package screen

import (
	"errors"
	"fmt"

	"bitbucket.org/hevanto/ui/uiwidget"
	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/layout"
)

// The constants for the Containers
//
// Available yaml options for all containers:
//   - id: The ID for exporting the container to code
//   - decorators: The decorators to wrap the container into
//   - hidden: Wether the container is hidden or not
type Container string

const (
	// HScroll Container
	//
	// Available yaml options:
	//	- content: The content of the container
	HScroll Container = "HScroll"

	// Scroll Container
	//
	// Available yaml options:
	//	- content: The content of the container
	Scroll Container = "Scroll"

	// VScroll Container
	//
	// Available yaml options:
	//	- content: The content of the container
	VScroll Container = "VScroll"
)

// Build builds the container and decorator for the given Container and Element,
// using the provided ScreenHandler to fetch functions, data bindings, etc.
//
// Parameters:
// - e *Element - the element to build the container for
// - s ScreenHandler - the screen handler for the container
//
// Returns the CanvasObject for the widget, the CanvasObject for the decorator
// I fno decorators are specified, the widget and decorator will be the same.
func (cnt Container) Build(
	e *Element,
	s ScreenHandler,
) (
	cont fyne.CanvasObject,
	decorator fyne.CanvasObject,
	err error,
) {
	switch cnt {
	case HScroll:
		cont, err = cnt.buildHScrollContainer(e, s)
	case Scroll:
		cont, err = cnt.buildScrollContainer(e, s)
	case VScroll:
		cont, err = cnt.buildVScrollContainer(e, s)
	default:
		err = errors.New("invalid container")
	}
	if err != nil {
		return
	}

	decorator = cont
	if e.Decorators != nil {
		for _, dec := range e.Decorators {
			switch dec {
			case "Border":
				decorator = uiwidget.NewWidgetBorder(decorator)
			case "HCenter":
				decorator = container.NewHBox(
					layout.NewSpacer(),
					decorator,
					layout.NewSpacer())
			case "VCenter":
				decorator = container.NewVBox(
					layout.NewSpacer(),
					decorator,
					layout.NewSpacer())
			}
		}
	}

	if e.Hidden {
		decorator.Hide()
	}
	return
}

func (ctn Container) buildHScrollContainer(
	e *Element,
	s ScreenHandler,
) (c fyne.CanvasObject, err error) {
	if e.Content == nil {
		err = errors.New("HScroll: no content defined")
		return
	}

	content, err := e.Content.BuildUI(s)
	if err != nil {
		err = fmt.Errorf("HScroll: failed to build content: %w", err)
		return
	}
	c = container.NewHScroll(content)
	return
}

func (ctn Container) buildScrollContainer(
	e *Element,
	s ScreenHandler,
) (c fyne.CanvasObject, err error) {
	if e.Content == nil {
		err = errors.New("Scroll: no content defined")
		return
	}

	content, err := e.Content.BuildUI(s)
	if err != nil {
		err = fmt.Errorf("Scroll: failed to build content: %w", err)
		return
	}
	c = container.NewScroll(content)
	return
}

func (ctn Container) buildVScrollContainer(
	e *Element,
	s ScreenHandler,
) (c fyne.CanvasObject, err error) {
	if e.Content == nil {
		err = errors.New("VScroll: no content defined")
		return
	}

	content, err := e.Content.BuildUI(s)
	if err != nil {
		err = fmt.Errorf("VScroll: failed to build content: %w", err)
		return
	}
	c = container.NewScroll(content)
	return
}