From 43dbdd8d68f939f95f78f4931ab0538b6cb84681 Mon Sep 17 00:00:00 2001
From: mcrakhman <rakhmanov.m@gmail.com>
Date: Sun, 3 Jul 2022 17:51:14 +0200
Subject: [PATCH] Add plain text document state

---
 data/plaintextdocstate.go | 61 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 data/plaintextdocstate.go

diff --git a/data/plaintextdocstate.go b/data/plaintextdocstate.go
new file mode 100644
index 00000000..d661d635
--- /dev/null
+++ b/data/plaintextdocstate.go
@@ -0,0 +1,61 @@
+package data
+
+import (
+	"fmt"
+
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/data/pb"
+	"github.com/gogo/protobuf/proto"
+)
+
+type PlainTextDocumentState struct {
+	LastChangeId string
+	Text         string
+}
+
+func NewPlainTextDocumentState(text string, id string) *PlainTextDocumentState {
+	return &PlainTextDocumentState{
+		LastChangeId: id,
+		Text:         text,
+	}
+}
+
+func (p *PlainTextDocumentState) ApplyChange(change []byte, id string) (DocumentState, error) {
+	var changesData pb.PlainTextChangeData
+	err := proto.Unmarshal(change, &changesData)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, content := range changesData.GetContent() {
+		err = p.applyChange(content)
+		if err != nil {
+			return nil, err
+		}
+	}
+	p.LastChangeId = id
+	return p, nil
+}
+
+func (p *PlainTextDocumentState) applyChange(ch *pb.PlainTextChangeContent) error {
+	switch {
+	case ch.GetTextAppend() != nil:
+		text := ch.GetTextAppend().GetText()
+		p.Text += text
+	}
+	return nil
+}
+
+type PlainTextDocumentStateProvider struct{}
+
+func (p *PlainTextDocumentStateProvider) ProvideFromInitialChange(change []byte, id string) (DocumentState, error) {
+	var changesData pb.PlainTextChangeData
+	err := proto.Unmarshal(change, &changesData)
+	if err != nil {
+		return nil, err
+	}
+
+	if changesData.GetSnapshot() == nil {
+		return nil, fmt.Errorf("could not create state from empty snapshot")
+	}
+	return NewPlainTextDocumentState(changesData.GetSnapshot().GetText(), id), nil
+}