package chat

// chat server funcs which aren't specific to the server struct

import (
	"bytes"
	"crypto/md5"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"

	"github.com/golang-jwt/jwt"
)

var Address = "127.0.0.1:8000"
var JwtSecret = os.Getenv("secret")

func checkToken(token string) (username string, ok bool) {
	type ParsedToken struct {
		Username string
		jwt.StandardClaims
	}
	var t ParsedToken

	jwt, err := jwt.ParseWithClaims(token, &t, func(t *jwt.Token) (interface{}, error) {
		return []byte(JwtSecret), nil
	})

	if err != nil {
		return "", false
	}

	if userToken, ok := jwt.Claims.(*ParsedToken); ok && jwt.Valid {
		return userToken.Username, true
	} else {
		fmt.Println(err)
		return "", false
	}
}

func encodeJson(data interface{}) ([]byte, bool) {
	if jsonData, err := json.Marshal(data); err != nil {
		fmt.Fprintln(os.Stderr, "Could not marshal json data", data)
		return nil, false
	} else {
		return jsonData, true
	}
}

func decodeJson(body *io.ReadCloser, w *http.ResponseWriter, message interface{}) {
	if err := json.NewDecoder(*body).Decode(&message); err != nil {
		fmt.Fprintln(os.Stderr, "Error decoding", err.Error())
		if w != nil && (*w) != nil {
			(*w).WriteHeader(http.StatusBadRequest)
			(*w).Write([]byte(`{"error":"bad message"}`))
		}
	}
}

func dbHandleError(body *io.ReadCloser, w *http.ResponseWriter) (message string) {
	type ErrorMessage struct {
		Error string `json:"error"`
	}
	var error ErrorMessage
	decodeJson(body, w, &error)
	return error.Error
}

func isAcceptedMIMEType(mime string) bool {
	switch mime {
	case "image/bmp",
		"image/gif",
		"image/jpeg",
		"image/png",
		"audio/mpeg",
		"video/webm":
		return true
	}
	return false
}

func uploadFile(fileContents *[]byte, fileName, mimeType string) (res *http.Response, err error) {
	type FileObject struct {
		FileName string   `json:"filename"`
		FileType string   `json:"filetype"`
		Contents []byte   `json:"contents"`
		Sum      [16]byte `json:"sum"`
	}

	file := FileObject{
		fileName, mimeType, *fileContents, md5.Sum(*fileContents),
	}

	jsonData, ok := encodeJson(&file)
	if !ok {
		fmt.Fprintln(os.Stderr, "error encoding file data")
		return
	}

	res, err = http.Post(DbAddress+"/file", "application/json", bytes.NewBuffer(jsonData))
	if err != nil {
		fmt.Fprintln(os.Stderr, "file POST error:", err)
	}
	return
}