local popup = require'plenary.popup'
local gcm = require'presser.context_manager'

local a = vim.api

local steamers = {}

local Steamer = {}
Steamer.__index = Steamer

-- @Description: Construct a new instance of a window and buffer using the 'plenary.popup' module.
-- @Params:
--    + `_type` ~ string denoting which context manager is owner of the window.
--    + `placeholder` ~ string allowing for placeholder text to be placed within the buffer when constructed.
--    + `opts` ~ a table of additional options to be provided when constructing the window.
-- @Returns: nil. Constructs a new window and stores the window's ID in a global table.
--
-- @Dev: This function is to be as generic for creating a window whilst allowing for as much customisation over the
-- window/buffer which are to be constructed. Users are to access this function so is not part of the module export.
-- However, it's used by all internal built-ins which are meant to be used by users. Consider a class constructor in
-- C++, this function is akin to that behaviour and is responsible for constructing the window/buffer and ensuring it
-- can be tracked by Vim itself.
function Steamer:new ( _ctx, label, opts )
  local opts = opts or {}
  if not opts.placeholder then
    opts["placeholder"] = ""
  end
  
  local buf_opts = {
    minwidth = 80, -- getwin_w() / 2 - ((getwin_w() % 2) / 2),
    borderchars = { "─", "│", "─", "│", "╭", "╮", "╯", "╰" },
  }

  if opts.window then
    for k,v in pairs( opts.window ) do
      buf_opts[k] = v
    end
  end

  print("building window: ", opts.placeholder, buf_opts )
  local obj = popup.create( opts.placeholder, buf_opts )
  gcm.update( _ctx, { id = obj, what = label, allowed = opts.allowed } )
  -- :TODO: call update function in context manager
--  table.insert( manager[_type], obj )
--  g.presser_buf_ctx = manager

  -- :@Dev: handle for keybindings (TODO: any future stuff below here once window is made)
  local buf_id = function ()
    return a.nvim_win_get_buf(obj)
  end

  -- handle for key bindings
  if opts.keybinds then
    for mode, mode_map in pairs( opts.keybinds ) do
      mode = string.lower(mode)

      for key_bind, key_action in pairs(mode_map) do
        local key_bind = a.nvim_replace_termcodes(key_bind, true, false, true),
        a.nvim_buf_set_keymap(buf_id(), mode, key_bind, key_action,
          { noremap = true, silent = true }
        )
      end
    end
  end
end

steamers.new = function ( ctx, opts )
  -- error if the provided option is not type string
  assert( type(opts.label) == "string", "Should be string, found type: " .. type(opts.label) ) 

  -- @Dev: function can provide greater wrapper options in future.

  return Steamer:new( ctx, opts.label, opts.steamer )
end

steamers._Steamer = Steamer

return steamers