open_loops/
state.rs

1//! Runtime state at `<base>/state.toml` (separate from declarative `config.toml`).
2//! Holds the active `@context` chosen via the CLI.
3use anyhow::{Context, Result};
4use serde::{Deserialize, Serialize};
5use std::path::{Path, PathBuf};
6
7#[derive(Debug, Default, Serialize, Deserialize, PartialEq, Eq)]
8struct StateFile {
9    #[serde(default)]
10    current_context: Option<String>,
11}
12
13pub struct State {
14    path: PathBuf,
15    current_context: Option<String>,
16}
17
18impl State {
19    /// Loads `<base>/state.toml`. Missing file yields empty state.
20    ///
21    /// On first run, migrates `current_context` or legacy `default_context` from
22    /// `config.toml` if present, then writes `state.toml`.
23    pub fn load(base: &Path) -> Result<Self> {
24        let path = base.join("state.toml");
25        if path.exists() {
26            let raw = std::fs::read_to_string(&path)
27                .with_context(|| format!("reading {}", path.display()))?;
28            let file: StateFile = toml::from_str(&raw)
29                .with_context(|| format!("invalid state.toml at {}", path.display()))?;
30            return Ok(Self {
31                path,
32                current_context: file.current_context,
33            });
34        }
35
36        let mut state = Self {
37            path,
38            current_context: None,
39        };
40        if let Some(legacy) = legacy_context_from_config(base)? {
41            state.current_context = Some(legacy);
42            state.save()?;
43        }
44        Ok(state)
45    }
46
47    pub fn current_context(&self) -> Option<&str> {
48        self.current_context.as_deref()
49    }
50
51    pub fn set_current_context(&mut self, name: Option<String>) -> Result<()> {
52        if self.current_context == name {
53            return Ok(());
54        }
55        self.current_context = name;
56        self.save()
57    }
58
59    fn save(&self) -> Result<()> {
60        let parent = self.path.parent().ok_or_else(|| {
61            anyhow::anyhow!("path has no parent directory: {}", self.path.display())
62        })?;
63        std::fs::create_dir_all(parent)?;
64        let file = StateFile {
65            current_context: self.current_context.clone(),
66        };
67        std::fs::write(&self.path, toml::to_string_pretty(&file)?)?;
68        Ok(())
69    }
70}
71
72fn legacy_context_from_config(base: &Path) -> Result<Option<String>> {
73    let config_path = base.join("config.toml");
74    let raw = match std::fs::read_to_string(&config_path) {
75        Ok(s) => s,
76        Err(e) if e.kind() == std::io::ErrorKind::NotFound => return Ok(None),
77        Err(e) => return Err(e).context(format!("reading {}", config_path.display())),
78    };
79    let table: toml::Value = toml::from_str(&raw)
80        .with_context(|| format!("invalid config.toml at {}", config_path.display()))?;
81    Ok(table
82        .get("current_context")
83        .or_else(|| table.get("default_context"))
84        .and_then(|v| v.as_str())
85        .map(str::to_string))
86}
87
88#[cfg(test)]
89mod tests {
90    use super::*;
91
92    #[test]
93    fn empty_when_file_missing_and_no_legacy_config() {
94        let tmp = tempfile::tempdir().unwrap();
95        let state = State::load(tmp.path()).unwrap();
96        assert_eq!(state.current_context(), None);
97        assert!(!tmp.path().join("state.toml").exists());
98    }
99
100    #[test]
101    fn set_persists_current_context() {
102        let tmp = tempfile::tempdir().unwrap();
103        let mut state = State::load(tmp.path()).unwrap();
104        state.set_current_context(Some("work".into())).unwrap();
105        let loaded = State::load(tmp.path()).unwrap();
106        assert_eq!(loaded.current_context(), Some("work"));
107    }
108
109    #[test]
110    fn clear_removes_current_context() {
111        let tmp = tempfile::tempdir().unwrap();
112        let mut state = State::load(tmp.path()).unwrap();
113        state.set_current_context(Some("work".into())).unwrap();
114        state.set_current_context(None).unwrap();
115        let loaded = State::load(tmp.path()).unwrap();
116        assert_eq!(loaded.current_context(), None);
117    }
118
119    #[test]
120    fn migrates_legacy_default_context_from_config() {
121        let tmp = tempfile::tempdir().unwrap();
122        std::fs::write(
123            tmp.path().join("config.toml"),
124            r#"
125roots = []
126
127default_context = "work"
128"#,
129        )
130        .unwrap();
131        let state = State::load(tmp.path()).unwrap();
132        assert_eq!(state.current_context(), Some("work"));
133        assert!(tmp.path().join("state.toml").exists());
134    }
135}
open_loops/state.rs

open_loops/
state.rs
