From d31a5053cf88d4c61a86ce07f02684e000a50e14 Mon Sep 17 00:00:00 2001
From: Stephen Searles <stephen.searles@gmail.com>
Date: Mon, 12 Jun 2017 23:44:50 -0700
Subject: [PATCH] fixes and cleanups

---
 acedoc.go |  5 +++--
 client.go | 10 +++++++++-
 delta.go  | 43 ++++++++++++++++++++++++++++++++++++++-----
 3 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/acedoc.go b/acedoc.go
index 299383c..3de1da1 100644
--- a/acedoc.go
+++ b/acedoc.go
@@ -74,7 +74,7 @@ func (d Delta) rows() uint {
 }
 
 func (d Delta) cols() uint {
-	r := d.End.Column
+	r := d.End.Column - d.Start.Column
 	return r
 }
 
@@ -86,7 +86,8 @@ func (d *Document) Contents() string {
 }
 
 type Position struct {
-	Row, Column uint
+	Row    uint `json:"row"`
+	Column uint `json:"column"`
 }
 
 func (d *Document) InDocument(pos Position) bool {
diff --git a/client.go b/client.go
index 3b40e2a..e886e29 100644
--- a/client.go
+++ b/client.go
@@ -96,7 +96,12 @@ func (c *Client) Error() error {
 
 // PushDeltas pushes deltas into the document.
 func (c *Client) PushDeltas(d ...Delta) error {
-	return c.doc.Apply(d...)
+	ds := make([]Delta, len(d))
+	for i := range d {
+		ds[i] = d[i]
+		ds[i].source = c
+	}
+	return c.doc.Apply(ds...)
 }
 
 func (c *Client) pullDeltas() []Delta {
@@ -125,6 +130,9 @@ func (c *Client) pullDeltas() []Delta {
 		if d.Equal(Delta{}) {
 			continue
 		}
+		if d.source == c {
+			continue
+		}
 
 		ds = append(ds, d)
 		if len(ds) == maxSize {
diff --git a/delta.go b/delta.go
index bc34c1e..b15b8fb 100644
--- a/delta.go
+++ b/delta.go
@@ -45,10 +45,40 @@ const (
 	DeltaRemove DeltaAction = false
 )
 
+func (d DeltaAction) String() string {
+	if d == DeltaInsert {
+		return "insert"
+	}
+	return "remove"
+}
+
+func (d DeltaAction) MarshalJSON() ([]byte, error) {
+	if d == DeltaInsert {
+		return []byte(`"insert"`), nil
+	}
+	return []byte(`"remove"`), nil
+}
+
+func (d *DeltaAction) UnmarshalJSON(b []byte) error {
+	fmt.Println(string(b))
+	if string(b) == "null" {
+		return nil
+	}
+
+	if string(b) == `"insert"` {
+		*d = DeltaInsert
+	}
+
+	return nil
+}
+
 type Delta struct {
-	Action     DeltaAction
-	Lines      []string
-	Start, End Position
+	Action DeltaAction `json:"action"`
+	Lines  []string    `json:"lines"`
+	Start  Position    `json:"start"`
+	End    Position    `json:"end"`
+
+	source *Client
 }
 
 func (d Delta) Equal(other Delta) bool {
@@ -162,6 +192,9 @@ func (d *Document) Apply(dls ...Delta) error {
 
 		d.deltas = append(d.deltas, dl)
 		for _, c := range d.clients {
+			if dl.source == c {
+				continue
+			}
 			c.ch <- dl
 		}
 	}
@@ -184,8 +217,8 @@ func (d *Document) validate(dl Delta) error {
 
 	lastDlLine := dl.line(dl.nRows() - 1)
 
-	if uint(len(lastDlLine)) != dl.cols() {
-		return fmt.Errorf("delta has %d chars on the final line, but positions show range of %d chars", len(lastDlLine), dl.cols())
+	if uint(len(lastDlLine)) != dl.End.Column {
+		return fmt.Errorf("delta has %d chars on the final line, but positions show range of %d chars", len(lastDlLine), dl.End.Column)
 	}
 
 	return nil