-- Built on top of https://github.com/vimichael/floatingtodo.nvim and the pull request https://github.com/vimichael/floatingtodo.nvim/pull/3.
-- All credits to the original authors.
-- Original repo: https://github.com/lukas-reineke/indent-blankline.nvim

local M = {}

local win = nil

local default_opts = {
  target_file = "~/notes/todo.md", -- todo file path
  border = "single",              -- border style
  auto_save = true,               -- automatically save on quit
  width = 0.70,
  height = 0.8,
  position = "center",
}

local function expand_path(path)
  if path:sub(1, 1) == "~" then
    return os.getenv("HOME") .. path:sub(2)
  end
  return path
end

-- local function center_in(outer, inner)
-- 	return (outer - inner) / 2
-- end
local function calculate_position(position)
  local posx, posy = 0.5, 0.5

  -- custom position
  if type(position) == "table" then
    posx, posy = position[1], position[2]
  end

  -- preset position
  if position == "center" then
    posx, posy = 0.5, 0.5
  elseif position == "topleft" then
    posx, posy = 0, 0
  elseif position == "topright" then
    posx, posy = 1, 0
  elseif position == "bottomleft" then
    posx, posy = 0, 1
  elseif position == "bottomright" then
    posx, posy = 1, 1
  end

  return posx, posy
end

local function win_config(opts)
  local width = math.min(math.floor(vim.o.columns * opts.width), 82)
  local height = math.floor(vim.o.lines * opts.height)

  local posx, posy = calculate_position(opts.position)

  local col = math.floor((vim.o.columns - width) * posx)
  local row = math.floor((vim.o.lines - height) * posy)

  return {
    relative = "editor",
    width = width,
    height = height,
    col = col,
    row = row,
    border = opts.border,
  }
end

local function open_floating_file(opts)
  local expanded_path = expand_path(opts.target_file)

  if vim.fn.filereadable(expanded_path) == 0 then
    vim.notify("todo file does not exist at directory: " .. expanded_path, vim.log.levels.ERROR)
    return
  end

  local buf = vim.fn.bufnr(expanded_path, true)

  if buf == -1 then
    buf = vim.api.nvim_create_buf(false, false)
    vim.api.nvim_buf_set_name(buf, expanded_path)
  end

  vim.bo[buf].swapfile = false

  if win ~= nil and vim.api.nvim_win_is_valid(win) then
    vim.api.nvim_set_current_win(win)
    return
  end

  win = vim.api.nvim_open_win(buf, true, win_config(opts))

  vim.api.nvim_buf_set_keymap(buf, "n", "q", "", {
    noremap = true,
    silent = true,
    callback = function()
      if vim.api.nvim_get_option_value("modified", { buf = buf }) then
        if opts.auto_save then
          vim.api.nvim_buf_call(buf, function()
            vim.cmd("write")
          end)
          vim.api.nvim_win_close(0, true)
        else
          vim.notify("Save your changes before closing.", vim.log.levels.WARN)
        end
      else
        vim.api.nvim_win_close(0, true)
        win = nil -- why is this needed?
      end
    end,
  })
end

local function setup_user_commands(opts)
  vim.api.nvim_create_user_command("Td", function()
    open_floating_file(opts)
  end, {})
end

local function setup_keymap(opts)
  vim.keymap.set("n", "<leader>td", function()
    open_floating_file(opts)
  end, { desc = "Open floating todo" })
end

M.setup = function(opts)
  opts = vim.tbl_deep_extend("force", default_opts, opts or {})
  setup_user_commands(opts)
  setup_keymap(opts)
end

return M