package main

import (
	"github.com/gen2brain/raylib-go/raylib"
)

type ClientAuth struct {

}

type LoginState int

const (
	LOGIN_STATE_CREDENTIALS LoginState = iota
	LOGIN_STATE_ATTEMPTING
	LOGIN_STATE_ERROR
)

type ButtonState int

const (
	BUTTON_STATE_IDLE ButtonState = iota
	BUTTON_STATE_HOVER
	BUTTON_STATE_PRESSED
)

type ClientState struct {
	auth *ClientAuth
	login LoginState
	login_button ButtonState
	ui_scale uint
	window_scale rl.Vector2
}

const (
	WIDTH  uint = 1600
  HEIGHT uint = 1000
)

func scale(original rl.Rectangle, ui_scale uint, window_scale rl.Vector2) rl.Rectangle {
	return rl.Rectangle{
X: original.X/window_scale.X,
		Y: original.Y/window_scale.Y,
		Width: original.Width*float32(ui_scale)/window_scale.X,
		Height: original.Height*float32(ui_scale)/window_scale.Y,
	}
}

func center(original rl.Rectangle, off_x, off_y int, window_scale rl.Vector2, width, height uint) rl.Rectangle {
	return rl.Rectangle{
		X: (float32(width) /window_scale.X - original.Width )/2 + float32(off_x)/window_scale.X,
		Y: (float32(height)/window_scale.Y - original.Height)/2 + float32(off_y)/window_scale.Y,
		Width: original.Width,
		Height: original.Height,
	}
}

func button(rectangle rl.Rectangle, idle, hover, pressed rl.Color, text string, font_size int32, text_color rl.Color, last_state ButtonState) (action bool, next_state ButtonState) {
	over := rl.CheckCollisionPointRec(rl.GetMousePosition(), rectangle)
	action = false
	next_state = last_state

	if(rl.IsMouseButtonPressed(rl.MouseButtonLeft) && over) {
		next_state = BUTTON_STATE_PRESSED
	} else if(rl.IsMouseButtonReleased(rl.MouseButtonLeft) && last_state == BUTTON_STATE_PRESSED) {
		next_state = BUTTON_STATE_IDLE
		if(over) {
			action = true
		}
	} else if(rl.IsMouseButtonUp(rl.MouseButtonLeft)) {
		if(last_state == BUTTON_STATE_IDLE && over) {
			next_state = BUTTON_STATE_HOVER
		} else if (last_state == BUTTON_STATE_HOVER && !over) {
			next_state = BUTTON_STATE_IDLE
		}	
	}
	
	var color rl.Color
	switch(next_state) {
	case BUTTON_STATE_HOVER:
		color = hover
	case BUTTON_STATE_PRESSED:
		color = pressed
	default:
		color = idle
	}
	rl.DrawRectangleRec(rectangle, color)
	text_size := rl.MeasureTextEx(rl.GetFontDefault(), text, float32(font_size), 1.0)
	rl.DrawText(text, int32(rectangle.X + rectangle.Width/2 - text_size.X/2), int32(rectangle.Y + rectangle.Height/2 - text_size.Y/2), font_size, text_color)

	return action, next_state
}

func main() {
	state := ClientState{
		auth: nil,
		login: LOGIN_STATE_CREDENTIALS,
		login_button: BUTTON_STATE_IDLE,
		ui_scale: 1,
	}

	rl.SetConfigFlags(rl.FlagWindowHighdpi)
	rl.InitWindow(0, 0, "roleplay")
	rl.SetExitKey(0)
	rl.SetTargetFPS(60)

	state.window_scale = rl.GetWindowScaleDPI()
	rl.SetWindowSize(int(float32(WIDTH)/state.window_scale.X), int(float32(HEIGHT)/state.window_scale.Y))

	for(rl.WindowShouldClose() == false) {
		if(state.auth == nil) {
			// Draw login
			rl.BeginDrawing()
			rl.ClearBackground(rl.White)

			logo_rect := scale(rl.Rectangle{Width: 1200, Height: 300}, state.ui_scale, state.window_scale)
			logo_rect = center(logo_rect, 0, -300, state.window_scale, WIDTH, HEIGHT)
			rl.DrawRectangleRec(logo_rect, rl.Gray)

			form_rect := scale(rl.Rectangle{Width: 600, Height: 400}, state.ui_scale, state.window_scale)
			form_rect = center(form_rect, 0, 150, state.window_scale, WIDTH, HEIGHT)
			rl.DrawRectangleRec(form_rect, rl.Gray)

			switch(state.login) {
			case LOGIN_STATE_CREDENTIALS:
				submit_rect := scale(rl.Rectangle{Width: 100, Height: 50}, state.ui_scale, state.window_scale)
				submit_rect = center(submit_rect, 0, 300, state.window_scale, WIDTH, HEIGHT)
				var submit_action bool
				submit_action, state.login_button = button(submit_rect, rl.Black, rl.Brown, rl.Red, "Submit", 12, rl.White, state.login_button)
				if submit_action {
					state.login = LOGIN_STATE_ATTEMPTING
				}
			case LOGIN_STATE_ATTEMPTING:
				text := "Logging in..."
				text_size := rl.MeasureTextEx(rl.GetFontDefault(), text, 20, 1.0)
				text_rect := center(rl.Rectangle{Width: text_size.X, Height: text_size.Y}, 0, 0, state.window_scale, WIDTH, HEIGHT)
				rl.DrawText(text, int32(text_rect.X), int32(text_rect.Y), 20, rl.Black)
			case LOGIN_STATE_ERROR:
				text := "Error: {TODO}"
				text_size := rl.MeasureTextEx(rl.GetFontDefault(), text, 20, 1.0)
				text_rect := center(rl.Rectangle{Width: text_size.X, Height: text_size.Y}, 0, 0, state.window_scale, WIDTH, HEIGHT)
				rl.DrawText(text, int32(text_rect.X), int32(text_rect.Y), 20, rl.Black)
			}

			rl.EndDrawing()
		} else {
			// Draw game
		}
	}
}