From f37b6c7cf5ee6a02251a2598e1451af568336bf0 Mon Sep 17 00:00:00 2001
From: Patrick Klitzke <philologos14@gmail.com>
Date: Mon, 21 Aug 2023 11:30:38 +0900
Subject: [PATCH] date: Adds support datetime for parameter -d

This resolved issue #5177.

The PR adds a new enum  HumanDuration(Duration), HumanDateTime(DateTime<FixedOffset>) and uses  parse_datetime::parse_datetime::from_str  to support datetime if relative time cannot be parsed.

Furthermore tests are added for tests/by-util/test_date.rs.
---
 src/uu/date/src/date.rs    | 13 ++++++++++---
 tests/by-util/test_date.rs | 39 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/src/uu/date/src/date.rs b/src/uu/date/src/date.rs
index 745fd54239c..afb056bdebb 100644
--- a/src/uu/date/src/date.rs
+++ b/src/uu/date/src/date.rs
@@ -92,7 +92,8 @@ enum DateSource {
     Now,
     Custom(String),
     File(PathBuf),
-    Human(Duration),
+    HumanDuration(Duration),
+    HumanDateTime(DateTime<FixedOffset>)
 }
 
 enum Iso8601Format {
@@ -167,7 +168,9 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
 
     let date_source = if let Some(date) = matches.get_one::<String>(OPT_DATE) {
         if let Ok(duration) = parse_datetime::from_str(date.as_str()) {
-            DateSource::Human(duration)
+            DateSource::HumanDuration(duration)
+        } else if let Ok(date_time) = parse_datetime::parse_datetime::from_str(date.as_str()) {
+            DateSource::HumanDateTime(date_time)
         } else {
             DateSource::Custom(date.into())
         }
@@ -221,7 +224,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
                 let iter = std::iter::once(date);
                 Box::new(iter)
             }
-            DateSource::Human(relative_time) => {
+            DateSource::HumanDuration(relative_time) => {
                 // Get the current DateTime<FixedOffset> for things like "1 year ago"
                 let current_time = DateTime::<FixedOffset>::from(Local::now());
                 // double check the result is overflow or not of the current_time + relative_time
@@ -239,6 +242,10 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
                     }
                 }
             }
+            DateSource::HumanDateTime(date) => {
+                let iter = std::iter::once(Ok(date));
+                Box::new(iter)
+            }
             DateSource::File(ref path) => {
                 if path.is_dir() {
                     return Err(USimpleError::new(
diff --git a/tests/by-util/test_date.rs b/tests/by-util/test_date.rs
index a65f02fa4c7..4ce335cda1b 100644
--- a/tests/by-util/test_date.rs
+++ b/tests/by-util/test_date.rs
@@ -368,7 +368,7 @@ fn test_unsupported_format() {
 }
 
 #[test]
-fn test_date_string_human() {
+fn test_date_string_human_relative_time() {
     let date_formats = vec![
         "1 year ago",
         "1 year",
@@ -390,6 +390,43 @@ fn test_date_string_human() {
     }
 }
 
+#[test]
+fn test_date_string_human_date_time() {
+    let date_formats = vec![
+        // unix timestamp format
+        "@0",
+        "@2",
+        "@10",
+        "@100",
+        "@2000",
+        "@1234400000",
+        "@1334400000",
+        "@1692582913",
+        "@2092582910",
+        // format YYYY-MM-DD
+        "2012-01-01",
+        "1999-01-12",
+        "2012-01-12",
+        // format YYYY-MM-DD HH:mm
+        "1970-01-01 00:00",
+        "2000-02-29 12:34",
+        "2100-02-28 23:59",
+        "2012-12-31 05:30",
+        "1800-01-01 18:45",
+        "9999-12-31 11:11",
+        "2023-08-21 14:55", //
+    ];
+    let re = Regex::new(r"^\d{4}-\d{2}-\d{2} \d{2}:\d{2}\n$").unwrap();
+    for date_format in date_formats {
+        new_ucmd!()
+            .arg("-d")
+            .arg(date_format)
+            .arg("+%Y-%m-%d %S:%M")
+            .succeeds()
+            .stdout_matches(&re);
+    }
+}
+
 #[test]
 fn test_invalid_date_string() {
     new_ucmd!()