specfold-core 0.4.0

//! Finds and loads spec.toml, and answers questions about the loaded configuration.

use super::defaults::{self, CONFIG_FILE};
use super::paths;
use super::types::RawConfig;
use crate::model::registry::Registry;
use crate::workspace::vcs;
use anyhow::{Context, Result, bail};
use std::path::{Path, PathBuf};

#[derive(Debug, Clone)]
pub struct Config {
    /// Repository root: the directory holding spec.toml.
    pub root: PathBuf,
    pub raw: RawConfig,
    pub registry: Registry,
    /// True when no spec.toml was found and defaults are in use.
    pub implicit: bool,
}

impl Config {
    /// Finds spec.toml in `start` or its ancestors. Without one, the nearest git root (or `start`)
    /// is used with defaults, so the tool works in any directory.
    pub fn discover(start: &Path) -> Result<Self> {
        let start = start.canonicalize().with_context(|| format!("cannot open {}", start.display()))?;
        let mut dir = Some(start.as_path());
        while let Some(d) = dir {
            let candidate = d.join(CONFIG_FILE);
            if candidate.is_file() {
                return Self::load(&candidate);
            }
            dir = d.parent();
        }
        let root = vcs::git_root(&start).unwrap_or(start);
        Ok(Self::from_raw(root, RawConfig::default(), true))
    }

    pub fn load(path: &Path) -> Result<Self> {
        let text = std::fs::read_to_string(path).with_context(|| format!("cannot read {}", path.display()))?;
        let raw: RawConfig = match toml::from_str(&text) {
            Ok(r) => r,
            Err(e) => {
                let (_, changes) = super::upgrade::plan(&text, super::upgrade::RENAMED);
                let hint =
                    if changes.is_empty() { String::new() } else { "; renamed keys: spec init --upgrade".into() };
                return Err(anyhow::Error::new(e).context(format!("invalid {}{hint}", path.display())));
            }
        };
        if raw.spec.schema > defaults::schema() {
            return Err(newer_schema(path, raw.spec.schema));
        }
        if raw.spec.schema != defaults::schema() {
            bail!(
                "{}: schema {} is older than this version reads ({}); preview the upgrade: spec init --upgrade",
                path.display(),
                raw.spec.schema,
                defaults::schema()
            );
        }
        // C141: one guard with a mistyped range would stop every `spec guard` run later.
        for g in &raw.guards {
            if !matches!(g.range.as_str(), "staged" | "push" | "all") && !g.range.contains("..") {
                bail!(
                    "{}: guard '{}' has range = \"{}\"; use \"staged\", \"push\", \"all\" or a git range such as \"origin/main..HEAD\" (spec explain config)",
                    path.display(),
                    g.name,
                    g.range
                );
            }
        }
        for k in &raw.owners.kinds {
            if let Some(why) = crate::workspace::owners::patterns::kind_pattern_problem(&k.pattern) {
                bail!("{}: {why}; next: spec explain config", path.display());
            }
        }
        if let Some((why, value)) = super::validate::pattern_problem(&raw) {
            let at = text.lines().position(|l| l.contains(&value)).map(|n| format!(" at line {}", n + 1));
            bail!("{}{}: {why}; next: spec explain config", path.display(), at.unwrap_or_default());
        }
        // C184: guards sharing a baseline file overwrite each other's entries on --write-baseline.
        let mut seen: Vec<(&str, String)> = Vec::new();
        for g in &raw.guards {
            let Some(b) = g.baseline.as_deref() else { continue };
            let b = same_file_key(path.parent().unwrap_or(Path::new(".")), b);
            if let Some((other, _)) = seen.iter().find(|(_, x)| *x == b) {
                bail!(
                    "{}: guards '{other}' and '{}' both write the baseline file \"{b}\"; give each guard its own baseline file; next: spec explain config",
                    path.display(),
                    g.name
                );
            }
            seen.push((&g.name, b));
        }
        let root = path.parent().unwrap_or(Path::new(".")).to_path_buf();
        Ok(Self::from_raw(root, raw, false))
    }

    pub fn from_raw(root: PathBuf, raw: RawConfig, implicit: bool) -> Self {
        let registry = Registry::new(&raw.types);
        Config { root, raw, registry, implicit }
    }

    pub fn spec_dir(&self) -> &str {
        &self.raw.spec.dir
    }

    pub fn manifests(&self) -> Vec<String> {
        match &self.raw.owners.manifests {
            Some(m) => m.clone(),
            None => defaults::MANIFESTS.iter().map(|s| s.to_string()).collect(),
        }
    }

    pub fn root_owner(&self) -> &str {
        &self.raw.owners.root
    }

    pub fn local_dir(&self) -> &str {
        &self.raw.local.path
    }

    pub fn expand_path(&self, p: &str) -> PathBuf {
        paths::expand(&self.root, p)
    }
}

/// The refusal for a spec.toml whose schema is newer than this binary reads; `spec check` and
/// `spec init --upgrade` (C170) both give it.
pub fn newer_schema(path: &Path, schema: u32) -> anyhow::Error {
    anyhow::anyhow!(
        "{}: schema {schema} was written by a newer specfold (this version reads {}); install the latest spec",
        path.display(),
        defaults::schema()
    )
}

/// C186: a baseline path as one string per file: relative to the repository root, with `.` and
/// `..` resolved lexically, so `./b.json`, `x/../b.json` and `<root>/b.json` compare equal.
fn same_file_key(root: &Path, p: &str) -> String {
    // C194/C195: resolve the deepest part of the path that exists (symbolic links included)
    // before any lexical clean-up, then apply the rest; `lnk/sub/..` is judged where the
    // write would land. Kept root-relative so it compares with the lexical keys below.
    if let Ok(croot) = root.canonicalize() {
        let abs = root.join(p);
        let comps: Vec<_> = abs.components().collect();
        for k in (1..=comps.len()).rev() {
            let Ok(mut out) = comps[..k].iter().collect::<std::path::PathBuf>().canonicalize() else {
                continue;
            };
            for c in &comps[k..] {
                match c {
                    std::path::Component::ParentDir => {
                        out.pop();
                    }
                    std::path::Component::Normal(n) => out.push(n),
                    _ => {}
                }
            }
            return match out.strip_prefix(&croot) {
                Ok(r) => r.to_string_lossy().replace('\\', "/"),
                Err(_) => out.to_string_lossy().into_owned(),
            };
        }
    }
    let p = Path::new(p);
    let rel = p.strip_prefix(root).unwrap_or(p);
    let mut parts: Vec<&str> = vec![];
    for c in rel.to_str().unwrap_or_default().split(['/', '\\']) {
        match c {
            "" | "." => {}
            ".." if parts.last().is_some_and(|l| *l != "..") => {
                parts.pop();
            }
            other => parts.push(other),
        }
    }
    parts.join("/")
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn parses_full_config() {
        let raw: RawConfig = toml::from_str(
            r#"
[spec]
schema = 1
[owners]
root = "ws"
retired = ["services/old"]
[[owners.kinds]]
pattern = "services/*"
id = "{1}"
[public]
paths = ["libs/open"]
[public.companion]
"libs/open" = "services/open"
[external.notes]
path = "~/notes"
[files.store]
kind = "dir"
path = "/tmp/store"
[types.adr]
statuses = ["draft", "active"]
[types.memo]
key = "slug"
[[guards]]
name = "public"
paths = ["libs/open/**"]
deny_terms = ["internal-name"]
"#,
        )
        .unwrap();
        let cfg = Config::from_raw(PathBuf::from("/r"), raw, false);
        assert_eq!(cfg.root_owner(), "ws");
        assert!(cfg.registry.get("memo").is_some());
        assert_eq!(cfg.registry.get("adr").unwrap().statuses.len(), 2);
        assert_eq!(cfg.raw.guards[0].range, "staged");
    }

    #[test]
    fn unknown_keys_are_refused() {
        assert!(toml::from_str::<RawConfig>("[spec]\nschema = 1\ntypo = 2\n").is_err());
    }
}