package tins2020

import (
	"errors"
	"fmt"

	"github.com/veandco/go-sdl2/img"
	"github.com/veandco/go-sdl2/sdl"
	"opslag.de/schobers/fs/vfs"
)

type Texture struct {
	texture *sdl.Texture
	rect    *sdl.Rect
}

func NewTextureFromSurface(renderer *sdl.Renderer, surface *sdl.Surface) (*Texture, error) {
	texture, err := renderer.CreateTextureFromSurface(surface)
	if err != nil {
		return nil, err
	}
	return &Texture{texture: texture, rect: &sdl.Rect{X: 0, Y: 0, W: surface.W, H: surface.H}}, nil
}

func (t *Texture) Rect() *sdl.Rect { return t.rect }

func (t *Texture) RectOffset(offset Point) *sdl.Rect {
	return &sdl.Rect{X: offset.X, Y: offset.Y, W: t.rect.W, H: t.rect.H}
}

func (t *Texture) Copy(renderer *sdl.Renderer, target *sdl.Rect) {
	renderer.Copy(t.texture, t.rect, target)
}

// func (t *Texture) CopyF(renderer *sdl.Renderer, target *sdl.FRect) {
// 	renderer.CopyF(t.texture, t.rect, target) // Depends on SDL >=2.0.10
// }

func (t *Texture) Destroy() { t.texture.Destroy() }

type Textures struct {
	dir      vfs.CopyDir
	renderer *sdl.Renderer
	textures map[string]*Texture
}

func (t *Textures) Init(renderer *sdl.Renderer, dir vfs.CopyDir) {
	t.dir = dir
	t.renderer = renderer
	t.textures = map[string]*Texture{}
}

func (t *Textures) Load(name, path string, other ...string) error {
	err := t.load(name, path)
	if err != nil {
		return err
	}
	if len(other) == 0 {
		return nil
	}
	if len(other)%2 != 0 {
		return errors.New("expected name/path pairs")
	}
	for i := 0; i < len(other); i += 2 {
		err = t.load(other[i], other[i+1])
		if err != nil {
			return fmt.Errorf("error loading '%s'; error: %v", other[i], err)
		}
	}
	return nil
}

func (t *Textures) load(name, path string) error {
	texturePath, err := t.dir.Retrieve(path)
	if err != nil {
		return err
	}
	surface, err := img.Load(texturePath)
	if err != nil {
		return err
	}
	defer surface.Free()
	texture, err := NewTextureFromSurface(t.renderer, surface)
	if err != nil {
		return err
	}
	t.textures[name] = texture
	return nil
}

func (t *Textures) Texture(name string) *Texture { return t.textures[name] }

func (t *Textures) Destroy() {
	if t.textures == nil {
		return
	}
	for _, t := range t.textures {
		t.Destroy()
	}
}