From 99d4ad4bd4965ff236eeaf9d4081c446c0617fd0 Mon Sep 17 00:00:00 2001
From: Daniel <845765@qq.com>
Date: Thu, 24 Apr 2025 20:48:16 +0800
Subject: [PATCH] :art: Improve export PDF watermark font
 https://github.com/siyuan-note/siyuan/issues/14693

---
 kernel/go.mod          |  2 +-
 kernel/go.sum          |  4 ++--
 kernel/model/export.go | 48 ++++++++++++++++++++++++++++++++++++------
 3 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/kernel/go.mod b/kernel/go.mod
index 170492187..3f7d8d979 100644
--- a/kernel/go.mod
+++ b/kernel/go.mod
@@ -197,7 +197,7 @@ require (
 
 replace github.com/mattn/go-sqlite3 => github.com/88250/go-sqlite3 v1.14.13-0.20231214121541-e7f54c482950
 
-replace github.com/pdfcpu/pdfcpu => github.com/88250/pdfcpu v0.3.14-0.20241201033812-5a93b7586a01
+replace github.com/pdfcpu/pdfcpu => github.com/88250/pdfcpu v0.3.14-0.20250424122812-f10e8d9d8d46
 
 //replace github.com/88250/lute => F:\golang\gopath\src\github.com\88250\lute
 //replace github.com/siyuan-note/dejavu => D:\88250\dejavu
diff --git a/kernel/go.sum b/kernel/go.sum
index d7f98b047..ba9aff6dd 100644
--- a/kernel/go.sum
+++ b/kernel/go.sum
@@ -16,8 +16,8 @@ github.com/88250/gulu v1.2.3-0.20250227144607-7f4570b0d689 h1:39y5g7vnFAIcXhTN3I
 github.com/88250/gulu v1.2.3-0.20250227144607-7f4570b0d689/go.mod h1:c8uVw25vW2W4dhJ/j4iYsX5H1hc19spim266jO5x2hU=
 github.com/88250/lute v1.7.7-0.20250423133018-cff81864be77 h1:Ky/O9dd9CJ6UZ4Ye8aWpycdlSuYtUKis5UuZLvsRa4w=
 github.com/88250/lute v1.7.7-0.20250423133018-cff81864be77/go.mod h1:WYyUw//5yVw9BJnoVjx7rI/3szsISxNZCYGOqTIrV0o=
-github.com/88250/pdfcpu v0.3.14-0.20241201033812-5a93b7586a01 h1:AcFe63RXjIh1XtX/dc4Es3U8bYKjlEkvavHd1nFBOHM=
-github.com/88250/pdfcpu v0.3.14-0.20241201033812-5a93b7586a01/go.mod h1:fVfOloBzs2+W2VJCCbq60XIxc3yJHAZ0Gahv1oO0gyI=
+github.com/88250/pdfcpu v0.3.14-0.20250424122812-f10e8d9d8d46 h1:Bq1JsDfVbHKUxNL/B2JXd8cC/1h6aFjrlXpGycnh0Hk=
+github.com/88250/pdfcpu v0.3.14-0.20250424122812-f10e8d9d8d46/go.mod h1:fVfOloBzs2+W2VJCCbq60XIxc3yJHAZ0Gahv1oO0gyI=
 github.com/88250/vitess-sqlparser v0.0.0-20210205111146-56a2ded2aba1 h1:48T899JQDwyyRu9yXHePYlPdHtpJfrJEUGBMH3SMBWY=
 github.com/88250/vitess-sqlparser v0.0.0-20210205111146-56a2ded2aba1/go.mod h1:U3pckKQIgxxkmZjV5yXQjHdGxQK0o/vEZeZ6cQsxfHw=
 github.com/BurntSushi/toml v1.3.2/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
diff --git a/kernel/model/export.go b/kernel/model/export.go
index e8fb80fa6..e7459201c 100644
--- a/kernel/model/export.go
+++ b/kernel/model/export.go
@@ -1041,6 +1041,10 @@ func ProcessPDF(id, p string, merge, removeAssets, watermark bool) (err error) {
 		logging.LogErrorf("mkdir [%s] failed: %s", font.UserFontDir, mkdirErr)
 		return
 	}
+	if loadErr := api.LoadUserFonts(); nil != loadErr {
+		logging.LogErrorf("load user fonts failed: %s", loadErr)
+	}
+
 	pdfCtx, ctxErr := api.ReadContextFile(p)
 	if nil != ctxErr {
 		logging.LogErrorf("read pdf context failed: %s", ctxErr)
@@ -1098,7 +1102,43 @@ func processPDFWatermark(pdfCtx *model.Context, watermark bool) {
 			}
 			m[kv[0]] = kv[1]
 		}
-		m["fontname"] = "LXGWWenKaiLite-Regular"
+
+		useDefaultFont := true
+		if "" != m["fontname"] {
+			listFonts, e := api.ListFonts()
+			var builtInFontNames []string
+			if nil != e {
+				logging.LogInfof("listFont failed: %s", e)
+			} else {
+				for _, f := range listFonts {
+					if strings.Contains(f, "(") {
+						f = f[:strings.Index(f, "(")]
+					}
+					f = strings.TrimSpace(f)
+					if strings.Contains(f, ":") || "" == f || strings.Contains(f, "Corefonts") || strings.Contains(f, "Userfonts") {
+						continue
+					}
+
+					builtInFontNames = append(builtInFontNames, f)
+				}
+
+				for _, font := range builtInFontNames {
+					if font == m["fontname"] {
+						useDefaultFont = false
+						break
+					}
+				}
+			}
+		}
+		if useDefaultFont {
+			m["fontname"] = "LXGWWenKaiLite-Regular"
+			fontPath := filepath.Join(util.AppearancePath, "fonts", "LxgwWenKai-Lite-1.501", "LXGWWenKaiLite-Regular.ttf")
+			err := api.InstallFonts([]string{fontPath})
+			if err != nil {
+				logging.LogErrorf("install font [%s] failed: %s", fontPath, err)
+			}
+		}
+
 		descBuilder := bytes.Buffer{}
 		for k, v := range m {
 			descBuilder.WriteString(k)
@@ -1108,12 +1148,6 @@ func processPDFWatermark(pdfCtx *model.Context, watermark bool) {
 		}
 		desc = descBuilder.String()
 		desc = desc[:len(desc)-1]
-
-		fontPath := filepath.Join(util.AppearancePath, "fonts", "LxgwWenKai-Lite-1.501", "LXGWWenKaiLite-Regular.ttf")
-		err := api.InstallFonts([]string{fontPath})
-		if err != nil {
-			logging.LogErrorf("install font [%s] failed: %s", fontPath, err)
-		}
 	}
 
 	logging.LogInfof("add PDF watermark [mode=%s, str=%s, desc=%s]", mode, str, desc)