package render

import (
	"bytes"
	"context"
	"embed"
	"html/template"
	"io"
	"io/fs"
)

type Render struct {
	fs            embed.FS
	t             *template.Template
	FileExtension string
}

type Data map[string]interface{}

func NewRender(efs embed.FS, t *template.Template) Render {
	tr := Render{
		fs: efs,
		t:  t,
	}

	return tr
}

func NewRenderWithoutTemplate(ets embed.FS) (Render, error) {
	tmpl, err := template.ParseFS(ets, "templates/*")
	if err != nil {
		return Render{}, err
	}

	r := NewRender(ets, tmpl)
	return r, nil
}

func (r Render) Render(ctx context.Context, w io.Writer, name string, data interface{}) error {
	tmpl := template.Must(r.t.Clone())
	_, err := fs.Stat(r.fs, "templates/"+name+".txt")
	if err == nil {
		tmpl = template.Must(tmpl.ParseFS(r.fs, "templates/"+name+".txt"))
	}
	_, err = fs.Stat(r.fs, "templates/"+name+".html")
	if err == nil {
		tmpl = template.Must(tmpl.ParseFS(r.fs, "templates/"+name+".html"))
	}
	_, err = fs.Stat(r.fs, "templates/"+name)
	if err == nil {
		tmpl = template.Must(tmpl.ParseFS(r.fs, "templates/"+name))
	}
	return tmpl.ExecuteTemplate(w, name, data)
}

func (r Render) RenderToString(ctx context.Context, name string, data interface{}) (string, error) {
	var output bytes.Buffer
	err := r.Render(ctx, &output, name, data)
	if err != nil {
		return "", err
	}
	return output.String(), nil
}