Add sorting functionality

There is a command and config option. The criteria are a list of the
sort criterion and each can be individually reversed.

This only includes support for sorting in the maildir backend currently.
The other backends are not supported in this patch.

2 files changed, 72 insertions, 1 deletions

diff --git a/lib/msgstore.go b/lib/msgstore.go
index 1f18fbf..b0392ba 100644
--- a/lib/msgstore.go
+++ b/lib/msgstore.go
@@ -25,6 +25,8 @@ type MessageStore struct {
 	resultIndex int
 	filter      bool
 
+	defaultSortCriteria []*types.SortCriterion
+
 	// Map of uids we've asked the worker to fetch
 	onUpdate       func(store *MessageStore) // TODO: multiple onUpdate handlers
 	onUpdateDirs   func()
@@ -38,6 +40,7 @@ type MessageStore struct {
 
 func NewMessageStore(worker *types.Worker,
 	dirInfo *models.DirectoryInfo,
+	defaultSortCriteria []*types.SortCriterion,
 	triggerNewEmail func(*models.MessageInfo),
 	triggerDirectoryChange func()) *MessageStore {
 
@@ -49,6 +52,8 @@ func NewMessageStore(worker *types.Worker,
 		bodyCallbacks:   make(map[uint32][]func(io.Reader)),
 		headerCallbacks: make(map[uint32][]func(*types.MessageInfo)),
 
+		defaultSortCriteria: defaultSortCriteria,
+
 		pendingBodies:  make(map[uint32]interface{}),
 		pendingHeaders: make(map[uint32]interface{}),
 		worker:         worker,
@@ -151,7 +156,9 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 	switch msg := msg.(type) {
 	case *types.DirectoryInfo:
 		store.DirInfo = *msg.Info
-		store.worker.PostAction(&types.FetchDirectoryContents{}, nil)
+		store.worker.PostAction(&types.FetchDirectoryContents{
+			SortCriteria: store.defaultSortCriteria,
+		}, nil)
 		update = true
 	case *types.DirectoryContents:
 		newMap := make(map[uint32]*models.MessageInfo)
@@ -434,3 +441,11 @@ func (store *MessageStore) ModifyLabels(uids []uint32, add, remove []string,
 		Remove: remove,
 	}, cb)
 }
+
+func (store *MessageStore) Sort(criteria []*types.SortCriterion, cb func()) {
+	store.worker.PostAction(&types.FetchDirectoryContents{
+		SortCriteria: criteria,
+	}, func(msg types.WorkerMessage) {
+		cb()
+	})
+}
diff --git a/lib/sort/sort.go b/lib/sort/sort.go
new file mode 100644
index 0000000..89c36a9
--- /dev/null
+++ b/lib/sort/sort.go
@@ -0,0 +1,56 @@
+package sort
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"git.sr.ht/~sircmpwn/aerc/worker/types"
+)
+
+func GetSortCriteria(args []string) ([]*types.SortCriterion, error) {
+	var sortCriteria []*types.SortCriterion
+	reverse := false
+	for _, arg := range args {
+		if arg == "-r" {
+			reverse = true
+			continue
+		}
+		field, err := parseSortField(arg)
+		if err != nil {
+			return nil, err
+		}
+		sortCriteria = append(sortCriteria, &types.SortCriterion{
+			Field:   field,
+			Reverse: reverse,
+		})
+		reverse = false
+	}
+	if reverse {
+		return nil, errors.New("Expected argument to reverse")
+	}
+	return sortCriteria, nil
+}
+
+func parseSortField(arg string) (types.SortField, error) {
+	switch strings.ToLower(arg) {
+	case "arrival":
+		return types.SortArrival, nil
+	case "cc":
+		return types.SortCc, nil
+	case "date":
+		return types.SortDate, nil
+	case "from":
+		return types.SortFrom, nil
+	case "read":
+		return types.SortRead, nil
+	case "size":
+		return types.SortSize, nil
+	case "subject":
+		return types.SortSubject, nil
+	case "to":
+		return types.SortTo, nil
+	default:
+		return types.SortArrival, fmt.Errorf("%v is not a valid sort criterion", arg)
+	}
+}