---@diagnostic disable-next-line: deprecated
local uv = vim.uv or vim.loop

local _is_win = vim.fn.has("win32") == 1 or vim.fn.has("win64") == 1
local _is_linux = vim.fn.has("linux") == 1 and
    (vim.fn.has("nvim-0.12") == 1 and vim.fn.has("android") == 0)

if vim.v.servername and #vim.v.servername > 0 then
  pcall(vim.fn.serverstop, vim.v.servername)
end

---@return string
local function windows_pipename()
  local tmpname = vim.fn.tempname()
  tmpname = string.gsub(tmpname, "\\", "")
  return ([[\\.\pipe\%s]]):format(tmpname)
end

local function new_pipe()
  local tmp = _is_win and windows_pipename() or vim.fn.tempname()
  local socket = assert(uv.new_pipe(false))
  uv.pipe_bind(socket, tmp)
  return socket, tmp
end

local function server_listen(server_socket, server_socket_path)
  uv.listen(server_socket, 10, function(_)
    local receive_socket = assert(uv.new_pipe(false))
    uv.accept(server_socket, receive_socket)

    -- Avoid dangling temp dir on premature process kills (live grep)
    -- see more complete note in spawn.lua
    if not _is_win then
      uv.fs_unlink(server_socket_path)
      local tmpdir = vim.fn.fnamemodify(server_socket_path, ":h")
      if tmpdir and #tmpdir > 0 then uv.fs_rmdir(tmpdir) end
    end

    local finish = function()
      uv.close(receive_socket)
      uv.close(server_socket)
      -- on windows: ci fail when use uv.stop()
      -- on linux: zero event can freeze
      -- https://github.com/ibhagwan/fzf-lua/pull/1955#issuecomment-2785474217
      -- uv.stop()
      vim.schedule_wrap(vim.cmd.cquit)({ count = 0, bang = true })
    end

    -- if _is_linux then
    --   while true do
    --     local len = uv.fs_sendfile(1, receive_socket:fileno(), 0, 1024 * 1024)
    --     local eof = len == 0
    --     if eof then finish() end
    --   end
    -- end

    receive_socket:read_start(function(err, data)
      assert(not err)
      if not data then return finish() end
      io.write(data)
    end)
  end)
end

local server_socket, server_socket_path = new_pipe()
server_listen(server_socket, server_socket_path)
---@diagnostic disable-next-line: param-type-mismatch
-- TODO: makes `uv.listen` never return or callback
-- local thread = uv.new_thread(server_listen, server_socket, server_socket_path)
-- io.stdout:write(string.format("thread %s\n", tostring(thread)))

---@class fzf-lua.rpc.Ctx
---@field function_id string An identifier for the RPC function to be executed.
---@field pipe_path string The path to the Unix domain socket for RPC communication.
---@field selection? string[] The selected item(s) (expanded from field expression).
---@field env table<string, string> Environment variables inherited by the RPC process.

---@param opts table
local rpc_nvim_exec_lua = function(opts)
  ---@type fzf-lua.rpc.Ctx
  local ctx = {
    function_id = opts.fnc_id,
    pipe_path = server_socket_path,
    selection = opts.selection,
    env = uv.os_environ(),
  }
  local success, errmsg = pcall(function()
    local chan_id = vim.fn.sockconnect("pipe", opts.fzf_lua_server, { rpc = true })
    vim.rpcrequest(chan_id, "nvim_exec_lua",
      [[return require"fzf-lua.shell".get_func((...).function_id)(...)]], { ctx })
    vim.fn.chanclose(chan_id)
  end)

  if not success or opts.debug == "v" or opts.debug == 2 then
    io.stderr:write(("[DEBUG] debug = %s\n"):format(opts.debug))
    io.stderr:write(("[DEBUG] function ID = %d\n"):format(opts.fnc_id))
    io.stderr:write(("[DEBUG] fzf_lua_server = %s\n"):format(opts.fzf_lua_server))
    for i, v in pairs(_G.arg) do
      io.stderr:write(("[DEBUG] argv[%d] = %s\n"):format(i, v))
    end
    for _, var in ipairs({ "LINES", "COLUMNS" }) do
      io.stderr:write(("[DEBUG] $%s = %s\n"):format(var, os.getenv(var) or "<null>"))
    end
  end

  if not success then
    io.stderr:write(("FzfLua Error: %s\n"):format(errmsg or "<null>"))
    os.exit(1)
  end

  while true do
    vim.wait(100)
  end
end

local args = vim.deepcopy(_G.arg)
args[0] = nil -- remove filename
rpc_nvim_exec_lua({
  fnc_id = tonumber(table.remove(args, 1)),
  debug = (function()
    local ret = table.remove(args, 1)
    if ret == "nil" then
      return nil
    elseif ret == "true" then
      return true
    elseif ret == "false" then
      return false
    else
      return tonumber(ret) or tostring(ret)
    end
  end)(),
  selection = args,
  fzf_lua_server = vim.env.FZF_LUA_SERVER or vim.env.SKIM_FZF_LUA_SERVER or vim.env.NVIM,
})