local M = {}

local state = {
  buf = nil,
  win = nil,
  job = nil,
}

local function is_valid_window(win)
  return win and vim.api.nvim_win_is_valid(win)
end

local function is_valid_buffer(buf)
  return buf and vim.api.nvim_buf_is_valid(buf)
end

local function open_side_window()
  vim.cmd("botright vertical 80new")
  state.win = vim.api.nvim_get_current_win()
end

local function start_terminal()
  state.buf = vim.api.nvim_create_buf(false, true)
  vim.api.nvim_set_option_value("bufhidden", "hide", { buf = state.buf })
  vim.api.nvim_set_option_value("filetype", "opencode", { buf = state.buf })
  vim.api.nvim_buf_set_name(state.buf, "opencode")

  vim.api.nvim_win_set_buf(state.win, state.buf)
  state.job = vim.fn.termopen("opencode", {
    on_exit = function()
      state.job = nil
    end,
  })
end

function M.toggle()
  if is_valid_window(state.win) then
    vim.api.nvim_win_close(state.win, false)
    state.win = nil
    return
  end

  open_side_window()

  if is_valid_buffer(state.buf) then
    vim.api.nvim_win_set_buf(state.win, state.buf)
  else
    start_terminal()
  end

  vim.cmd("startinsert")
end

function M.setup()
  vim.api.nvim_create_user_command("OpenCodeToggle", function()
    M.toggle()
  end, {})
end

return M