package descriptors

import (
	"fmt"
	"strings"

	ui "github.com/DegustatorPonos/RuinesOfRafdolon/UI"
	rl "github.com/gen2brain/raylib-go/raylib"
)

type UIElementDescriptor struct {
	Type string
	Weight float32
	Style StyleDescriptor

	// For labels
	Text string
	Alignment string

	// For grid elements
	Children []UIElementDescriptor
	Spacing float32
}

func InitUIParser() {
	typeParsers = map[string]func(*UIElementDescriptor) ui.UIElement {
		ui.VoidTypeName: parseAsVoid,
		ui.LabelTypeName: parseAsLabel,
		ui.GridRowTypeName: parseAsGridRow,
	}
}

// The item type to its parser relationship
var typeParsers map[string]func(*UIElementDescriptor) ui.UIElement

func (base *UIElementDescriptor) Parse() (ui.UIElement, error) {
	var elemType = strings.ToLower(base.Type)
	var descFunc, exists = typeParsers[elemType]
	if exists {
		return descFunc(base), nil
	}
	return nil, fmt.Errorf("Unknown UI element type")
}

func parseAsVoid(base *UIElementDescriptor) ui.UIElement {
	return &ui.Void {
		Weight: base.Weight,
	}
}

func parseAsLabel(base *UIElementDescriptor) ui.UIElement {
	var alignment ui.TextAlignment
	switch strings.ToLower(base.Alignment) {
	case "center":
		alignment = ui.Center
	case "start":
		alignment = ui.Start
	}

	return &ui.Label {
		Weight: base.Weight,
		Text: base.Text,
		Alignment: alignment,
		Style: base.Style.Parse(),
	}
}

func parseAsGridRow(base *UIElementDescriptor) ui.UIElement {
	var outp = ui.GridRow {
		Weight: base.Weight,
		Spacing: base.Spacing,
		Style: base.Style.Parse(),
		Objects: make([]ui.UIElement, 0, len(base.Children)),
	}
	for _, v := range base.Children {
		var child, parseErr = v.Parse()
		if parseErr != nil {
			rl.TraceLog(rl.LogWarning, "Failed to parse a parent element of a grid row: %v", parseErr.Error())
			continue
		}
		outp.Objects = append(outp.Objects, child)
	}
	return &outp
}