Merge remote-tracking branch 'origin/master' into issue97

* origin/master:
  Duplication issue fixed.
  Some multiple-ness.
  Test fixed.
  Resynced and moved some functions around #78
  added functionnal option pattern for url parsing
  usage example, README
  calendar parsing url support

README.md

@@ -6,13 +6,18 @@ A  ICS / ICal parser and serialiser for Golang.
 Because the other libraries didn't quite do what I needed.
 
 Usage, parsing:
-```
+```golang
     cal, err := ParseCalendar(strings.NewReader(input))
 
 ```
 
-Creating:
+Usage, parsing from a URL :
+```golang
+    cal, err := ParseCalendar("an-ics-url")
 ```
+
+Creating:
+```golang
   cal := ics.NewCalendar()
   cal.SetMethod(ics.MethodRequest)
   event := cal.AddEvent(fmt.Sprintf("id@domain", p.SessionKey.IntID()))

calendar.go

@@ -3,11 +3,14 @@ package ics
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"errors"
 	"fmt"
 	"io"
 	"reflect"
 	"strings"
+	"net/http"
+	"reflect"
 	"time"
 )
 
@@ -63,8 +66,111 @@ const (
 	ComponentPropertyTzid            = ComponentProperty(PropertyTzid)
 	ComponentPropertyComment         = ComponentProperty(PropertyComment)
 	ComponentPropertyRelatedTo       = ComponentProperty(PropertyRelatedTo)
+	ComponentPropertyMethod          = ComponentProperty(PropertyMethod)
+	ComponentPropertyRecurrenceId    = ComponentProperty(PropertyRecurrenceId)
+	ComponentPropertyDuration        = ComponentProperty(PropertyDuration)
+	ComponentPropertyContact         = ComponentProperty(PropertyContact)
+	ComponentPropertyRequestStatus   = ComponentProperty(PropertyRequestStatus)
+	ComponentPropertyRDate           = ComponentProperty(PropertyRdate)
 )
 
+// Required returns the rules from the RFC as to if they are required or not for any particular component type
+// If unspecified or incomplete, it returns false. -- This list is incomplete verify source. Happy to take PRs with reference
+// iana-prop and x-props are not covered as it would always be true and require an exhaustive list.
+func (cp ComponentProperty) Required(c Component) bool {
+	// https://www.rfc-editor.org/rfc/rfc5545#section-3.6.1
+	switch cp {
+	case ComponentPropertyDtstamp, ComponentPropertyUniqueId:
+		switch c.(type) {
+		case *VEvent:
+			return true
+		}
+	case ComponentPropertyDtStart:
+		switch c := c.(type) {
+		case *VEvent:
+			return !c.HasProperty(ComponentPropertyMethod)
+		}
+	}
+	return false
+}
+
+// Exclusive returns the ComponentProperty's using the rules from the RFC as to if one or more existing properties are prohibiting this one
+// If unspecified or incomplete, it returns false. -- This list is incomplete verify source. Happy to take PRs with reference
+// iana-prop and x-props are not covered as it would always be true and require an exhaustive list.
+func (cp ComponentProperty) Exclusive(c Component) []ComponentProperty {
+	// https://www.rfc-editor.org/rfc/rfc5545#section-3.6.1
+	switch cp {
+	case ComponentPropertyDtEnd:
+		switch c := c.(type) {
+		case *VEvent:
+			if c.HasProperty(ComponentPropertyDuration) {
+				return []ComponentProperty{ComponentPropertyDuration}
+			}
+		}
+	case ComponentPropertyDuration:
+		switch c := c.(type) {
+		case *VEvent:
+			if c.HasProperty(ComponentPropertyDtEnd) {
+				return []ComponentProperty{ComponentPropertyDtEnd}
+			}
+		}
+	}
+	return nil
+}
+
+// Singular returns the rules from the RFC as to if the spec states that if "Must not occur more than once"
+// iana-prop and x-props are not covered as it would always be true and require an exhaustive list.
+func (cp ComponentProperty) Singular(c Component) bool {
+	// https://www.rfc-editor.org/rfc/rfc5545#section-3.6.1
+	switch cp {
+	case ComponentPropertyClass, ComponentPropertyCreated, ComponentPropertyDescription, ComponentPropertyGeo,
+		ComponentPropertyLastModified, ComponentPropertyLocation, ComponentPropertyOrganizer, ComponentPropertyPriority,
+		ComponentPropertySequence, ComponentPropertyStatus, ComponentPropertySummary, ComponentPropertyTransp,
+		ComponentPropertyUrl, ComponentPropertyRecurrenceId:
+		switch c.(type) {
+		case *VEvent:
+			return true
+		}
+	}
+	return false
+}
+
+// Optional returns the rules from the RFC as to if the spec states that if these are optional
+// iana-prop and x-props are not covered as it would always be true and require an exhaustive list.
+func (cp ComponentProperty) Optional(c Component) bool {
+	// https://www.rfc-editor.org/rfc/rfc5545#section-3.6.1
+	switch cp {
+	case ComponentPropertyClass, ComponentPropertyCreated, ComponentPropertyDescription, ComponentPropertyGeo,
+		ComponentPropertyLastModified, ComponentPropertyLocation, ComponentPropertyOrganizer, ComponentPropertyPriority,
+		ComponentPropertySequence, ComponentPropertyStatus, ComponentPropertySummary, ComponentPropertyTransp,
+		ComponentPropertyUrl, ComponentPropertyRecurrenceId, ComponentPropertyRrule, ComponentPropertyAttach,
+		ComponentPropertyAttendee, ComponentPropertyCategories, ComponentPropertyComment,
+		ComponentPropertyContact, ComponentPropertyExdate, ComponentPropertyRequestStatus, ComponentPropertyRelatedTo,
+		ComponentPropertyResources, ComponentPropertyRDate:
+		switch c.(type) {
+		case *VEvent:
+			return true
+		}
+	}
+	return false
+}
+
+// Multiple returns the rules from the RFC as to if the spec states explicitly if multiple are allowed
+// iana-prop and x-props are not covered as it would always be true and require an exhaustive list.
+func (cp ComponentProperty) Multiple(c Component) bool {
+	// https://www.rfc-editor.org/rfc/rfc5545#section-3.6.1
+	switch cp {
+	case ComponentPropertyAttach, ComponentPropertyAttendee, ComponentPropertyCategories, ComponentPropertyComment,
+		ComponentPropertyContact, ComponentPropertyExdate, ComponentPropertyRequestStatus, ComponentPropertyRelatedTo,
+		ComponentPropertyResources, ComponentPropertyRDate:
+		switch c.(type) {
+		case *VEvent:
+			return true
+		}
+	}
+	return false
+}
+
 func ComponentPropertyExtended(s string) ComponentProperty {
 	return ComponentProperty("X-" + strings.TrimPrefix("X-", s))
 }
@@ -473,6 +579,108 @@ func (cal *Calendar) setProperty(property Property, value string, params ...Prop
 	cal.CalendarProperties = append(cal.CalendarProperties, r)
 }
 
+func (calendar *Calendar) AddEvent(id string) *VEvent {
+	e := NewEvent(id)
+	calendar.Components = append(calendar.Components, e)
+	return e
+}
+
+func (calendar *Calendar) AddVEvent(e *VEvent) {
+	calendar.Components = append(calendar.Components, e)
+}
+
+func (calendar *Calendar) Events() (r []*VEvent) {
+	r = []*VEvent{}
+	for i := range calendar.Components {
+		switch event := calendar.Components[i].(type) {
+		case *VEvent:
+			r = append(r, event)
+		}
+	}
+	return
+}
+
+func (calendar *Calendar) RemoveEvent(id string) {
+	for i := range calendar.Components {
+		switch event := calendar.Components[i].(type) {
+		case *VEvent:
+			if event.Id() == id {
+				if len(calendar.Components) > i+1 {
+					calendar.Components = append(calendar.Components[:i], calendar.Components[i+1:]...)
+				} else {
+					calendar.Components = calendar.Components[:i]
+				}
+				return
+			}
+		}
+	}
+}
+
+func WithCustomClient(client *http.Client) *http.Client {
+	return client
+}
+
+func WithCustomRequest(request *http.Request) *http.Request {
+	return request
+}
+
+func ParseCalendarFromUrl(url string, opts ...any) (*Calendar, error) {
+	var ctx context.Context
+	var req *http.Request
+	var client HttpClientLike = http.DefaultClient
+	for opti, opt := range opts {
+		switch opt := opt.(type) {
+		case *http.Client:
+			client = opt
+		case HttpClientLike:
+			client = opt
+		case func() *http.Client:
+			client = opt()
+		case *http.Request:
+			req = opt
+		case func() *http.Request:
+			req = opt()
+		case context.Context:
+			ctx = opt
+		case func() context.Context:
+			ctx = opt()
+		default:
+			return nil, fmt.Errorf("unknown optional argument %d on ParseCalendarFromUrl: %s", opti, reflect.TypeOf(opt))
+		}
+	}
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if req == nil {
+		var err error
+		req, err = http.NewRequestWithContext(ctx, "GET", url, nil)
+		if err != nil {
+			return nil, fmt.Errorf("creating http request: %w", err)
+		}
+	}
+	return parseCalendarFromHttpRequest(client, req)
+}
+
+type HttpClientLike interface {
+	Do(req *http.Request) (*http.Response, error)
+}
+
+func parseCalendarFromHttpRequest(client HttpClientLike, request *http.Request) (*Calendar, error) {
+	resp, err := client.Do(request)
+	if err != nil {
+		return nil, fmt.Errorf("http request: %w", err)
+	}
+	defer func(closer io.ReadCloser) {
+		if derr := closer.Close(); derr != nil && err == nil {
+			err = fmt.Errorf("http request close: %w", derr)
+		}
+	}(resp.Body)
+	var cal *Calendar
+	cal, err = ParseCalendar(resp.Body)
+	// This allows the defer func to change the error
+	return cal, err
+}
+
 func ParseCalendar(r io.Reader) (*Calendar, error) {
 	state := "begin"
 	c := &Calendar{}

calendar_test.go

@@ -4,8 +4,12 @@ import (
 	"bytes"
 	"embed"
 	"github.com/google/go-cmp/cmp"
+	"bytes"
+	_ "embed"
 	"io"
 	"io/fs"
+	"net/http"
+	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -461,3 +465,33 @@ func TestIssue97(t *testing.T) {
 		t.Fatalf("cannot read test directory: %v", err)
 	}
 }
+
+type MockHttpClient struct {
+	Response *http.Response
+	Error    error
+}
+
+func (m *MockHttpClient) Do(req *http.Request) (*http.Response, error) {
+	return m.Response, m.Error
+}
+
+var (
+	_ HttpClientLike = &MockHttpClient{}
+	//go:embed "testdata/rfc5545sec4/input1.ics"
+	input1TestData []byte
+)
+
+func TestIssue77(t *testing.T) {
+	url := "https://proseconsult.umontpellier.fr/jsp/custom/modules/plannings/direct_cal.jsp?data=58c99062bab31d256bee14356aca3f2423c0f022cb9660eba051b2653be722c4c7f281e4e3ad06b85d3374100ac416a4dc5c094f7d1a811b903031bde802c7f50e0bd1077f9461bed8f9a32b516a3c63525f110c026ed6da86f487dd451ca812c1c60bb40b1502b6511435cf9908feb2166c54e36382c1aa3eb0ff5cb8980cdb,1"
+
+	_, err := ParseCalendarFromUrl(url, &MockHttpClient{
+		Response: &http.Response{
+			StatusCode: 200,
+			Body:       io.NopCloser(bytes.NewReader(input1TestData)),
+		},
+	})
+
+	if err != nil {
+		t.Fatalf("Error reading file: %s", err)
+	}
+}