snap/context.go

package snap

import (
	"bytes"
	"encoding/json"
	"io/ioutil"
	"net/http"

	"git.twelvetwelve.org/library/snap/auth"
	"github.com/gorilla/mux"
)

type Context struct {
	srv  *Server
	auth *auth.AuthData

	w    http.ResponseWriter
	r    *http.Request
	vars *Vars
	form *Form
}

type SnapContent struct {
	User           string
	UserProperties map[string]string
	Theme          string
	Meta           map[string]string
	Content        interface{}
}

func (c *Context) GetRequest() *http.Request {
	return c.r
}

func (c *Context) Writer() http.ResponseWriter {
	return c.w
}

func (c *Context) GetUser() string {
	if c.auth == nil {
		return ""
	}
	return c.auth.User
}

func (c *Context) Error(code int, msg string) {
	c.srv.renderError(c.w, code, msg)
}

func (c *Context) ErrorObject(code int, obj interface{}) {
	msg, err := json.Marshal(obj)
	if err != nil {
		c.Error(http.StatusInternalServerError, "Internal Server Error")
		return
	}
	c.Error(code, string(msg))
}

func (c *Context) Reply(msg string) {
	c.srv.reply(c.w, msg)
}

func (c *Context) ReplyWithHeaders(msg string, kv map[string]string) {
	h := c.w.Header()
	for k, v := range kv {
		h.Add(k, v)
	}
	c.srv.reply(c.w, msg)
}

func (c *Context) ReplyObject(obj interface{}) {
	compact := c.r.Header.Get("Compact")
	msg, err := json.Marshal(obj)
	if err != nil {
		c.Error(http.StatusInternalServerError, "Internal Server Error")
		return
	}

	if compact == "" {
		var pretty bytes.Buffer
		err := json.Indent(&pretty, msg, "", "   ")
		if err == nil {
			msg = pretty.Bytes()
		}
	}

	c.Reply(string(msg))
}

func (c *Context) GetObject(obj interface{}) error {
	data, err := ioutil.ReadAll(c.r.Body)
	defer c.r.Body.Close()
	if err != nil {
		return err
	}
	return json.Unmarshal(data, obj)
}

func (c *Context) Render(tmpl string, content interface{}) {
	c.srv.render(c.w, tmpl, content)
}

func (c *Context) RenderEx(tmpl string, content interface{}) {
	cnt := SnapContent{
		User:    c.GetUser(),
		Theme:   c.srv.theme,
		Meta:    c.srv.meta,
		Content: content,
	}

	if c.auth != nil {
		cnt.UserProperties = c.auth.Properties
	}

	c.srv.render(c.w, tmpl, &cnt)
}

func (c *Context) RenderWithMeta(tmpl string, meta map[string]string, content interface{}) {
	// Merge metas
	if meta == nil {
		meta = make(map[string]string)
	}

	for k, v := range c.srv.meta {
		if _, ok := meta[k]; !ok {
			meta[k] = v
		}
	}

	cnt := SnapContent{
		User:    c.GetUser(),
		Theme:   c.srv.theme,
		Meta:    meta,
		Content: content,
	}

	if c.auth != nil {
		cnt.UserProperties = c.auth.Properties
	}

	c.srv.render(c.w, tmpl, &cnt)
}

func (c *Context) Form() (*Options, error) {
	if c.form != nil {
		return &Options{
			kv: c.form,
		}, nil
	}

	err := c.r.ParseForm()
	if err != nil {
		return nil, err
	}
	c.form = &Form{
		r: c.r,
	}

	return &Options{
		kv: c.form,
	}, nil
}

func (c *Context) Redirect(url string) {
	http.Redirect(c.w, c.r, url, http.StatusSeeOther)
}

func (c *Context) QueryValue(key string) string {
	return c.r.URL.Query().Get(key)
}

func (c *Context) QueryHas(key string) bool {
	_, ok := c.r.URL.Query()[key]
	return ok
}

func (c *Context) QueryValueWithDefault(key string, def string) string {
	val := c.r.URL.Query().Get(key)
	if val == "" {
		return def
	}
	return val
}

func (c *Context) ReadObject(object interface{}) error {
	defer c.r.Body.Close()
	decoder := json.NewDecoder(c.r.Body)
	return decoder.Decode(object)
}

func (c *Context) ParseVars() *Options {
	if c.vars == nil {
		c.vars = &Vars{
			vars: mux.Vars(c.r),
		}
	}

	return &Options{
		kv: c.vars,
	}
}