From 17855d37a4274f7a463bf455cbfd8268c1f327a2 Mon Sep 17 00:00:00 2001
From: Jonathan Turner <jonathan.d.turner@gmail.com>
Date: Mon, 16 Sep 2019 19:52:58 +1200
Subject: [PATCH] Add env command

---
 src/cli.rs          |  1 +
 src/commands.rs     |  2 ++
 src/commands/env.rs | 68 +++++++++++++++++++++++++++++++++++++++++++++
 src/data/dict.rs    |  4 +++
 4 files changed, 75 insertions(+)
 create mode 100644 src/commands/env.rs

diff --git a/src/cli.rs b/src/cli.rs
index 68c652c772..0bc8856195 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -244,6 +244,7 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
             whole_stream_command(Tags),
             whole_stream_command(First),
             whole_stream_command(Last),
+            whole_stream_command(Env),
             whole_stream_command(FromCSV),
             whole_stream_command(FromTSV),
             whole_stream_command(FromINI),
diff --git a/src/commands.rs b/src/commands.rs
index c6cc7b7285..af612d5752 100644
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -13,6 +13,7 @@ pub(crate) mod date;
 pub(crate) mod debug;
 pub(crate) mod echo;
 pub(crate) mod enter;
+pub(crate) mod env;
 pub(crate) mod exit;
 pub(crate) mod fetch;
 pub(crate) mod first;
@@ -78,6 +79,7 @@ pub(crate) use date::Date;
 pub(crate) use debug::Debug;
 pub(crate) use echo::Echo;
 pub(crate) use enter::Enter;
+pub(crate) use env::Env;
 pub(crate) use exit::Exit;
 pub(crate) use fetch::Fetch;
 pub(crate) use first::First;
diff --git a/src/commands/env.rs b/src/commands/env.rs
new file mode 100644
index 0000000000..6fc26507cc
--- /dev/null
+++ b/src/commands/env.rs
@@ -0,0 +1,68 @@
+use crate::data::{Dictionary, Value};
+use crate::errors::ShellError;
+use crate::prelude::*;
+use crate::TaggedDictBuilder;
+
+use crate::commands::WholeStreamCommand;
+use crate::parser::registry::Signature;
+use indexmap::IndexMap;
+
+pub struct Env;
+
+impl WholeStreamCommand for Env {
+    fn name(&self) -> &str {
+        "env"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("env")
+    }
+
+    fn usage(&self) -> &str {
+        "Get the current environment."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        env(args, registry)
+    }
+}
+
+pub fn get_environment(tag: Tag) -> Result<Tagged<Value>, Box<dyn std::error::Error>> {
+    let mut indexmap = IndexMap::new();
+
+    let path = std::env::current_dir()?;
+    indexmap.insert("cwd".to_string(), Value::path(path).tagged(tag));
+
+    if let Some(home) = dirs::home_dir() {
+        indexmap.insert("home".to_string(), Value::path(home).tagged(tag));
+    }
+
+    let temp = std::env::temp_dir();
+    indexmap.insert("temp".to_string(), Value::path(temp).tagged(tag));
+
+    let mut dict = TaggedDictBuilder::new(tag);
+    for v in std::env::vars() {
+        dict.insert(v.0, Value::string(v.1));
+    }
+    if !dict.is_empty() {
+        indexmap.insert("vars".to_string(), dict.into_tagged_value());
+    }
+
+    Ok(Value::Row(Dictionary::from(indexmap)).tagged(tag))
+}
+
+pub fn env(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+
+    let mut env_out = VecDeque::new();
+    let tag = args.call_info.name_tag;
+
+    let value = get_environment(tag)?;
+    env_out.push_back(value);
+
+    Ok(env_out.to_output_stream())
+}
diff --git a/src/data/dict.rs b/src/data/dict.rs
index eba68a7f8a..c14c86dd90 100644
--- a/src/data/dict.rs
+++ b/src/data/dict.rs
@@ -169,6 +169,10 @@ impl TaggedDictBuilder {
     pub fn into_tagged_dict(self) -> Tagged<Dictionary> {
         Dictionary { entries: self.dict }.tagged(self.tag)
     }
+
+    pub fn is_empty(&self) -> bool {
+        self.dict.is_empty()
+    }
 }
 
 impl From<TaggedDictBuilder> for Tagged<Value> {