cmd('printf %s "' .. M.directory .. '"')
    M.directory_expanded = M.directory
  end
  return M.directory
end

-- get a user confirmation
-- return true if user selected yes, false otherwise
local function confirm(path, pid)
  local choices = 'no\nyes'
  local prompt = path .. ' for PID '..pid .. ' exists. Edit anyway:'
  local cmd = 'printf %s \'' .. choices .. '\' | vis-menu -b -p \'' .. prompt .. '\''

  -- local status, output = vis:pipe(nil, {start = 0, finish = 0}, cmd)
  local menu = assert(io.popen(cmd))
  local output = menu:read('*a')
  local _, _, status = menu:close()
  vis:redraw()

  if status == 0 then
    return 'yes' == output:sub(1, 3)
  end
  return false
end

local created_locks = {}

vis.events.subscribe(vis.events.FILE_OPEN, function(file)
  if created_locks[file.path] or not file.path then
    -- either a noname buffer, or already locked by us
    return
  end
  local lfile_path = lockfiles.lock_file_path(get_lock_dir(), file.path)
  local lock_pid = lockfiles.create_lock_file(get_lock_dir(), lfile_path)
  if lockfiles.vis_pid == lock_pid then
    created_locks[file.path] = lfile_path
  elseif not confirm(lfile_path, lock_pid) then
    vis:exit(1)
  end
end)

vis.events.subscribe(vis.events.FILE_CLOSE, function(file)
  if not file.path then
    return
  end
  local lfile_path = created_locks[file.path]
  if lfile_path then
    lockfiles.delete_lock_file(lfile_path)
    created_locks[file.path] = nil
  end
end)

vis.events.subscribe(vis.events.QUIT, function()
  for _, lfile_path in pairs(created_locks) do
    if lfile_path then
      lockfiles.delete_lock_file(lfile_path)
    end
  end
  created_locks = {}
end)

return M