package page

import (
	"fmt"

	"github.com/go-gl/gl/v3.3-core/gl"
	"github.com/go-gl/mathgl/mgl32"
	"github.com/veandco/go-sdl2/sdl"
	"rhemawavetech.com/rhemawave/internal/colors"
	"rhemawavetech.com/rhemawave/internal/fontManager"
	"rhemawavetech.com/rhemawave/internal/shaderManager"
)

type MessagePage struct {
	Base
	message      StringItem
	instructions StringItem
	msgDim       mgl32.Vec2
	instDim      mgl32.Vec2
	textShader   *shaderManager.Shader
	msgPos       mgl32.Vec2
	instPos      mgl32.Vec2
}

func (p *MessagePage) Init(ctx *PageCtx) error {
	var err error
	var ok bool

	if ctx.Msg == "" {
		ctx.Msg = "This is an example message because no message was passed"
	}

	if ctx.Inst == "" {
		ctx.Inst = "Press F1 to exit"
	}

	if err = p.Base.Init(ctx); err != nil {
		return fmt.Errorf("failed to init Base page: %w", err)
	}

	// Fetch and cache shader
	sm := shaderManager.Get()
	p.textShader, ok = sm.Get("text")
	if !ok {
		return fmt.Errorf("failed to fetch text shader")
	}

	fm := fontManager.Get()
	font, ok := fm.GetFont("Roboto-Regular")
	if !ok {
		return fmt.Errorf("unable to fetch font")
	}

	p.message, err = NewStringItem(ctx.Msg, font, colors.Orange)
	if err != nil {
		return fmt.Errorf("unable to create message string texture: %w", err)
	}

	p.instructions, err = NewStringItem(ctx.Inst, font, colors.White)
	if err != nil {
		return fmt.Errorf("unable to create instructions string texture: %w", err)
	}

	baseFontSize := float32(p.Context.CfgPtr.StandardFontSize)
	p.message.Scale(float32(48) / baseFontSize)
	p.instructions.Scale(float32(28) / baseFontSize)

	// Cache scaled dimensions — never recomputed unless textures are replaced
	p.msgDim = p.message.RawDimensions()
	p.instDim = p.instructions.RawDimensions()

	p.msgPos = mgl32.Vec2{
		float32(p.Base.ScreenCenterX) - p.msgDim[0]/2,
		float32(p.Base.ScreenCenterY) - p.msgDim[1]/2,
	}
	p.instPos = mgl32.Vec2{
		float32(p.Base.ScreenCenterX) - p.instDim[0]/2,
		float32(20),
	}

	return nil
}

func (p *MessagePage) HandleEvent(event *sdl.Event) error {
	return nil
}

func (p *MessagePage) Update(dt float32) error {
	return nil
}

func (p *MessagePage) Render() error {
	p.Base.RenderTexture(p.textShader, p.message.ID, p.msgPos, p.msgDim, colors.Orange)
	p.Base.RenderTexture(p.textShader, p.instructions.ID, p.instPos, p.instDim, colors.White)

	return nil
}

func (p *MessagePage) Destroy() error {
	gl.DeleteTextures(1, &p.message.ID)
	gl.DeleteTextures(1, &p.instructions.ID)
	return p.Base.Destroy()
}

func (p *MessagePage) SetMessage(msg string) error {
	return nil
}

func (p *MessagePage) SetInstructions(inst string) error {
	return nil
}