package ncurses

import (
	"fmt"
	"sync/atomic"

	"github.com/ebitengine/purego"
)

var ncurses atomic.Value

func Init() error {
  if ncurses.Load() == nil {
    lib, err := purego.Dlopen(LIBRARY_PATH, purego.RTLD_GLOBAL | purego.RTLD_LAZY)
    if err != nil {
      return err
    }
    ncurses.CompareAndSwap(nil, lib)
  }
  
  return nil
}

type loaded_function[T any] struct {
  name string
  value atomic.Value
  library *atomic.Value
}

func NewLoadedFunction[T any](library *atomic.Value, name string) loaded_function[T] {
  return loaded_function[T]{
    name: name,
    value: atomic.Value{},
    library: library,
  }
}

func(f *loaded_function[T]) Load() T {
  if f.library.Load() == nil {
    panic(fmt.Sprintf("Attempted to call library function %s before loading library", f.name))
  } else if f.value.Load() == nil {
    var tmp T
    purego.RegisterLibFunc(&tmp, f.library.Load().(uintptr), f.name)
    f.value.CompareAndSwap(nil, tmp)
  }
  return f.value.Load().(T)
}

type Window uintptr

type voidFP func() int
type winFP func(window Window) int

type initscrFP func() Window
var InitScr = NewLoadedFunction[initscrFP](&ncurses, "initscr")
var EndWin = NewLoadedFunction[voidFP](&ncurses, "endwin")

type newwinFP func(nlines, ncols, begin_x, begin_y int) Window
var NewWin = NewLoadedFunction[newwinFP](&ncurses, "newwin")
var DelWin = NewLoadedFunction[winFP](&ncurses, "delwin")
type dupwinFP func(window Window) Window
var DupWin = NewLoadedFunction[dupwinFP](&ncurses, "dupwin")

var Refresh = NewLoadedFunction[voidFP](&ncurses, "refresh")
var WRefresh = NewLoadedFunction[winFP](&ncurses, "wrefresh")
var WNOutRefresh = NewLoadedFunction[winFP](&ncurses, "wnoutrefresh")
var DoUpdate = NewLoadedFunction[voidFP](&ncurses, "doupdate")

type waddstrFP func(window Window, str string) int
var WAddStr = NewLoadedFunction[waddstrFP](&ncurses, "waddstr")

type waddnstrFP func(window Window, str string, n int) int
var WAddNStr = NewLoadedFunction[waddstrFP](&ncurses, "waddnstr")

var GetMaxY = NewLoadedFunction[winFP](&ncurses, "getmaxy")
var GetMaxX = NewLoadedFunction[winFP](&ncurses, "getmaxx")

type mvwaddstrFP func(window Window, x, y int, str string) int
var MvWAddStr = NewLoadedFunction[mvwaddstrFP](&ncurses, "mvwaddstr")