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zeph_common/
trust_level.rs

1// SPDX-FileCopyrightText: 2026 Andrei G <bug-ops>
2// SPDX-License-Identifier: MIT OR Apache-2.0
3
4//! Trust tier enum for skill execution permissions.
5//!
6//! [`SkillTrustLevel`] is the single source of truth for trust-level semantics across all
7//! Zeph crates. It lives in `zeph-common` so both `zeph-skills` and `zeph-tools` can depend
8//! on it without introducing a circular dependency.
9
10use std::fmt;
11use std::str::FromStr;
12
13use serde::{Deserialize, Serialize};
14
15/// Trust tier controlling what a skill is allowed to do.
16///
17/// The ordering from most to least trusted is: `Trusted` → `Verified` → `Quarantined` →
18/// `Blocked`. Use [`SkillTrustLevel::severity`] to compare levels numerically, or
19/// [`SkillTrustLevel::min_trust`] to find the least-trusted of two levels.
20///
21/// # Examples
22///
23/// ```rust
24/// use zeph_common::SkillTrustLevel;
25///
26/// let level = SkillTrustLevel::Quarantined;
27/// assert!(level.is_active());
28/// assert_eq!(level.severity(), 2);
29/// ```
30#[derive(Debug, Clone, Copy, Default, PartialEq, Eq, Hash, Deserialize, Serialize)]
31#[serde(rename_all = "lowercase")]
32pub enum SkillTrustLevel {
33    /// Built-in or user-audited skill: full tool access.
34    Trusted,
35    /// Signature or hash verified: default tool access.
36    Verified,
37    /// Newly imported or hash-mismatch: restricted tool access.
38    #[default]
39    Quarantined,
40    /// Explicitly disabled by user or auto-blocked by anomaly detector.
41    Blocked,
42}
43
44impl SkillTrustLevel {
45    /// Ordered severity: lower value = more trusted.
46    ///
47    /// # Examples
48    ///
49    /// ```rust
50    /// use zeph_common::SkillTrustLevel;
51    ///
52    /// assert!(SkillTrustLevel::Trusted.severity() < SkillTrustLevel::Blocked.severity());
53    /// ```
54    #[must_use]
55    pub fn severity(self) -> u8 {
56        match self {
57            Self::Trusted => 0,
58            Self::Verified => 1,
59            Self::Quarantined => 2,
60            Self::Blocked => 3,
61        }
62    }
63
64    /// Returns the least-trusted (highest severity) of two levels.
65    ///
66    /// # Examples
67    ///
68    /// ```rust
69    /// use zeph_common::SkillTrustLevel;
70    ///
71    /// let result = SkillTrustLevel::Trusted.min_trust(SkillTrustLevel::Quarantined);
72    /// assert_eq!(result, SkillTrustLevel::Quarantined);
73    /// ```
74    #[must_use]
75    pub fn min_trust(self, other: Self) -> Self {
76        if self.severity() >= other.severity() {
77            self
78        } else {
79            other
80        }
81    }
82
83    /// Returns `true` if the level is not `Blocked`.
84    ///
85    /// # Examples
86    ///
87    /// ```rust
88    /// use zeph_common::SkillTrustLevel;
89    ///
90    /// assert!(SkillTrustLevel::Quarantined.is_active());
91    /// assert!(!SkillTrustLevel::Blocked.is_active());
92    /// ```
93    #[must_use]
94    pub fn is_active(self) -> bool {
95        !matches!(self, Self::Blocked)
96    }
97}
98
99impl FromStr for SkillTrustLevel {
100    type Err = String;
101
102    fn from_str(s: &str) -> Result<Self, Self::Err> {
103        match s {
104            "trusted" => Ok(Self::Trusted),
105            "verified" => Ok(Self::Verified),
106            "quarantined" => Ok(Self::Quarantined),
107            "blocked" => Ok(Self::Blocked),
108            other => Err(format!(
109                "unknown trust level '{other}'; expected: trusted, verified, quarantined, blocked"
110            )),
111        }
112    }
113}
114
115impl fmt::Display for SkillTrustLevel {
116    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
117        match self {
118            Self::Trusted => f.write_str("trusted"),
119            Self::Verified => f.write_str("verified"),
120            Self::Quarantined => f.write_str("quarantined"),
121            Self::Blocked => f.write_str("blocked"),
122        }
123    }
124}
125
126#[cfg(test)]
127mod tests {
128    use super::*;
129
130    #[test]
131    fn severity_ordering() {
132        assert!(SkillTrustLevel::Trusted.severity() < SkillTrustLevel::Verified.severity());
133        assert!(SkillTrustLevel::Verified.severity() < SkillTrustLevel::Quarantined.severity());
134        assert!(SkillTrustLevel::Quarantined.severity() < SkillTrustLevel::Blocked.severity());
135    }
136
137    #[test]
138    fn min_trust_picks_least_trusted() {
139        assert_eq!(
140            SkillTrustLevel::Trusted.min_trust(SkillTrustLevel::Quarantined),
141            SkillTrustLevel::Quarantined
142        );
143        assert_eq!(
144            SkillTrustLevel::Blocked.min_trust(SkillTrustLevel::Trusted),
145            SkillTrustLevel::Blocked
146        );
147    }
148
149    #[test]
150    fn is_active() {
151        assert!(SkillTrustLevel::Trusted.is_active());
152        assert!(SkillTrustLevel::Verified.is_active());
153        assert!(SkillTrustLevel::Quarantined.is_active());
154        assert!(!SkillTrustLevel::Blocked.is_active());
155    }
156
157    #[test]
158    fn default_is_quarantined() {
159        assert_eq!(SkillTrustLevel::default(), SkillTrustLevel::Quarantined);
160    }
161
162    #[test]
163    fn display() {
164        assert_eq!(SkillTrustLevel::Trusted.to_string(), "trusted");
165        assert_eq!(SkillTrustLevel::Blocked.to_string(), "blocked");
166        assert_eq!(SkillTrustLevel::Quarantined.to_string(), "quarantined");
167        assert_eq!(SkillTrustLevel::Verified.to_string(), "verified");
168    }
169
170    #[test]
171    fn serde_roundtrip() {
172        let level = SkillTrustLevel::Quarantined;
173        let json = serde_json::to_string(&level).unwrap();
174        assert_eq!(json, "\"quarantined\"");
175        let back: SkillTrustLevel = serde_json::from_str(&json).unwrap();
176        assert_eq!(back, level);
177    }
178
179    #[test]
180    fn min_trust_same_level_returns_self() {
181        assert_eq!(
182            SkillTrustLevel::Verified.min_trust(SkillTrustLevel::Verified),
183            SkillTrustLevel::Verified
184        );
185    }
186}