listmonk/utils.go

226 lines
5.2 KiB
Go

package main
import (
"bytes"
"crypto/rand"
"fmt"
"log"
"mime/multipart"
"net/http"
"reflect"
"regexp"
"strconv"
"strings"
"github.com/disintegration/imaging"
"github.com/jmoiron/sqlx"
"github.com/knadh/goyesql"
"github.com/labstack/echo"
"github.com/lib/pq"
)
var (
// This replaces all special characters
tagRegexp = regexp.MustCompile(`[^a-z0-9\-\s]`)
tagRegexpSpaces = regexp.MustCompile(`[\s]+`)
)
// ScanToStruct prepares a given set of Queries and assigns the resulting
// *sql.Stmt statements to the fields of a given struct, matching based on the name
// in the `query` tag in the struct field names.
func scanQueriesToStruct(obj interface{}, q goyesql.Queries, db *sqlx.DB) error {
ob := reflect.ValueOf(obj)
if ob.Kind() == reflect.Ptr {
ob = ob.Elem()
}
if ob.Kind() != reflect.Struct {
return fmt.Errorf("Failed to apply SQL statements to struct. Non struct type: %T", ob)
}
// Go through every field in the struct and look for it in the Args map.
for i := 0; i < ob.NumField(); i++ {
f := ob.Field(i)
if f.IsValid() {
if tag := ob.Type().Field(i).Tag.Get("query"); tag != "" && tag != "-" {
// Extract the value of the `query` tag.
var (
tg = strings.Split(tag, ",")
name string
)
if len(tg) == 2 {
if tg[0] != "-" && tg[0] != "" {
name = tg[0]
}
} else {
name = tg[0]
}
// Query name found in the field tag is not in the map.
if _, ok := q[name]; !ok {
return fmt.Errorf("query '%s' not found in query map", name)
}
if !f.CanSet() {
return fmt.Errorf("query field '%s' is unexported", ob.Type().Field(i).Name)
}
switch f.Type().String() {
case "string":
// Unprepared SQL query.
f.Set(reflect.ValueOf(q[name].Query))
case "*sqlx.Stmt":
// Prepared query.
stmt, err := db.Preparex(q[name].Query)
if err != nil {
return fmt.Errorf("Error preparing query '%s': %v", name, err)
}
f.Set(reflect.ValueOf(stmt))
}
}
}
}
return nil
}
// validateMIME is a helper function to validate uploaded file's MIME type
// against the slice of MIME types is given.
func validateMIME(typ string, mimes []string) (ok bool) {
if len(mimes) > 0 {
var (
ok = false
)
for _, m := range mimes {
if typ == m {
ok = true
break
}
}
if !ok {
return false
}
}
return true
}
// generateFileName appends the incoming file's name with a small random hash.
func generateFileName(fName string) string {
name := strings.TrimSpace(fName)
if name == "" {
name, _ = generateRandomString(10)
}
return name
}
// createThumbnail reads the file object and returns a smaller image
func createThumbnail(file *multipart.FileHeader) (*bytes.Reader, error) {
src, err := file.Open()
if err != nil {
return nil, err
}
defer src.Close()
img, err := imaging.Decode(src)
if err != nil {
return nil, echo.NewHTTPError(http.StatusInternalServerError,
fmt.Sprintf("Error decoding image: %v", err))
}
t := imaging.Resize(img, thumbnailSize, 0, imaging.Lanczos)
// Encode the image into a byte slice as PNG.
var buf bytes.Buffer
err = imaging.Encode(&buf, t, imaging.PNG)
if err != nil {
log.Fatal(err)
}
return bytes.NewReader(buf.Bytes()), nil
}
// Given an error, pqErrMsg will try to return pq error details
// if it's a pq error.
func pqErrMsg(err error) string {
if err, ok := err.(*pq.Error); ok {
if err.Detail != "" {
return fmt.Sprintf("%s. %s", err, err.Detail)
}
}
return err.Error()
}
// normalizeTags takes a list of string tags and normalizes them by
// lowercasing and removing all special characters except for dashes.
func normalizeTags(tags []string) []string {
var (
out []string
space = []byte(" ")
dash = []byte("-")
)
for _, t := range tags {
rep := bytes.TrimSpace(tagRegexp.ReplaceAll(bytes.ToLower([]byte(t)), space))
rep = tagRegexpSpaces.ReplaceAll(rep, dash)
if len(rep) > 0 {
out = append(out, string(rep))
}
}
return out
}
// makeMsgTpl takes a page title, heading, and message and returns
// a msgTpl that can be rendered as a HTML view. This is used for
// rendering arbitrary HTML views with error and success messages.
func makeMsgTpl(pageTitle, heading, msg string) msgTpl {
if heading == "" {
heading = pageTitle
}
err := msgTpl{}
err.Title = pageTitle
err.MessageTitle = heading
err.Message = msg
return err
}
// parseStringIDs takes a slice of numeric string IDs and
// parses each number into an int64 and returns a slice of the
// resultant values.
func parseStringIDs(s []string) ([]int64, error) {
vals := make([]int64, 0, len(s))
for _, v := range s {
i, err := strconv.ParseInt(v, 10, 64)
if err != nil {
return nil, err
}
if i < 1 {
return nil, fmt.Errorf("%d is not a valid ID", i)
}
vals = append(vals, i)
}
return vals, nil
}
// generateRandomString generates a cryptographically random, alphanumeric string of length n.
func generateRandomString(n int) (string, error) {
const dictionary = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
var bytes = make([]byte, n)
if _, err := rand.Read(bytes); err != nil {
return "", err
}
for k, v := range bytes {
bytes[k] = dictionary[v%byte(len(dictionary))]
}
return string(bytes), nil
}