Add helpdoc system with interactive viewer

30 files changed, 1071 insertions, 56 deletions

diff --git a/Cargo.lock b/Cargo.lock
index afc5e63..47482bd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1027,6 +1027,15 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
 [[package]]
+name = "helpdoc_system_macros"
+version = "0.1.0-dev"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
 name = "hex_display"
 version = "0.1.0"
 
@@ -1207,6 +1216,7 @@ dependencies = [
  "colored",
  "crossterm",
  "env_logger",
+ "helpdoc_system_macros",
  "just_enough_vcs",
  "just_fmt",
  "just_progress",
@@ -1219,6 +1229,7 @@ dependencies = [
  "serde",
  "serde_json",
  "serde_yaml",
+ "strip-ansi-escapes",
  "thiserror",
  "tokio",
  "toml 0.9.8",
diff --git a/Cargo.toml b/Cargo.toml
index e6c061f..4eba850 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,8 +9,9 @@ homepage = "https://github.com/JustEnoughVCS/CommandLine/"
 members = [
     "utils/",
     "tools/build_helper",
-    "macros/render_system_macros",
     "macros/cmd_system_macros",
+    "macros/helpdoc_system_macros",
+    "macros/render_system_macros",
 ]
 
 [workspace.package]
@@ -58,8 +59,9 @@ serde = { version = "1", features = ["derive"] }
 
 [dependencies]
 cli_utils = { path = "utils" }
-cmd_system_macros = { path = "macros/cmd_system_macros" }
 just_enough_vcs = { path = "../VersionControl", features = ["all"] }
+cmd_system_macros = { path = "macros/cmd_system_macros" }
+helpdoc_system_macros = { path = "macros/helpdoc_system_macros" }
 render_system_macros = { path = "macros/render_system_macros" }
 
 crossterm.workspace = true
@@ -77,6 +79,7 @@ ron = "0.11.0"
 rust-i18n = "3"
 serde_json = "1"
 serde_yaml = "0.9"
+strip_ansi_escapes = { version = "0.2", package = "strip-ansi-escapes" }
 tokio = { version = "1", features = ["full"] }
 toml = "0.9"
 walkdir = "2.5.0"
diff --git a/macros/helpdoc_system_macros/Cargo.toml b/macros/helpdoc_system_macros/Cargo.toml
new file mode 100644
index 0000000..c5c8483
--- /dev/null
+++ b/macros/helpdoc_system_macros/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "helpdoc_system_macros"
+edition = "2024"
+version.workspace = true
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2.workspace = true
+quote.workspace = true
+syn.workspace = true
diff --git a/macros/helpdoc_system_macros/src/lib.rs b/macros/helpdoc_system_macros/src/lib.rs
new file mode 100644
index 0000000..a9008bf
--- /dev/null
+++ b/macros/helpdoc_system_macros/src/lib.rs
@@ -0,0 +1,192 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use std::fs;
+use std::path::Path;
+use syn;
+
+#[proc_macro]
+pub fn generate_helpdoc_mapping(_input: TokenStream) -> TokenStream {
+    let manifest_dir =
+        std::env::var("CARGO_MANIFEST_DIR").expect("Failed to get CARGO_MANIFEST_DIR");
+    let repo_root = Path::new(&manifest_dir);
+    let helpdoc_dir = repo_root.join("resources").join("helpdoc");
+
+    if !helpdoc_dir.exists() {
+        return quote! {
+            fn get_doc(_doc_name: &str, _lang: &str) -> &'static str {
+                ""
+            }
+        }
+        .into();
+    }
+
+    let mut doc_entries = Vec::new();
+
+    scan_directory(&helpdoc_dir, &mut doc_entries, &helpdoc_dir);
+
+    let match_arms = generate_match_arms(&doc_entries);
+
+    let expanded = quote! {
+        fn get_doc(doc_name: &str, lang: &str) -> &'static str {
+            let key = format!("{}.{}", doc_name, lang);
+            match key.as_str() {
+                #(#match_arms)*
+                _ => "",
+            }
+        }
+    };
+
+    expanded.into()
+}
+
+fn scan_directory(dir: &Path, entries: &mut Vec<(String, String)>, base_dir: &Path) {
+    if let Ok(entries_iter) = fs::read_dir(dir) {
+        for entry in entries_iter.filter_map(Result::ok) {
+            let path = entry.path();
+
+            if path.is_dir() {
+                scan_directory(&path, entries, base_dir);
+            } else if let Some(extension) = path.extension() {
+                if extension == "md" {
+                    if let Ok(relative_path) = path.strip_prefix(base_dir) {
+                        if let Some(file_stem) = path.file_stem() {
+                            let file_stem_str = file_stem.to_string_lossy();
+
+                            if let Some(dot_pos) = file_stem_str.rfind('.') {
+                                let doc_name = &file_stem_str[..dot_pos];
+                                let lang = &file_stem_str[dot_pos + 1..];
+
+                                let parent = relative_path.parent();
+                                let full_doc_name = if let Some(parent) = parent {
+                                    if parent.to_string_lossy().is_empty() {
+                                        doc_name.to_string()
+                                    } else {
+                                        format!("{}/{}", parent.to_string_lossy(), doc_name)
+                                    }
+                                } else {
+                                    doc_name.to_string()
+                                };
+
+                                entries.push((full_doc_name, lang.to_string()));
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+fn generate_match_arms(entries: &[(String, String)]) -> Vec<proc_macro2::TokenStream> {
+    let mut arms = Vec::new();
+
+    for (doc_name, lang) in entries {
+        let key = format!("{}.{}", doc_name, lang);
+        let file_path = format!("resources/helpdoc/{}.{}.md", doc_name, lang);
+
+        let arm = quote! {
+            #key => include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/", #file_path)),
+        };
+
+        arms.push(arm);
+    }
+
+    arms
+}
+
+#[proc_macro]
+pub fn generate_helpdoc_list(_input: TokenStream) -> TokenStream {
+    let manifest_dir =
+        std::env::var("CARGO_MANIFEST_DIR").expect("Failed to get CARGO_MANIFEST_DIR");
+    let repo_root = Path::new(&manifest_dir);
+    let helpdoc_dir = repo_root.join("resources").join("helpdoc");
+
+    if !helpdoc_dir.exists() {
+        return quote! {
+            fn get_docs_list() -> Vec<&'static str> {
+                Vec::new()
+            }
+        }
+        .into();
+    }
+
+    let mut doc_entries = Vec::new();
+    scan_directory(&helpdoc_dir, &mut doc_entries, &helpdoc_dir);
+
+    let mut unique_docs = std::collections::HashSet::new();
+    for (doc_name, _) in &doc_entries {
+        unique_docs.insert(doc_name.clone());
+    }
+
+    let mut doc_list = Vec::new();
+    for doc_name in unique_docs {
+        doc_list.push(quote! {
+            #doc_name
+        });
+    }
+
+    let expanded = quote! {
+        fn get_docs_list() -> Vec<&'static str> {
+            vec![
+                #(#doc_list),*
+            ]
+        }
+    };
+
+    expanded.into()
+}
+
+#[proc_macro]
+pub fn generate_helpdoc_test(_input: TokenStream) -> TokenStream {
+    let manifest_dir =
+        std::env::var("CARGO_MANIFEST_DIR").expect("Failed to get CARGO_MANIFEST_DIR");
+    let repo_root = Path::new(&manifest_dir);
+    let helpdoc_dir = repo_root.join("resources").join("helpdoc");
+
+    if !helpdoc_dir.exists() {
+        return quote! {
+            #[cfg(test)]
+            mod helpdoc_tests {
+                #[test]
+                fn test_no_docs() {
+                }
+            }
+        }
+        .into();
+    }
+
+    let mut doc_entries = Vec::new();
+    scan_directory(&helpdoc_dir, &mut doc_entries, &helpdoc_dir);
+
+    let mut test_cases = Vec::new();
+
+    for (doc_name, lang) in &doc_entries {
+        let test_name_str = format!(
+            "test_doc_{}_{}",
+            doc_name
+                .replace('/', "_")
+                .replace('.', "_")
+                .replace('-', "_"),
+            lang.replace('-', "_")
+        );
+        let test_name = syn::Ident::new(&test_name_str, proc_macro2::Span::call_site());
+        let test_case = quote! {
+            #[test]
+            fn #test_name() {
+                let doc = super::get_doc(#doc_name, #lang);
+                assert!(!doc.is_empty(), "Document {}.{} should not be empty", #doc_name, #lang);
+            }
+        };
+
+        test_cases.push(test_case);
+    }
+
+    let expanded = quote! {
+        #[cfg(test)]
+        mod helpdoc_tests {
+            #(#test_cases)*
+        }
+    };
+
+    expanded.into()
+}
diff --git a/resources/helpdoc/Welcome_To_JVCS.en.md b/resources/helpdoc/Welcome_To_JVCS.en.md
new file mode 100644
index 0000000..f82f58e
--- /dev/null
+++ b/resources/helpdoc/Welcome_To_JVCS.en.md
@@ -0,0 +1 @@
+# Welcome
diff --git a/resources/helpdoc/Welcome_To_JVCS.zh-CN.md b/resources/helpdoc/Welcome_To_JVCS.zh-CN.md
new file mode 100644
index 0000000..2dfd3ee
--- /dev/null
+++ b/resources/helpdoc/Welcome_To_JVCS.zh-CN.md
@@ -0,0 +1 @@
+# 你好
diff --git a/resources/helpdoc/commands/hexdump.en.md b/resources/helpdoc/commands/hexdump.en.md
new file mode 100644
index 0000000..60d5275
--- /dev/null
+++ b/resources/helpdoc/commands/hexdump.en.md
@@ -0,0 +1,6 @@
+# Hexdump
+
+> Print binary information
+
+## Usage
+jvn hexdump <FILE>
diff --git a/resources/helpdoc/commands/hexdump.zh-CN.md b/resources/helpdoc/commands/hexdump.zh-CN.md
new file mode 100644
index 0000000..9b5b8ad
--- /dev/null
+++ b/resources/helpdoc/commands/hexdump.zh-CN.md
@@ -0,0 +1,6 @@
+# Hexdump
+
+> 打印二进制信息
+
+## 使用
+jvn hexdump <FILE>
diff --git a/resources/helpdoc/commands/sheetdump.en.md b/resources/helpdoc/commands/sheetdump.en.md
new file mode 100644
index 0000000..1616f12
--- /dev/null
+++ b/resources/helpdoc/commands/sheetdump.en.md
@@ -0,0 +1,13 @@
+# Sheetdump
+
+> Visually output the internal structure of a `Sheet`
+
+## Usage
+jvn sheetdump <SHEET_FILE>              # Default output
+jvn sheetdump <SHEET_FILE> --no-sort    # No sorting
+jvn sheetdump <SHEET_FILE> --no-pretty  # No prettifying
+
+## Tip
+You can also use `renderer override` to access the internal structure of a `Sheet`, 
+for example:
+jvn sheetdump <SHEET_FILE> --renderer json | jq ".mappings"
diff --git a/resources/helpdoc/commands/sheetdump.zh-CN.md b/resources/helpdoc/commands/sheetdump.zh-CN.md
new file mode 100644
index 0000000..0ae46ef
--- /dev/null
+++ b/resources/helpdoc/commands/sheetdump.zh-CN.md
@@ -0,0 +1,12 @@
+# Sheetdump
+
+> 可视化地输出 `Sheet` 的内部结构
+
+## 使用
+jvn sheetdump <SHEET_FILE>              # 默认输出
+jvn sheetdump <SHEET_FILE> --no-sort    # 无排序
+jvn sheetdump <SHEET_FILE> --no-pretty  # 无美化
+
+## 提示
+您也可以使用 `渲染器重载` 来访问 `Sheet` 的内部结构，例如
+jvn sheetdump <SHEET_FILE> --renderer json | jq ".mappings"
diff --git a/resources/helpdoc/commands/sheetedit.en.md b/resources/helpdoc/commands/sheetedit.en.md
new file mode 100644
index 0000000..80f2a7b
--- /dev/null
+++ b/resources/helpdoc/commands/sheetedit.en.md
@@ -0,0 +1,12 @@
+# Sheetedit
+
+> Edit `Sheet` files using your system editor
+
+## Usage
+jvn sheetedit <FILE>
+
+## Note
+It reads and uses a command-line editor program in the following priority order:
+1. JV\_TEXT\_EDITOR
+2. EDITOR
+3. If neither exists, it falls back to using `jvii`
diff --git a/resources/helpdoc/commands/sheetedit.zh-CN.md b/resources/helpdoc/commands/sheetedit.zh-CN.md
new file mode 100644
index 0000000..f30825a
--- /dev/null
+++ b/resources/helpdoc/commands/sheetedit.zh-CN.md
@@ -0,0 +1,12 @@
+# Sheetedit
+
+> 使用系统编辑器修改 `Sheet` 文件
+
+## 使用
+jvn sheetedit <FILE>
+
+## 注意
+它读取按照以下优先级寻找命令行编辑器程序：
+1. JV\_TEXT\_EDITOR
+2. EDITOR 
+3. 若都不存在，使用 `jvii` 回退
diff --git a/resources/locales/jvn/en.yml b/resources/locales/jvn/en.yml
index 6e632f2..7df57fd 100644
--- a/resources/locales/jvn/en.yml
+++ b/resources/locales/jvn/en.yml
@@ -1,28 +1,25 @@
-help: |
-  NO
-
 process_error:
   no_matching_command: |
     No matching command found!
-    Use `jv -h` to get help
+    Use `jvn -h` to get help
 
   no_matching_command_but_similar: |
     No matching command found, but similar commands were found:
-      jv %{similars}
+      jvn %{similars}
 
-    Use `jv -h` to get help
+    Use `jvn -h` to get help
 
   no_node_found: |
     Unable to find command `%{node}`
 
     This is usually a compilation-phase issue, not a user input error.
-    Please use `jv -v -C` to get detailed version traceback and contact the developers.
+    Please use `jvn -v -C` to get detailed version traceback and contact the developers.
 
     github: https://github.com/JustEnoughVCS/CommandLine/
 
   parse_error: |
     An error occurred while parsing your command arguments!
-    Please use `jv <command> --help` to view help
+    Please use `jvn <command> --help` to view help
 
   renderer_override_but_request_help: |
     Renderer override mode is enabled, but help output was requested.
@@ -38,7 +35,7 @@ process_error:
     Type conversion failed!
 
     This is usually a compilation-phase issue, not a user input error.
-    Please use `jv -v -C` to get detailed version traceback and contact the developers.
+    Please use `jvn -v -C` to get detailed version traceback and contact the developers.
 
     github: https://github.com/JustEnoughVCS/CommandLine/
 
@@ -57,19 +54,19 @@ prepare_error:
 
   local_config_not_found: |
     Failed to read workspace config. File may not exist or format mismatch.
-    Use `jv update` and try again.
+    Use `jvn update` and try again.
 
   latest_info_not_found: |
     Unable to read latest upstream info!
-    Use `jv update` and try again.
+    Use `jvn update` and try again.
 
   latest_file_data_not_exist: |
     Unable to read latest file info for member `%{member_id}`!
-    Use `jv update` and try again.
+    Use `jvn update` and try again.
 
   cached_sheet_not_found: |
     Unable to read cached upstream sheet `%{sheet_name}`!
-    Use `jv update` and try again.
+    Use `jvn update` and try again.
 
   local_sheet_not_found: |
     Unable to read local sheet `%{sheet_name}` for member `%{member_id}`.
@@ -80,7 +77,7 @@ prepare_error:
     Also, verify that a structure sheet is in use.
 
   no_sheet_in_use: |
-    No sheet in use. Use `jv use <structure_sheet_name>`.
+    No sheet in use. Use `jvn use <structure_sheet_name>`.
 
 execute_error:
   io: |
@@ -110,7 +107,7 @@ render_error:
   type_mismatch: |
     Render type mismatch!
     This is usually a compilation-phase issue, not a user input error.
-    Please use `jv -v -C` to get detailed version traceback and contact the developers.
+    Please use `jvn -v -C` to get detailed version traceback and contact the developers.
 
     github: https://github.com/JustEnoughVCS/CommandLine/
 
diff --git a/resources/locales/jvn/helpdoc_viewer/en.yml b/resources/locales/jvn/helpdoc_viewer/en.yml
new file mode 100644
index 0000000..1f5d9d4
--- /dev/null
+++ b/resources/locales/jvn/helpdoc_viewer/en.yml
@@ -0,0 +1,5 @@
+helpdoc_viewer:
+  tree_area_hint: |
+      _List_ | ↑↓: Page | ←→/Space: Switch view | Q: Quit
+  content_area_hint: |
+      _Read_ | ↑↓: Page | ←→/Space: Switch view | Q: Quit
diff --git a/resources/locales/jvn/helpdoc_viewer/zh-CN.yml b/resources/locales/jvn/helpdoc_viewer/zh-CN.yml
new file mode 100644
index 0000000..65825d5
--- /dev/null
+++ b/resources/locales/jvn/helpdoc_viewer/zh-CN.yml
@@ -0,0 +1,5 @@
+helpdoc_viewer:
+  tree_area_hint: |
+      _列表_ | ↑↓: 翻页 | ←→/Space: 切换视图 | Q: 退出
+  content_area_hint: |
+      _阅读_ | ↑↓: 浏览 | ←→/Space: 切换视图 | Q: 退出
diff --git a/resources/locales/jvn/zh-CN.yml b/resources/locales/jvn/zh-CN.yml
index f62b53b..ff1b67a 100644
--- a/resources/locales/jvn/zh-CN.yml
+++ b/resources/locales/jvn/zh-CN.yml
@@ -1,27 +1,24 @@
-help: |
-  NO
-
 process_error:
   no_matching_command: |
-    无法匹配该命令，使用 `jv -h` 查看帮助
+    无法匹配该命令，使用 `jvn -h` 查看帮助
 
   no_matching_command_but_similar: |
     无法找到匹配的命令，但找到相似命令：
-      jv %{similars}
+      jvn %{similars}
 
-    使用 `jv -h` 查看帮助
+    使用 `jvn -h` 查看帮助
 
   no_node_found: |
     无法找到命令 `%{node}`
 
     这通常是编译期造成的问题，而非用户的错误输入
-    请使用 `jv -v -C` 获得详细的版本追溯，并联系开发人员
+    请使用 `jvn -v -C` 获得详细的版本追溯，并联系开发人员
 
     github: https://github.com/JustEnoughVCS/CommandLine/
 
   parse_error: |
     在将您的命令参数进行解析时出现错误！
-    请使用 `jv <命令> --help` 查看帮助
+    请使用 `jvn <命令> --help` 查看帮助
 
   renderer_override_but_request_help: |
     启用渲染器覆盖模式，但请求输出帮助信息
@@ -37,7 +34,7 @@ process_error:
     类型转换失败！
 
     这通常是编译期造成的问题，而非用户的错误输入
-    请使用 `jv -v -C` 获得详细的版本追溯，并联系开发人员
+    请使用 `jvn -v -C` 获得详细的版本追溯，并联系开发人员
 
     github: https://github.com/JustEnoughVCS/CommandLine/
 
@@ -56,19 +53,19 @@ prepare_error:
 
   local_config_not_found: |
     读取本地工作区配置文件失败，它可能不存在或格式不匹配
-    请使用 `jv update` 更新工作区信息后再尝试
+    请使用 `jvn update` 更新工作区信息后再尝试
 
   latest_info_not_found: |
     无法找到或读取最新上游信息！
-    请使用 `jv update` 更新工作区信息后再尝试
+    请使用 `jvn update` 更新工作区信息后再尝试
 
   latest_file_data_not_exist: |
     无法找到或读取成员 `%{member_id}` 的最新文件信息！
-    请使用 `jv update` 更新工作区信息后再尝试
+    请使用 `jvn update` 更新工作区信息后再尝试
 
   cached_sheet_not_found: |
     无法找到或读取上游结构表 `%{sheet_name}` 的缓存信息！
-    请使用 `jv update` 更新工作区信息后再尝试
+    请使用 `jvn update` 更新工作区信息后再尝试
 
   local_sheet_not_found: |
     无法找到或读取成员 `%{member_id}` 的本地结构表 `%{sheet_name}`
@@ -78,7 +75,7 @@ prepare_error:
     请检查当前工作区是否正确设置上游，并正在使用结构表
 
   no_sheet_in_use: |
-    当前没有在使用表，请使用 `jv use <结构表名称>` 使用一张结构表
+    当前没有在使用表，请使用 `jvn use <结构表名称>` 使用一张结构表
 
 execute_error:
   io: |
@@ -108,7 +105,7 @@ render_error:
   type_mismatch: |
     渲染类型不匹配！
     这通常是编译期造成的问题，而非用户的错误输入
-    请使用 `jv -v -C` 获得详细的版本追溯，并联系开发人员
+    请使用 `jvn -v -C` 获得详细的版本追溯，并联系开发人员
 
     github: https://github.com/JustEnoughVCS/CommandLine/
 
diff --git a/src/bin/jvn.rs b/src/bin/jvn.rs
index 3a95a45..0e5a9f6 100644
--- a/src/bin/jvn.rs
+++ b/src/bin/jvn.rs
@@ -11,6 +11,7 @@ use just_enough_vcs_cli::{
             processer::jv_cmd_process,
         },
         debug::verbose_logger::init_verbose_logger,
+        helpdoc::helpdoc_viewer,
     },
 };
 use just_progress::{
@@ -100,7 +101,7 @@ async fn main() {
     // Handle help when no arguments provided
     if args.len() < 1 && help {
         warn!("{}", t!("verbose.no_arguments"));
-        eprintln!("{}", md(t!("help")));
+        helpdoc_viewer::display_with_lang("Welcome_To_JVCS", &lang).await;
         exit(1);
     }
 
diff --git a/src/cmds/arg/helpdoc.rs b/src/cmds/arg/helpdoc.rs
new file mode 100644
index 0000000..3a34123
--- /dev/null
+++ b/src/cmds/arg/helpdoc.rs
@@ -0,0 +1,6 @@
+use clap::Parser;
+
+#[derive(Parser, Debug)]
+pub struct JVHelpdocArgument {
+    pub doc_name: String,
+}
diff --git a/src/cmds/cmd/helpdoc.rs b/src/cmds/cmd/helpdoc.rs
new file mode 100644
index 0000000..8b692ee
--- /dev/null
+++ b/src/cmds/cmd/helpdoc.rs
@@ -0,0 +1,49 @@
+use crate::{
+    cmd_output,
+    cmds::{
+        arg::helpdoc::JVHelpdocArgument, collect::empty::JVEmptyCollect,
+        r#in::helpdoc::JVHelpdocInput, out::none::JVNoneOutput,
+    },
+    systems::{
+        cmd::{
+            cmd_system::JVCommandContext,
+            errors::{CmdExecuteError, CmdPrepareError},
+        },
+        helpdoc::helpdoc_viewer,
+    },
+};
+use cmd_system_macros::exec;
+use std::any::TypeId;
+
+pub struct JVHelpdocCommand;
+type Cmd = JVHelpdocCommand;
+type Arg = JVHelpdocArgument;
+type In = JVHelpdocInput;
+type Collect = JVEmptyCollect;
+
+async fn help_str() -> String {
+    helpdoc_viewer::display("Welcome_To_JVCS").await;
+    String::new()
+}
+
+async fn prepare(args: &Arg, ctx: &JVCommandContext) -> Result<In, CmdPrepareError> {
+    Ok(JVHelpdocInput {
+        name: args.doc_name.clone(),
+        lang: ctx.lang.clone(),
+    })
+}
+
+async fn collect(_args: &Arg, _ctx: &JVCommandContext) -> Result<Collect, CmdPrepareError> {
+    Ok(JVEmptyCollect)
+}
+
+#[exec]
+async fn exec(
+    input: In,
+    _collect: Collect,
+) -> Result<(Box<dyn std::any::Any + Send + 'static>, TypeId), CmdExecuteError> {
+    helpdoc_viewer::display_with_lang(&input.name.as_str(), &input.lang.as_str()).await;
+    cmd_output!(JVNoneOutput => JVNoneOutput)
+}
+
+crate::command_template!();
diff --git a/src/cmds/cmd/hexdump.rs b/src/cmds/cmd/hexdump.rs
index 66022ef..928b626 100644
--- a/src/cmds/cmd/hexdump.rs
+++ b/src/cmds/cmd/hexdump.rs
@@ -6,9 +6,12 @@ use crate::{
         arg::single_file::JVSingleFileArgument, collect::single_file::JVSingleFileCollect,
         r#in::empty::JVEmptyInput, out::hex::JVHexOutput,
     },
-    systems::cmd::{
-        cmd_system::JVCommandContext,
-        errors::{CmdExecuteError, CmdPrepareError},
+    systems::{
+        cmd::{
+            cmd_system::JVCommandContext,
+            errors::{CmdExecuteError, CmdPrepareError},
+        },
+        helpdoc::helpdoc_viewer,
     },
 };
 use cmd_system_macros::exec;
@@ -20,8 +23,9 @@ type Arg = JVSingleFileArgument;
 type In = JVEmptyInput;
 type Collect = JVSingleFileCollect;
 
-fn help_str() -> String {
-    "Hello".to_string()
+async fn help_str() -> String {
+    helpdoc_viewer::display("commands/hexdump").await;
+    String::new()
 }
 
 async fn prepare(_args: &Arg, _ctx: &JVCommandContext) -> Result<In, CmdPrepareError> {
diff --git a/src/cmds/cmd/sheetdump.rs b/src/cmds/cmd/sheetdump.rs
index fefa6d4..8140a0d 100644
--- a/src/cmds/cmd/sheetdump.rs
+++ b/src/cmds/cmd/sheetdump.rs
@@ -8,9 +8,12 @@ use crate::{
         r#in::sheetdump::JVSheetdumpInput,
         out::{mappings::JVMappingsOutput, mappings_pretty::JVMappingsPrettyOutput},
     },
-    systems::cmd::{
-        cmd_system::JVCommandContext,
-        errors::{CmdExecuteError, CmdPrepareError},
+    systems::{
+        cmd::{
+            cmd_system::JVCommandContext,
+            errors::{CmdExecuteError, CmdPrepareError},
+        },
+        helpdoc::helpdoc_viewer,
     },
 };
 use cmd_system_macros::exec;
@@ -25,8 +28,9 @@ type Arg = JVSheetdumpArgument;
 type In = JVSheetdumpInput;
 type Collect = JVSheetdumpCollect;
 
-fn help_str() -> String {
-    todo!()
+async fn help_str() -> String {
+    helpdoc_viewer::display("commands/sheetdump").await;
+    String::new()
 }
 
 async fn prepare(args: &Arg, _ctx: &JVCommandContext) -> Result<In, CmdPrepareError> {
diff --git a/src/cmds/cmd/sheetedit.rs b/src/cmds/cmd/sheetedit.rs
index 2dfbbfb..08918f4 100644
--- a/src/cmds/cmd/sheetedit.rs
+++ b/src/cmds/cmd/sheetedit.rs
@@ -4,9 +4,12 @@ use crate::{
         arg::sheetedit::JVSheeteditArgument, collect::single_file::JVSingleFileCollect,
         r#in::sheetedit::JVSheeteditInput, out::none::JVNoneOutput,
     },
-    systems::cmd::{
-        cmd_system::JVCommandContext,
-        errors::{CmdExecuteError, CmdPrepareError},
+    systems::{
+        cmd::{
+            cmd_system::JVCommandContext,
+            errors::{CmdExecuteError, CmdPrepareError},
+        },
+        helpdoc::helpdoc_viewer,
     },
 };
 use cli_utils::{
@@ -26,8 +29,9 @@ type Arg = JVSheeteditArgument;
 type In = JVSheeteditInput;
 type Collect = JVSingleFileCollect;
 
-fn help_str() -> String {
-    todo!()
+async fn help_str() -> String {
+    helpdoc_viewer::display("commands/sheetedit").await;
+    String::new()
 }
 
 async fn prepare(args: &Arg, _ctx: &JVCommandContext) -> Result<In, CmdPrepareError> {
diff --git a/src/cmds/in/helpdoc.rs b/src/cmds/in/helpdoc.rs
new file mode 100644
index 0000000..6b72d43
--- /dev/null
+++ b/src/cmds/in/helpdoc.rs
@@ -0,0 +1,4 @@
+pub struct JVHelpdocInput {
+    pub name: String,
+    pub lang: String,
+}
diff --git a/src/systems.rs b/src/systems.rs
index 2ca53be..e0d4491 100644
--- a/src/systems.rs
+++ b/src/systems.rs
@@ -1,3 +1,4 @@
 pub mod cmd;
 pub mod debug;
+pub mod helpdoc;
 pub mod render;
diff --git a/src/systems/cmd/cmd_system.rs b/src/systems/cmd/cmd_system.rs
index 67f5c7f..3ae4d5e 100644
--- a/src/systems/cmd/cmd_system.rs
+++ b/src/systems/cmd/cmd_system.rs
@@ -28,7 +28,7 @@ where
     Collect: Send,
 {
     /// Get help string for the command
-    fn get_help_str() -> String;
+    fn get_help_str() -> impl Future<Output = String> + Send;
 
     /// Run the command and convert the result into type-agnostic serialized information,
     /// then hand it over to the universal renderer for rendering.
@@ -72,7 +72,10 @@ where
             // skip execution and directly render help information
             if ctx.help {
                 let mut r = JVRenderResult::default();
-                r_println!(r, "{}", Self::get_help_str());
+                let help_str = Self::get_help_str().await;
+                if !help_str.is_empty() {
+                    r_println!(r, "{}", help_str);
+                }
                 return Ok(r);
             }
 
@@ -112,7 +115,7 @@ where
                             t = type_name::<Argument>()
                         )
                     );
-                    return Err(CmdProcessError::ParseError(Self::get_help_str()));
+                    return Err(CmdProcessError::ParseError(Self::get_help_str().await));
                 }
             };
 
diff --git a/src/systems/cmd/macros.rs b/src/systems/cmd/macros.rs
index 093d178..e9af1ac 100644
--- a/src/systems/cmd/macros.rs
+++ b/src/systems/cmd/macros.rs
@@ -51,7 +51,7 @@
 /// type Collect = JVCustomCollect;
 ///
 /// /// Return a string, rendered when the user needs help (command specifies `--help` or syntax error)
-/// fn help_str() -> String {
+/// async fn help_str() -> String {
 ///     todo!()
 /// }
 ///
@@ -97,7 +97,7 @@
 /// type In = JVCustomInput;
 /// type Collect = JVCustomCollect;
 ///
-/// fn help_str() -> String {
+/// async fn help_str() -> String {
 ///     todo!()
 /// }
 ///
@@ -121,8 +121,8 @@
 macro_rules! command_template {
     () => {
         impl $crate::systems::cmd::cmd_system::JVCommand<Arg, In, Collect> for Cmd {
-            fn get_help_str() -> String {
-                help_str()
+            async fn get_help_str() -> String {
+                help_str().await
             }
 
             async fn prepare(
diff --git a/src/systems/helpdoc.rs b/src/systems/helpdoc.rs
new file mode 100644
index 0000000..4e5b2a6
--- /dev/null
+++ b/src/systems/helpdoc.rs
@@ -0,0 +1,18 @@
+pub mod helpdoc_viewer;
+
+helpdoc_system_macros::generate_helpdoc_mapping!();
+helpdoc_system_macros::generate_helpdoc_list!();
+helpdoc_system_macros::generate_helpdoc_test!();
+
+pub fn get_helpdoc<'a>(doc_name: &'a str, lang: &'a str) -> &'a str {
+    let doc = get_doc(doc_name, lang);
+    if doc.is_empty() && lang != "en" {
+        get_doc(doc_name, "en")
+    } else {
+        doc
+    }
+}
+
+pub fn get_helpdoc_list<'a>() -> Vec<&'a str> {
+    get_docs_list()
+}
diff --git a/src/systems/helpdoc/helpdoc_viewer.rs b/src/systems/helpdoc/helpdoc_viewer.rs
new file mode 100644
index 0000000..1968775
--- /dev/null
+++ b/src/systems/helpdoc/helpdoc_viewer.rs
@@ -0,0 +1,636 @@
+use crate::systems::helpdoc::{get_helpdoc, get_helpdoc_list};
+use cli_utils::{display::markdown::Markdown, env::locales::current_locales};
+use crossterm::{
+    cursor::{Hide, MoveTo, Show},
+    event::{self, Event, KeyCode, KeyEvent, KeyModifiers},
+    execute,
+    style::{Color, Print, ResetColor, SetBackgroundColor, SetForegroundColor},
+    terminal::{
+        Clear, ClearType, EnterAlternateScreen, LeaveAlternateScreen, disable_raw_mode,
+        enable_raw_mode,
+    },
+};
+use rust_i18n::t;
+use std::{
+    collections::{BTreeMap, HashMap},
+    io::{Write, stdout},
+};
+
+struct HelpdocViewer {
+    /// Current language
+    lang: String,
+
+    /// Document tree structure
+    doc_tree: DocTree,
+
+    /// Currently selected document path
+    current_doc: String,
+
+    /// Scroll position history
+    scroll_history: HashMap<String, usize>,
+
+    /// Current focus area
+    focus: FocusArea,
+
+    /// Currently selected node index in tree view
+    tree_selection_index: usize,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+enum FocusArea {
+    Tree,
+    Content,
+}
+
+#[derive(Debug, Clone)]
+struct DocTreeNode {
+    /// Node name
+    name: String,
+
+    /// Full document path
+    path: String,
+
+    /// Child nodes
+    children: BTreeMap<String, DocTreeNode>,
+
+    /// Whether it is a document file
+    is_document: bool,
+}
+
+#[derive(Debug, Clone)]
+struct DocTree {
+    /// Root node
+    root: DocTreeNode,
+
+    /// Flattened document list
+    flat_docs: Vec<String>,
+}
+
+impl HelpdocViewer {
+    fn new(default_doc: &str, lang: &str) -> Self {
+        // Build the document tree
+        let doc_tree = Self::build_doc_tree();
+
+        // Validate if the default document exists
+        let current_doc = if doc_tree.contains_doc(default_doc) {
+            default_doc.to_string()
+        } else {
+            // If the default document does not exist, use the first document
+            doc_tree.flat_docs.first().cloned().unwrap_or_default()
+        };
+
+        // Calculate the initial tree selection index
+        let tree_selection_index = doc_tree
+            .flat_docs
+            .iter()
+            .position(|doc| *doc == current_doc)
+            .unwrap_or(0);
+
+        Self {
+            lang: lang.to_string(),
+            doc_tree,
+            current_doc,
+            scroll_history: HashMap::new(),
+            focus: FocusArea::Content,
+            tree_selection_index,
+        }
+    }
+
+    /// Build document tree
+    fn build_doc_tree() -> DocTree {
+        // Get all document list
+        let doc_list = get_helpdoc_list();
+
+        // Create root node
+        let mut root = DocTreeNode {
+            name: "helpdoc".to_string(),
+            path: "".to_string(),
+            children: BTreeMap::new(),
+            is_document: false,
+        };
+
+        // Build tree structure for each document path
+        for doc_path in doc_list {
+            Self::add_doc_to_tree(&mut root, doc_path);
+        }
+
+        // Build flattened document list
+        let flat_docs = Self::flatten_doc_tree(&root);
+
+        DocTree { root, flat_docs }
+    }
+
+    /// Add document to tree
+    fn add_doc_to_tree(root: &mut DocTreeNode, doc_path: &str) {
+        let parts: Vec<&str> = doc_path.split('/').collect();
+
+        // Use recursive helper function to avoid borrowing issues
+        Self::add_doc_to_tree_recursive(root, &parts, 0);
+    }
+
+    /// Recursively add document to tree
+    fn add_doc_to_tree_recursive(node: &mut DocTreeNode, parts: &[&str], depth: usize) {
+        if depth >= parts.len() {
+            return;
+        }
+
+        let part = parts[depth];
+        let is_document = depth == parts.len() - 1;
+        let current_path = parts[0..=depth].join("/");
+
+        // Check if node already exists, create if not
+        if !node.children.contains_key(part) {
+            let new_node = DocTreeNode {
+                name: part.to_string(),
+                path: current_path.clone(),
+                children: BTreeMap::new(),
+                is_document,
+            };
+            node.children.insert(part.to_string(), new_node);
+        }
+
+        // Get mutable reference to child node
+        if let Some(child) = node.children.get_mut(part) {
+            // If this is a document node, ensure it's marked as document
+            if is_document {
+                child.is_document = true;
+            }
+            // Recursively process next part
+            Self::add_doc_to_tree_recursive(child, parts, depth + 1);
+        }
+    }
+
+    /// Flatten document tree
+    fn flatten_doc_tree(node: &DocTreeNode) -> Vec<String> {
+        let mut result = Vec::new();
+
+        if node.is_document && !node.path.is_empty() {
+            result.push(node.path.clone());
+        }
+
+        // Traverse child nodes in alphabetical order
+        for child in node.children.values() {
+            result.extend(Self::flatten_doc_tree(child));
+        }
+
+        result
+    }
+
+    /// Get current document content
+    fn current_doc_content(&self) -> String {
+        let content = get_helpdoc(&self.current_doc, &self.lang);
+        if content.is_empty() {
+            format!("Document '{}.{}' not found", self.current_doc, self.lang)
+        } else {
+            content.to_string()
+        }
+    }
+
+    /// Get formatted document content
+    fn formatted_doc_content(&self) -> Vec<String> {
+        let content = self.current_doc_content();
+        let formatted = content.markdown();
+        formatted.lines().map(|s| s.to_string()).collect()
+    }
+
+    /// Run viewer
+    async fn run(&mut self) -> std::io::Result<()> {
+        enable_raw_mode()?;
+        execute!(stdout(), EnterAlternateScreen, Hide)?;
+
+        let mut should_exit = false;
+
+        while !should_exit {
+            self.draw()?;
+
+            if event::poll(std::time::Duration::from_millis(100))? {
+                if let Event::Key(key) = event::read()? {
+                    should_exit = self.handle_key(key);
+                }
+            }
+        }
+
+        execute!(stdout(), Show, LeaveAlternateScreen)?;
+        disable_raw_mode()?;
+
+        Ok(())
+    }
+
+    /// Draw interface
+    fn draw(&self) -> std::io::Result<()> {
+        let (width, height) = crossterm::terminal::size()?;
+
+        if height <= 3 {
+            let content = self.current_doc_content();
+            println!("{}", content);
+            return Ok(());
+        }
+
+        execute!(stdout(), Clear(ClearType::All))?;
+
+        let tree_width = 25;
+        let content_width = width - tree_width - 1;
+
+        // Draw title
+        execute!(
+            stdout(),
+            MoveTo(0, 0),
+            SetForegroundColor(Color::Cyan),
+            Print(format!("JVCS Help Docs - {}", self.lang)),
+            ResetColor
+        )?;
+
+        // Draw separator line
+        for y in 1..height {
+            execute!(stdout(), MoveTo(tree_width, y), Print("│"))?;
+        }
+
+        // Draw tree view
+        self.draw_tree(0, 2, tree_width, height - 4)?;
+
+        // Draw content area
+        self.draw_content(tree_width + 1, 2, content_width, height - 4)?;
+
+        // Draw status bar
+        self.draw_status_bar(height - 1, width)?;
+
+        stdout().flush()?;
+        Ok(())
+    }
+
+    /// Draw tree view
+    fn draw_tree(&self, x: u16, y: u16, width: u16, height: u16) -> std::io::Result<()> {
+        // Draw tree view title
+        execute!(
+            stdout(),
+            MoveTo(x, y - 1),
+            SetForegroundColor(Color::Yellow),
+            Print("Documents"),
+            ResetColor
+        )?;
+
+        // Recursively draw tree structure
+        let mut line_counter = 0;
+        let max_lines = height as usize;
+
+        // Skip root node, start drawing from children
+        for child in self.doc_tree.root.children.values() {
+            line_counter = self.draw_tree_node(child, x, y, width, 0, line_counter, max_lines)?;
+            if line_counter >= max_lines {
+                break;
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Recursively draw tree node
+    fn draw_tree_node(
+        &self,
+        node: &DocTreeNode,
+        x: u16,
+        start_y: u16,
+        width: u16,
+        depth: usize,
+        mut line_counter: usize,
+        max_lines: usize,
+    ) -> std::io::Result<usize> {
+        if line_counter >= max_lines {
+            return Ok(line_counter);
+        }
+
+        let line_y = start_y + line_counter as u16;
+        line_counter += 1;
+
+        // Build indentation and suffix
+        let indent = "  ".repeat(depth);
+        let suffix = if node.children.is_empty() { "" } else { "/" };
+
+        // If this is the currently selected document, highlight it (white background, black text)
+        let is_selected = node.path == self.current_doc;
+
+        if is_selected {
+            // Highlight with white background and black text
+            execute!(
+                stdout(),
+                MoveTo(x, line_y),
+                SetForegroundColor(Color::Black),
+                SetBackgroundColor(Color::White),
+                Print(" ".repeat(width as usize)),
+                MoveTo(x, line_y),
+                SetForegroundColor(Color::Black),
+            )?;
+        } else {
+            // Normal display
+            execute!(
+                stdout(),
+                MoveTo(x, line_y),
+                SetForegroundColor(Color::White),
+                SetBackgroundColor(Color::Black),
+            )?;
+        }
+
+        // Display node name
+        let display_text = format!("{}  {}{}", indent, node.name, suffix);
+        execute!(stdout(), Print(display_text))?;
+        execute!(stdout(), ResetColor, SetBackgroundColor(Color::Black))?;
+
+        // Recursively draw child nodes
+        if !node.children.is_empty() {
+            for child in node.children.values() {
+                line_counter = self.draw_tree_node(
+                    child,
+                    x,
+                    start_y,
+                    width,
+                    depth + 1,
+                    line_counter,
+                    max_lines,
+                )?;
+                if line_counter >= max_lines {
+                    break;
+                }
+            }
+        }
+
+        Ok(line_counter)
+    }
+
+    /// Draw content area
+    fn draw_content(&self, x: u16, y: u16, width: u16, height: u16) -> std::io::Result<()> {
+        // Draw content area title
+        execute!(
+            stdout(),
+            MoveTo(x, y - 1),
+            SetForegroundColor(Color::Yellow),
+            Print(format!("> {}", self.current_doc)),
+            ResetColor
+        )?;
+
+        // Get formatted content
+        let content_lines = self.formatted_doc_content();
+        let scroll_pos = self
+            .scroll_history
+            .get(&self.current_doc)
+            .copied()
+            .unwrap_or(0);
+        let start_line = scroll_pos.min(content_lines.len().saturating_sub(1));
+        let end_line = (start_line + height as usize).min(content_lines.len());
+
+        for (i, line) in content_lines
+            .iter()
+            .enumerate()
+            .take(end_line)
+            .skip(start_line)
+        {
+            let line_y = y + i as u16 - start_line as u16;
+            let display_line = if line.len() > width as usize {
+                let mut end = width as usize;
+                while end > 0 && !line.is_char_boundary(end) {
+                    end -= 1;
+                }
+                if end == 0 {
+                    // If the first character is multi-byte, display at least one character
+                    let mut end = 1;
+                    while end < line.len() && !line.is_char_boundary(end) {
+                        end += 1;
+                    }
+                    &line[..end]
+                } else {
+                    &line[..end]
+                }
+            } else {
+                line
+            };
+
+            execute!(stdout(), MoveTo(x, line_y), Print(display_line))?;
+        }
+
+        // Display scroll position indicator
+        if content_lines.len() > height as usize && content_lines.len() > 0 {
+            let scroll_percent = if content_lines.len() > 0 {
+                (scroll_pos * 100) / content_lines.len()
+            } else {
+                0
+            };
+            execute!(
+                stdout(),
+                MoveTo(x + width - 5, y - 1),
+                SetForegroundColor(Color::DarkGrey),
+                Print(format!("{:3}%", scroll_percent)),
+                ResetColor
+            )?;
+        }
+
+        Ok(())
+    }
+
+    /// Draw status bar
+    fn draw_status_bar(&self, y: u16, width: u16) -> std::io::Result<()> {
+        // Draw status bar background
+        execute!(
+            stdout(),
+            MoveTo(0, y),
+            SetForegroundColor(Color::Black),
+            Print(" ".repeat(width as usize)),
+            MoveTo(0, y),
+            SetForegroundColor(Color::White),
+        )?;
+
+        let status_text = match self.focus {
+            FocusArea::Tree => t!("helpdoc_viewer.tree_area_hint").to_string().markdown(),
+            FocusArea::Content => t!("helpdoc_viewer.content_area_hint")
+                .to_string()
+                .markdown(),
+        }
+        .to_string();
+
+        let truncated_text = if status_text.len() > width as usize {
+            &status_text[..width as usize]
+        } else {
+            &status_text
+        };
+        execute!(stdout(), Print(truncated_text))?;
+        execute!(stdout(), ResetColor)?;
+
+        Ok(())
+    }
+
+    /// Handle key input
+    fn handle_key(&mut self, key: KeyEvent) -> bool {
+        match key.code {
+            KeyCode::Char('q') | KeyCode::Esc => return true,
+            KeyCode::Char(' ') => self.toggle_focus(),
+            KeyCode::Left => self.move_left(),
+            KeyCode::Right => self.move_right(),
+            KeyCode::Up => self.move_up(),
+            KeyCode::Down => self.move_down(),
+            KeyCode::Char('g') if key.modifiers == KeyModifiers::NONE => self.go_to_top(),
+            KeyCode::Char('G') if key.modifiers == KeyModifiers::SHIFT => self.go_to_bottom(),
+            KeyCode::Enter => self.select_item(),
+            _ => {}
+        }
+        false
+    }
+
+    /// Toggle focus area
+    fn toggle_focus(&mut self) {
+        self.focus = match self.focus {
+            FocusArea::Tree => FocusArea::Content,
+            FocusArea::Content => FocusArea::Tree,
+        };
+    }
+
+    /// Move left
+    fn move_left(&mut self) {
+        if self.focus == FocusArea::Content {
+            self.focus = FocusArea::Tree;
+        }
+    }
+
+    /// Move right
+    fn move_right(&mut self) {
+        if self.focus == FocusArea::Tree {
+            self.focus = FocusArea::Content;
+        }
+    }
+
+    /// Move up
+    fn move_up(&mut self) {
+        match self.focus {
+            FocusArea::Tree => self.previous_doc(),
+            FocusArea::Content => self.scroll_up(),
+        }
+    }
+
+    /// Move down
+    fn move_down(&mut self) {
+        match self.focus {
+            FocusArea::Tree => self.next_doc(),
+            FocusArea::Content => self.scroll_down(),
+        }
+    }
+
+    /// Scroll to top
+    fn go_to_top(&mut self) {
+        match self.focus {
+            FocusArea::Content => {
+                self.scroll_history.insert(self.current_doc.clone(), 0);
+            }
+            FocusArea::Tree => {
+                // Select first document
+                self.tree_selection_index = 0;
+                if let Some(first_doc) = self.doc_tree.flat_docs.first() {
+                    self.current_doc = first_doc.clone();
+                }
+            }
+        }
+    }
+
+    /// Scroll to bottom
+    fn go_to_bottom(&mut self) {
+        match self.focus {
+            FocusArea::Content => {
+                let content_lines = self.formatted_doc_content();
+                if content_lines.len() > 10 {
+                    self.scroll_history
+                        .insert(self.current_doc.clone(), content_lines.len() - 10);
+                }
+            }
+            FocusArea::Tree => {
+                // Select last document
+                self.tree_selection_index = self.doc_tree.flat_docs.len().saturating_sub(1);
+                if let Some(last_doc) = self.doc_tree.flat_docs.last() {
+                    self.current_doc = last_doc.clone();
+                }
+            }
+        }
+    }
+
+    /// Select current item
+    fn select_item(&mut self) {
+        match self.focus {
+            FocusArea::Tree => {
+                // Update current document to the one selected in tree view
+                if let Some(doc) = self.doc_tree.flat_docs.get(self.tree_selection_index) {
+                    self.current_doc = doc.clone();
+                }
+                // Switch focus to content area
+                self.focus = FocusArea::Content;
+            }
+            _ => {}
+        }
+    }
+
+    /// Previous document
+    fn previous_doc(&mut self) {
+        if self.tree_selection_index > 0 {
+            self.tree_selection_index -= 1;
+            if let Some(doc) = self.doc_tree.flat_docs.get(self.tree_selection_index) {
+                self.current_doc = doc.clone();
+                // Reset scroll position
+                self.scroll_history.remove(&self.current_doc);
+            }
+        }
+    }
+
+    /// Next document
+    fn next_doc(&mut self) {
+        if self.tree_selection_index + 1 < self.doc_tree.flat_docs.len() {
+            self.tree_selection_index += 1;
+            if let Some(doc) = self.doc_tree.flat_docs.get(self.tree_selection_index) {
+                self.current_doc = doc.clone();
+                // Reset scroll position
+                self.scroll_history.remove(&self.current_doc);
+            }
+        }
+    }
+
+    /// Scroll up
+    fn scroll_up(&mut self) {
+        let current_scroll = self
+            .scroll_history
+            .get(&self.current_doc)
+            .copied()
+            .unwrap_or(0);
+        if current_scroll > 0 {
+            self.scroll_history
+                .insert(self.current_doc.clone(), current_scroll - 1);
+        }
+    }
+
+    /// Scroll down
+    fn scroll_down(&mut self) {
+        let content_lines = self.formatted_doc_content();
+        let current_scroll = self
+            .scroll_history
+            .get(&self.current_doc)
+            .copied()
+            .unwrap_or(0);
+        if current_scroll + 1 < content_lines.len() {
+            self.scroll_history
+                .insert(self.current_doc.clone(), current_scroll + 1);
+        }
+    }
+}
+
+impl DocTree {
+    /// Check if document exists
+    fn contains_doc(&self, doc_path: &str) -> bool {
+        self.flat_docs.contains(&doc_path.to_string())
+    }
+}
+
+/// Display help document viewer
+pub async fn display_with_lang(default_focus_doc: &str, lang: &str) {
+    let mut viewer = HelpdocViewer::new(default_focus_doc, lang);
+
+    if let Err(e) = viewer.run().await {
+        eprintln!("Error running helpdoc viewer: {}", e);
+    }
+}
+
+/// Display help document viewer
+pub async fn display(default_focus_doc: &str) {
+    display_with_lang(default_focus_doc, current_locales().as_str()).await;
+}
diff --git a/utils/src/display.rs b/utils/src/display.rs
index 16c94a9..5b452ce 100644
--- a/utils/src/display.rs
+++ b/utils/src/display.rs
@@ -1,3 +1,3 @@
-pub mod colorful;
+pub mod markdown;
 pub mod pager;
 pub mod table;
diff --git a/utils/src/display/colorful.rs b/utils/src/display/markdown.rs
index 40f83bf..40f83bf 100644
--- a/utils/src/display/colorful.rs
+++ b/utils/src/display/markdown.rs