feat: complete Rust port of claude-statusline

Port the entire 2236-line bash statusline script to Rust.
Implements all 25 sections, 3-phase layout engine (render, priority
drop, flex/justify), file-based caching with flock, 9-level terminal
width detection, trend sparklines, and deep-merge JSON config.

Release binary: 864K with LTO. Render time: <1ms warm.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/config.rs

@@ -0,0 +1,721 @@
+use serde::Deserialize;
+use serde_json::Value;
+use std::collections::HashMap;
+
+const DEFAULTS_JSON: &str = include_str!("../defaults.json");
+
+// ── Top-level Config ────────────────────────────────────────────────────
+
+#[derive(Debug, Deserialize)]
+pub struct Config {
+    pub version: u32,
+    pub global: GlobalConfig,
+    pub colors: ThemeColors,
+    pub glyphs: GlyphConfig,
+    pub presets: HashMap<String, Vec<Vec<String>>>,
+    pub layout: LayoutValue,
+    pub sections: Sections,
+    pub custom: Vec<CustomCommand>,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        serde_json::from_str(DEFAULTS_JSON).expect("embedded defaults must parse")
+    }
+}
+
+// ── Layout: preset name or explicit array ───────────────────────────────
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(untagged)]
+pub enum LayoutValue {
+    Preset(String),
+    Custom(Vec<Vec<String>>),
+}
+
+impl Default for LayoutValue {
+    fn default() -> Self {
+        Self::Preset("standard".into())
+    }
+}
+
+// ── Global settings ─────────────────────────────────────────────────────
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct GlobalConfig {
+    pub separator: String,
+    pub justify: JustifyMode,
+    pub vcs: String,
+    pub width: Option<u16>,
+    pub width_margin: u16,
+    pub cache_dir: String,
+    pub cache_gc_days: u16,
+    pub cache_gc_interval_hours: u16,
+    pub cache_ttl_jitter_pct: u8,
+    pub responsive: bool,
+    pub breakpoints: Breakpoints,
+    pub render_budget_ms: u64,
+    pub theme: String,
+    pub color: ColorMode,
+    pub warn_unknown_keys: bool,
+    pub shell_enabled: bool,
+    pub shell_allowlist: Vec<String>,
+    pub shell_denylist: Vec<String>,
+    pub shell_timeout_ms: u64,
+    pub shell_max_output_bytes: usize,
+    pub shell_failure_threshold: u8,
+    pub shell_cooldown_ms: u64,
+    pub shell_env: HashMap<String, String>,
+    pub cache_version: u32,
+    pub drop_strategy: String,
+    pub breakpoint_hysteresis: u16,
+}
+
+impl Default for GlobalConfig {
+    fn default() -> Self {
+        Self {
+            separator: " | ".into(),
+            justify: JustifyMode::Left,
+            vcs: "auto".into(),
+            width: None,
+            width_margin: 4,
+            cache_dir: "/tmp/claude-sl-{session_id}".into(),
+            cache_gc_days: 7,
+            cache_gc_interval_hours: 24,
+            cache_ttl_jitter_pct: 10,
+            responsive: true,
+            breakpoints: Breakpoints::default(),
+            render_budget_ms: 8,
+            theme: "auto".into(),
+            color: ColorMode::Auto,
+            warn_unknown_keys: true,
+            shell_enabled: true,
+            shell_allowlist: Vec::new(),
+            shell_denylist: Vec::new(),
+            shell_timeout_ms: 200,
+            shell_max_output_bytes: 8192,
+            shell_failure_threshold: 3,
+            shell_cooldown_ms: 30_000,
+            shell_env: HashMap::new(),
+            cache_version: 1,
+            drop_strategy: "tiered".into(),
+            breakpoint_hysteresis: 2,
+        }
+    }
+}
+
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub enum JustifyMode {
+    #[default]
+    Left,
+    Spread,
+    SpaceBetween,
+}
+
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum ColorMode {
+    #[default]
+    Auto,
+    Always,
+    Never,
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct Breakpoints {
+    pub narrow: u16,
+    pub medium: u16,
+}
+
+impl Default for Breakpoints {
+    fn default() -> Self {
+        Self {
+            narrow: 60,
+            medium: 100,
+        }
+    }
+}
+
+// ── Color palettes ──────────────────────────────────────────────────────
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub struct ThemeColors {
+    pub dark: HashMap<String, String>,
+    pub light: HashMap<String, String>,
+}
+
+// ── Glyph config ────────────────────────────────────────────────────────
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub struct GlyphConfig {
+    pub enabled: bool,
+    pub set: HashMap<String, String>,
+    pub fallback: HashMap<String, String>,
+}
+
+// ── Shared section base (flattened into each section) ───────────────────
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(default)]
+pub struct SectionBase {
+    pub enabled: bool,
+    pub priority: u8,
+    pub flex: bool,
+    pub min_width: Option<u16>,
+    pub prefix: Option<String>,
+    pub suffix: Option<String>,
+    pub pad: Option<u16>,
+    pub align: Option<String>,
+    pub color: Option<String>,
+}
+
+impl Default for SectionBase {
+    fn default() -> Self {
+        Self {
+            enabled: true,
+            priority: 2,
+            flex: false,
+            min_width: None,
+            prefix: None,
+            suffix: None,
+            pad: None,
+            align: None,
+            color: None,
+        }
+    }
+}
+
+// ── Per-section typed configs ───────────────────────────────────────────
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub struct Sections {
+    pub model: SectionBase,
+    pub provider: SectionBase,
+    pub project: ProjectSection,
+    pub vcs: VcsSection,
+    pub beads: BeadsSection,
+    pub context_bar: ContextBarSection,
+    pub context_usage: ContextUsageSection,
+    pub context_remaining: ContextRemainingSection,
+    pub tokens_raw: TokensRawSection,
+    pub cache_efficiency: SectionBase,
+    pub cost: CostSection,
+    pub cost_velocity: SectionBase,
+    pub token_velocity: SectionBase,
+    pub cost_trend: TrendSection,
+    pub context_trend: ContextTrendSection,
+    pub lines_changed: SectionBase,
+    pub duration: SectionBase,
+    pub tools: ToolsSection,
+    pub turns: CachedSection,
+    pub load: CachedSection,
+    pub version: SectionBase,
+    pub time: TimeSection,
+    pub output_style: SectionBase,
+    pub hostname: SectionBase,
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct ProjectSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub truncate: TruncateConfig,
+}
+
+impl Default for ProjectSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                priority: 1,
+                ..Default::default()
+            },
+            truncate: TruncateConfig {
+                enabled: true,
+                max: 30,
+                style: "middle".into(),
+            },
+        }
+    }
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(default)]
+pub struct TruncateConfig {
+    pub enabled: bool,
+    pub max: usize,
+    pub style: String,
+}
+
+impl Default for TruncateConfig {
+    fn default() -> Self {
+        Self {
+            enabled: false,
+            max: 0,
+            style: "right".into(),
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct VcsSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub prefer: String,
+    pub show_ahead_behind: bool,
+    pub show_dirty: bool,
+    pub untracked: String,
+    pub submodules: bool,
+    pub fast_mode: bool,
+    pub truncate: TruncateConfig,
+    pub ttl: VcsTtl,
+}
+
+impl Default for VcsSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                priority: 1,
+                min_width: Some(8),
+                ..Default::default()
+            },
+            prefer: "auto".into(),
+            show_ahead_behind: true,
+            show_dirty: true,
+            untracked: "normal".into(),
+            submodules: false,
+            fast_mode: false,
+            truncate: TruncateConfig {
+                enabled: true,
+                max: 25,
+                style: "right".into(),
+            },
+            ttl: VcsTtl::default(),
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct VcsTtl {
+    pub branch: u64,
+    pub dirty: u64,
+    pub ahead_behind: u64,
+}
+
+impl Default for VcsTtl {
+    fn default() -> Self {
+        Self {
+            branch: 3,
+            dirty: 5,
+            ahead_behind: 30,
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct BeadsSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub show_wip: bool,
+    pub show_wip_count: bool,
+    pub show_ready_count: bool,
+    pub show_open_count: bool,
+    pub show_closed_count: bool,
+    pub ttl: u64,
+}
+
+impl Default for BeadsSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                priority: 3,
+                ..Default::default()
+            },
+            show_wip: true,
+            show_wip_count: true,
+            show_ready_count: true,
+            show_open_count: true,
+            show_closed_count: true,
+            ttl: 30,
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct ContextBarSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub bar_width: u16,
+    pub thresholds: Thresholds,
+}
+
+impl Default for ContextBarSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                priority: 1,
+                flex: true,
+                min_width: Some(15),
+                ..Default::default()
+            },
+            bar_width: 10,
+            thresholds: Thresholds {
+                warn: 50.0,
+                danger: 70.0,
+                critical: 85.0,
+            },
+        }
+    }
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(default)]
+pub struct Thresholds {
+    pub warn: f64,
+    pub danger: f64,
+    pub critical: f64,
+}
+
+impl Default for Thresholds {
+    fn default() -> Self {
+        Self {
+            warn: 50.0,
+            danger: 70.0,
+            critical: 85.0,
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct ContextUsageSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub capacity: u64,
+    pub thresholds: Thresholds,
+}
+
+impl Default for ContextUsageSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                enabled: false,
+                priority: 2,
+                ..Default::default()
+            },
+            capacity: 200_000,
+            thresholds: Thresholds::default(),
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct ContextRemainingSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub format: String,
+    pub thresholds: Thresholds,
+}
+
+impl Default for ContextRemainingSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                enabled: false,
+                priority: 2,
+                ..Default::default()
+            },
+            format: "{remaining} left".into(),
+            thresholds: Thresholds::default(),
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct TokensRawSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub format: String,
+}
+
+impl Default for TokensRawSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                priority: 3,
+                ..Default::default()
+            },
+            format: "{input} in/{output} out".into(),
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct CostSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub thresholds: Thresholds,
+}
+
+impl Default for CostSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                priority: 1,
+                ..Default::default()
+            },
+            thresholds: Thresholds {
+                warn: 5.0,
+                danger: 8.0,
+                critical: 10.0,
+            },
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct TrendSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub width: u8,
+}
+
+impl Default for TrendSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                priority: 3,
+                ..Default::default()
+            },
+            width: 8,
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct ContextTrendSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub width: u8,
+    pub thresholds: Thresholds,
+}
+
+impl Default for ContextTrendSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                priority: 3,
+                ..Default::default()
+            },
+            width: 8,
+            thresholds: Thresholds::default(),
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct ToolsSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub show_last_name: bool,
+    pub ttl: u64,
+}
+
+impl Default for ToolsSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                priority: 2,
+                min_width: Some(6),
+                ..Default::default()
+            },
+            show_last_name: true,
+            ttl: 2,
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct CachedSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub ttl: u64,
+}
+
+impl Default for CachedSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                priority: 3,
+                ..Default::default()
+            },
+            ttl: 10,
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub struct TimeSection {
+    #[serde(flatten)]
+    pub base: SectionBase,
+    pub format: String,
+}
+
+impl Default for TimeSection {
+    fn default() -> Self {
+        Self {
+            base: SectionBase {
+                enabled: false,
+                priority: 3,
+                ..Default::default()
+            },
+            format: "%H:%M".into(),
+        }
+    }
+}
+
+// ── Custom command sections ─────────────────────────────────────────────
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct CustomCommand {
+    pub id: String,
+    #[serde(default)]
+    pub command: Option<String>,
+    #[serde(default)]
+    pub exec: Option<Vec<String>>,
+    #[serde(default)]
+    pub format: Option<String>,
+    #[serde(default)]
+    pub label: Option<String>,
+    #[serde(default = "default_custom_ttl")]
+    pub ttl: u64,
+    #[serde(default = "default_priority")]
+    pub priority: u8,
+    #[serde(default)]
+    pub flex: bool,
+    #[serde(default)]
+    pub min_width: Option<u16>,
+    #[serde(default)]
+    pub color: Option<CustomColor>,
+    #[serde(default)]
+    pub default_color: Option<String>,
+    #[serde(default)]
+    pub prefix: Option<String>,
+    #[serde(default)]
+    pub suffix: Option<String>,
+    #[serde(default)]
+    pub pad: Option<u16>,
+    #[serde(default)]
+    pub align: Option<String>,
+}
+
+fn default_custom_ttl() -> u64 {
+    30
+}
+fn default_priority() -> u8 {
+    2
+}
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct CustomColor {
+    #[serde(rename = "match", default)]
+    pub match_map: HashMap<String, String>,
+}
+
+// ── Deep merge ──────────────────────────────────────────────────────────
+
+/// Recursive JSON merge: user values win, arrays replaced entirely.
+pub fn deep_merge(base: &mut Value, patch: &Value) {
+    match (base, patch) {
+        (Value::Object(base_map), Value::Object(patch_map)) => {
+            for (k, v) in patch_map {
+                let entry = base_map.entry(k.clone()).or_insert(Value::Null);
+                deep_merge(entry, v);
+            }
+        }
+        (base, patch) => {
+            *base = patch.clone();
+        }
+    }
+}
+
+// ── Config loading ──────────────────────────────────────────────────────
+
+/// Load config: embedded defaults deep-merged with user overrides.
+pub fn load_config(explicit_path: Option<&str>) -> Result<(Config, Vec<String>), crate::Error> {
+    let mut base: Value = serde_json::from_str(DEFAULTS_JSON)?;
+
+    let user_path = explicit_path
+        .map(std::path::PathBuf::from)
+        .or_else(|| {
+            std::env::var("CLAUDE_STATUSLINE_CONFIG")
+                .ok()
+                .map(Into::into)
+        })
+        .or_else(xdg_config_path)
+        .or_else(dot_config_path)
+        .unwrap_or_else(|| {
+            let mut p = dirs_home().unwrap_or_default();
+            p.push(".claude/statusline.json");
+            p
+        });
+
+    if user_path.exists() {
+        let user_json: Value = serde_json::from_str(&std::fs::read_to_string(&user_path)?)?;
+        deep_merge(&mut base, &user_json);
+    } else if explicit_path.is_some() {
+        return Err(crate::Error::ConfigNotFound(
+            user_path.display().to_string(),
+        ));
+    }
+
+    let mut warnings = Vec::new();
+    let config: Config = serde_ignored::deserialize(base, |path| {
+        warnings.push(format!("unknown config key: {path}"));
+    })?;
+
+    Ok((config, warnings))
+}
+
+fn xdg_config_path() -> Option<std::path::PathBuf> {
+    let val = std::env::var("XDG_CONFIG_HOME").ok()?;
+    let mut p = std::path::PathBuf::from(val);
+    p.push("claude/statusline.json");
+    if p.exists() {
+        Some(p)
+    } else {
+        None
+    }
+}
+
+fn dot_config_path() -> Option<std::path::PathBuf> {
+    let mut p = dirs_home()?;
+    p.push(".config/claude/statusline.json");
+    if p.exists() {
+        Some(p)
+    } else {
+        None
+    }
+}
+
+fn dirs_home() -> Option<std::path::PathBuf> {
+    std::env::var("HOME").ok().map(Into::into)
+}