Refactor rarely changing engine state into its own struct (#3612)

* WIP

* Finish up EngineState refactor

* Fix Windows calls

* Fix Windows calls

* Fix Windows calls

crates/nu-command/src/commands/autoview/command.rs

@@ -59,7 +59,7 @@ pub fn autoview(args: CommandArgs) -> Result<OutputStream, ShellError> {
     if let Some(x) = input_stream.next() {
         match input_stream.next() {
             Some(y) => {
-                let ctrl_c = context.ctrl_c.clone();
+                let ctrl_c = context.ctrl_c().clone();
                 let xy = vec![x, y];
                 let xy_stream = xy.into_iter().chain(input_stream).interruptible(ctrl_c);
 
@@ -192,7 +192,7 @@ pub fn autoview(args: CommandArgs) -> Result<OutputStream, ShellError> {
                     } => {
                         let pivot_mode = configuration.pivot_mode();
 
-                        let term_width = context.host.lock().width();
+                        let term_width = context.host().lock().width();
                         if pivot_mode.is_always()
                             || (pivot_mode.is_auto()
                                 && (row

crates/nu-command/src/commands/classified/external.rs

@@ -27,7 +27,7 @@ pub(crate) fn run_external_command(
     trace!(target: "nu::run::external", "-> {}", command.name);
 
     context.sync_path_to_env();
-    if !context.host.lock().is_external_cmd(&command.name) {
+    if !context.host().lock().is_external_cmd(&command.name) {
         return Err(ShellError::labeled_error(
             "Command not found",
             format!("command {} not found", &command.name),
@@ -59,7 +59,7 @@ fn run_with_stdin(
     input: InputStream,
     external_redirection: ExternalRedirection,
 ) -> Result<InputStream, ShellError> {
-    let path = context.shell_manager.path();
+    let path = context.shell_manager().path();
 
     let mut command_args = vec![];
     for arg in command.args.iter() {

crates/nu-command/src/commands/config/get.rs

@@ -41,7 +41,7 @@ pub fn get(args: CommandArgs) -> Result<OutputStream, ShellError> {
 
     let column_path = args.req(0)?;
 
-    let result = if let Some(global_cfg) = &ctx.configs.lock().global_config {
+    let result = if let Some(global_cfg) = &ctx.configs().lock().global_config {
         let result = UntaggedValue::row(global_cfg.vars.clone()).into_value(&name);
         let value = crate::commands::get::get_column_path(&column_path, &result)?;
         Ok(match value {

crates/nu-command/src/commands/config/remove.rs

@@ -43,7 +43,7 @@ pub fn remove(args: CommandArgs) -> Result<OutputStream, ShellError> {
 
     let key = remove.to_string();
 
-    let result = if let Some(global_cfg) = &mut ctx.configs.lock().global_config {
+    let result = if let Some(global_cfg) = &mut ctx.configs().lock().global_config {
         if global_cfg.vars.contains_key(&key) {
             global_cfg.vars.swap_remove(&key);
             global_cfg.write()?;

crates/nu-command/src/commands/config/set.rs

@@ -57,7 +57,7 @@ pub fn set(args: CommandArgs) -> Result<OutputStream, ShellError> {
     let column_path = args.req(0)?;
     let mut value: Value = args.req(1)?;
 
-    let result = if let Some(global_cfg) = &mut ctx.configs.lock().global_config {
+    let result = if let Some(global_cfg) = &mut ctx.configs().lock().global_config {
         let configuration = UntaggedValue::row(global_cfg.vars.clone()).into_value(&name);
 
         if let UntaggedValue::Table(rows) = &value.value {

crates/nu-command/src/commands/config/set_into.rs

@@ -45,7 +45,7 @@ pub fn set_into(args: CommandArgs) -> Result<OutputStream, ShellError> {
     let rows: Vec<Value> = args.input.collect();
     let key = set_into.to_string();
 
-    let result = if let Some(global_cfg) = &mut ctx.configs.lock().global_config {
+    let result = if let Some(global_cfg) = &mut ctx.configs().lock().global_config {
         if rows.is_empty() {
             return Err(ShellError::labeled_error(
                 "No values given for set_into",

crates/nu-command/src/commands/dataframe/dtypes.rs

@@ -31,6 +31,7 @@ impl WholeStreamCommand for DataFrame {
     }
 }
 
+#[allow(clippy::needless_collect)]
 fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
     let tag = args.call_info.name_tag.clone();
 

crates/nu-command/src/commands/enter.rs

@@ -73,7 +73,7 @@ fn enter(args: CommandArgs) -> Result<ActionStream, ShellError> {
     let head = args.call_info.args.head.clone();
     let context = args.context.clone();
     let scope = args.scope().clone();
-    let path = args.context.shell_manager.path();
+    let path = args.context.shell_manager().path();
 
     let location: Tagged<PathBuf> = args.req(0)?;
     let encoding: Option<Tagged<String>> = args.get_flag("encoding")?;

crates/nu-command/src/commands/history.rs

@@ -31,7 +31,7 @@ fn history(args: CommandArgs) -> Result<ActionStream, ShellError> {
 
     let clear = args.has_flag("clear");
 
-    let path = if let Some(global_cfg) = &ctx.configs.lock().global_config {
+    let path = if let Some(global_cfg) = &ctx.configs().lock().global_config {
         nu_data::config::path::history_path_or_default(global_cfg)
     } else {
         nu_data::config::path::default_history_path()

crates/nu-command/src/commands/run_external.rs

@@ -102,7 +102,7 @@ impl WholeStreamCommand for RunExternalCommand {
                 };
 
                 let result = external_context
-                    .shell_manager
+                    .shell_manager()
                     .cd(cd_args, args.call_info.name_tag);
 
                 return Ok(result?.to_action_stream());
@@ -138,7 +138,7 @@ fn maybe_autocd_dir(cmd: &ExternalCommand, ctx: &mut EvaluationContext) -> Optio
         || (cmd.args.is_empty()
             && PathBuf::from(name).is_dir()
             && dunce::canonicalize(name).is_ok()
-            && !ctx.host.lock().is_external_cmd(name))
+            && !ctx.host().lock().is_external_cmd(name))
     {
         Some(name)
     } else {
@@ -151,11 +151,11 @@ fn maybe_autocd_dir(cmd: &ExternalCommand, ctx: &mut EvaluationContext) -> Optio
             if name.ends_with(':') {
                 // This looks like a drive shortcut. We need to a) switch drives and b) go back to the previous directory we were viewing on that drive
                 // But first, we need to save where we are now
-                let current_path = ctx.shell_manager.path();
+                let current_path = ctx.shell_manager().path();
 
                 let split_path: Vec<_> = current_path.split(':').collect();
                 if split_path.len() > 1 {
-                    ctx.windows_drives_previous_cwd
+                    ctx.windows_drives_previous_cwd()
                         .lock()
                         .insert(split_path[0].to_string(), current_path);
                 }
@@ -163,7 +163,7 @@ fn maybe_autocd_dir(cmd: &ExternalCommand, ctx: &mut EvaluationContext) -> Optio
                 let name = name.to_uppercase();
                 let new_drive: Vec<_> = name.split(':').collect();
 
-                if let Some(val) = ctx.windows_drives_previous_cwd.lock().get(new_drive[0]) {
+                if let Some(val) = ctx.windows_drives_previous_cwd().lock().get(new_drive[0]) {
                     val.to_string()
                 } else {
                     name