More work on porting diff kitten

tools/cmd/diff/render.go

@@ -0,0 +1,143 @@
+// License: GPLv3 Copyright: 2023, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package diff
+
+import (
+	"fmt"
+	"kitty/tools/utils"
+	"kitty/tools/utils/style"
+	"kitty/tools/wcswidth"
+	"strconv"
+	"strings"
+)
+
+var _ = fmt.Print
+
+type LineType int
+
+const (
+	TITLE_LINE LineType = iota
+	CHANGE_LINE
+	IMAGE_LINE
+)
+
+type Reference struct {
+	path    string
+	linenum int
+}
+
+type LogicalLine struct {
+	src                  Reference
+	line_type            LineType
+	margin_size, columns int
+	screen_lines         []string
+}
+
+func fit_in(text string, count int) string {
+	truncated := wcswidth.TruncateToVisualLength(text, count)
+	if len(truncated) >= len(text) {
+		return text
+	}
+	if count > 1 {
+		truncated = wcswidth.TruncateToVisualLength(text, count-1)
+	}
+	return truncated + `…`
+}
+
+func fill_in(text string, sz int) string {
+	w := wcswidth.Stringwidth(text)
+	if w < sz {
+		text += strings.Repeat(` `, (sz - w))
+	}
+	return text
+}
+
+func place_in(text string, sz int) string {
+	return fill_in(fit_in(text, sz), sz)
+}
+
+var title_format, text_format, margin_format, added_format, removed_format, added_margin_format, removed_margin_format, filler_format, margin_filler_format, hunk_margin_format, hunk_format func(...any) string
+
+func create_formatters() {
+	ctx := style.Context{AllowEscapeCodes: true}
+	text_format = ctx.SprintFunc(fmt.Sprintf("bg=%s", conf.Background.AsRGBSharp()))
+	filler_format = ctx.SprintFunc(fmt.Sprintf("bg=%s", conf.Filler_bg.AsRGBSharp()))
+	if conf.Margin_filler_bg.IsNull {
+		margin_filler_format = ctx.SprintFunc(fmt.Sprintf("bg=%s", conf.Filler_bg.AsRGBSharp()))
+	} else {
+		margin_filler_format = ctx.SprintFunc(fmt.Sprintf("bg=%s", conf.Margin_filler_bg.Color.AsRGBSharp()))
+	}
+	added_format = ctx.SprintFunc(fmt.Sprintf("bg=%s", conf.Added_bg.AsRGBSharp()))
+	added_margin_format = ctx.SprintFunc(fmt.Sprintf("fg=%s bg=%s", conf.Margin_fg.AsRGBSharp(), conf.Added_margin_bg.AsRGBSharp()))
+	removed_format = ctx.SprintFunc(fmt.Sprintf("bg=%s", conf.Removed_bg.AsRGBSharp()))
+	removed_margin_format = ctx.SprintFunc(fmt.Sprintf("fg=%s bg=%s", conf.Margin_fg.AsRGBSharp(), conf.Removed_margin_bg.AsRGBSharp()))
+	title_format = ctx.SprintFunc(fmt.Sprintf("fg=%s bg=%s", conf.Title_fg.AsRGBSharp(), conf.Title_bg.AsRGBSharp()))
+	margin_format = ctx.SprintFunc(fmt.Sprintf("fg=%s bg=%s", conf.Margin_fg.AsRGBSharp(), conf.Margin_bg.AsRGBSharp()))
+	hunk_format = ctx.SprintFunc(fmt.Sprintf("fg=%s bg=%s", conf.Margin_fg.AsRGBSharp(), conf.Hunk_bg.AsRGBSharp()))
+	hunk_margin_format = ctx.SprintFunc(fmt.Sprintf("fg=%s bg=%s", conf.Margin_fg.AsRGBSharp(), conf.Hunk_margin_bg.AsRGBSharp()))
+}
+
+func title_lines(left_path, right_path string, columns, margin_size int, ans []*LogicalLine) []*LogicalLine {
+	left_name, right_name := path_name_map[left_path], path_name_map[right_path]
+	name := ""
+	m := strings.Repeat(` `, margin_size)
+	if right_name != "" && right_name != left_name {
+		n1 := fit_in(m+sanitize(left_name), columns/2-margin_size)
+		n1 = place_in(n1, columns/2)
+		n2 := fit_in(m+sanitize(right_name), columns/2-margin_size)
+		n2 = place_in(n2, columns/2)
+		name = n1 + n2
+	} else {
+		name = place_in(m+sanitize(left_name), columns)
+	}
+	ll := LogicalLine{columns: columns, margin_size: margin_size, line_type: TITLE_LINE, src: Reference{path: left_path, linenum: 0}}
+	l1 := ll
+	l1.screen_lines = []string{title_format(name)}
+	l2 := ll
+	l2.screen_lines = []string{title_format(name)}
+	return append(ans, &l1, &l2)
+}
+
+type LogicalLines struct {
+	lines                []*LogicalLine
+	margin_size, columns int
+}
+
+func render(collection *Collection, diff_map map[string]*Patch, columns int) (*LogicalLines, error) {
+	largest_line_number := 0
+	collection.Apply(func(path, typ, changed_path string) error {
+		if typ == "diff" {
+			patch := diff_map[path]
+			if patch != nil {
+				largest_line_number = utils.Max(largest_line_number, patch.largest_line_number)
+			}
+		}
+		return nil
+	})
+	margin_size := utils.Max(3, len(strconv.Itoa(largest_line_number))+1)
+	ans := make([]*LogicalLine, 0, 1024)
+	err := collection.Apply(func(path, item_type, changed_path string) error {
+		ans = title_lines(path, changed_path, columns, margin_size, ans)
+
+		is_binary := !is_path_text(path)
+		if !is_binary && item_type == `diff` && !is_path_text(changed_path) {
+			is_binary = true
+		}
+		is_img := is_binary && is_image(path) || (item_type == `diff` && is_image(changed_path))
+		_ = is_img
+
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return &LogicalLines{lines: ans[:len(ans)-1], margin_size: margin_size, columns: columns}, nil
+}
+
+func (self *LogicalLines) num_of_screen_lines() (ans int) {
+	for _, l := range self.lines {
+		ans += len(l.screen_lines)
+	}
+	return
+}