X-Git-Url: https://git.giacomolli.uk/onechat/blobdiff_plain/7b6d0a81e0f3c8e33b1b76d5ecbc5bdb25a87249..c781f79f3c8cb9a7577ee1574d196988da2719b3:/view.go

diff --git a/view.go b/view.go
index e392364..1b3ed6a 100644
--- a/view.go
+++ b/view.go
@@ -23,42 +23,6 @@ const (
 	viewPending = "(not summarized yet: zoom it)"
 )
 
-// newView returns an empty view with the limits high and low.
-func newView(high, low int) *View {
-	return &View{
-		high:  high,
-		low:   low,
-		nodes: make(map[nodeKey]Node),
-	}
-}
-
-// restoreView returns the view of state with the limits high and low. Each line
-// must continue the one before it, and each line above level 0 must be built.
-func restoreView(state ViewState, high, low int, tree ViewNodeReader) (*View, error) {
-	v := newView(high, low)
-	v.merging = state.Merging
-	for _, pair := range state.Lines {
-		line := nodeKey{pair[0], pair[1]}
-		if line.level < 0 || line.level >= bits.UintSize-2 || line.index < 0 || line.index<<line.level != v.end {
-			return nil, fmt.Errorf("view line (%d, %d) does not start at message %d", line.level, line.index, v.end)
-		}
-
-		built, err := v.load(tree, line)
-		if err != nil {
-			return nil, err
-		}
-
-		if line.level > 0 && !built {
-			return nil, fmt.Errorf("view line (%d, %d) is not built", line.level, line.index)
-		}
-
-		v.lines = append(v.lines, line)
-		v.end = nodeEnd(line.level, line.index)
-	}
-
-	return v, nil
-}
-
 // View is a list of tree nodes that covers messages 0 to end-1 without a gap,
 // oldest first. Each new message appends its leaf as a line. Once the size of
 // the view goes above high, one batch merges the most due sibling pairs until
@@ -77,12 +41,33 @@ func restoreView(state ViewState, high, low int, tree ViewNodeReader) (*View, er
 type View struct {
 	high    int
 	low     int
-	lines   []nodeKey
-	nodes   map[nodeKey]Node
+	lines   []NodeKey
+	nodes   map[NodeKey]Node
 	end     int
 	merging bool
 }
 
+// ViewState is the saved form of a View. The limits are not part of it.
+type ViewState struct {
+	Lines   [][2]int `json:"lines"`
+	Merging bool     `json:"merging"`
+}
+
+// ViewNodeReader gives the built nodes of a tree.
+type ViewNodeReader interface {
+	Built(level, index int) (bool, error)
+	Node(level, index int) (Node, bool, error)
+}
+
+// newView returns an empty view with the limits high and low.
+func newView(high, low int) *View {
+	return &View{
+		high:  high,
+		low:   low,
+		nodes: make(map[NodeKey]Node),
+	}
+}
+
 // State returns the saved form of the view.
 func (v *View) State() ViewState {
 	state := ViewState{
@@ -100,7 +85,7 @@ func (v *View) State() ViewState {
 // Append adds the leaf of the next message as a line and merges when the view
 // is too large. It tells if a merge changed the view.
 func (v *View) Append(tree ViewNodeReader) (bool, error) {
-	line := nodeKey{0, v.end}
+	line := NodeKey{0, v.end}
 	_, err := v.load(tree, line)
 	if err != nil {
 		return false, err
@@ -118,8 +103,8 @@ func (v *View) Append(tree ViewNodeReader) (bool, error) {
 // either nest or do not overlap, so the result covers the messages without a
 // gap.
 func (v *View) Coarsen(other *View, tree ViewNodeReader) error {
-	lines := make([]nodeKey, 0, len(v.lines))
-	nodes := make(map[nodeKey]Node, len(v.nodes))
+	lines := make([]NodeKey, 0, len(v.lines))
+	nodes := make(map[NodeKey]Node, len(v.nodes))
 	mine, theirs := 0, 0
 	for start := 0; start < v.end; {
 		line := v.lines[mine]
@@ -154,7 +139,7 @@ func (v *View) Coarsen(other *View, tree ViewNodeReader) error {
 
 // Refresh keeps node when it is the node of a pending line.
 func (v *View) Refresh(node Node) {
-	key := nodeKey{node.Level, node.Index}
+	key := NodeKey{node.Level, node.Index}
 	for n := len(v.lines) - 1; n >= 0; n-- {
 		line := v.lines[n]
 		if line == key {
@@ -168,6 +153,18 @@ func (v *View) Refresh(node Node) {
 	}
 }
 
+// Pending tells if a line of the view is not built yet.
+func (v *View) Pending() bool {
+	for _, line := range v.lines {
+		_, built := v.nodes[line]
+		if !built {
+			return true
+		}
+	}
+
+	return false
+}
+
 // Render returns the view as the model reads it: one line "id+n|text" for each
 // node inside <chat> tags, with the newlines of the text as spaces.
 func (v *View) Render() string {
@@ -185,7 +182,9 @@ func (v *View) LinesWithout(skip map[int]bool) []string {
 		}
 
 		var text strings.Builder
+
 		v.renderLine(&text, line)
+
 		lines = append(lines, text.String())
 	}
 
@@ -197,7 +196,9 @@ func (v *View) LinesWithout(skip map[int]bool) []string {
 // sees a pending mark or a part of a message.
 func (v *View) Context(end int) string {
 	var text strings.Builder
+
 	text.WriteString("<chat>\n")
+
 	for _, line := range v.lines {
 		_, built := v.nodes[line]
 		if !built || nodeEnd(line.level, line.index) > end {
@@ -213,7 +214,7 @@ func (v *View) Context(end int) string {
 }
 
 // load keeps the node of line when it is built, and tells if it is.
-func (v *View) load(tree ViewNodeReader, line nodeKey) (bool, error) {
+func (v *View) load(tree ViewNodeReader, line NodeKey) (bool, error) {
 	node, built, err := tree.Node(line.level, line.index)
 	if err != nil || !built {
 		return false, err
@@ -240,7 +241,7 @@ func (v *View) fit(tree ViewNodeReader) (bool, error) {
 		}
 
 		left, right := v.lines[best], v.lines[best+1]
-		parent := nodeKey{left.level + 1, left.index / 2}
+		parent := NodeKey{left.level + 1, left.index / 2}
 		_, err = v.load(tree, parent)
 		if err != nil {
 			return merged, err
@@ -249,6 +250,7 @@ func (v *View) fit(tree ViewNodeReader) (bool, error) {
 		size += v.lineSize(parent) - v.lineSize(left) - v.lineSize(right)
 		delete(v.nodes, left)
 		delete(v.nodes, right)
+
 		v.lines[best] = parent
 		v.lines = append(v.lines[:best+1], v.lines[best+2:]...)
 		merged = true
@@ -260,7 +262,7 @@ func (v *View) fit(tree ViewNodeReader) (bool, error) {
 }
 
 // renderLine writes one view line, "id+n|text", and a newline.
-func (v *View) renderLine(text *strings.Builder, line nodeKey) {
+func (v *View) renderLine(text *strings.Builder, line NodeKey) {
 	body := viewPending
 	node, built := v.nodes[line]
 	if built {
@@ -304,7 +306,7 @@ func (v *View) mostDue(tree ViewNodeReader) (int, error) {
 
 		built, err := tree.Built(left.level+1, left.index/2)
 		if err != nil {
-			return -1, err
+			return -1, fmt.Errorf("check parent node: %w", err)
 		}
 
 		if built {
@@ -317,7 +319,7 @@ func (v *View) mostDue(tree ViewNodeReader) (int, error) {
 }
 
 // lineSize returns the size of a view line.
-func (v *View) lineSize(line nodeKey) int {
+func (v *View) lineSize(line NodeKey) int {
 	node, built := v.nodes[line]
 	if !built {
 		return len(viewPending)
@@ -326,14 +328,29 @@ func (v *View) lineSize(line nodeKey) int {
 	return node.Size
 }
 
-// ViewState is the saved form of a View. The limits are not part of it.
-type ViewState struct {
-	Lines   [][2]int `json:"lines"`
-	Merging bool     `json:"merging"`
-}
+// restoreView returns the view of state with the limits high and low. Each line
+// must continue the one before it, and each line above level 0 must be built.
+func restoreView(state ViewState, high, low int, tree ViewNodeReader) (*View, error) {
+	v := newView(high, low)
+	v.merging = state.Merging
+	for _, pair := range state.Lines {
+		line := NodeKey{pair[0], pair[1]}
+		if line.level < 0 || line.level >= bits.UintSize-2 || line.index < 0 || line.index<<line.level != v.end {
+			return nil, fmt.Errorf("view line (%d, %d) does not start at message %d", line.level, line.index, v.end)
+		}
 
-// ViewNodeReader gives the built nodes of a tree.
-type ViewNodeReader interface {
-	Built(level, index int) (bool, error)
-	Node(level, index int) (Node, bool, error)
+		built, err := v.load(tree, line)
+		if err != nil {
+			return nil, err
+		}
+
+		if line.level > 0 && !built {
+			return nil, fmt.Errorf("view line (%d, %d) is not built", line.level, line.index)
+		}
+
+		v.lines = append(v.lines, line)
+		v.end = nodeEnd(line.level, line.index)
+	}
+
+	return v, nil
 }