Better caldav support (#73)

vendor/github.com/samedi/caldav-go/handlers/multistatus.go

@@ -0,0 +1,207 @@
+package handlers
+
+import (
+	"encoding/xml"
+	"fmt"
+	"github.com/samedi/caldav-go/data"
+	"github.com/samedi/caldav-go/global"
+	"github.com/samedi/caldav-go/ixml"
+	"github.com/samedi/caldav-go/lib"
+	"net/http"
+)
+
+// Wraps a multistatus response. It contains the set of `Responses`
+// that will serve to build the final XML. Multistatus responses are
+// used by the REPORT and PROPFIND methods.
+type multistatusResp struct {
+	// The set of multistatus responses used to build each of the <DAV:response> nodes.
+	Responses []msResponse
+	// Flag that XML should be minimal or not
+	// [defined in the draft https://tools.ietf.org/html/draft-murchison-webdav-prefer-05]
+	Minimal bool
+}
+
+type msResponse struct {
+	Href      string
+	Found     bool
+	Propstats msPropstats
+}
+
+type msPropstats map[int]msProps
+
+// Adds a msProp to the map with the key being the prop status.
+func (stats msPropstats) Add(prop msProp) {
+	stats[prop.Status] = append(stats[prop.Status], prop)
+}
+
+func (stats msPropstats) Clone() msPropstats {
+	clone := make(msPropstats)
+
+	for k, v := range stats {
+		clone[k] = v
+	}
+
+	return clone
+}
+
+type msProps []msProp
+
+type msProp struct {
+	Tag      xml.Name
+	Content  string
+	Contents []string
+	Status   int
+}
+
+// Function that processes all the required props for a given resource.
+// ## Params
+// resource: the target calendar resource.
+// reqprops: set of required props that must be processed for the resource.
+// ## Returns
+// The set of props (msProp) processed. Each prop is mapped to a HTTP status code.
+// So if a prop is found and processed ok, it'll be mapped to 200. If it's not found,
+// it'll be mapped to 404, and so on.
+func (ms *multistatusResp) Propstats(resource *data.Resource, reqprops []xml.Name) msPropstats {
+	if resource == nil {
+		return nil
+	}
+
+	result := make(msPropstats)
+
+	for _, ptag := range reqprops {
+		pvalue := msProp{
+			Tag:    ptag,
+			Status: http.StatusOK,
+		}
+
+		pfound := false
+		switch ptag {
+		case ixml.CALENDAR_DATA_TG:
+			pvalue.Content, pfound = resource.GetContentData()
+			if pfound {
+				pvalue.Content = ixml.EscapeText(pvalue.Content)
+			}
+		case ixml.GET_ETAG_TG:
+			pvalue.Content, pfound = resource.GetEtag()
+		case ixml.GET_CONTENT_TYPE_TG:
+			pvalue.Content, pfound = resource.GetContentType()
+		case ixml.GET_CONTENT_LENGTH_TG:
+			pvalue.Content, pfound = resource.GetContentLength()
+		case ixml.DISPLAY_NAME_TG:
+			pvalue.Content, pfound = resource.GetDisplayName()
+			if pfound {
+				pvalue.Content = ixml.EscapeText(pvalue.Content)
+			}
+		case ixml.GET_LAST_MODIFIED_TG:
+			pvalue.Content, pfound = resource.GetLastModified(http.TimeFormat)
+		case ixml.OWNER_TG:
+			pvalue.Content, pfound = resource.GetOwnerPath()
+		case ixml.GET_CTAG_TG:
+			pvalue.Content, pfound = resource.GetEtag()
+		case ixml.PRINCIPAL_URL_TG,
+			ixml.PRINCIPAL_COLLECTION_SET_TG,
+			ixml.CALENDAR_USER_ADDRESS_SET_TG,
+			ixml.CALENDAR_HOME_SET_TG:
+			pvalue.Content, pfound = ixml.HrefTag(resource.Path), true
+		case ixml.RESOURCE_TYPE_TG:
+			if resource.IsCollection() {
+				pvalue.Content, pfound = ixml.Tag(ixml.COLLECTION_TG, "")+ixml.Tag(ixml.CALENDAR_TG, ""), true
+
+				if resource.IsPrincipal() {
+					pvalue.Content += ixml.Tag(ixml.PRINCIPAL_TG, "")
+				}
+			} else {
+				// resourcetype must be returned empty for non-collection elements
+				pvalue.Content, pfound = "", true
+			}
+		case ixml.CURRENT_USER_PRINCIPAL_TG:
+			if global.User != nil {
+				path := fmt.Sprintf("/%s/", global.User.Name)
+				pvalue.Content, pfound = ixml.HrefTag(path), true
+			}
+		case ixml.SUPPORTED_CALENDAR_COMPONENT_SET_TG:
+			if resource.IsCollection() {
+				for _, component := range global.SupportedComponents {
+					// TODO: use ixml somehow to build the below tag
+					compTag := fmt.Sprintf(`<C:comp name="%s"/>`, component)
+					pvalue.Contents = append(pvalue.Contents, compTag)
+				}
+				pfound = true
+			}
+		}
+
+		if !pfound {
+			pvalue.Status = http.StatusNotFound
+		}
+
+		result.Add(pvalue)
+	}
+
+	return result
+}
+
+// Adds a new `msResponse` to the `Responses` array.
+func (ms *multistatusResp) AddResponse(href string, found bool, propstats msPropstats) {
+	ms.Responses = append(ms.Responses, msResponse{
+		Href:      href,
+		Found:     found,
+		Propstats: propstats,
+	})
+}
+
+func (ms *multistatusResp) ToXML() string {
+	// init multistatus
+	var bf lib.StringBuffer
+	bf.Write(`<?xml version="1.0" encoding="UTF-8"?>`)
+	bf.Write(`<D:multistatus %s>`, ixml.Namespaces())
+
+	// iterate over event hrefs and build multistatus XML on the fly
+	for _, response := range ms.Responses {
+		bf.Write("<D:response>")
+		bf.Write(ixml.HrefTag(response.Href))
+
+		if response.Found {
+			propstats := response.Propstats.Clone()
+
+			if ms.Minimal {
+				delete(propstats, http.StatusNotFound)
+
+				if len(propstats) == 0 {
+					bf.Write("<D:propstat>")
+					bf.Write("<D:prop/>")
+					bf.Write(ixml.StatusTag(http.StatusOK))
+					bf.Write("</D:propstat>")
+					bf.Write("</D:response>")
+
+					continue
+				}
+			}
+
+			for status, props := range propstats {
+				bf.Write("<D:propstat>")
+				bf.Write("<D:prop>")
+				for _, prop := range props {
+					bf.Write(ms.propToXML(prop))
+				}
+				bf.Write("</D:prop>")
+				bf.Write(ixml.StatusTag(status))
+				bf.Write("</D:propstat>")
+			}
+		} else {
+			// if does not find the resource set 404
+			bf.Write(ixml.StatusTag(http.StatusNotFound))
+		}
+		bf.Write("</D:response>")
+	}
+	bf.Write("</D:multistatus>")
+
+	return bf.String()
+}
+
+func (ms *multistatusResp) propToXML(prop msProp) string {
+	for _, content := range prop.Contents {
+		prop.Content += content
+	}
+	xmlString := ixml.Tag(prop.Tag, prop.Content)
+	return xmlString
+}