From 358c5055e90461e90583c788400221363d8d1627 Mon Sep 17 00:00:00 2001
From: foxxorcat <95907542+foxxorcat@users.noreply.github.com>
Date: Sun, 20 Aug 2023 13:08:57 +0800
Subject: [PATCH] fix(lanzou): download not find file sgin (close #5046 in
 #5048)

---
 drivers/lanzou/help.go | 77 ++++++++++++++++++++++++++++++++++++++++++
 drivers/lanzou/util.go |  9 +++--
 2 files changed, 83 insertions(+), 3 deletions(-)

diff --git a/drivers/lanzou/help.go b/drivers/lanzou/help.go
index 89f8e071..f5b8ce42 100644
--- a/drivers/lanzou/help.go
+++ b/drivers/lanzou/help.go
@@ -125,6 +125,83 @@ func findJSVarFunc(key, data string) string {
 	return values[1]
 }
 
+var findFunction = regexp.MustCompile(`(?ims)^function[^{]+`)
+var findFunctionAll = regexp.MustCompile(`(?is)function[^{]+`)
+
+// 查找所有方法位置
+func findJSFunctionIndex(data string, all bool) [][2]int {
+	findFunction := findFunction
+	if all {
+		findFunction = findFunctionAll
+	}
+
+	indexs := findFunction.FindAllStringIndex(data, -1)
+	fIndexs := make([][2]int, 0, len(indexs))
+
+	for _, index := range indexs {
+		if len(index) != 2 {
+			continue
+		}
+		count, data := 0, data[index[1]:]
+		for ii, v := range data {
+			if v == ' ' && count == 0 {
+				continue
+			}
+			if v == '{' {
+				count++
+			}
+
+			if v == '}' {
+				count--
+			}
+			if count == 0 {
+				fIndexs = append(fIndexs, [2]int{index[0], index[1] + ii + 1})
+				break
+			}
+		}
+	}
+	return fIndexs
+}
+
+// 删除JS全局方法
+func removeJSGlobalFunction(html string) string {
+	indexs := findJSFunctionIndex(html, false)
+	block := make([]string, len(indexs))
+	for i, next := len(indexs)-1, len(html); i >= 0; i-- {
+		index := indexs[i]
+		block[i] = html[index[1]:next]
+		next = index[0]
+	}
+	return strings.Join(block, "")
+}
+
+// 根据名称获取方法
+func getJSFunctionByName(html string, name string) (string, error) {
+	indexs := findJSFunctionIndex(html, true)
+	for _, index := range indexs {
+		data := html[index[0]:index[1]]
+		if regexp.MustCompile(`function\s+` + name + `[()\s]+{`).MatchString(data) {
+			return data, nil
+		}
+	}
+	return "", fmt.Errorf("not find %s function", name)
+}
+
+// 解析html中的JSON,选择最长的数据
+func htmlJsonToMap2(html string) (map[string]string, error) {
+	datas := findDataReg.FindAllStringSubmatch(html, -1)
+	var sData string
+	for _, data := range datas {
+		if len(datas) > 0 && len(data[1]) > len(sData) {
+			sData = data[1]
+		}
+	}
+	if sData == "" {
+		return nil, fmt.Errorf("not find data")
+	}
+	return jsonToMap(sData, html), nil
+}
+
 // 解析html中的JSON
 func htmlJsonToMap(html string) (map[string]string, error) {
 	datas := findDataReg.FindStringSubmatch(html)
diff --git a/drivers/lanzou/util.go b/drivers/lanzou/util.go
index 6e2f05cc..272cbbfe 100644
--- a/drivers/lanzou/util.go
+++ b/drivers/lanzou/util.go
@@ -346,7 +346,11 @@ func (d *LanZou) getFilesByShareUrl(shareID, pwd string, sharePageData string) (
 
 	// 需要密码
 	if strings.Contains(sharePageData, "pwdload") || strings.Contains(sharePageData, "passwddiv") {
-		param, err := htmlFormToMap(sharePageData)
+		sharePageData, err := getJSFunctionByName(sharePageData, "down_p")
+		if err != nil {
+			return nil, err
+		}
+		param, err := htmlJsonToMap(sharePageData)
 		if err != nil {
 			return nil, err
 		}
@@ -370,8 +374,7 @@ func (d *LanZou) getFilesByShareUrl(shareID, pwd string, sharePageData string) (
 		if err != nil {
 			return nil, err
 		}
-		nextPageData := RemoveNotes(string(data))
-
+		nextPageData := removeJSGlobalFunction(RemoveNotes(string(data)))
 		param, err = htmlJsonToMap(nextPageData)
 		if err != nil {
 			return nil, err