package webcontroller

import (
	"encoding/json"
	"html/template"
	"net/http"
	"time"

	"fornaxian.tech/log"
	"fornaxian.tech/util"
)

// TemplateData is the data for the page template, res/template/wrap.html
type TemplateData struct {
	APIEndpoint template.URL
	Hostname    template.HTML
	CacheID     int64

	// Describe the site by default, or the file on a filesystem page
	Title  string
	OGData ogData

	// Embedded in the page as window.user and window.initial_node, so the JS
	// doesn't have to request them. Left empty when they were not requested
	User json.RawMessage
	Node json.RawMessage
}

// The cache ID is used to invalidate caches when the webserver is restarted.
// It's rounded to a full hour to prevent cached from being emptied too often if
// the server is regularly restarted
var cacheID = time.Now().Unix() / 3600

func (wc *WebController) newTemplateData(r *http.Request) *TemplateData {
	return &TemplateData{
		APIEndpoint: template.URL(wc.config.APIURLExternal),
		Hostname:    template.HTML(wc.hostname),
		CacheID:     cacheID,
		Title:       "Nova.storage",
		OGData:      siteOGData(r),
	}
}

func (wc *WebController) parseTemplate() *template.Template {
	return template.Must(template.ParseFiles(wc.config.ResourceDir + "/template/wrap.html"))
}

// renderPage writes the page which loads the Svelte app. In debug mode the
// template is parsed on every request, so changes show up without a restart
func (wc *WebController) renderPage(w http.ResponseWriter, r *http.Request, td *TemplateData) {
	var tpl = wc.tpl
	if wc.config.DebugMode {
		tpl = wc.parseTemplate()
	}
	if r.Method == "HEAD" {
		return
	}
	if err := tpl.Execute(w, td); err != nil && !util.IsNetError(err) {
		log.Error("Error executing page template: %s", err)
	}
}