storage: break filesystem.go into multiple files

storage/filesystem.go

@@ -1,24 +1,16 @@
 package storage
 
 import (
-	"context"
 	"crypto/sha1"
 	"encoding/base64"
-	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
-	"io/fs"
-	"io/ioutil"
-	"net/http"
 	"os"
 	"path"
 	"path/filepath"
 	"regexp"
 	"strings"
 
-	"github.com/emersion/go-ical"
-	"github.com/emersion/go-vcard"
 	"github.com/emersion/go-webdav"
 	"github.com/emersion/go-webdav/caldav"
 	"github.com/emersion/go-webdav/carddav"
@@ -35,6 +27,7 @@ type filesystemBackend struct {
 
 var (
 	validFilenameRegex  = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9_-]+(.[a-zA-Z]+)?$`)
+	defaultResourceName = "default"
 )
 
 func NewFilesystem(fsPath, caldavPrefix, carddavPrefix string, userPrincipalBackend webdav.UserPrincipalBackend) (caldav.Backend, carddav.Backend, error) {
@@ -54,24 +47,6 @@ func NewFilesystem(fsPath, caldavPrefix, carddavPrefix string, userPrincipalBack
 	return backend, backend, nil
 }
 
-func (b *filesystemBackend) AddressbookHomeSetPath(ctx context.Context) (string, error) {
-	upPath, err := b.CurrentUserPrincipal(ctx)
-	if err != nil {
-		return "", err
-	}
-
-	return path.Join(upPath, b.carddavPrefix) + "/", nil
-}
-
-func (b *filesystemBackend) CalendarHomeSetPath(ctx context.Context) (string, error) {
-	upPath, err := b.CurrentUserPrincipal(ctx)
-	if err != nil {
-		return "", err
-	}
-
-	return path.Join(upPath, b.caldavPrefix) + "/", nil
-}
-
 func ensureLocalDir(path string) error {
 	if _, err := os.Stat(path); os.IsNotExist(err) {
 		err = os.MkdirAll(path, 0755)
@@ -84,7 +59,7 @@ func ensureLocalDir(path string) error {
 
 // don't use this directly, use localCalDAVPath or localCardDAVPath instead.
 func (b *filesystemBackend) safeLocalPath(homeSetPath string, urlPath string) (string, error) {
-	localPath := filepath.Join(b.path, homeSetPath, "default")
+	localPath := filepath.Join(b.path, homeSetPath, defaultResourceName)
 	if err := ensureLocalDir(localPath); err != nil {
 		return "", err
 	}
@@ -97,12 +72,12 @@ func (b *filesystemBackend) safeLocalPath(homeSetPath string, urlPath string) (s
 	// TODO this changes once multiple addess books are supported
 	dir, file := path.Split(urlPath)
 	// only accept resources in default calendar/adress book for now
-	if path.Clean(dir) != path.Join(homeSetPath, "default") {
+	if path.Clean(dir) != path.Join(homeSetPath, defaultResourceName) {
 		if strings.HasPrefix(dir, homeSetPath) {
-			err := fmt.Errorf("invalid request path: %s (%s is not %s)", urlPath, dir, path.Join(homeSetPath, "default"))
+			err := fmt.Errorf("invalid request path: %s (%s is not %s)", urlPath, dir, path.Join(homeSetPath, defaultResourceName))
 			return "", webdav.NewHTTPError(400, err)
 		} else {
-			err := fmt.Errorf("Access to resource outside of home set: %s", urlPath)
+			err := fmt.Errorf("access to resource outside of home set: %s", urlPath)
 			return "", webdav.NewHTTPError(403, err)
 		}
 	}
@@ -117,24 +92,6 @@ func (b *filesystemBackend) safeLocalPath(homeSetPath string, urlPath string) (s
 	return filepath.Join(localPath, file), nil
 }
 
-func (b *filesystemBackend) localCalDAVPath(ctx context.Context, urlPath string) (string, error) {
-	homeSetPath, err := b.CalendarHomeSetPath(ctx)
-	if err != nil {
-		return "", err
-	}
-
-	return b.safeLocalPath(homeSetPath, urlPath)
-}
-
-func (b *filesystemBackend) localCardDAVPath(ctx context.Context, urlPath string) (string, error) {
-	homeSetPath, err := b.AddressbookHomeSetPath(ctx)
-	if err != nil {
-		return "", err
-	}
-
-	return b.safeLocalPath(homeSetPath, urlPath)
-}
-
 func etagForFile(path string) (string, error) {
 	f, err := os.Open(path)
 	if err != nil {
@@ -150,533 +107,3 @@ func etagForFile(path string) (string, error) {
 
 	return base64.StdEncoding.EncodeToString(csum[:]), nil
 }
-
-func vcardPropFilter(card vcard.Card, props []string) vcard.Card {
-	if card == nil {
-		return nil
-	}
-
-	if len(props) == 0 {
-		return card
-	}
-
-	result := make(vcard.Card)
-	result["VERSION"] = card["VERSION"]
-	for _, prop := range props {
-		value, ok := card[prop]
-		if ok {
-			result[prop] = value
-		}
-	}
-
-	return result
-}
-
-func vcardFromFile(path string, propFilter []string) (vcard.Card, error) {
-	f, err := os.Open(path)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-
-	dec := vcard.NewDecoder(f)
-	card, err := dec.Decode()
-	if err != nil {
-		return nil, err
-	}
-
-	return vcardPropFilter(card, propFilter), nil
-}
-
-func calendarFromFile(path string, propFilter []string) (*ical.Calendar, error) {
-	f, err := os.Open(path)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-
-	dec := ical.NewDecoder(f)
-	cal, err := dec.Decode()
-	if err != nil {
-		return nil, err
-	}
-
-	return cal, nil
-	// TODO implement
-	//return icalPropFilter(cal, propFilter), nil
-}
-
-func createDefaultAddressBook(path, localPath string) error {
-	// TODO what should the default address book look like?
-	defaultAB := carddav.AddressBook{
-		Path:                 path,
-		Name:                 "My contacts",
-		Description:          "Default address book",
-		MaxResourceSize:      1024,
-		SupportedAddressData: nil,
-	}
-	blob, err := json.MarshalIndent(defaultAB, "", "  ")
-	if err != nil {
-		return fmt.Errorf("error creating default address book: %s", err.Error())
-	}
-	err = os.WriteFile(localPath, blob, 0644)
-	if err != nil {
-		return fmt.Errorf("error writing default address book: %s", err.Error())
-	}
-	return nil
-}
-
-func (b *filesystemBackend) AddressBook(ctx context.Context) (*carddav.AddressBook, error) {
-	debug.Printf("filesystem.AddressBook()")
-	localPath, err := b.localCardDAVPath(ctx, "")
-	if err != nil {
-		return nil, err
-	}
-	localPath = filepath.Join(localPath, "addressbook.json")
-
-	debug.Printf("loading addressbook from %s", localPath)
-
-	data, readErr := ioutil.ReadFile(localPath)
-	if os.IsNotExist(readErr) {
-		urlPath, err := b.AddressbookHomeSetPath(ctx)
-		if err != nil {
-			return nil, err
-		}
-		urlPath = path.Join(urlPath, "default") + "/"
-		debug.Printf("creating default addressbook (URL:path): %s:%s", urlPath, localPath)
-		err = createDefaultAddressBook(urlPath, localPath)
-		if err != nil {
-			return nil, err
-		}
-		data, readErr = ioutil.ReadFile(localPath)
-	}
-	if readErr != nil {
-		return nil, fmt.Errorf("error opening address book: %s", readErr.Error())
-	}
-	var addressBook carddav.AddressBook
-	err = json.Unmarshal(data, &addressBook)
-	if err != nil {
-		return nil, fmt.Errorf("error reading address book: %s", err.Error())
-	}
-
-	return &addressBook, nil
-}
-
-func (b *filesystemBackend) GetAddressObject(ctx context.Context, objPath string, req *carddav.AddressDataRequest) (*carddav.AddressObject, error) {
-	debug.Printf("filesystem.GetAddressObject(%s, %v)", objPath, req)
-	localPath, err := b.localCardDAVPath(ctx, objPath)
-	if err != nil {
-		return nil, err
-	}
-
-	info, err := os.Stat(localPath)
-	if err != nil {
-		if errors.Is(err, fs.ErrNotExist) {
-			return nil, webdav.NewHTTPError(404, err)
-		}
-		return nil, err
-	}
-
-	var propFilter []string
-	if req != nil && !req.AllProp {
-		propFilter = req.Props
-	}
-
-	card, err := vcardFromFile(localPath, propFilter)
-	if err != nil {
-		return nil, err
-	}
-
-	etag, err := etagForFile(localPath)
-	if err != nil {
-		return nil, err
-	}
-
-	obj := carddav.AddressObject{
-		Path:          objPath,
-		ModTime:       info.ModTime(),
-		ContentLength: info.Size(),
-		ETag:          etag,
-		Card:          card,
-	}
-	return &obj, nil
-}
-
-func (b *filesystemBackend) loadAllContacts(ctx context.Context, propFilter []string) ([]carddav.AddressObject, error) {
-	var result []carddav.AddressObject
-
-	localPath, err := b.localCardDAVPath(ctx, "")
-	if err != nil {
-		return result, err
-	}
-
-	homeSetPath, err := b.AddressbookHomeSetPath(ctx)
-	if err != nil {
-		return result, err
-	}
-
-	err = filepath.Walk(localPath, func(filename string, info os.FileInfo, err error) error {
-		if !info.Mode().IsRegular() || filepath.Ext(filename) != ".vcf" {
-			return nil
-		}
-
-		card, err := vcardFromFile(filename, propFilter)
-		if err != nil {
-			return err
-		}
-
-		etag, err := etagForFile(filename)
-		if err != nil {
-			return err
-		}
-
-		obj := carddav.AddressObject{
-			Path:          path.Join(homeSetPath, "default", filepath.Base(filename)),
-			ModTime:       info.ModTime(),
-			ContentLength: info.Size(),
-			ETag:          etag,
-			Card:          card,
-		}
-		result = append(result, obj)
-		return nil
-	})
-
-	debug.Printf("filesystem.loadAllContacts() returning %d results from %s", len(result), localPath)
-	return result, err
-}
-
-func (b *filesystemBackend) loadAllCalendars(ctx context.Context, propFilter []string) ([]caldav.CalendarObject, error) {
-	var result []caldav.CalendarObject
-
-	localPath, err := b.localCalDAVPath(ctx, "")
-	if err != nil {
-		return result, err
-	}
-
-	homeSetPath, err := b.CalendarHomeSetPath(ctx)
-	if err != nil {
-		return result, err
-	}
-
-	err = filepath.Walk(localPath, func(filename string, info os.FileInfo, err error) error {
-		// Skip address book meta data files
-		if !info.Mode().IsRegular() || filepath.Ext(filename) != ".ics" {
-			return nil
-		}
-
-		cal, err := calendarFromFile(filename, propFilter)
-		if err != nil {
-			fmt.Printf("load calendar error for %s: %v\n", filename, err)
-			return err
-		}
-
-		etag, err := etagForFile(filename)
-		if err != nil {
-			return err
-		}
-
-		obj := caldav.CalendarObject{
-			Path:          path.Join(homeSetPath, "default", filepath.Base(filename)),
-			ModTime:       info.ModTime(),
-			ContentLength: info.Size(),
-			ETag:          etag,
-			Data:          cal,
-		}
-		result = append(result, obj)
-		return nil
-	})
-
-	debug.Printf("filesystem.loadAllCalendars() returning %d results from %s", len(result), localPath)
-	return result, err
-}
-
-func (b *filesystemBackend) ListAddressObjects(ctx context.Context, req *carddav.AddressDataRequest) ([]carddav.AddressObject, error) {
-	debug.Printf("filesystem.ListAddressObjects(%v)", req)
-	var propFilter []string
-	if req != nil && !req.AllProp {
-		propFilter = req.Props
-	}
-
-	return b.loadAllContacts(ctx, propFilter)
-}
-
-func (b *filesystemBackend) QueryAddressObjects(ctx context.Context, query *carddav.AddressBookQuery) ([]carddav.AddressObject, error) {
-	debug.Printf("filesystem.QueryAddressObjects(%v)", query)
-	var propFilter []string
-	if query != nil && !query.DataRequest.AllProp {
-		propFilter = query.DataRequest.Props
-	}
-
-	result, err := b.loadAllContacts(ctx, propFilter)
-	if err != nil {
-		return result, err
-	}
-
-	return carddav.Filter(query, result)
-}
-
-func (b *filesystemBackend) PutAddressObject(ctx context.Context, objPath string, card vcard.Card, opts *carddav.PutAddressObjectOptions) (loc string, err error) {
-	debug.Printf("filesystem.PutAddressObject(%v, %v, %v)", objPath, card, opts)
-
-	// Object always get saved as <UID>.vcf
-	dirname, _ := path.Split(objPath)
-	objPath = path.Join(dirname, card.Value(vcard.FieldUID)+".vcf")
-
-	localPath, err := b.localCardDAVPath(ctx, objPath)
-	if err != nil {
-		return "", err
-	}
-
-	flags := os.O_RDWR | os.O_CREATE | os.O_TRUNC
-	// TODO handle IfNoneMatch == ETag
-	if opts.IfNoneMatch.IsWildcard() {
-		// Make sure we're not overwriting an existing file
-		flags |= os.O_EXCL
-	} else if opts.IfMatch.IsWildcard() {
-		// Make sure we _are_ overwriting an existing file
-		flags &= ^os.O_CREATE
-	} else if opts.IfMatch.IsSet() {
-		// Make sure we overwrite the _right_ file
-		etag, err := etagForFile(localPath)
-		if err != nil {
-			return "", webdav.NewHTTPError(http.StatusPreconditionFailed, err)
-		}
-		want, err := opts.IfMatch.ETag()
-		if err != nil {
-			return "", webdav.NewHTTPError(http.StatusBadRequest, err)
-		}
-		if want != etag {
-			err = fmt.Errorf("If-Match does not match current ETag (%s/%s)", want, etag)
-			return "", webdav.NewHTTPError(http.StatusPreconditionFailed, err)
-		}
-	}
-
-	f, err := os.OpenFile(localPath, flags, 0666)
-	if os.IsExist(err) {
-		return "", carddav.NewPreconditionError(carddav.PreconditionNoUIDConflict)
-	} else if err != nil {
-		return "", err
-	}
-	defer f.Close()
-
-	enc := vcard.NewEncoder(f)
-	err = enc.Encode(card)
-	if err != nil {
-		return "", err
-	}
-
-	return objPath, nil
-}
-
-func (b *filesystemBackend) DeleteAddressObject(ctx context.Context, path string) error {
-	debug.Printf("filesystem.DeleteAddressObject(%s)", path)
-
-	localPath, err := b.localCardDAVPath(ctx, path)
-	if err != nil {
-		return err
-	}
-	err = os.Remove(localPath)
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
-func createDefaultCalendar(path, localPath string) error {
-	// TODO what should the default calendar look like?
-	defaultC := caldav.Calendar{
-		Path:            path,
-		Name:            "My calendar",
-		Description:     "Default calendar",
-		MaxResourceSize: 4096,
-	}
-	blob, err := json.MarshalIndent(defaultC, "", "  ")
-	if err != nil {
-		return fmt.Errorf("error creating default calendar: %s", err.Error())
-	}
-	err = os.WriteFile(localPath, blob, 0644)
-	if err != nil {
-		return fmt.Errorf("error writing default calendar: %s", err.Error())
-	}
-	return nil
-}
-
-func (b *filesystemBackend) Calendar(ctx context.Context) (*caldav.Calendar, error) {
-	debug.Printf("filesystem.Calendar()")
-
-	localPath, err := b.localCalDAVPath(ctx, "")
-	if err != nil {
-		return nil, err
-	}
-	localPath = filepath.Join(localPath, "calendar.json")
-
-	debug.Printf("loading calendar from %s", localPath)
-
-	data, readErr := ioutil.ReadFile(localPath)
-	if os.IsNotExist(readErr) {
-		urlPath, err := b.CalendarHomeSetPath(ctx)
-		if err != nil {
-			return nil, err
-		}
-		urlPath = path.Join(urlPath, "default") + "/"
-		debug.Printf("creating default calendar (URL:path): %s:%s", urlPath, localPath)
-		err = createDefaultCalendar(urlPath, localPath)
-		if err != nil {
-			return nil, err
-		}
-		data, readErr = ioutil.ReadFile(localPath)
-	}
-	if readErr != nil {
-		return nil, fmt.Errorf("error opening calendar: %s", readErr.Error())
-	}
-	var calendar caldav.Calendar
-	err = json.Unmarshal(data, &calendar)
-	if err != nil {
-		return nil, fmt.Errorf("error reading calendar: %s", err.Error())
-	}
-
-	return &calendar, nil
-}
-
-func (b *filesystemBackend) GetCalendarObject(ctx context.Context, objPath string, req *caldav.CalendarCompRequest) (*caldav.CalendarObject, error) {
-	debug.Printf("filesystem.GetCalendarObject(%s, %v)", objPath, req)
-
-	localPath, err := b.localCalDAVPath(ctx, objPath)
-	if err != nil {
-		return nil, err
-	}
-
-	info, err := os.Stat(localPath)
-	if err != nil {
-		if errors.Is(err, fs.ErrNotExist) {
-			debug.Printf("not found: %s", localPath)
-			return nil, webdav.NewHTTPError(404, err)
-		}
-		return nil, err
-	}
-
-	var propFilter []string
-	if req != nil && !req.AllProps {
-		propFilter = req.Props
-	}
-
-	calendar, err := calendarFromFile(localPath, propFilter)
-	if err != nil {
-		debug.Printf("error reading calendar: %v", err)
-		return nil, err
-	}
-
-	etag, err := etagForFile(localPath)
-	if err != nil {
-		return nil, err
-	}
-
-	obj := caldav.CalendarObject{
-		Path:          objPath,
-		ModTime:       info.ModTime(),
-		ContentLength: info.Size(),
-		ETag:          etag,
-		Data:          calendar,
-	}
-	return &obj, nil
-	return nil, fmt.Errorf("not implemented")
-}
-
-func (b *filesystemBackend) ListCalendarObjects(ctx context.Context, req *caldav.CalendarCompRequest) ([]caldav.CalendarObject, error) {
-	debug.Printf("filesystem.ListCalendarObjects(%v)", req)
-
-	var propFilter []string
-	if req != nil && !req.AllProps {
-		propFilter = req.Props
-	}
-
-	return b.loadAllCalendars(ctx, propFilter)
-}
-
-func (b *filesystemBackend) QueryCalendarObjects(ctx context.Context, query *caldav.CalendarQuery) ([]caldav.CalendarObject, error) {
-	debug.Printf("filesystem.QueryCalendarObjects(%v)", query)
-
-	var propFilter []string
-	if query != nil && !query.CompRequest.AllProps {
-		propFilter = query.CompRequest.Props
-	}
-
-	result, err := b.loadAllCalendars(ctx, propFilter)
-	if err != nil {
-		return result, err
-	}
-
-	return caldav.Filter(query, result)
-}
-
-func (b *filesystemBackend) PutCalendarObject(ctx context.Context, objPath string, calendar *ical.Calendar, opts *caldav.PutCalendarObjectOptions) (loc string, err error) {
-	debug.Printf("filesystem.PutCalendarObject(%s, %v, %v)", objPath, calendar, opts)
-
-	_, uid, err := caldav.ValidateCalendarObject(calendar)
-	if err != nil {
-		return "", caldav.NewPreconditionError(caldav.PreconditionValidCalendarObjectResource)
-	}
-
-	// Object always get saved as <UID>.ics
-	dirname, _ := path.Split(objPath)
-	objPath = path.Join(dirname, uid+".ics")
-
-	localPath, err := b.localCalDAVPath(ctx, objPath)
-	if err != nil {
-		return "", err
-	}
-
-	flags := os.O_RDWR | os.O_CREATE | os.O_TRUNC
-	// TODO handle IfNoneMatch == ETag
-	if opts.IfNoneMatch.IsWildcard() {
-		// Make sure we're not overwriting an existing file
-		flags |= os.O_EXCL
-	} else if opts.IfMatch.IsWildcard() {
-		// Make sure we _are_ overwriting an existing file
-		flags &= ^os.O_CREATE
-	} else if opts.IfMatch.IsSet() {
-		// Make sure we overwrite the _right_ file
-		etag, err := etagForFile(localPath)
-		if err != nil {
-			return "", webdav.NewHTTPError(http.StatusPreconditionFailed, err)
-		}
-		want, err := opts.IfMatch.ETag()
-		if err != nil {
-			return "", webdav.NewHTTPError(http.StatusBadRequest, err)
-		}
-		if want != etag {
-			err = fmt.Errorf("If-Match does not match current ETag (%s/%s)", want, etag)
-			return "", webdav.NewHTTPError(http.StatusPreconditionFailed, err)
-		}
-	}
-
-	f, err := os.OpenFile(localPath, flags, 0666)
-	if os.IsExist(err) {
-		return "", caldav.NewPreconditionError(caldav.PreconditionNoUIDConflict)
-	} else if err != nil {
-		return "", err
-	}
-	defer f.Close()
-
-	enc := ical.NewEncoder(f)
-	err = enc.Encode(calendar)
-	if err != nil {
-		return "", err
-	}
-
-	return objPath, nil
-}
-
-func (b *filesystemBackend) DeleteCalendarObject(ctx context.Context, path string) error {
-	debug.Printf("filesystem.DeleteCalendarObject(%s)", path)
-
-	localPath, err := b.localCalDAVPath(ctx, path)
-	if err != nil {
-		return err
-	}
-	err = os.Remove(localPath)
-	if err != nil {
-		return err
-	}
-	return nil
-}

storage/filesystem_caldav.go

@@ -0,0 +1,303 @@
+package storage
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/fs"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+
+	"github.com/emersion/go-ical"
+	"github.com/emersion/go-webdav"
+	"github.com/emersion/go-webdav/caldav"
+
+	"git.sr.ht/~sircmpwn/tokidoki/debug"
+)
+
+func (b *filesystemBackend) CalendarHomeSetPath(ctx context.Context) (string, error) {
+	upPath, err := b.CurrentUserPrincipal(ctx)
+	if err != nil {
+		return "", err
+	}
+
+	return path.Join(upPath, b.caldavPrefix) + "/", nil
+}
+
+func (b *filesystemBackend) localCalDAVPath(ctx context.Context, urlPath string) (string, error) {
+	homeSetPath, err := b.CalendarHomeSetPath(ctx)
+	if err != nil {
+		return "", err
+	}
+
+	return b.safeLocalPath(homeSetPath, urlPath)
+}
+
+func calendarFromFile(path string, propFilter []string) (*ical.Calendar, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	dec := ical.NewDecoder(f)
+	cal, err := dec.Decode()
+	if err != nil {
+		return nil, err
+	}
+
+	return cal, nil
+	// TODO implement
+	//return icalPropFilter(cal, propFilter), nil
+}
+
+func (b *filesystemBackend) loadAllCalendars(ctx context.Context, propFilter []string) ([]caldav.CalendarObject, error) {
+	var result []caldav.CalendarObject
+
+	localPath, err := b.localCalDAVPath(ctx, "")
+	if err != nil {
+		return result, err
+	}
+
+	homeSetPath, err := b.CalendarHomeSetPath(ctx)
+	if err != nil {
+		return result, err
+	}
+
+	err = filepath.Walk(localPath, func(filename string, info os.FileInfo, err error) error {
+		if err != nil {
+			return fmt.Errorf("error accessing %s: %s", filename, err)
+		}
+
+		// Skip address book meta data files
+		if !info.Mode().IsRegular() || filepath.Ext(filename) != ".ics" {
+			return nil
+		}
+
+		cal, err := calendarFromFile(filename, propFilter)
+		if err != nil {
+			fmt.Printf("load calendar error for %s: %v\n", filename, err)
+			return err
+		}
+
+		etag, err := etagForFile(filename)
+		if err != nil {
+			return err
+		}
+
+		obj := caldav.CalendarObject{
+			Path:          path.Join(homeSetPath, defaultResourceName, filepath.Base(filename)),
+			ModTime:       info.ModTime(),
+			ContentLength: info.Size(),
+			ETag:          etag,
+			Data:          cal,
+		}
+		result = append(result, obj)
+		return nil
+	})
+
+	debug.Printf("filesystem.loadAllCalendars() returning %d results from %s", len(result), localPath)
+	return result, err
+}
+
+func createDefaultCalendar(path, localPath string) error {
+	// TODO what should the default calendar look like?
+	defaultC := caldav.Calendar{
+		Path:            path,
+		Name:            "My calendar",
+		Description:     "Default calendar",
+		MaxResourceSize: 4096,
+	}
+	blob, err := json.MarshalIndent(defaultC, "", "  ")
+	if err != nil {
+		return fmt.Errorf("error creating default calendar: %s", err.Error())
+	}
+	err = os.WriteFile(localPath, blob, 0644)
+	if err != nil {
+		return fmt.Errorf("error writing default calendar: %s", err.Error())
+	}
+	return nil
+}
+
+func (b *filesystemBackend) Calendar(ctx context.Context) (*caldav.Calendar, error) {
+	debug.Printf("filesystem.Calendar()")
+
+	localPath, err := b.localCalDAVPath(ctx, "")
+	if err != nil {
+		return nil, err
+	}
+	localPath = filepath.Join(localPath, "calendar.json")
+
+	debug.Printf("loading calendar from %s", localPath)
+
+	data, readErr := ioutil.ReadFile(localPath)
+	if os.IsNotExist(readErr) {
+		urlPath, err := b.CalendarHomeSetPath(ctx)
+		if err != nil {
+			return nil, err
+		}
+		urlPath = path.Join(urlPath, defaultResourceName) + "/"
+		debug.Printf("creating default calendar (URL:path): %s:%s", urlPath, localPath)
+		err = createDefaultCalendar(urlPath, localPath)
+		if err != nil {
+			return nil, err
+		}
+		data, readErr = ioutil.ReadFile(localPath)
+	}
+	if readErr != nil {
+		return nil, fmt.Errorf("error opening calendar: %s", readErr.Error())
+	}
+	var calendar caldav.Calendar
+	err = json.Unmarshal(data, &calendar)
+	if err != nil {
+		return nil, fmt.Errorf("error reading calendar: %s", err.Error())
+	}
+
+	return &calendar, nil
+}
+
+func (b *filesystemBackend) GetCalendarObject(ctx context.Context, objPath string, req *caldav.CalendarCompRequest) (*caldav.CalendarObject, error) {
+	debug.Printf("filesystem.GetCalendarObject(%s, %v)", objPath, req)
+
+	localPath, err := b.localCalDAVPath(ctx, objPath)
+	if err != nil {
+		return nil, err
+	}
+
+	info, err := os.Stat(localPath)
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			debug.Printf("not found: %s", localPath)
+			return nil, webdav.NewHTTPError(404, err)
+		}
+		return nil, err
+	}
+
+	var propFilter []string
+	if req != nil && !req.AllProps {
+		propFilter = req.Props
+	}
+
+	calendar, err := calendarFromFile(localPath, propFilter)
+	if err != nil {
+		debug.Printf("error reading calendar: %v", err)
+		return nil, err
+	}
+
+	etag, err := etagForFile(localPath)
+	if err != nil {
+		return nil, err
+	}
+
+	obj := caldav.CalendarObject{
+		Path:          objPath,
+		ModTime:       info.ModTime(),
+		ContentLength: info.Size(),
+		ETag:          etag,
+		Data:          calendar,
+	}
+	return &obj, nil
+}
+
+func (b *filesystemBackend) ListCalendarObjects(ctx context.Context, req *caldav.CalendarCompRequest) ([]caldav.CalendarObject, error) {
+	debug.Printf("filesystem.ListCalendarObjects(%v)", req)
+
+	var propFilter []string
+	if req != nil && !req.AllProps {
+		propFilter = req.Props
+	}
+
+	return b.loadAllCalendars(ctx, propFilter)
+}
+
+func (b *filesystemBackend) QueryCalendarObjects(ctx context.Context, query *caldav.CalendarQuery) ([]caldav.CalendarObject, error) {
+	debug.Printf("filesystem.QueryCalendarObjects(%v)", query)
+
+	var propFilter []string
+	if query != nil && !query.CompRequest.AllProps {
+		propFilter = query.CompRequest.Props
+	}
+
+	result, err := b.loadAllCalendars(ctx, propFilter)
+	if err != nil {
+		return result, err
+	}
+
+	return caldav.Filter(query, result)
+}
+
+func (b *filesystemBackend) PutCalendarObject(ctx context.Context, objPath string, calendar *ical.Calendar, opts *caldav.PutCalendarObjectOptions) (loc string, err error) {
+	debug.Printf("filesystem.PutCalendarObject(%s, %v, %v)", objPath, calendar, opts)
+
+	_, uid, err := caldav.ValidateCalendarObject(calendar)
+	if err != nil {
+		return "", caldav.NewPreconditionError(caldav.PreconditionValidCalendarObjectResource)
+	}
+
+	// Object always get saved as <UID>.ics
+	dirname, _ := path.Split(objPath)
+	objPath = path.Join(dirname, uid+".ics")
+
+	localPath, err := b.localCalDAVPath(ctx, objPath)
+	if err != nil {
+		return "", err
+	}
+
+	flags := os.O_RDWR | os.O_CREATE | os.O_TRUNC
+	// TODO handle IfNoneMatch == ETag
+	if opts.IfNoneMatch.IsWildcard() {
+		// Make sure we're not overwriting an existing file
+		flags |= os.O_EXCL
+	} else if opts.IfMatch.IsWildcard() {
+		// Make sure we _are_ overwriting an existing file
+		flags &= ^os.O_CREATE
+	} else if opts.IfMatch.IsSet() {
+		// Make sure we overwrite the _right_ file
+		etag, err := etagForFile(localPath)
+		if err != nil {
+			return "", webdav.NewHTTPError(http.StatusPreconditionFailed, err)
+		}
+		want, err := opts.IfMatch.ETag()
+		if err != nil {
+			return "", webdav.NewHTTPError(http.StatusBadRequest, err)
+		}
+		if want != etag {
+			err = fmt.Errorf("If-Match does not match current ETag (%s/%s)", want, etag)
+			return "", webdav.NewHTTPError(http.StatusPreconditionFailed, err)
+		}
+	}
+
+	f, err := os.OpenFile(localPath, flags, 0666)
+	if os.IsExist(err) {
+		return "", caldav.NewPreconditionError(caldav.PreconditionNoUIDConflict)
+	} else if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	enc := ical.NewEncoder(f)
+	err = enc.Encode(calendar)
+	if err != nil {
+		return "", err
+	}
+
+	return objPath, nil
+}
+
+func (b *filesystemBackend) DeleteCalendarObject(ctx context.Context, path string) error {
+	debug.Printf("filesystem.DeleteCalendarObject(%s)", path)
+
+	localPath, err := b.localCalDAVPath(ctx, path)
+	if err != nil {
+		return err
+	}
+	err = os.Remove(localPath)
+	if err != nil {
+		return err
+	}
+	return nil
+}

storage/filesystem_carddav.go

@@ -0,0 +1,310 @@
+package storage
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/fs"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+
+	"github.com/emersion/go-vcard"
+	"github.com/emersion/go-webdav"
+	"github.com/emersion/go-webdav/carddav"
+
+	"git.sr.ht/~sircmpwn/tokidoki/debug"
+)
+
+func (b *filesystemBackend) AddressbookHomeSetPath(ctx context.Context) (string, error) {
+	upPath, err := b.CurrentUserPrincipal(ctx)
+	if err != nil {
+		return "", err
+	}
+
+	return path.Join(upPath, b.carddavPrefix) + "/", nil
+}
+
+func (b *filesystemBackend) localCardDAVPath(ctx context.Context, urlPath string) (string, error) {
+	homeSetPath, err := b.AddressbookHomeSetPath(ctx)
+	if err != nil {
+		return "", err
+	}
+
+	return b.safeLocalPath(homeSetPath, urlPath)
+}
+
+func vcardPropFilter(card vcard.Card, props []string) vcard.Card {
+	if card == nil {
+		return nil
+	}
+
+	if len(props) == 0 {
+		return card
+	}
+
+	result := make(vcard.Card)
+	result["VERSION"] = card["VERSION"]
+	for _, prop := range props {
+		value, ok := card[prop]
+		if ok {
+			result[prop] = value
+		}
+	}
+
+	return result
+}
+
+func vcardFromFile(path string, propFilter []string) (vcard.Card, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	dec := vcard.NewDecoder(f)
+	card, err := dec.Decode()
+	if err != nil {
+		return nil, err
+	}
+
+	return vcardPropFilter(card, propFilter), nil
+}
+
+func createDefaultAddressBook(path, localPath string) error {
+	// TODO what should the default address book look like?
+	defaultAB := carddav.AddressBook{
+		Path:                 path,
+		Name:                 "My contacts",
+		Description:          "Default address book",
+		MaxResourceSize:      1024,
+		SupportedAddressData: nil,
+	}
+	blob, err := json.MarshalIndent(defaultAB, "", "  ")
+	if err != nil {
+		return fmt.Errorf("error creating default address book: %s", err.Error())
+	}
+	err = os.WriteFile(localPath, blob, 0644)
+	if err != nil {
+		return fmt.Errorf("error writing default address book: %s", err.Error())
+	}
+	return nil
+}
+
+func (b *filesystemBackend) AddressBook(ctx context.Context) (*carddav.AddressBook, error) {
+	debug.Printf("filesystem.AddressBook()")
+	localPath, err := b.localCardDAVPath(ctx, "")
+	if err != nil {
+		return nil, err
+	}
+	localPath = filepath.Join(localPath, "addressbook.json")
+
+	debug.Printf("loading addressbook from %s", localPath)
+
+	data, readErr := ioutil.ReadFile(localPath)
+	if os.IsNotExist(readErr) {
+		urlPath, err := b.AddressbookHomeSetPath(ctx)
+		if err != nil {
+			return nil, err
+		}
+		urlPath = path.Join(urlPath, defaultResourceName) + "/"
+		debug.Printf("creating default addressbook (URL:path): %s:%s", urlPath, localPath)
+		err = createDefaultAddressBook(urlPath, localPath)
+		if err != nil {
+			return nil, err
+		}
+		data, readErr = ioutil.ReadFile(localPath)
+	}
+	if readErr != nil {
+		return nil, fmt.Errorf("error opening address book: %s", readErr.Error())
+	}
+	var addressBook carddav.AddressBook
+	err = json.Unmarshal(data, &addressBook)
+	if err != nil {
+		return nil, fmt.Errorf("error reading address book: %s", err.Error())
+	}
+
+	return &addressBook, nil
+}
+
+func (b *filesystemBackend) GetAddressObject(ctx context.Context, objPath string, req *carddav.AddressDataRequest) (*carddav.AddressObject, error) {
+	debug.Printf("filesystem.GetAddressObject(%s, %v)", objPath, req)
+	localPath, err := b.localCardDAVPath(ctx, objPath)
+	if err != nil {
+		return nil, err
+	}
+
+	info, err := os.Stat(localPath)
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			return nil, webdav.NewHTTPError(404, err)
+		}
+		return nil, err
+	}
+
+	var propFilter []string
+	if req != nil && !req.AllProp {
+		propFilter = req.Props
+	}
+
+	card, err := vcardFromFile(localPath, propFilter)
+	if err != nil {
+		return nil, err
+	}
+
+	etag, err := etagForFile(localPath)
+	if err != nil {
+		return nil, err
+	}
+
+	obj := carddav.AddressObject{
+		Path:          objPath,
+		ModTime:       info.ModTime(),
+		ContentLength: info.Size(),
+		ETag:          etag,
+		Card:          card,
+	}
+	return &obj, nil
+}
+
+func (b *filesystemBackend) loadAllContacts(ctx context.Context, propFilter []string) ([]carddav.AddressObject, error) {
+	var result []carddav.AddressObject
+
+	localPath, err := b.localCardDAVPath(ctx, "")
+	if err != nil {
+		return result, err
+	}
+
+	homeSetPath, err := b.AddressbookHomeSetPath(ctx)
+	if err != nil {
+		return result, err
+	}
+
+	err = filepath.Walk(localPath, func(filename string, info os.FileInfo, err error) error {
+		if err != nil {
+			return fmt.Errorf("error accessing %s: %s", filename, err)
+		}
+
+		if !info.Mode().IsRegular() || filepath.Ext(filename) != ".vcf" {
+			return nil
+		}
+
+		card, err := vcardFromFile(filename, propFilter)
+		if err != nil {
+			return err
+		}
+
+		etag, err := etagForFile(filename)
+		if err != nil {
+			return err
+		}
+
+		obj := carddav.AddressObject{
+			Path:          path.Join(homeSetPath, defaultResourceName, filepath.Base(filename)),
+			ModTime:       info.ModTime(),
+			ContentLength: info.Size(),
+			ETag:          etag,
+			Card:          card,
+		}
+		result = append(result, obj)
+		return nil
+	})
+
+	debug.Printf("filesystem.loadAllContacts() returning %d results from %s", len(result), localPath)
+	return result, err
+}
+
+func (b *filesystemBackend) ListAddressObjects(ctx context.Context, req *carddav.AddressDataRequest) ([]carddav.AddressObject, error) {
+	debug.Printf("filesystem.ListAddressObjects(%v)", req)
+	var propFilter []string
+	if req != nil && !req.AllProp {
+		propFilter = req.Props
+	}
+
+	return b.loadAllContacts(ctx, propFilter)
+}
+
+func (b *filesystemBackend) QueryAddressObjects(ctx context.Context, query *carddav.AddressBookQuery) ([]carddav.AddressObject, error) {
+	debug.Printf("filesystem.QueryAddressObjects(%v)", query)
+	var propFilter []string
+	if query != nil && !query.DataRequest.AllProp {
+		propFilter = query.DataRequest.Props
+	}
+
+	result, err := b.loadAllContacts(ctx, propFilter)
+	if err != nil {
+		return result, err
+	}
+
+	return carddav.Filter(query, result)
+}
+
+func (b *filesystemBackend) PutAddressObject(ctx context.Context, objPath string, card vcard.Card, opts *carddav.PutAddressObjectOptions) (loc string, err error) {
+	debug.Printf("filesystem.PutAddressObject(%v, %v, %v)", objPath, card, opts)
+
+	// Object always get saved as <UID>.vcf
+	dirname, _ := path.Split(objPath)
+	objPath = path.Join(dirname, card.Value(vcard.FieldUID)+".vcf")
+
+	localPath, err := b.localCardDAVPath(ctx, objPath)
+	if err != nil {
+		return "", err
+	}
+
+	flags := os.O_RDWR | os.O_CREATE | os.O_TRUNC
+	// TODO handle IfNoneMatch == ETag
+	if opts.IfNoneMatch.IsWildcard() {
+		// Make sure we're not overwriting an existing file
+		flags |= os.O_EXCL
+	} else if opts.IfMatch.IsWildcard() {
+		// Make sure we _are_ overwriting an existing file
+		flags &= ^os.O_CREATE
+	} else if opts.IfMatch.IsSet() {
+		// Make sure we overwrite the _right_ file
+		etag, err := etagForFile(localPath)
+		if err != nil {
+			return "", webdav.NewHTTPError(http.StatusPreconditionFailed, err)
+		}
+		want, err := opts.IfMatch.ETag()
+		if err != nil {
+			return "", webdav.NewHTTPError(http.StatusBadRequest, err)
+		}
+		if want != etag {
+			err = fmt.Errorf("If-Match does not match current ETag (%s/%s)", want, etag)
+			return "", webdav.NewHTTPError(http.StatusPreconditionFailed, err)
+		}
+	}
+
+	f, err := os.OpenFile(localPath, flags, 0666)
+	if os.IsExist(err) {
+		return "", carddav.NewPreconditionError(carddav.PreconditionNoUIDConflict)
+	} else if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	enc := vcard.NewEncoder(f)
+	err = enc.Encode(card)
+	if err != nil {
+		return "", err
+	}
+
+	return objPath, nil
+}
+
+func (b *filesystemBackend) DeleteAddressObject(ctx context.Context, path string) error {
+	debug.Printf("filesystem.DeleteAddressObject(%s)", path)
+
+	localPath, err := b.localCardDAVPath(ctx, path)
+	if err != nil {
+		return err
+	}
+	err = os.Remove(localPath)
+	if err != nil {
+		return err
+	}
+	return nil
+}