package main

import (
	"crypto/sha512"
	"encoding/hex"
	"errors"
	"html/template"
	"io"
	"net/http"
	"strconv"
	"time"

	"muse/storage"

	"github.com/labstack/echo"
	"github.com/labstack/echo/middleware"
)

type (
	Response struct {
		Ok      bool   `json:"ok"`
		Message string `json:"message"`
	}
	TemplateRenderer struct {
		template *template.Template
	}
	Template string
)

const (
	adminUsername = "danolo"
	adminPassword = "bd4cad796950f50352225de3c773d8f3c39622bc17f34ad661eabe615cdf6d32751c5751e0648dc17d890f40330018334a2ae899878f200f6dc80121ddb70cc9"
)

var (
	list *storage.EntryList = &storage.EntryList{
		Filename: "/var/lib/muse.json",
		ModTime:  time.Unix(0, 0),
	}
)

// TemplateRenderer
func (renderer *TemplateRenderer) Render(w io.Writer, name string, data interface{}, c echo.Context) error {
	return renderer.template.ExecuteTemplate(w, name, data)
}

func (template Template) TemplateController(c echo.Context) (err error) {
	entries, err := list.GetEntries()
	if err == nil {
		err = c.Render(http.StatusOK, string(template), struct {
			Entries []*storage.Entry
			Today   storage.JSTime
		}{
			Entries: entries,
			Today:   storage.JSTime(time.Now()),
		})
	}
	return
}

func AddController(c echo.Context) (err error) {
	entry := new(storage.Entry)
	err = c.Bind(entry)
	if err == nil {
		if c.FormValue("date") == "" {
			entry.Date = storage.JSTime(time.Now())
		}
		err = list.AddEntry(entry)
	}
	if err == nil {
		err = c.Redirect(http.StatusFound, "..")
	}
	return
}

func DelController(c echo.Context) error {
	var url string
	var status int
	var pos int

	pos, err := strconv.Atoi(c.Param("index"))
	if err == nil {
		err = list.DeleteElement(pos)
	}

	if err == nil {
		url = "../.."
		status = http.StatusFound
	} else {
		status = http.StatusInternalServerError
	}

	return c.Redirect(status, url)
}

func DelConfirmController(c echo.Context) error {
	var entries []*storage.Entry
	failed := c.QueryParam("failed")
	indexStr := c.Param("index")
	index, err := strconv.Atoi(indexStr)
	if err == nil {
		entries, err = list.GetEntries()
	}
	if index >= len(entries) {
		err = errors.New("Index out of range")
	}
	if err == nil {
		err = c.Render(http.StatusOK, "del.html", struct {
			Index  int
			Elem   *storage.Entry
			Failed string
		}{
			Index:  index,
			Elem:   entries[index],
			Failed: failed,
		})
	}
	return err
}

func auth(username, password string, c echo.Context) (bool, error) {
	hash := sha512.Sum512([]byte(password))
	hashString := hex.EncodeToString(hash[:])
	if username == adminUsername && hashString == adminPassword {
		return true, nil
	}
	return false, nil
}

func RSSController(c echo.Context) (err error) {
	if blob, err := list.GetFeed().ToRss(); err == nil {
		c.Blob(http.StatusOK, "application/xml", []byte(blob))
	}
	return
}

func main() {
	e := echo.New()

	e.Renderer = &TemplateRenderer{
		template: template.Must(template.ParseGlob("templates/*.html")),
	}

	e.GET("/", Template("index.html").TemplateController)
	e.GET("/rss", RSSController)

	e.Static("/static", "static")

	admin := e.Group("/admin", middleware.BasicAuth(auth))
	admin.POST("/add", AddController)
	admin.POST("/del/:index", DelController)
	admin.GET("/del/:index", DelConfirmController)
	admin.GET("/", Template("admin.html").TemplateController)
	admin.Static("/static", "admin/static")

	e.Logger.Fatal(e.Start(":30303"))
}