pushkin-core 0.2.1

//! `pushkin.toml` parsing (spec §11). Strict by construction: serde with
//! `deny_unknown_fields` everywhere, unknown-key errors enriched with
//! nearest-candidate suggestions, mapping→contract references resolved once
//! at the boundary (spec §7.1) so shorthand never silently changes meaning.
//!
//! One proportionality exception, mechanical rather than judged (F79,
//! ADR-0007): a field wrapped in [`DisplayOnly`] degrades an unrecognized
//! string to its default and carries the raw value for disclosure, because a
//! typo in a field that reaches no verdict should cost a NOTE line, not every
//! verb. Every other key and value keeps rejecting.

use globset::{Glob, GlobSet, GlobSetBuilder};
use serde::de::value::StrDeserializer;
use serde::de::{DeserializeOwned, Deserializer};
use serde::Deserialize;
use thiserror::Error;

pub const SUPPORTED_VERSION: u32 = 1;

/// Keys a typo in the manifest is matched against for candidate suggestions.
const KNOWN_KEYS: &[&str] = &[
    "version",
    "schema_epoch",
    "canonical",
    "authoring",
    "contracts",
    "name",
    "source",
    "emit",
    "mappings",
    "glob",
    "require",
    "gates",
    "suppression_comments",
    "protected_paths",
    "read_only_paths",
    "retrieval_paths",
    "retrieval_tool",
    "db",
    "direction",
    "provider",
    "rls_tests",
    "features",
    "git_hooks",
    "floor",
    "commands",
    "run",
    "scope",
    "inputs",
    "install",
    "on_stop",
    "on_new_read_only",
    "reconcile_ignored",
    "covers_ignored_of",
];

#[derive(Debug, Error)]
pub enum ManifestError {
    #[error("manifest is not valid TOML or violates the schema: {message}")]
    Invalid { message: String },
    #[error("manifest version {found} is unsupported (this binary supports {supported})")]
    UnsupportedVersion { found: u32, supported: u32 },
    #[error(
        "mapping references undeclared contract '{reference}'; declared contracts: {candidates}"
    )]
    UnknownContract {
        reference: String,
        candidates: String,
    },
    #[error("glob '{glob}' is invalid: {message}")]
    BadGlob { glob: String, message: String },
    #[error(
        "schema_epoch must be a positive integer (a human increments it on \
         epoch-sensitive change, R9); found {found}"
    )]
    NonPositiveEpoch { found: u32 },
    #[error(
        "[[floor.commands]] declares duplicate name '{name}'; every floor \
         command needs a unique name (--skip and covers_ignored_of both \
         address commands by name)"
    )]
    DuplicateFloorCommand { name: String },
    #[error(
        "floor command '{name}' declares an empty `run` array; a command with \
         nothing to run cannot produce a verdict (remove the entry, or give it \
         an argv: run = [\"cargo\", \"fmt\", \"--check\"])"
    )]
    EmptyFloorRun { name: String },
    #[error(
        "floor command '{name}' declares covers_ignored_of = '{reference}', \
         which is not a declared command; declared commands: {candidates}"
    )]
    UnknownFloorCoverage {
        name: String,
        reference: String,
        candidates: String,
    },
    #[error(
        "floor command '{name}' declares covers_ignored_of = '{name}' — a \
         command cannot cover its own ignored tests; the accounting would \
         balance while executing nothing new"
    )]
    SelfFloorCoverage { name: String },
}

#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
#[serde(transparent)]
pub struct ContractName(String);

impl ContractName {
    #[must_use]
    pub fn as_str(&self) -> &str {
        &self.0
    }
}

#[derive(Debug, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct Contract {
    pub name: ContractName,
    pub source: String,
    pub emit: Vec<String>,
}

#[derive(Debug, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct Mapping {
    pub glob: String,
    pub contracts: Vec<ContractName>,
    pub require: Option<String>,
}

#[derive(Debug, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct Gates {
    pub suppression_comments: Option<String>,
    #[serde(default)]
    pub protected_paths: Vec<String>,
    /// Globs whose COMMITTED files are read-only to agents: new files may
    /// be created (the RED-suite authoring window), files in git HEAD may
    /// not be modified — N10 ("committed first, read-only hereafter") as a
    /// product gate. Unwaivable, like `protected_paths`.
    #[serde(default)]
    pub read_only_paths: Vec<String>,
    /// SPIKE — the read contract. Globs whose files an agent must reach
    /// through `retrieval_tool` rather than an unbounded whole-file read.
    ///
    /// A read carrying an explicit range is allowed **on the `Read` surface**,
    /// where the host supplies `offset`/`limit` as structured fields the gate
    /// can verify: that is the deliberate shape, and the host's
    /// read-before-edit gate needs it. A shell reader gets no such allowance,
    /// because a bound spelled inside a command string can only be inferred
    /// and `head -999999` is indistinguishable from `head -50`. The asymmetry
    /// is the verifiability of the bound, not an inconsistency (hook-matcher-gap
    /// charter, Addendum D, HM-10).
    #[serde(default)]
    pub retrieval_paths: Vec<String>,
    /// The tool a denied read is redirected to. A manifest string, never a
    /// hard-coded vendor, so a future in-tree Pushkin index can take the
    /// slot without changing the gate.
    pub retrieval_tool: Option<String>,
}

/// `[db]` (spec §5.3, §10): drift-gate configuration. `direction` names
/// the source of truth — "contract" (generated DDL is desired state) or
/// "database" (introspected schema is; contracts must follow).
#[derive(Debug, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct Db {
    pub direction: DbDirection,
    pub provider: Option<String>,
    pub rls_tests: Option<String>,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Deserialize)]
#[serde(rename_all = "lowercase")]
pub enum DbDirection {
    Contract,
    Database,
}

/// `[features]` — repo-level switches for whole enforcement planes,
/// committed in the manifest so every surface (init, doctor, the
/// pre-commit floor, CI) reads one truth. The manifest is a protected
/// path, so the switch is human-owned by construction. Absent table =
/// every feature enabled: only a positively parsed `false` turns a
/// plane off, mirroring the N13 principle (act on positive probes,
/// never on ambiguity).
#[derive(Debug, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct Features {
    /// The git-plane floor as one switch: the lefthook pre-commit
    /// block, the native `.git/hooks` shim, and the staged check they
    /// both run. `false` = init refuses to install either surface,
    /// doctor stops checking them, and `check --staged` passes with a
    /// stderr notice. Deliberately NOT covered: agent-side write gating
    /// (`hook`, stdin `check`) — the flag turns off commit protection,
    /// never write-time contract enforcement.
    #[serde(default = "default_enabled")]
    pub git_hooks: bool,
}

impl Default for Features {
    fn default() -> Self {
        Self {
            git_hooks: default_enabled(),
        }
    }
}

fn default_enabled() -> bool {
    true
}

/// `[floor]` (spec §8.2 stage 5) — the declared mechanical floor: the one
/// committed list of commands `pushkin floor`, the `Makefile`, `scripts/floor.sh`
/// and CI all read, so "mirrors CI commands exactly" is a fact rather than a
/// promise someone has to remember.
///
/// Optional. A repo without a declared floor is a valid manifest; `pushkin
/// floor` is the surface that refuses to run against one, because pre-empting
/// that here would break every other verb on a manifest that was never wrong.
#[derive(Debug, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct Floor {
    /// Run in declared order. Order is load-bearing: it is the order the verb
    /// executes and reports in.
    #[serde(default)]
    pub commands: Vec<FloorCommand>,
}

/// How far a command's verdict reaches — **declared, never inferred.**
///
/// Nothing in this pass executes differently per scope; everything runs
/// whole-repo. The field exists because the alternative is a tool guessing at
/// decomposability, and a wrong guess narrows the check silently. It is the
/// contract a future warm charter reads, recorded honestly now while the facts
/// are in front of us: only `cargo fmt --check` is per-file faithful (and only
/// for a NAMED file — `cargo fmt` discovery skips cfg-gated out-of-line modules,
/// rustfmt #4034), clippy is a whole-crate rustc driver, and cargo test targets
/// are crate-level binaries.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum FloorScope {
    PerFile,
    PerCrate,
    WholeRepo,
}

/// What a command's verdict depends on BEYOND the repo contents.
///
/// `network` is the honest one: `cargo deny`'s `advisories` check consults the
/// `RustSec` DB, so the floor is not a pure function of the commit — an unchanged
/// commit can newly fail when an advisory publishes. The verb discloses that in
/// its output rather than letting it ambush the next unrelated PR (F69 rider).
///
/// `machine` is the second one, and it has a different cause: a command that
/// measures wall-clock time answers about the machine as much as about the
/// commit. `bench` asserts a latency threshold, so a busy machine fails a commit
/// that passes quiet — observed as a full floor going RED at 836/1 under
/// concurrent cargo builds and green at 837/0 on the same tree idle (F76
/// addendum). Disclosed separately from `network` because the reasons differ and
/// a reader who cannot tell them apart learns to skip both.
///
/// `repo` is the `Default` because it is what an unrecognized value degrades
/// to (F79, ADR-0007): the most conservative reading, claiming no dependency
/// the command did not declare, so a typo never adds a command to the network
/// or machine disclosure and never removes one spelled correctly.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum FloorInputs {
    #[default]
    Repo,
    Toolchain,
    Network,
    Machine,
}

/// The marker for a manifest field whose value PROVABLY reaches no verdict
/// (F79, ADR-0007 Option A).
///
/// Strictness in this file is proportional to consequence. An unknown KEY may
/// be a gate rule being silently ignored, so it rejects (ADR-0001). An unknown
/// value in a field that only feeds disclosure text costs one NOTE line, and
/// charging it the whole-manifest price took every verb down together — in the
/// fail-open direction (F71). So: a field wrapped in this type degrades an
/// unrecognized **string** to `T::default()` and keeps the raw text, so the
/// value carries its own provenance to wherever it is rendered. A value of the
/// wrong TOML type is a malformed manifest, not a typo, and still rejects.
///
/// The leniency is a property of the type, not of a reviewer's per-field call:
/// `crates/pushkin-core/tests/manifest_display_only.rs` scans this file and
/// asserts the marker sits on exactly one field. Wrapping another field changes
/// that list, which is what makes it a reviewed act rather than a silent
/// widening — Option C of the record (every unknown value warns) is the
/// N13-forbidden shape, and this guard is what keeps A from drifting into it.
///
/// Compares equal to the value it carries, so call sites and committed suites
/// that compare against the plain enum keep reading naturally. A degradation
/// is never silent: the consumer that renders the field owns the disclosure.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct DisplayOnly<T> {
    value: T,
    degraded_from: Option<String>,
}

impl<T> DisplayOnly<T> {
    #[must_use]
    pub fn value(&self) -> &T {
        &self.value
    }

    /// The raw text the parser did not recognize, when the value degraded.
    #[must_use]
    pub fn degraded_from(&self) -> Option<&str> {
        self.degraded_from.as_deref()
    }
}

impl<T: PartialEq> PartialEq<T> for DisplayOnly<T> {
    fn eq(&self, other: &T) -> bool {
        self.value == *other
    }
}

impl<'de, T: DeserializeOwned + Default> Deserialize<'de> for DisplayOnly<T> {
    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
        let raw = String::deserialize(deserializer)?;
        let recognized = T::deserialize(StrDeserializer::<D::Error>::new(&raw));
        Ok(match recognized {
            Ok(value) => Self {
                value,
                degraded_from: None,
            },
            Err(_) => Self {
                value: T::default(),
                degraded_from: Some(raw),
            },
        })
    }
}

#[derive(Debug, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct FloorCommand {
    /// Unique across the table: `--skip` and `covers_ignored_of` both address
    /// commands by name.
    pub name: String,
    /// argv, never a shell string — a shell string is an injection surface and
    /// a quoting-bug surface, and neither belongs in a gate.
    pub run: Vec<String>,
    pub scope: FloorScope,
    /// Display-only (F79): its three readers are all disclosure text in the
    /// floor verb, so an unrecognized value degrades to `repo` with a NOTE
    /// instead of rejecting the manifest.
    pub inputs: DisplayOnly<FloorInputs>,
    /// The install hint a missing binary's error carries (the `db.rs`
    /// `run_tool` pattern: an absent tool is a loud named failure, never a
    /// silent skip).
    pub install: Option<String>,
    /// Whether the Stop sweep runs this command. Default `false` — the
    /// conservative posture, and the whole Stop integration ships dark until a
    /// human rules a command in.
    #[serde(default)]
    pub on_stop: bool,
    /// Whether this command runs as a pre-RED lint gate: when a commit stages a
    /// NEW file under a `read_only_paths` glob, `check --staged` runs this
    /// command before the file is frozen (F72). Default `false`, mirroring
    /// `on_stop` — the mechanism ships dark until a human opts a command in.
    #[serde(default)]
    pub on_new_read_only: bool,
    /// Whether this command's output carries cargo-test-shaped `test result:`
    /// lines whose ignored count must be accounted for.
    #[serde(default)]
    pub reconcile_ignored: bool,
    /// Declares that THIS command executes the tests the named command reported
    /// as ignored. The link is declared rather than guessed because the
    /// accounting is only as trustworthy as the claim it checks.
    pub covers_ignored_of: Option<String>,
}

#[derive(Debug, Deserialize)]
#[serde(deny_unknown_fields)]
struct RawManifest {
    version: u32,
    schema_epoch: Option<u32>,
    canonical: String,
    authoring: String,
    #[serde(default)]
    contracts: Vec<Contract>,
    #[serde(default)]
    mappings: Vec<Mapping>,
    gates: Gates,
    db: Option<Db>,
    #[serde(default)]
    features: Features,
    floor: Option<Floor>,
}

/// A parsed, boundary-resolved manifest. Globs are compiled once here.
pub struct Manifest {
    pub version: u32,
    /// R9 (approved 2026-08-13): the workspace-wide schema epoch, owned by
    /// the manifest and human-incremented. The SOLE source authoring,
    /// compile, and the daemon probe read. Absent key = 1 (pre-R9
    /// manifests keep parsing; the repo's own manifest declares it).
    pub schema_epoch: u32,
    pub canonical: String,
    pub authoring: String,
    pub contracts: Vec<Contract>,
    pub mappings: Vec<Mapping>,
    pub gates: Gates,
    pub db: Option<Db>,
    pub features: Features,
    /// `[floor]` — absent when the repo declares no mechanical floor. The verb
    /// owns that refusal, not the parser.
    pub floor: Option<Floor>,
    mapping_globs: GlobSet,
    protected_globs: GlobSet,
    read_only_globs: GlobSet,
    retrieval_globs: GlobSet,
}

impl std::fmt::Debug for Manifest {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        // GlobSet has no Debug; show the declarative fields only.
        f.debug_struct("Manifest")
            .field("version", &self.version)
            .field("schema_epoch", &self.schema_epoch)
            .field("canonical", &self.canonical)
            .field("authoring", &self.authoring)
            .field("contracts", &self.contracts)
            .field("mappings", &self.mappings)
            .field("gates", &self.gates)
            .field("db", &self.db)
            .field("features", &self.features)
            .field("floor", &self.floor)
            .finish_non_exhaustive()
    }
}

impl Manifest {
    /// Parses and boundary-resolves manifest text.
    ///
    /// # Errors
    /// Returns `ManifestError` on TOML/schema violations (with candidate
    /// suggestions for unknown keys), unsupported versions, undeclared
    /// contract references, and invalid globs.
    pub fn parse(text: &str) -> Result<Self, ManifestError> {
        let raw: RawManifest = toml::from_str(text).map_err(|e| enrich_unknown_key(&e))?;

        if raw.version != SUPPORTED_VERSION {
            return Err(ManifestError::UnsupportedVersion {
                found: raw.version,
                supported: SUPPORTED_VERSION,
            });
        }
        if let Some(0) = raw.schema_epoch {
            return Err(ManifestError::NonPositiveEpoch { found: 0 });
        }
        resolve_contract_references(&raw)?;
        if let Some(floor) = raw.floor.as_ref() {
            validate_floor(floor)?;
        }

        let mapping_globs = build_globset(raw.mappings.iter().map(|m| m.glob.as_str()))?;
        let protected_globs = build_globset(raw.gates.protected_paths.iter().map(String::as_str))?;
        let read_only_globs = build_globset(raw.gates.read_only_paths.iter().map(String::as_str))?;
        let retrieval_globs = build_globset(raw.gates.retrieval_paths.iter().map(String::as_str))?;

        Ok(Self {
            version: raw.version,
            schema_epoch: raw.schema_epoch.unwrap_or(1),
            canonical: raw.canonical,
            authoring: raw.authoring,
            contracts: raw.contracts,
            mappings: raw.mappings,
            gates: raw.gates,
            db: raw.db,
            features: raw.features,
            floor: raw.floor,
            mapping_globs,
            protected_globs,
            read_only_globs,
            retrieval_globs,
        })
    }

    /// First mapping whose glob matches `path`, if any.
    #[must_use]
    pub fn mapping_for(&self, path: &str) -> Option<&Mapping> {
        self.mapping_globs
            .matches(path)
            .first()
            .map(|&index| &self.mappings[index])
    }

    #[must_use]
    pub fn is_protected(&self, path: &str) -> bool {
        self.protected_globs.is_match(path)
    }

    /// Whether `path` falls under a `read_only_paths` glob. Committed-ness
    /// is the caller's question (it needs git); this is only the glob half.
    #[must_use]
    pub fn is_read_only(&self, path: &str) -> bool {
        self.read_only_globs.is_match(path)
    }

    /// Whether `path` falls under a `retrieval_paths` glob. Whether the
    /// READ was bounded is the caller's question; this is only the glob
    /// half, mirroring `is_read_only`.
    #[must_use]
    pub fn is_retrieval_gated(&self, path: &str) -> bool {
        self.retrieval_globs.is_match(path)
    }

    /// The declared retrieval destination, if the manifest names one.
    #[must_use]
    pub fn retrieval_tool(&self) -> Option<&str> {
        self.gates.retrieval_tool.as_deref()
    }

    /// The `[features]` git-plane switch. `true` unless the manifest
    /// positively declares `git_hooks = false`.
    #[must_use]
    pub fn git_hooks_enabled(&self) -> bool {
        self.features.git_hooks
    }
}

fn resolve_contract_references(raw: &RawManifest) -> Result<(), ManifestError> {
    let declared: Vec<&str> = raw.contracts.iter().map(|c| c.name.as_str()).collect();
    for mapping in &raw.mappings {
        for reference in &mapping.contracts {
            if !declared.contains(&reference.as_str()) {
                return Err(ManifestError::UnknownContract {
                    reference: reference.as_str().to_owned(),
                    candidates: declared.join(", "),
                });
            }
        }
    }
    Ok(())
}

/// The `[floor]` invariants serde cannot express: names unique, every `run`
/// non-empty, and every `covers_ignored_of` resolving to some OTHER declared
/// command.
///
/// The coverage rules exist because the ignored-test accounting is only as
/// trustworthy as the claim it checks. A dangling reference makes the accounting
/// vacuous; self-coverage balances its arithmetic while executing nothing new.
/// Both are the shape of defect `scripts/floor.sh` was written to prevent — a
/// floor citation that counts less than it claims (D7(a), F62).
fn validate_floor(floor: &Floor) -> Result<(), ManifestError> {
    let mut seen: Vec<&str> = Vec::with_capacity(floor.commands.len());
    for command in &floor.commands {
        if seen.contains(&command.name.as_str()) {
            return Err(ManifestError::DuplicateFloorCommand {
                name: command.name.clone(),
            });
        }
        seen.push(&command.name);
        if command.run.is_empty() {
            return Err(ManifestError::EmptyFloorRun {
                name: command.name.clone(),
            });
        }
    }
    // Resolved by name across the WHOLE table, so a coverer may be declared
    // before the command it covers; a forward-only scan would make the link
    // order-dependent and the error message a lie.
    for command in &floor.commands {
        let Some(reference) = command.covers_ignored_of.as_deref() else {
            continue;
        };
        if reference == command.name {
            return Err(ManifestError::SelfFloorCoverage {
                name: command.name.clone(),
            });
        }
        if !seen.contains(&reference) {
            return Err(ManifestError::UnknownFloorCoverage {
                name: command.name.clone(),
                reference: reference.to_owned(),
                candidates: seen.join(", "),
            });
        }
    }
    Ok(())
}

fn build_globset<'a>(globs: impl Iterator<Item = &'a str>) -> Result<GlobSet, ManifestError> {
    let mut builder = GlobSetBuilder::new();
    for glob in globs {
        let compiled = Glob::new(glob).map_err(|error| ManifestError::BadGlob {
            glob: glob.to_owned(),
            message: error.to_string(),
        })?;
        builder.add(compiled);
    }
    builder.build().map_err(|error| ManifestError::BadGlob {
        glob: "<combined>".to_owned(),
        message: error.to_string(),
    })
}

/// Appends nearest-candidate suggestions to serde's "unknown field" errors so
/// every rejection is a retry prompt (design principle 5).
fn enrich_unknown_key(error: &toml::de::Error) -> ManifestError {
    let message = error.to_string();
    let Some(unknown) = extract_unknown_field(&message) else {
        return ManifestError::Invalid { message };
    };
    let candidates = nearest_keys(&unknown);
    if candidates.is_empty() {
        return ManifestError::Invalid { message };
    }
    ManifestError::Invalid {
        message: format!("{message}; did you mean: {}?", candidates.join(", ")),
    }
}

fn extract_unknown_field(message: &str) -> Option<String> {
    let marker = "unknown field `";
    let start = message.find(marker)? + marker.len();
    let rest = &message[start..];
    let end = rest.find('`')?;
    Some(rest[..end].to_owned())
}

fn nearest_keys(unknown: &str) -> Vec<&'static str> {
    let mut scored: Vec<(usize, &'static str)> = KNOWN_KEYS
        .iter()
        .map(|&key| (levenshtein(unknown, key), key))
        .filter(|&(distance, _)| distance <= 3)
        .collect();
    scored.sort_unstable();
    scored.into_iter().take(3).map(|(_, key)| key).collect()
}

pub(crate) fn levenshtein(a: &str, b: &str) -> usize {
    let a_chars: Vec<char> = a.chars().collect();
    let b_chars: Vec<char> = b.chars().collect();
    let mut previous: Vec<usize> = (0..=b_chars.len()).collect();
    let mut current = vec![0usize; b_chars.len() + 1];

    for (i, &a_char) in a_chars.iter().enumerate() {
        current[0] = i + 1;
        for (j, &b_char) in b_chars.iter().enumerate() {
            let substitution = usize::from(a_char != b_char);
            current[j + 1] = (previous[j] + substitution)
                .min(previous[j + 1] + 1)
                .min(current[j] + 1);
        }
        std::mem::swap(&mut previous, &mut current);
    }
    previous[b_chars.len()]
}