From a9d321f731b13b6cdbd3f8069d6bd60558038edf Mon Sep 17 00:00:00 2001
From: nsfisis <nsfisis@gmail.com>
Date: Fri, 15 May 2026 00:57:02 +0900
Subject: feat(port): port RuleWatchNode.php

---
 .../src/dependency_resolver/rule_watch_node.rs     | 70 ++++++++++++++++++++++
 1 file changed, 70 insertions(+)

(limited to 'crates/shirabe/src/dependency_resolver/rule_watch_node.rs')

diff --git a/crates/shirabe/src/dependency_resolver/rule_watch_node.rs b/crates/shirabe/src/dependency_resolver/rule_watch_node.rs
index c7b50df..4161268 100644
--- a/crates/shirabe/src/dependency_resolver/rule_watch_node.rs
+++ b/crates/shirabe/src/dependency_resolver/rule_watch_node.rs
@@ -1 +1,71 @@
 //! ref: composer/src/Composer/DependencyResolver/RuleWatchNode.php
+
+use crate::dependency_resolver::decisions::Decisions;
+use crate::dependency_resolver::generic_rule::RuleLiterals;
+
+pub struct RuleWatchNode {
+    pub watch1: i64,
+    pub watch2: i64,
+    pub(crate) rule: Box<dyn RuleLiterals>,
+}
+
+impl std::fmt::Debug for RuleWatchNode {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("RuleWatchNode")
+            .field("watch1", &self.watch1)
+            .field("watch2", &self.watch2)
+            .finish()
+    }
+}
+
+impl RuleWatchNode {
+    pub fn new(rule: Box<dyn RuleLiterals>) -> Self {
+        let literals = rule.get_literals();
+        let literal_count = literals.len();
+        let watch1 = if literal_count > 0 { literals[0] } else { 0 };
+        let watch2 = if literal_count > 1 { literals[1] } else { 0 };
+
+        Self { watch1, watch2, rule }
+    }
+
+    pub fn watch2_on_highest(&mut self, decisions: &Decisions) {
+        let literals = self.rule.get_literals();
+
+        // if there are only 2 elements, both are being watched anyway
+        if literals.len() < 3 || self.rule.is_multi_conflict_rule() {
+            return;
+        }
+
+        let literals: Vec<i64> = literals.clone();
+        let mut watch_level: i64 = 0;
+
+        for literal in &literals {
+            let level = decisions.decision_level(*literal);
+
+            if level > watch_level {
+                self.watch2 = *literal;
+                watch_level = level;
+            }
+        }
+    }
+
+    pub fn get_rule(&self) -> &dyn RuleLiterals {
+        self.rule.as_ref()
+    }
+
+    pub fn get_other_watch(&self, literal: i64) -> i64 {
+        if self.watch1 == literal {
+            return self.watch2;
+        }
+
+        self.watch1
+    }
+
+    pub fn move_watch(&mut self, from: i64, to: i64) {
+        if self.watch1 == from {
+            self.watch1 = to;
+        } else {
+            self.watch2 = to;
+        }
+    }
+}
-- 
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