Add `flat` command (#177)

* add `flat` command

* fix bulk_rename command

* fix `open_file` commands

* update docs

* fix errors found by clippy

* fix errors found by clippy::unnecessary-to-owned

* fix open and open_with commands

* fix: crash on root dirs

15 files changed, 201 insertions, 75 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 081941e..9a4c329 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -393,6 +393,7 @@ dependencies = [
  "unicode-segmentation",
  "unicode-width",
  "users",
+ "walkdir",
  "whoami",
  "xdg",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index bad3957..66084ca 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -38,6 +38,7 @@ unicode-width = "^0"
 users = "^0"
 whoami = "^1"
 xdg = "^2"
+walkdir = "^2"
 
 [features]
 devicons = [ "phf" ]
diff --git a/docs/configuration/keymap.toml.md b/docs/configuration/keymap.toml.md
index 8cc9def..1086f04 100644
--- a/docs/configuration/keymap.toml.md
+++ b/docs/configuration/keymap.toml.md
@@ -124,6 +124,10 @@ function joshuto() {
     - `line_nums 0` or `line_nums none`: disable displaying
     - `line_nums 1` or `line_nums absolute`: enable absolute numbers for each entry
     - `line_nums 2` or `line_nums relative`: enable numbers relative to selected entry
+ - `flat`: flattens the directory view up to the specified depth.
+    - `flat 3`: flatten directory upto 3 directories deep.
+    depth of 0 corresponds to the current directory.
+    its direct descendents have depth 1, and their descendents have depth 2, and so on.
 
 ## Navigation
  - `cursor_move_up`: moves the cursor up by x amount
diff --git a/src/commands/bulk_rename.rs b/src/commands/bulk_rename.rs
index 43facee..096869e 100644
--- a/src/commands/bulk_rename.rs
+++ b/src/commands/bulk_rename.rs
@@ -33,18 +33,18 @@ pub fn _bulk_rename(context: &mut AppContext) -> JoshutoResult {
     let mut file_path = path::PathBuf::from(&tmp_directory);
     file_path.push(rand_str);
 
-    let paths = context
+    let entries = context
         .tab_context_ref()
         .curr_tab_ref()
         .curr_list_ref()
-        .map_or(vec![], |s| s.get_selected_paths());
+        .map_or(vec![], |s| s.iter_selected().collect());
 
     /* write file names into temporary file to edit */
     {
         let mut file = fs::File::create(&file_path)?;
-        for path in paths.iter() {
-            let file_name = path.file_name().unwrap();
-            let file_name_as_bytes = file_name.to_str().unwrap().as_bytes();
+        for path in entries.iter() {
+            let file_name = path.file_name();
+            let file_name_as_bytes = file_name.as_bytes();
             file.write_all(file_name_as_bytes)?;
             file.write_all(&[b'\n'])?;
         }
@@ -66,7 +66,7 @@ pub fn _bulk_rename(context: &mut AppContext) -> JoshutoResult {
         }
     }
 
-    let mut paths_renamed: Vec<path::PathBuf> = Vec::with_capacity(paths.len());
+    let mut paths_renamed: Vec<path::PathBuf> = Vec::with_capacity(entries.len());
     {
         let file = std::fs::File::open(&file_path)?;
 
@@ -82,7 +82,7 @@ pub fn _bulk_rename(context: &mut AppContext) -> JoshutoResult {
         }
         std::fs::remove_file(&file_path)?;
     }
-    if paths_renamed.len() < paths.len() {
+    if paths_renamed.len() < entries.len() {
         return Err(JoshutoError::new(
             JoshutoErrorKind::Io(io::ErrorKind::InvalidInput),
             "Insufficient inputs".to_string(),
@@ -90,8 +90,8 @@ pub fn _bulk_rename(context: &mut AppContext) -> JoshutoResult {
     }
 
     println!("{}", termion::clear::All);
-    for (p, q) in paths.iter().zip(paths_renamed.iter()) {
-        println!("{:?} -> {:?}", p, q);
+    for (p, q) in entries.iter().zip(paths_renamed.iter()) {
+        println!("{:?} -> {:?}", p.file_name(), q);
     }
     print!("Continue with rename? (Y/n): ");
     std::io::stdout().flush()?;
@@ -102,11 +102,11 @@ pub fn _bulk_rename(context: &mut AppContext) -> JoshutoResult {
 
     let user_input_trimmed = user_input.trim();
     if user_input_trimmed != "n" || user_input_trimmed != "no" {
-        for (p, q) in paths.iter().zip(paths_renamed.iter()) {
+        for (p, q) in entries.iter().zip(paths_renamed.iter()) {
             let mut handle = process::Command::new("mv")
                 .arg("-iv")
                 .arg("--")
-                .arg(p)
+                .arg(p.file_name())
                 .arg(q)
                 .spawn()?;
             handle.wait()?;
diff --git a/src/commands/flat.rs b/src/commands/flat.rs
new file mode 100644
index 0000000..632b321
--- /dev/null
+++ b/src/commands/flat.rs
@@ -0,0 +1,80 @@
+use std::io;
+use std::path::Path;
+
+use crate::config::option::DisplayOption;
+use crate::context::AppContext;
+use crate::error::JoshutoResult;
+use crate::fs::{JoshutoDirEntry, JoshutoDirList, JoshutoMetadata};
+
+use walkdir::WalkDir;
+
+fn _is_hidden(entry: &walkdir::DirEntry) -> bool {
+    entry
+        .file_name()
+        .to_str()
+        .map(|s| s.starts_with('.'))
+        .unwrap_or(false)
+}
+
+pub fn _walk_directory(
+    path: &Path,
+    options: &DisplayOption,
+    depth: usize,
+) -> io::Result<Vec<JoshutoDirEntry>> {
+    let results: Vec<JoshutoDirEntry> = WalkDir::new(path)
+        .max_depth(depth)
+        .into_iter()
+        .filter_entry(|e| {
+            if options.show_hidden() {
+                true
+            } else {
+                !_is_hidden(e)
+            }
+        })
+        .filter(|e| {
+            if let Ok(e) = e.as_ref() {
+                e.path().to_str().cmp(&path.to_str()).is_ne()
+            } else {
+                true
+            }
+        })
+        .filter_map(|res| JoshutoDirEntry::from_walk(&res.ok()?, path, options).ok())
+        .collect();
+
+    Ok(results)
+}
+
+pub fn flatten(depth: usize, context: &mut AppContext) -> JoshutoResult {
+    let path = context.tab_context_ref().curr_tab_ref().cwd().to_path_buf();
+
+    let options = context.config_ref().display_options_ref().clone();
+
+    let mut index: Option<usize> = context
+        .tab_context_ref()
+        .curr_tab_ref()
+        .curr_list_ref()
+        .map(|lst| lst.get_index())
+        .unwrap_or(None);
+    let viewport_index: usize = context
+        .tab_context_ref()
+        .curr_tab_ref()
+        .curr_list_ref()
+        .map(|lst| lst.first_index_for_viewport())
+        .unwrap_or(0);
+
+    let mut contents = _walk_directory(path.as_path(), &options, depth)?;
+    let history = context.tab_context_mut().curr_tab_mut().history_mut();
+
+    if contents.is_empty() {
+        index = None;
+    }
+
+    let sort_options = options.sort_options_ref();
+    contents.sort_by(|f1, f2| sort_options.compare(f1, f2));
+
+    let metadata = JoshutoMetadata::from(path.as_path())?;
+    let dirlist = JoshutoDirList::new(path.clone(), contents, index, viewport_index, metadata);
+    history.insert(path, dirlist);
+
+    Ok(())
+}
diff --git a/src/commands/mod.rs b/src/commands/mod.rs
index 1f447c2..f4e0ee5 100644
--- a/src/commands/mod.rs
+++ b/src/commands/mod.rs
@@ -4,6 +4,7 @@ pub mod command_line;
 pub mod cursor_move;
 pub mod delete_files;
 pub mod file_ops;
+pub mod flat;
 pub mod line_nums;
 pub mod new_directory;
 pub mod numbered_command;
diff --git a/src/commands/open_file.rs b/src/commands/open_file.rs
index 24acae1..dfcbb9a 100644
--- a/src/commands/open_file.rs
+++ b/src/commands/open_file.rs
@@ -26,7 +26,7 @@ pub fn get_options<'a>(path: &path::Path) -> Vec<&'a AppMimetypeEntry> {
 
 pub fn open(context: &mut AppContext, backend: &mut TuiBackend) -> JoshutoResult {
     let curr_list = context.tab_context_ref().curr_tab_ref().curr_list_ref();
-    let entry = curr_list.and_then(|s| s.curr_entry_ref());
+    let entry = curr_list.and_then(|s| s.curr_entry_ref().cloned());
 
     match entry {
         None => (),
@@ -35,16 +35,15 @@ pub fn open(context: &mut AppContext, backend: &mut TuiBackend) -> JoshutoResult
             change_directory::cd(path.as_path(), context)?;
             reload::soft_reload(context.tab_context_ref().index, context)?;
         }
-        Some(_) => {
-            let paths = curr_list.map_or_else(Vec::new, |s| s.get_selected_paths());
-            let path = paths.get(0).ok_or_else(|| {
-                JoshutoError::new(
-                    JoshutoErrorKind::Io(io::ErrorKind::NotFound),
-                    String::from("No files selected"),
-                )
-            })?;
-
-            let files: Vec<&std::ffi::OsStr> = paths.iter().filter_map(|e| e.file_name()).collect();
+        Some(entry) => {
+            let paths = curr_list.map_or_else(Vec::new, |s| s.iter_selected().cloned().collect());
+            let path = if paths.is_empty() {
+                entry.file_path()
+            } else {
+                paths.get(0).unwrap().file_path()
+            };
+
+            let files: Vec<&str> = paths.iter().map(|e| e.file_name()).collect();
             let options = get_options(path);
             let option = options.iter().find(|option| option.program_exists());
 
@@ -160,20 +159,25 @@ where
 }
 
 pub fn open_with_interactive(context: &mut AppContext, backend: &mut TuiBackend) -> JoshutoResult {
-    let paths = context
+    let mut paths = context
         .tab_context_ref()
         .curr_tab_ref()
         .curr_list_ref()
-        .map_or(vec![], |s| s.get_selected_paths());
+        .map_or(vec![], |s| s.iter_selected().cloned().collect());
 
     if paths.is_empty() {
-        return Err(JoshutoError::new(
-            JoshutoErrorKind::Io(io::ErrorKind::NotFound),
-            String::from("No files selected"),
-        ));
+        paths.push(
+            context
+                .tab_context_ref()
+                .curr_tab_ref()
+                .curr_list_ref()
+                .and_then(|s| s.curr_entry_ref())
+                .unwrap()
+                .clone(),
+        );
     }
-    let files: Vec<&std::ffi::OsStr> = paths.iter().filter_map(|e| e.file_name()).collect();
-    let options = get_options(paths[0].as_path());
+    let files: Vec<&str> = paths.iter().map(|e| e.file_name()).collect();
+    let options = get_options(paths[0].file_path());
 
     open_with_helper(context, backend, options, &files)?;
     Ok(())
@@ -188,7 +192,7 @@ pub fn open_with_index(
         .tab_context_ref()
         .curr_tab_ref()
         .curr_list_ref()
-        .map_or(vec![], |s| s.get_selected_paths());
+        .map_or(vec![], |s| s.iter_selected().cloned().collect());
 
     if paths.is_empty() {
         return Err(JoshutoError::new(
@@ -196,8 +200,8 @@ pub fn open_with_index(
             String::from("No files selected"),
         ));
     }
-    let files: Vec<&std::ffi::OsStr> = paths.iter().filter_map(|e| e.file_name()).collect();
-    let options = get_options(paths[0].as_path());
+    let files: Vec<&str> = paths.iter().map(|e| e.file_name()).collect();
+    let options = get_options(paths[0].file_path());
 
     if index >= options.len() {
         return Err(JoshutoError::new(
diff --git a/src/commands/show_tasks.rs b/src/commands/show_tasks.rs
index ae2a43a..4b22860 100644
--- a/src/commands/show_tasks.rs
+++ b/src/commands/show_tasks.rs
@@ -21,29 +21,25 @@ pub fn show_tasks(
         if let Ok(event) = context.poll_event() {
             match event {
                 AppEvent::Termion(key) => {
-                    match key {
-                        key => match keymap_t.task_view.get(&key) {
-                            None => {
-                                context
-                                    .message_queue_mut()
-                                    .push_info(format!("Unmapped input: {}", key.to_string()));
+                    let key = key;
+                    match keymap_t.task_view.get(&key) {
+                        None => {
+                            context
+                                .message_queue_mut()
+                                .push_info(format!("Unmapped input: {}", key.to_string()));
+                        }
+                        Some(CommandKeybind::SimpleKeybind(command)) => {
+                            if let Command::ShowTasks = command {
+                                break;
                             }
-                            Some(CommandKeybind::SimpleKeybind(command)) => match command {
-                                Command::ShowTasks => break,
-                                _ => {}
-                            },
-                            Some(CommandKeybind::CompositeKeybind(m)) => {
-                                let cmd =
-                                    process_event::get_input_while_composite(backend, context, m);
+                        }
+                        Some(CommandKeybind::CompositeKeybind(m)) => {
+                            let cmd = process_event::get_input_while_composite(backend, context, m);
 
-                                if let Some(command) = cmd {
-                                    match command {
-                                        Command::ShowTasks => break,
-                                        _ => {}
-                                    }
-                                }
+                            if let Some(Command::ShowTasks) = cmd {
+                                break;
                             }
-                        },
+                        }
                     }
                     context.flush_event();
                 }
diff --git a/src/fs/entry.rs b/src/fs/entry.rs
index 4dbaeb4..8337bc4 100644
--- a/src/fs/entry.rs
+++ b/src/fs/entry.rs
@@ -20,37 +20,30 @@ impl JoshutoDirEntry {
     pub fn from(direntry: &fs::DirEntry, options: &DisplayOption) -> io::Result<Self> {
         let path = direntry.path();
 
-        let mut metadata = JoshutoMetadata::from(&path)?;
         let name = direntry
             .file_name()
             .as_os_str()
             .to_string_lossy()
             .to_string();
 
-        if options.automatically_count_files() && metadata.file_type().is_dir() {
-            if let Ok(size) = get_directory_size(path.as_path()) {
-                metadata.update_directory_size(size);
-            }
-        }
+        Self::gen_entry(path, name, options)
+    }
 
-        #[cfg(feature = "devicons")]
-        let label = if options.show_icons() {
-            create_icon_label(name.as_str(), &metadata)
-        } else {
-            name.clone()
-        };
+    pub fn from_walk(
+        direntry: &walkdir::DirEntry,
+        base: &path::Path,
+        options: &DisplayOption,
+    ) -> io::Result<Self> {
+        let path = direntry.path().to_path_buf();
 
-        #[cfg(not(feature = "devicons"))]
-        let label = name.clone();
+        let name = direntry
+            .path()
+            .strip_prefix(base)
+            .unwrap()
+            .to_string_lossy()
+            .to_string();
 
-        Ok(Self {
-            name,
-            label,
-            path,
-            metadata,
-            selected: false,
-            _marked: false,
-        })
+        Self::gen_entry(path, name, options)
     }
 
     pub fn file_name(&self) -> &str {
@@ -84,6 +77,35 @@ impl JoshutoDirEntry {
             None => "",
         }
     }
+
+    fn gen_entry(path: path::PathBuf, name: String, options: &DisplayOption) -> io::Result<Self> {
+        let mut metadata = JoshutoMetadata::from(&path)?;
+
+        if options.automatically_count_files() && metadata.file_type().is_dir() {
+            if let Ok(size) = get_directory_size(path.as_path()) {
+                metadata.update_directory_size(size);
+            }
+        }
+
+        #[cfg(feature = "devicons")]
+        let label = if options.show_icons() {
+            create_icon_label(name.as_str(), &metadata)
+        } else {
+            name.clone()
+        };
+
+        #[cfg(not(feature = "devicons"))]
+        let label = name.clone();
+
+        Ok(Self {
+            name,
+            label,
+            path,
+            metadata,
+            selected: false,
+            _marked: false,
+        })
+    }
 }
 
 impl std::fmt::Display for JoshutoDirEntry {
diff --git a/src/key_command/command.rs b/src/key_command/command.rs
index 3cc0cb3..495cff5 100644
--- a/src/key_command/command.rs
+++ b/src/key_command/command.rs
@@ -69,6 +69,8 @@ pub enum Command {
 
     SwitchLineNums(LineNumberStyle),
 
+    Flat(usize),
+
     Sort(SortType),
     SortReverse,
 
diff --git a/src/key_command/constants.rs b/src/key_command/constants.rs
index 6e4ea09..ba5db2e 100644
--- a/src/key_command/constants.rs
+++ b/src/key_command/constants.rs
@@ -75,6 +75,7 @@ cmd_constants![
     (CMD_SUBDIR_FZF, "subdir_fzf"),
     (CMD_ZOXIDE, "z"),
     (CMD_ZOXIDE_INTERACTIVE, "zi"),
+    (CMD_FLAT, "flat"),
 ];
 
 pub fn complete_command(partial_command: &str) -> Vec<Pair> {
diff --git a/src/key_command/impl_appcommand.rs b/src/key_command/impl_appcommand.rs
index 68f4824..c04ade7 100644
--- a/src/key_command/impl_appcommand.rs
+++ b/src/key_command/impl_appcommand.rs
@@ -63,6 +63,8 @@ impl AppCommand for Command {
 
             Self::ShowTasks => CMD_SHOW_TASKS,
 
+            Self::Flat(_) => CMD_FLAT,
+
             Self::Sort(_) => CMD_SORT,
             Self::SortReverse => CMD_SORT_REVERSE,
 
diff --git a/src/key_command/impl_appexecute.rs b/src/key_command/impl_appexecute.rs
index bf2b9fc..3f88f4b 100644
--- a/src/key_command/impl_appexecute.rs
+++ b/src/key_command/impl_appexecute.rs
@@ -95,6 +95,8 @@ impl AppExecute for Command {
             }
             Self::SwitchLineNums(d) => line_nums::switch_line_numbering(context, *d),
 
+            Self::Flat(depth) => flat::flatten(*depth, context),
+
             Self::ToggleHiddenFiles => show_hidden::toggle_hidden(context),
 
             Self::TabSwitch(i) => {
diff --git a/src/key_command/impl_comment.rs b/src/key_command/impl_comment.rs
index 59f0d00..bd5e4e6 100644
--- a/src/key_command/impl_comment.rs
+++ b/src/key_command/impl_comment.rs
@@ -85,6 +85,8 @@ impl CommandComment for Command {
 
             Self::SwitchLineNums(_) => "Switch line numbering",
 
+            Self::Flat(_) => "Flattern directory list",
+
             Self::Sort(sort_type) => match sort_type {
                 SortType::Lexical => "Sort lexically",
                 SortType::Mtime => "Sort by modifiaction time",
diff --git a/src/key_command/impl_from_str.rs b/src/key_command/impl_from_str.rs
index 7a19cce..c09fe66 100644
--- a/src/key_command/impl_from_str.rs
+++ b/src/key_command/impl_from_str.rs
@@ -316,6 +316,14 @@ impl std::str::FromStr for Command {
                 _ => LineNumberStyle::None,
             };
             Ok(Self::SwitchLineNums(policy))
+        } else if command == CMD_FLAT {
+            match arg.parse::<usize>() {
+                Ok(i) => Ok(Self::Flat(i + 1)),
+                Err(e) => Err(JoshutoError::new(
+                    JoshutoErrorKind::InvalidParameters,
+                    format!("{}: {}", command, e),
+                )),
+            }
         } else {
             Err(JoshutoError::new(
                 JoshutoErrorKind::UnrecognizedCommand,