qurl/pages/submit.go

package pages

import (
	"bytes"
	"fmt"
	"html/template"
	"net/http"
	"net"
	"qurl/qurl"
	"qurl/static"
	"qurl/storage"
	"time"
)

type SubmitHandler struct {
	Storage  storage.Storage
	template *template.Template
}

type submitPage struct {
	Message string
	URL     string
}

func (ctx *SubmitHandler) Init() error {
	ctx.template = template.New("submit.html")

	_, err := ctx.template.Parse(string(static.Assets["submit.html"]))
	if err != nil {
		return err
	}
	return nil
}

func (ctx *SubmitHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	var pg submitPage

	u := r.FormValue("url")
	if u == "" {
		pg.Message = "Not a valid URL."
	} else {
		q, err := ctx.Storage.GetQURLByURL(u)
		if err != nil {
			http.Error(w, fmt.Sprintf("Database error: %s", err.Error()),
				http.StatusInternalServerError)
			return
		}

		if q != nil {
			pg.Message = "URL already exists."
			pg.URL = fmt.Sprintf("https://qurl.org/%s", qurl.ToString(q.ID))
		} else {
			q = &qurl.QURL{
				URL:     u,
				Created: time.Now(),
			}
			if h, _, err := net.SplitHostPort(r.RemoteAddr); err == nil && h != "" {
				q.IP = net.ParseIP(h)
			}
			if b := r.Header.Get("User-Agent"); b != "" {
				q.Browser = b
			}

			err := q.CheckValid()
			if err != nil {
				pg.Message = err.Error()
			} else {
				err := ctx.Storage.AddQURL(q)
				if err != nil {
					http.Error(w, fmt.Sprintf("Database error: %s", err.Error()),
						http.StatusInternalServerError)
					return
				}

				pg.Message = "URL Added."
				pg.URL = fmt.Sprintf("https://qurl.org/%s", qurl.ToString(q.ID))
			}
		}
	}

	var buf bytes.Buffer
	err := ctx.template.Execute(&buf, pg)
	if err != nil {
		http.Error(w, fmt.Sprintf("Template execute error: %s", err.Error()),
			http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Length", fmt.Sprintf("%d", buf.Len()))
	w.Header().Set("Content-Type", "text/html")
	w.Write(buf.Bytes())
}