local M = {}

function M.dump(o)
  if type(o) == 'table' then
    local s = '{'
    for k, v in pairs(o) do
      if type(k) ~= 'number' then k = '"' .. k .. '"' end
      s = s .. ' [' .. k .. '] = ' .. M.dump(v) .. ','
    end
    return s .. '} '
  else
    return tostring(o)
  end
end

-- Coroutine-based async/await helpers
function M.await(callback_fn)
  local co = coroutine.running()
  if not co then error 'await must be called inside async' end

  local result, err
  local done = false

  callback_fn(function(res, e)
    result = res
    err = e
    done = true
    if coroutine.status(co) == 'suspended' then coroutine.resume(co) end
  end)

  if not done then coroutine.yield() end
  if err then error(err) end
  return result
end

function M.awaitAll(callback_fns)
  local co = coroutine.running()
  if not co then error 'awaitAll must be called inside async' end

  local results = {}
  local pending = #callback_fns
  local err = nil

  for i, fn in ipairs(callback_fns) do
    fn(function(res, e)
      if e then err = e end
      results[i] = res
      pending = pending - 1
      if pending == 0 and coroutine.status(co) == 'suspended' then coroutine.resume(co) end
    end)
  end

  if pending > 0 then coroutine.yield() end
  if err then error(err) end
  return results
end

function M.async(fn)
  return function(...)
    local args = { ... }
    local co = coroutine.create(function() fn(table.unpack(args)) end)
    local ok, err = coroutine.resume(co)
    if not ok then print('Async error: ' .. tostring(err)) end
  end
end

-- Execute a shell command, returns a callback function for use with await
function M.exec(cmd)
  return function(resolve)
    sbar.exec(cmd, function(result, exit_code)
      if exit_code ~= 0 then
        resolve(nil, string.format('Exit Code: %s Message: %s', tostring(exit_code), M.dump(result)))
      else
        resolve(result, nil)
      end
    end)
  end
end

return M