package main

import (
	"crypto/sha256"
	"flag"
	"fmt"
	"html/template"
	"io/ioutil"
	"log"
	"net/http"
	"strconv"
	"strings"

	"github.com/gorilla/mux"
)

var (
	port *int
)

func registerHTTPFlags() {
	port = flag.Int("port", 8080, "The port for HTTP")
}

func setupHTTPServer() http.Server {
	r := mux.NewRouter()

	r.HandleFunc("/", indexHandler)
	r.HandleFunc("/create", createGetHandler).Methods("GET")
	r.HandleFunc("/create", createPostHandler).Methods("POST")
	r.HandleFunc("/view", viewGetHandler).Methods("GET")
	r.HandleFunc("/edit", editGetHandler).Methods("GET")
	r.HandleFunc("/edit", editPostHandler).Methods("POST")
	r.HandleFunc("/delete", deleteHandler)
	r.HandleFunc("/editSelect", editSelectGetHandler).Methods("GET")
	r.HandleFunc("/api/getChallenges", getChallenges).Methods("GET")

	return http.Server{
		Addr:    fmt.Sprintf("0.0.0.0:%d", *port),
		Handler: r,
	}
}

// Host the index file
func indexHandler(w http.ResponseWriter, r *http.Request) {
	readFileToResponse(w, "/index.html")
}

func createGetHandler(w http.ResponseWriter, r *http.Request) {
	log.Println("create GET")
	readFileToResponse(w, "/create.html")
}

// createPostHandler handles HTTP POST requests to the /create endpoint creating
// new challenges in the database
func createPostHandler(w http.ResponseWriter, r *http.Request) {

	// parse the Post Request form
	r.ParseForm()

	points, err := strconv.ParseInt(r.Form.Get("challengePoints"), 10, 64)
	if err != nil {
		log.Printf("Could not parse points: %v", err)
		return
	}

	var static bool
	if r.Form.Get("challengeStatic") == "on" {
		static = true
	} else if r.Form.Get("challengeStatic") == "off" {
		static = false
	} else {
		log.Printf("Could not parse static: %v", r.Form.Get("challengeStatic"))
		return
	}

	// Define the new challenge
	newChallenge := Challenge{
		Name:        r.Form.Get("challengeName"),
		Description: r.Form.Get("challengeDescription"),
		Flag:        r.Form.Get("challengeFlag"),
		Container:   r.Form.Get("challengeContainer"),
		Category:    r.Form.Get("challengeCategory"),
		Points:      int(points),
		Static:      static,
	}

	// Create the new challenge in the database
	uuid, err := dbNewChallenge(newChallenge)
	if err != nil {
		log.Println(err)
		return
	}
	log.Printf("Create a new challenge. UUID: %s", uuid)
	http.Redirect(w, r, "/view", http.StatusSeeOther)
}

// viewGetHandler returns a list of all challenges in the database
func viewGetHandler(w http.ResponseWriter, r *http.Request) {
	// get all challenges from the db
	challs := dbGetAllChallenges()

	// define a challenges struct storing the challenges.
	// This struct can be used in a template
	challenges := Challenges{}

	for _, chal := range challs {
		challenges.Challenge = append(challenges.Challenge, chal)
	}

	// define a new template to render the challenges in
	t := template.New("")
	t, err := t.ParseFiles("./hosted/view.html")
	if err != nil {
		log.Println(err)
		return
	}

	// execure the template using the challenges struct
	t.ExecuteTemplate(w, "view", challenges)
}

func editSelectGetHandler(w http.ResponseWriter, r *http.Request) {
	// get all challenges from the db
	challs := dbGetAllChallenges()

	// define a challenges struct storing the challenges.
	// This struct can be used in a template
	challenges := Challenges{}

	for _, chal := range challs {
		challenges.Challenge = append(challenges.Challenge, chal)
	}

	// define a new template to render the challenges in
	t := template.New("")
	t, err := t.ParseFiles("./hosted/edit.html")
	if err != nil {
		log.Println(err)
		return
	}

	// execure the template using the challenges struct
	t.ExecuteTemplate(w, "edit", challenges)
}

func editGetHandler(w http.ResponseWriter, r *http.Request) {
	var uuid string

	if r.URL.Query()["uuid"] == nil {
		log.Println("editnoparam")
		http.Redirect(w, r, "/editSelect", http.StatusSeeOther)
		return
	}
	uuid = r.URL.Query()["uuid"][0]

	log.Printf("fetching challenge with the uuid %s", uuid)

	chall, err := dbGetChallengeByUUID(uuid)
	if err != nil {
		log.Println(err)
	}

	// define a new template to render the challenges in
	t := template.New("")
	t, err = t.ParseFiles("./hosted/edit_uuid.html")
	if err != nil {
		log.Println(err)
		return
	}

	// execute the template using the challenges struct
	t.ExecuteTemplate(w, "edit_uuid", chall)
	return
}

func editPostHandler(w http.ResponseWriter, r *http.Request) {
	log.Println("edit POST")
	// parse the Post Request form
	err := r.ParseForm()
	if err != nil {
		log.Println("could not parse the http post form!")
		return
	}

	// parse the challenge points
	points, err := strconv.ParseInt(r.PostFormValue("challengePoints"), 10, 64)
	if err != nil {
		log.Printf("Could not parse points: %v (%#v)", err, r.Form.Get("challengePoints"))
		return
	}

	// parse the static value
	var static bool
	if r.Form.Get("challengeStatic") == "true" {
		static = true
	} else if r.Form.Get("challengeStatic") == "false" {
		static = false
	} else {
		log.Println("[edit POST] Could not parse static: %v", r.Form.Get("challengeStatic"))
		return
	}

	// define the new edited challenge
	editedChallenge := Challenge{
		UUID:        r.Form.Get("challengeUUID"),
		Name:        r.Form.Get("challengeName"),
		Description: r.Form.Get("challengeDescription"),
		Flag:        r.Form.Get("challengeFlag"),
		Container:   r.Form.Get("challengeContainer"),
		Category:    r.Form.Get("challengeCategory"),
		Points:      int(points),
		Static:      static,
	}

	// update the challenge in the database
	EditError := dbEditChallengeUUID(r.Form.Get("challengeUUID"), editedChallenge)
	if EditError != nil {
		log.Println("Could not edit:")
		log.Println(EditError)
	}

	log.Println("done editing challenge!")

	http.Redirect(w, r, "/edit", http.StatusSeeOther)
}

func deleteHandler(w http.ResponseWriter, r *http.Request) {
	err := r.ParseForm()
	if err != nil {
		log.Println("deleteHandler could not parse the form")
		log.Println(err)
	}

	if r.URL.Query()["uuid"] == nil {
		log.Println("delete: no uuid given")
		return
	}
	uuid := r.URL.Query()["uuid"][0]
	log.Printf("Deleteing challenge with uuid %s\n", uuid)

	dbDeleteChallengeByUUID(uuid)
	http.Redirect(w, r, "/editSelect", http.StatusSeeOther)
}

// Helper function to host files off of "hosted/" directory
func readFileToResponse(w http.ResponseWriter, path string) {
	requestedFile := strings.Replace(path, "..", "", -1)

	contents, readError := ioutil.ReadFile(fmt.Sprintf("hosted/%s", requestedFile))

	if readError != nil {
		w.Write([]byte(fmt.Sprintf("unable to read %s", requestedFile)))
	} else {
		w.Write([]byte(contents))
	}
}

func stripChallenge(challenge Challenge) StrippedChallenge {
	// Hash the flag using sha256
	FlagSha256Sum := fmt.Sprintf("%x", sha256.Sum256([]byte(challenge.Flag)))

	strippedChallenge := StrippedChallenge{
		Name:        challenge.Name,
		Description: challenge.Description,
		FlagHash:    FlagSha256Sum,
		Container:   challenge.Container,
		Category:    challenge.Category,
		Points:      challenge.Points,
		Static:      challenge.Static,
	}

	return strippedChallenge
}