WeKnora deployment source with the reviewed wiki identity, summary and recovery fixes

internal/infrastructure/docparser/markdown_image_scanner.go

@@ -0,0 +1,262 @@
+package docparser
+
+import (
+	"strings"
+
+	"github.com/Tencent/WeKnora/internal/types"
+)
+
+type markdownImageTargetSpan struct {
+	TargetStart int
+	TargetEnd   int
+}
+
+func scanMarkdownImageTargets(markdown string) []markdownImageTargetSpan {
+	var spans []markdownImageTargetSpan
+	for i := 0; i+1 < len(markdown); i++ {
+		if markdown[i] != '!' || markdown[i+1] != '[' || isEscaped(markdown, i) {
+			continue
+		}
+
+		altEnd := findMarkdownImageAltEnd(markdown, i+2)
+		if altEnd == -1 {
+			continue
+		}
+
+		targetStart := altEnd + 2
+		targetEnd, ok := findMarkdownImageTargetEnd(markdown, targetStart)
+		if !ok {
+			i = altEnd
+			continue
+		}
+		spans = append(spans, markdownImageTargetSpan{
+			TargetStart: targetStart,
+			TargetEnd:   targetEnd,
+		})
+		i = targetEnd
+	}
+	return spans
+}
+
+func findMarkdownImageAltEnd(markdown string, start int) int {
+	for i := start; i+1 < len(markdown); i++ {
+		if markdown[i] == ']' && markdown[i+1] == '(' && !isEscaped(markdown, i) {
+			return i
+		}
+	}
+	return -1
+}
+
+func findMarkdownImageTargetEnd(markdown string, start int) (int, bool) {
+	parenDepth := 1
+	inAngleDestination := false
+	seenNonSpace := false
+	var inQuote byte
+
+	for i := start; i < len(markdown); i++ {
+		ch := markdown[i]
+		if ch == '\\' {
+			i++
+			continue
+		}
+
+		if !seenNonSpace && !isMarkdownSpace(ch) {
+			seenNonSpace = true
+			if ch == '<' {
+				inAngleDestination = true
+				continue
+			}
+		}
+
+		if inAngleDestination {
+			if ch == '>' {
+				inAngleDestination = false
+			}
+			continue
+		}
+
+		if inQuote != 0 {
+			if ch == inQuote {
+				inQuote = 0
+			}
+			continue
+		}
+
+		if (ch == '"' || ch == '\'') && i > start && isMarkdownSpace(markdown[i-1]) {
+			inQuote = ch
+			continue
+		}
+
+		switch ch {
+		case '(':
+			parenDepth++
+		case ')':
+			parenDepth--
+			if parenDepth == 0 {
+				return i, true
+			}
+		}
+	}
+	return 0, false
+}
+
+func splitMarkdownImageTarget(
+	raw string,
+	refMap map[string]types.ImageRef,
+) (path string, pathStart int, pathEnd int, ok bool) {
+	start, end := trimMarkdownSpaceBounds(raw, 0, len(raw))
+	if start >= end {
+		return "", 0, 0, false
+	}
+
+	trimmed := raw[start:end]
+	if _, found := refMap[trimmed]; found {
+		return trimmed, start, end, true
+	}
+
+	if raw[start] == '<' {
+		return splitAngleMarkdownImageTarget(raw, start, end, refMap)
+	}
+
+	titleStart, found := parseMarkdownImageTitleSuffix(trimmed)
+	if !found {
+		return "", 0, 0, false
+	}
+
+	pathEnd = start + titleStart
+	for pathEnd > start && isMarkdownSpace(raw[pathEnd-1]) {
+		pathEnd--
+	}
+	if pathEnd == start {
+		return "", 0, 0, false
+	}
+
+	path = raw[start:pathEnd]
+	if _, found := refMap[path]; !found {
+		return "", 0, 0, false
+	}
+	return path, start, pathEnd, true
+}
+
+func splitAngleMarkdownImageTarget(
+	raw string,
+	start int,
+	end int,
+	refMap map[string]types.ImageRef,
+) (path string, pathStart int, pathEnd int, ok bool) {
+	closeIdx := -1
+	for i := start + 1; i < end; i++ {
+		if raw[i] == '>' && !isEscaped(raw, i) {
+			closeIdx = i
+			break
+		}
+	}
+	if closeIdx == -1 {
+		return "", 0, 0, false
+	}
+
+	path = raw[start+1 : closeIdx]
+	if _, found := refMap[path]; !found {
+		return "", 0, 0, false
+	}
+	if !isEmptyOrMarkdownImageTitleSuffix(raw[closeIdx+1 : end]) {
+		return "", 0, 0, false
+	}
+	return path, start + 1, closeIdx, true
+}
+
+func parseMarkdownImageTitleSuffix(raw string) (titleStart int, ok bool) {
+	_, end := trimMarkdownSpaceBounds(raw, 0, len(raw))
+	if end == 0 {
+		return 0, false
+	}
+
+	switch raw[end-1] {
+	case '"', '\'':
+		quote := raw[end-1]
+		for i := end - 2; i >= 0; i-- {
+			if raw[i] != quote || isEscaped(raw, i) {
+				continue
+			}
+			if i == 0 || !isMarkdownSpace(raw[i-1]) {
+				return 0, false
+			}
+			if markdownTitleHasBlankLine(raw[i+1 : end-1]) {
+				return 0, false
+			}
+			return i, true
+		}
+	case ')':
+		depth := 0
+		for i := end - 2; i >= 0; i-- {
+			if isEscaped(raw, i) {
+				continue
+			}
+			switch raw[i] {
+			case ')':
+				depth++
+			case '(':
+				if depth == 0 {
+					if i == 0 || !isMarkdownSpace(raw[i-1]) {
+						return 0, false
+					}
+					if markdownTitleHasBlankLine(raw[i+1 : end-1]) {
+						return 0, false
+					}
+					return i, true
+				}
+				depth--
+			}
+		}
+	}
+	return 0, false
+}
+
+func isEmptyOrMarkdownImageTitleSuffix(raw string) bool {
+	start, end := trimMarkdownSpaceBounds(raw, 0, len(raw))
+	if start == end {
+		return true
+	}
+	titleStart, ok := parseMarkdownImageTitleSuffix(raw[:end])
+	return ok && isAllMarkdownSpace(raw[:titleStart])
+}
+
+func markdownTitleHasBlankLine(title string) bool {
+	for _, line := range strings.Split(title, "\n") {
+		if strings.Trim(line, " \t") == "" {
+			return true
+		}
+	}
+	return false
+}
+
+func isAllMarkdownSpace(raw string) bool {
+	for i := 0; i < len(raw); i++ {
+		if !isMarkdownSpace(raw[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+func trimMarkdownSpaceBounds(raw string, start int, end int) (int, int) {
+	for start < end && isMarkdownSpace(raw[start]) {
+		start++
+	}
+	for end > start && isMarkdownSpace(raw[end-1]) {
+		end--
+	}
+	return start, end
+}
+
+func isMarkdownSpace(b byte) bool {
+	return b == ' ' || b == '\t' || b == '\n' || b == '\r'
+}
+
+func isEscaped(s string, pos int) bool {
+	backslashes := 0
+	for i := pos - 1; i >= 0 && s[i] == '\\'; i-- {
+		backslashes++
+	}
+	return backslashes%2 == 1
+}