From 8b6f28f187ecbe0dc0608f054e0c05ad402014ca Mon Sep 17 00:00:00 2001
From: zooeywm <zooeywm@gmail.com>
Date: Sat, 13 Jul 2024 22:06:54 +0800
Subject: [PATCH] feat: add `random` option to the `sort` command

---
 yazi-config/preset/keymap.toml     |  2 ++
 yazi-config/src/manager/sorting.rs |  3 +++
 yazi-core/src/folder/sorter.rs     | 30 +++++++++++++++++++++++++++++-
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/yazi-config/preset/keymap.toml b/yazi-config/preset/keymap.toml
index daa6b442..f3bec02b 100644
--- a/yazi-config/preset/keymap.toml
+++ b/yazi-config/preset/keymap.toml
@@ -119,6 +119,8 @@ keymap = [
 	{ on = [ ",", "N" ], run = "sort natural --reverse",         desc = "Sort naturally (reverse)" },
 	{ on = [ ",", "s" ], run = "sort size --reverse=no",         desc = "Sort by size" },
 	{ on = [ ",", "S" ], run = "sort size --reverse",            desc = "Sort by size (reverse)" },
+	{ on = [ ",", "r" ], run = "sort random --reverse=no",       desc = "Sort randomly" },
+	{ on = [ ",", "R" ], run = "sort random --reverse",          desc = "Sort randomly (reverse)" },
 
 	# Tabs
 	{ on = "t", run = "tab_create --current", desc = "Create a new tab with CWD" },
diff --git a/yazi-config/src/manager/sorting.rs b/yazi-config/src/manager/sorting.rs
index 6d060090..648efb87 100644
--- a/yazi-config/src/manager/sorting.rs
+++ b/yazi-config/src/manager/sorting.rs
@@ -14,6 +14,7 @@ pub enum SortBy {
 	Alphabetical,
 	Natural,
 	Size,
+	Random,
 }
 
 impl FromStr for SortBy {
@@ -28,6 +29,7 @@ impl FromStr for SortBy {
 			"alphabetical" => Self::Alphabetical,
 			"natural" => Self::Natural,
 			"size" => Self::Size,
+			"random" => Self::Random,
 			_ => bail!("invalid sort_by value: {s}"),
 		})
 	}
@@ -49,6 +51,7 @@ impl Display for SortBy {
 			Self::Alphabetical => "alphabetical",
 			Self::Natural => "natural",
 			Self::Size => "size",
+			Self::Random => "random",
 		})
 	}
 }
diff --git a/yazi-core/src/folder/sorter.rs b/yazi-core/src/folder/sorter.rs
index eb7079b7..284038ae 100644
--- a/yazi-core/src/folder/sorter.rs
+++ b/yazi-core/src/folder/sorter.rs
@@ -1,8 +1,25 @@
-use std::{cmp::Ordering, collections::HashMap, mem};
+use std::{cmp::Ordering, collections::HashMap, mem, time::{SystemTime, UNIX_EPOCH}};
 
 use yazi_config::manager::SortBy;
 use yazi_shared::{fs::{File, Url}, natsort, Transliterator};
 
+struct LcgRng {
+	seed: u64,
+}
+
+impl LcgRng {
+	const A: u64 = 6364136223846793005;
+	const C: u64 = 1;
+	const M: u64 = u64::MAX;
+
+	fn new(seed: u64) -> Self { LcgRng { seed } }
+
+	fn next(&mut self) -> u64 {
+		self.seed = (Self::A.wrapping_mul(self.seed).wrapping_add(Self::C)) % Self::M;
+		self.seed
+	}
+}
+
 #[derive(Clone, Copy, Default, PartialEq)]
 pub struct FilesSorter {
 	pub by:        SortBy,
@@ -60,6 +77,17 @@ impl FilesSorter {
 				let ord = self.cmp(aa.unwrap_or(a.len), bb.unwrap_or(b.len), self.promote(a, b));
 				if ord == Ordering::Equal { by_alphabetical(a, b) } else { ord }
 			}),
+			SortBy::Random => {
+				let start = SystemTime::now();
+				let since_epoch = start.duration_since(UNIX_EPOCH).expect("Time went backwards");
+				let seed = since_epoch.as_secs() ^ since_epoch.subsec_nanos() as u64;
+				let mut rng = LcgRng::new(seed);
+				items.sort_unstable_by(|a, b| {
+					let aa = rng.next();
+					let bb = rng.next();
+					self.cmp(aa, bb, self.promote(a, b))
+				})
+			}
 		}
 	}