Natural language

go.mod

@@ -2,6 +2,8 @@ module heckel.io/ntfy
 
 go 1.17
 
+replace github.com/olebedev/when => github.com/binwiederhier/when v0.0.1-binwiederhier2
+
 require (
 	cloud.google.com/go/firestore v1.6.1 // indirect
 	cloud.google.com/go/storage v1.18.2 // indirect
@@ -9,36 +11,39 @@ require (
 	github.com/BurntSushi/toml v0.4.1 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.1 // indirect
 	github.com/mattn/go-sqlite3 v1.14.9
+	github.com/olebedev/when v0.0.0-20190311101825-c3b538a97254
 	github.com/stretchr/testify v1.7.0
 	github.com/urfave/cli/v2 v2.3.0
 	golang.org/x/oauth2 v0.0.0-20211104180415-d3ed0bb246c8 // indirect
 	golang.org/x/time v0.0.0-20211116232009-f0f3c7e86c11
-	google.golang.org/api v0.61.0
+	google.golang.org/api v0.62.0
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )
 
 require (
 	cloud.google.com/go v0.99.0 // indirect
+	github.com/AlekSi/pointer v1.0.0 // indirect
 	github.com/census-instrumentation/opencensus-proto v0.3.0 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/cncf/udpa/go v0.0.0-20210930031921-04548b0d99d4 // indirect
 	github.com/cncf/xds/go v0.0.0-20211130200136-a8f946100490 // indirect
-	github.com/davecgh/go-spew v1.1.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/envoyproxy/go-control-plane v0.10.1 // indirect
 	github.com/envoyproxy/protoc-gen-validate v0.6.2 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/go-cmp v0.5.6 // indirect
 	github.com/googleapis/gax-go/v2 v2.1.1 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	go.opencensus.io v0.23.0 // indirect
 	golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d // indirect
-	golang.org/x/sys v0.0.0-20211124211545-fe61309f8881 // indirect
+	golang.org/x/sys v0.0.0-20211205182925-97ca703d548d // indirect
 	golang.org/x/text v0.3.7 // indirect
 	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
 	google.golang.org/appengine v1.6.7 // indirect
-	google.golang.org/genproto v0.0.0-20211206220100-3cb06788ce7f // indirect
+	google.golang.org/genproto v0.0.0-20211208223120-3a66f561d7aa // indirect
 	google.golang.org/grpc v1.42.0 // indirect
 	google.golang.org/protobuf v1.27.1 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect

go.sum

@@ -25,6 +25,7 @@ cloud.google.com/go v0.90.0/go.mod h1:kRX0mNRHe0e2rC6oNakvwQqzyDmg57xJ+SZU1eT2aD
 cloud.google.com/go v0.93.3/go.mod h1:8utlLll2EF5XMAV15woO4lSbWQlk8rer9aLOfLh7+YI=
 cloud.google.com/go v0.94.1/go.mod h1:qAlAugsXlC+JWO+Bke5vCtc9ONxjQT3drlTTnAplMW4=
 cloud.google.com/go v0.97.0/go.mod h1:GF7l59pYBVlXQIBLx3a761cZ41F9bBH3JUlihCt2Udc=
+cloud.google.com/go v0.98.0/go.mod h1:ua6Ush4NALrHk5QXDWnjvZHN93OuF0HfuEPq9I1X0cM=
 cloud.google.com/go v0.99.0 h1:y/cM2iqGgGi5D5DQZl6D9STN/3dR/Vx5Mp8s752oJTY=
 cloud.google.com/go v0.99.0/go.mod h1:w0Xx2nLzqWJPuozYQX+hFfCSI8WioryfRDzkoI/Y2ZA=
 cloud.google.com/go/bigquery v1.0.1/go.mod h1:i/xbL2UlR5RvWAURpBYZTtm/cXjCha9lbfbpx4poX+o=
@@ -51,12 +52,16 @@ cloud.google.com/go/storage v1.18.2/go.mod h1:AiIj7BWXyhO5gGVmYJ+S8tbkCx3yb0IMju
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 firebase.google.com/go v3.13.0+incompatible h1:3TdYC3DDi6aHn20qoRkxwGqNgdjtblwVAyRLQwGn/+4=
 firebase.google.com/go v3.13.0+incompatible/go.mod h1:xlah6XbEyW6tbfSklcfe5FHJIwjt8toICdV5Wh9ptHs=
+github.com/AlekSi/pointer v1.0.0 h1:KWCWzsvFxNLcmM5XmiqHsGTTsuwZMsLFwWF9Y+//bNE=
+github.com/AlekSi/pointer v1.0.0/go.mod h1:1kjywbfcPFCmncIxtk6fIEub6LKrfMz3gc5QKVOSOA8=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/toml v0.4.1 h1:GaI7EiDXDRfa8VshkTj7Fym7ha+y8/XxIgD2okUIjLw=
 github.com/BurntSushi/toml v0.4.1/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/antihax/optional v1.0.0/go.mod h1:uupD/76wgC+ih3iEmQUL+0Ugr19nfwCT1kdvxnR2qWY=
+github.com/binwiederhier/when v0.0.1-binwiederhier2 h1:BjQC7OQI4MK0vXeltn2BEuf0Tdh/M6YNh1JrepnVr2I=
+github.com/binwiederhier/when v0.0.1-binwiederhier2/go.mod h1:DPucAeQGDPUzYUt+NaWw6qsF5SFapWWToxEiVDh2aV0=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/census-instrumentation/opencensus-proto v0.3.0 h1:t/LhUZLVitR1Ow2YOnduCsavhwFUklBMoGVYUCqmCqk=
 github.com/census-instrumentation/opencensus-proto v0.3.0/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
@@ -84,8 +89,9 @@ github.com/cncf/xds/go v0.0.0-20211130200136-a8f946100490/go.mod h1:eXthEFrGJvWH
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.1 h1:r/myEWzV9lfsM1tFLgDyu0atFtJ1fXn261LKYj/3DxU=
 github.com/cpuguy83/go-md2man/v2 v2.0.1/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
@@ -199,6 +205,8 @@ github.com/lyft/protoc-gen-star v0.5.3/go.mod h1:V0xaHgaf5oCCqmcxYcWiDfTiKsZsRc8
 github.com/mattn/go-sqlite3 v1.14.9 h1:10HX2Td0ocZpYEjhilsuo6WWtUqttj2Kb0KtD86/KYA=
 github.com/mattn/go-sqlite3 v1.14.9/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/sftp v1.10.1/go.mod h1:lYOWFsE0bwd1+KfKJaKeuokY15vzFx25BLbzYYoAxZI=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
@@ -213,6 +221,7 @@ github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasO
 github.com/spf13/afero v1.3.3/go.mod h1:5KUK8ByomD5Ti5Artl0RtHeI5pTF7MIDuXL3yY520V4=
 github.com/spf13/afero v1.6.0/go.mod h1:Ai8FlHk4v/PARR026UzYexafAt9roJ7LcLMAmO6Z93I=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
@@ -390,8 +399,9 @@ golang.org/x/sys v0.0.0-20210823070655-63515b42dcdf/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20210908233432-aa78b53d3365/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210917161153-d61c044b1678/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20211124211545-fe61309f8881 h1:TyHqChC80pFkXWraUUf6RuB5IqFdQieMLwwCJokV2pc=
 golang.org/x/sys v0.0.0-20211124211545-fe61309f8881/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20211205182925-97ca703d548d h1:FjkYO/PPp4Wi0EAUOVLxePm7qVW4r4ctbWpURyuOD0E=
+golang.org/x/sys v0.0.0-20211205182925-97ca703d548d/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -495,8 +505,9 @@ google.golang.org/api v0.56.0/go.mod h1:38yMfeP1kfjsl8isn0tliTjIb1rJXcQi4UXlbqiv
 google.golang.org/api v0.57.0/go.mod h1:dVPlbZyBo2/OjBpmvNdpn2GRm6rPy75jyU7bmhdrMgI=
 google.golang.org/api v0.58.0/go.mod h1:cAbP2FsxoGVNwtgNAmmn3y5G1TWAiVYRmg4yku3lv+E=
 google.golang.org/api v0.59.0/go.mod h1:sT2boj7M9YJxZzgeZqXogmhfmRWDtPzT31xkieUbuZU=
-google.golang.org/api v0.61.0 h1:TXXKS1slM3b2bZNJwD5DV/Tp6/M2cLzLOLh9PjDhrw8=
 google.golang.org/api v0.61.0/go.mod h1:xQRti5UdCmoCEqFxcz93fTl338AVqDgyaDRuOZ3hg9I=
+google.golang.org/api v0.62.0 h1:PhGymJMXfGBzc4lBRmrx9+1w4w2wEzURHNGF/sD/xGc=
+google.golang.org/api v0.62.0/go.mod h1:dKmwPCydfsad4qCH08MSdgWjfHOyfpd4VtDGgRFdavw=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
 google.golang.org/appengine v1.5.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
@@ -566,9 +577,11 @@ google.golang.org/genproto v0.0.0-20211008145708-270636b82663/go.mod h1:5CzLGKJ6
 google.golang.org/genproto v0.0.0-20211016002631-37fc39342514/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20211028162531-8db9c33dc351/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20211118181313-81c1377c94b1/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
+google.golang.org/genproto v0.0.0-20211129164237-f09f9a12af12/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
+google.golang.org/genproto v0.0.0-20211203200212-54befc351ae9/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20211206160659-862468c7d6e0/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
-google.golang.org/genproto v0.0.0-20211206220100-3cb06788ce7f h1:QH7+Ym+7e2XV1dZIHapkXoeqHyNaCzn6MNp3JBaYYUc=
+google.golang.org/genproto v0.0.0-20211208223120-3a66f561d7aa h1:I0YcKz0I7OAhddo7ya8kMnvprhcWM045PmkBdMO9zN0=
-google.golang.org/genproto v0.0.0-20211206220100-3cb06788ce7f/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
+google.golang.org/genproto v0.0.0-20211208223120-3a66f561d7aa/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 google.golang.org/grpc v1.20.1/go.mod h1:10oTOabMzJvdu6/UiuZezV6QK5dSlG84ov/aaiqXj38=
 google.golang.org/grpc v1.21.1/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
@@ -594,6 +607,7 @@ google.golang.org/grpc v1.38.0/go.mod h1:NREThFqKR1f3iQ6oBuvc5LadQuXVGo9rkm5ZGrQ
 google.golang.org/grpc v1.39.0/go.mod h1:PImNr+rS9TWYb2O4/emRugxiyHZ5JyHW5F+RPnDzfrE=
 google.golang.org/grpc v1.39.1/go.mod h1:PImNr+rS9TWYb2O4/emRugxiyHZ5JyHW5F+RPnDzfrE=
 google.golang.org/grpc v1.40.0/go.mod h1:ogyxbiOoUXAkP+4+xa6PZSE9DZgIHtSpzjDTB9KAK34=
+google.golang.org/grpc v1.40.1/go.mod h1:ogyxbiOoUXAkP+4+xa6PZSE9DZgIHtSpzjDTB9KAK34=
 google.golang.org/grpc v1.42.0 h1:XT2/MFpuPFsEX2fWh3YQtHkZ+WYZFQRfaUgLZYj/p6A=
 google.golang.org/grpc v1.42.0/go.mod h1:k+4IHHFw41K8+bbowsex27ge2rCb65oeWqe4jJ590SU=
 google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.1.0/go.mod h1:6Kw0yEErY5E/yWrBtf03jp27GLLJujG4z/JK95pnjjw=

server/server.go

@@ -349,32 +349,18 @@ func parseHeaders(header http.Header, m *message) (cache bool, firebase bool, er
 			m.Tags = append(m.Tags, strings.TrimSpace(s))
 		}
 	}
-	atStr := readHeader(header, "x-at", "at", "x-schedule", "schedule", "sched")
+	whenStr := readHeader(header, "x-at", "at", "x-in", "in")
-	if atStr != "" {
+	if whenStr != "" {
 		if !cache {
 			return false, false, errHTTPBadRequest
 		}
-		at, err := strconv.Atoi(atStr)
+		at, err := util.ParseFutureTime(whenStr, time.Now())
 		if err != nil {
 			return false, false, errHTTPBadRequest
-		} else if int64(at) < time.Now().Add(minDelay).Unix() {
+		} else if at.Unix() < time.Now().Add(minDelay).Unix() {
 			return false, false, errHTTPBadRequest
 		}
-		m.Time = int64(at)
+		m.Time = at.Unix()
-	} else {
-		delayStr := readHeader(header, "x-delay", "delay", "x-in", "in")
-		if delayStr != "" {
-			if !cache {
-				return false, false, errHTTPBadRequest
-			}
-			delay, err := time.ParseDuration(delayStr)
-			if err != nil {
-				return false, false, errHTTPBadRequest
-			} else if delay < minDelay {
-				return false, false, errHTTPBadRequest
-			}
-			m.Time = time.Now().Add(delay).Unix()
-		}
 	}
 	return cache, firebase, nil
 }

util/time.go

@@ -0,0 +1,95 @@
+package util
+
+import (
+	"errors"
+	"github.com/olebedev/when"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+var (
+	errUnparsableTime = errors.New("unable to parse time")
+	durationStrRegex  = regexp.MustCompile(`(?i)^(\d+)\s*(d|days?|h|hours?|m|mins?|minutes?|s|secs?|seconds?)$`)
+)
+
+func ParseFutureTime(s string, now time.Time) (time.Time, error) {
+	s = strings.TrimSpace(s)
+	t, err := parseUnixTime(s, now)
+	if err == nil {
+		return t, nil
+	}
+	t, err = parseFromDuration(s, now)
+	if err == nil {
+		return t, nil
+	}
+	t, err = parseNaturalTime(s, now)
+	if err == nil {
+		return t, nil
+	}
+	return time.Time{}, errUnparsableTime
+}
+
+func parseFromDuration(s string, now time.Time) (time.Time, error) {
+	d, err := parseDuration(s)
+	if err == nil {
+		return now.Add(d), nil
+	}
+	return time.Time{}, errUnparsableTime
+}
+
+func parseDuration(s string) (time.Duration, error) {
+	d, err := time.ParseDuration(s)
+	if err == nil {
+		return d, nil
+	}
+	matches := durationStrRegex.FindStringSubmatch(s)
+	if matches != nil {
+		number, err := strconv.Atoi(matches[1])
+		if err != nil {
+			return 0, errUnparsableTime
+		}
+		switch unit := matches[2][0:1]; unit {
+		case "d":
+			return time.Duration(number) * 24 * time.Hour, nil
+		case "h":
+			return time.Duration(number) * time.Hour, nil
+		case "m":
+			return time.Duration(number) * time.Minute, nil
+		case "s":
+			return time.Duration(number) * time.Second, nil
+		default:
+			return 0, errUnparsableTime
+		}
+	}
+	return 0, errUnparsableTime
+}
+
+func parseUnixTime(s string, now time.Time) (time.Time, error) {
+	t, err := strconv.Atoi(s)
+	if err != nil {
+		return time.Time{}, err
+	} else if int64(t) < now.Unix() {
+		return time.Time{}, errUnparsableTime
+	}
+	return time.Unix(int64(t), 0), nil
+}
+
+func parseNaturalTime(s string, now time.Time) (time.Time, error) {
+	r, err := when.EN.Parse(s, now) // returns "nil, nil" if no matches!
+	if err != nil || r == nil {
+		return time.Time{}, errUnparsableTime
+	} else if r.Time.After(now) {
+		return r.Time, nil
+	}
+	// Hack: If the time is parsable, but not in the future,
+	// simply append "tomorrow, " to it.
+	r, err = when.EN.Parse("tomorrow, "+s, now) // returns "nil, nil" if no matches!
+	if err != nil || r == nil {
+		return time.Time{}, errUnparsableTime
+	} else if r.Time.After(now) {
+		return r.Time, nil
+	}
+	return time.Time{}, errUnparsableTime
+}

util/time_test.go

@@ -0,0 +1,60 @@
+package util
+
+import (
+	"github.com/stretchr/testify/require"
+	"testing"
+	"time"
+)
+
+var (
+	// 2021-12-10 10:17:23 (Friday)
+	base = time.Date(2021, 12, 10, 10, 17, 23, 0, time.UTC)
+)
+
+func TestParseFutureTime_11am_FutureTime(t *testing.T) {
+	d, err := ParseFutureTime("11am", base)
+	require.Nil(t, err)
+	require.Equal(t, time.Date(2021, 12, 10, 11, 0, 0, 0, time.UTC), d) // Same day
+}
+
+func TestParseFutureTime_9am_PastTime(t *testing.T) {
+	d, err := ParseFutureTime("9am", base)
+	require.Nil(t, err)
+	require.Equal(t, time.Date(2021, 12, 11, 9, 0, 0, 0, time.UTC), d) // Next day
+}
+
+func TestParseFutureTime_Monday_10_30pm_FutureTime(t *testing.T) {
+	d, err := ParseFutureTime("Monday, 10:30pm", base)
+	require.Nil(t, err)
+	require.Equal(t, time.Date(2021, 12, 13, 22, 30, 0, 0, time.UTC), d)
+}
+
+func TestParseFutureTime_30m(t *testing.T) {
+	d, err := ParseFutureTime("30m", base)
+	require.Nil(t, err)
+	require.Equal(t, time.Date(2021, 12, 10, 10, 47, 23, 0, time.UTC), d)
+}
+
+func TestParseFutureTime_30min(t *testing.T) {
+	d, err := ParseFutureTime("30min", base)
+	require.Nil(t, err)
+	require.Equal(t, time.Date(2021, 12, 10, 10, 47, 23, 0, time.UTC), d)
+}
+
+func TestParseFutureTime_3h(t *testing.T) {
+	d, err := ParseFutureTime("3h", base)
+	require.Nil(t, err)
+	require.Equal(t, time.Date(2021, 12, 10, 13, 17, 23, 0, time.UTC), d)
+}
+
+func TestParseFutureTime_1day(t *testing.T) {
+	d, err := ParseFutureTime("1 day", base)
+	require.Nil(t, err)
+	require.Equal(t, time.Date(2021, 12, 11, 10, 17, 23, 0, time.UTC), d)
+}
+
+func TestParseFutureTime_UnixTime(t *testing.T) {
+	d, err := ParseFutureTime("1639183911", base)
+	require.Nil(t, err)
+	require.Equal(t, time.Date(2021, 12, 10, 19, 51, 51, 0, time.Local), d)
+}