WIP: More advanced action parsing

This commit is contained in:
Philipp Heckel 2022-04-26 23:07:31 -04:00
parent 53646737e8
commit 574e72a974
3 changed files with 235 additions and 1 deletions

207
server/actions_parse.go Normal file
View file

@ -0,0 +1,207 @@
package server
import (
"errors"
"fmt"
"heckel.io/ntfy/util"
"regexp"
"strings"
"unicode/utf8"
)
// Heavily inspired by https://go.dev/src/text/template/parse/lex.go
// And thanks to Rob Pike (for Go, but also) for https://www.youtube.com/watch?v=HxaD_trXwRE
// action=view, label="Look ma, commas and \"quotes\" too", url=https://..
// "Look ma, a button",
// Look ma a button
// label=Look ma a=button
// label="Look ma, a button"
// "Look ma, \"quotes\""
// label="Look ma, \"quotes\""
// label=,
func parseActionsFromSimpleNew(s string) ([]*action, error) {
if !utf8.ValidString(s) {
return nil, errors.New("invalid string")
}
parser := &actionParser{
pos: 0,
input: s,
}
return parser.Parse()
}
type actionParser struct {
input string
pos int
}
const eof = rune(0)
func (p *actionParser) Parse() ([]*action, error) {
println("------------------------")
actions := make([]*action, 0)
for !p.eof() {
a, err := p.parseAction()
if err != nil {
return nil, err
} else if a == nil {
return actions, err
}
actions = append(actions, a)
}
return actions, nil
}
func (p *actionParser) parseAction() (*action, error) {
println("parseAction")
newAction := &action{
Headers: make(map[string]string),
Extras: make(map[string]string),
}
section := 0
for {
key, value, last, err := p.parseSection()
fmt.Printf("--> key=%s, value=%s, last=%t, err=%#v\n", key, value, last, err)
if err != nil {
return nil, err
} else if key == "" && section == 0 {
key = "action"
} else if key == "" && section == 1 {
key = "label"
} else if key == "" && section == 2 && util.InStringList([]string{"view", "http"}, newAction.Action) {
key = "url"
} else if key == "" {
return nil, wrapErrHTTP(errHTTPBadRequestActionsInvalid, "term '%s' unknown", value)
}
if strings.HasPrefix(key, "headers.") {
newAction.Headers[strings.TrimPrefix(key, "headers.")] = value
} else if strings.HasPrefix(key, "extras.") {
newAction.Extras[strings.TrimPrefix(key, "extras.")] = value
} else {
switch strings.ToLower(key) {
case "action":
newAction.Action = value
case "label":
newAction.Label = value
case "clear":
lvalue := strings.ToLower(value)
if !util.InStringList([]string{"true", "yes", "1", "false", "no", "0"}, lvalue) {
return nil, wrapErrHTTP(errHTTPBadRequestActionsInvalid, "'clear=%s' not allowed", value)
}
newAction.Clear = lvalue == "true" || lvalue == "yes" || lvalue == "1"
case "url":
newAction.URL = value
case "method":
newAction.Method = value
case "body":
newAction.Body = value
default:
return nil, wrapErrHTTP(errHTTPBadRequestActionsInvalid, "key '%s' unknown", key)
}
}
p.slurpSpaces()
if last {
return newAction, nil
}
section++
}
}
func (p *actionParser) parseSection() (key string, value string, last bool, err error) {
fmt.Printf("parseSection, pos=%d, len(input)=%d, input[pos:]=%s\n", p.pos, len(p.input), p.input[p.pos:])
p.slurpSpaces()
key = p.parseKey()
r, w := p.peek()
if r == eof || r == ';' || r == ',' {
p.pos += w
last = r == ';' || r == eof
return
} else if r == '"' {
value, last, err = p.parseQuotedValue()
return
}
value, last = p.parseValue()
return
}
func (p *actionParser) parseValue() (value string, last bool) {
start := p.pos
for {
r, w := p.peek()
if r == eof || r == ';' || r == ',' {
last = r == ';' || r == eof
value = p.input[start:p.pos]
p.pos += w
return
}
p.pos += w
}
}
func (p *actionParser) parseQuotedValue() (value string, last bool, err error) {
p.pos++
start := p.pos
var prev rune
for {
r, w := p.peek()
if r == eof {
err = errors.New("unexpected end of input")
return
} else if r == '"' && prev != '\\' {
value = p.input[start:p.pos]
p.pos += w
// Advance until after "," or ";"
p.slurpSpaces()
r, w := p.peek()
last = r == ';' || r == eof
if r != eof && r != ';' && r != ',' {
err = fmt.Errorf("unexpected character '%c' at position %d", r, p.pos)
return
}
p.pos += w
return
}
prev = r
p.pos += w
}
}
var keyRegex = regexp.MustCompile(`^[-.\w]+=`)
func (p *actionParser) parseKey() string {
key := keyRegex.FindString(p.input[p.pos:])
if key != "" {
p.pos += len(key)
return key[:len(key)-1]
}
return key
}
func (p *actionParser) peek() (rune, int) {
if p.pos >= len(p.input) {
return eof, 0
}
return utf8.DecodeRuneInString(p.input[p.pos:])
}
func (p *actionParser) eof() bool {
return p.pos >= len(p.input)
}
func (p *actionParser) slurpSpaces() {
for {
r, w := p.peek()
if r == eof || !isSpace(r) {
return
}
p.pos += w
}
}
func isSpace(r rune) bool {
return r == ' ' || r == '\t' || r == '\r' || r == '\n'
}

View file

@ -54,7 +54,7 @@ func parseActions(s string) (actions []*action, err error) {
if strings.HasPrefix(s, "[") {
actions, err = parseActionsFromJSON(s)
} else {
actions, err = parseActionsFromSimple(s)
actions, err = parseActionsFromSimpleNew(s)
}
if err != nil {
return nil, err

View file

@ -79,4 +79,31 @@ func TestParseActions(t *testing.T) {
require.Equal(t, 2, len(actions[0].Headers))
require.Equal(t, "application/json", actions[0].Headers["Content-Type"])
require.Equal(t, "Basic sdasffsf", actions[0].Headers["Authorization"])
actions, err = parseActions(`action=http, "Look ma, \"quotes\"; and semicolons", url=http://example.com`)
require.Nil(t, err)
require.Equal(t, 1, len(actions))
require.Equal(t, "http", actions[0].Action)
require.Equal(t, `Look ma, \"quotes\"; and semicolons`, actions[0].Label)
require.Equal(t, `http://example.com`, actions[0].URL)
actions, err = parseActions(`label="Out of order!" , action="http", url=http://example.com`)
require.Nil(t, err)
require.Equal(t, 1, len(actions))
require.Equal(t, "http", actions[0].Action)
require.Equal(t, `Out of order!`, actions[0].Label)
require.Equal(t, `http://example.com`, actions[0].URL)
actions, err = parseActions(`label="Out of order!" x, action="http", url=http://example.com`)
require.EqualError(t, err, "unexpected character 'x' at position 22")
actions, err = parseActions(`label="", action="http", url=http://example.com`)
require.EqualError(t, err, "invalid request: actions invalid, parameter 'label' is required")
actions, err = parseActions(`label=, action="http", url=http://example.com`)
require.EqualError(t, err, "invalid request: actions invalid, parameter 'label' is required")
actions, err = parseActions(`label="xx", action="http", url=http://example.com, what is this anyway`)
require.EqualError(t, err, "invalid request: actions invalid, term 'what is this anyway' unknown")
}