package ginpongo2

import (
	"fmt"
	"net/http"
	"strings"

	"github.com/flosch/pongo2"
	"github.com/gin-gonic/gin/render"
)

var Suffix = ".html.twig"

type Pongo struct {
	set     *pongo2.TemplateSet
	basedir string
}

func (p *Pongo) Instance(name string, data interface{}) render.Render {
	r := new(PongoRenderer)
	tpl, e := p.set.FromCache(fmt.Sprintf("%s%s%s", p.basedir, name, Suffix))
	if e != nil {
		panic(e)
	}
	r.tpl = tpl
	r.data = data
	return r
}

type PongoRenderer struct {
	tpl  *pongo2.Template
	data interface{}
}

func (r *PongoRenderer) Render(w http.ResponseWriter) error {
	if r.data == nil {
		r.data = make(pongo2.Context)
	}
	d := r.data.(pongo2.Context)
	return r.tpl.ExecuteWriter(d, w)
}

func (r *PongoRenderer) WriteContentType(w http.ResponseWriter) {
	if v := w.Header().Get("content-type"); len(v) == 0 {
		w.Header().Set("content-type", "text/html; charset=utf8")
	}
}

func New(basedir string, debug bool, loaders ...pongo2.TemplateLoader) *Pongo {
	p := new(Pongo)
	p.set = pongo2.NewSet("html")
	p.set.Debug = debug
	if !strings.HasSuffix(basedir, "/") {
		basedir = basedir + "/"
	}
	p.basedir = basedir
	if len(loaders) > 0 {
		p.set.AddLoader(loaders...)
	}
	return p
}