veredictum 0.1.3

// SPDX-FileCopyrightText: Veredictum contributors
// SPDX-License-Identifier: Apache-2.0

//! The universal-benchmark engine: comparative SPEED against any reachable
//! openEHR CDR, with no catalogue, no ixit and no artifact root.
//!
//! A bench run takes a base URL plus one credential and drives an EMBEDDED
//! pack: a seed phase that bulk-loads a fixed corpus through the public API
//! (closed-loop, reported as bulk-load throughput and labelled as such), then
//! measured phases that offer a seeded open-loop arrival schedule over a
//! closed operation vocabulary. Every latency is measured from the PLANNED
//! arrival instant, so coordinated omission cannot hide a stall. The measured
//! phases repeat, and the result carries every repetition plus the
//! cross-repetition median and inter-quartile range.
//!
//! An absolute number is anchored by a same-machine reference run: the same
//! pack, at the same seed, against a reference CDR composed from pinned image
//! digests on the host that measured the target. From the two the record
//! derives the relative index, a dimensionless ratio that travels between
//! machines where milliseconds do not.
//!
//! Two records are comparable only when the same features were switched on
//! behind them, so every pack defines named posture profiles, a run declares
//! exactly one, and black-box canaries bracket the measured window to check the
//! declaration against the running system. A canary that contradicts the
//! declaration refuses the run.
//!
//! What this engine is NOT is stated in [`BOUNDARY_STATEMENT`], which every
//! artifact and every rendered view carries verbatim.

pub mod baselines;
pub mod client;
pub mod compare;
pub mod fingerprint;
pub mod manifest;
pub mod pack;
pub mod posture;
pub mod relative;
pub mod render;
pub mod result;
pub mod run;

use std::path::PathBuf;

use thiserror::Error;

/// What a bench result is, and what it is never. Carried verbatim in every
/// emitted artifact, on the `bench` console output, and in every rendered
/// comparison.
pub const BOUNDARY_STATEMENT: &str = "This is a benchmark record for comparative speed. It is not a conformance record, not a certificate, and not a performance-class rating; a bench result may motivate a class run, never substitute for one.";

/// The methodology every bench run follows, stated in the artifact so a
/// reader never has to infer it from the numbers.
pub const METHODOLOGY: &str = "Seed once, measure N times. Measured phases are open-loop: arrivals fire at their planned instants regardless of any other request's completion, and every latency is measured from the planned arrival instant, so coordinated omission cannot hide a stall. Seed phases are closed-loop by construction and are reported as bulk-load throughput only.";

/// A failure of the benchmark engine.
///
/// Each variant renders the diagnostic the command line reports. Individual
/// arrival faults inside a measured phase are NOT errors here: they are
/// counted by class in the result.
///
/// Size posture: `clippy::result_large_err` fires crate-wide at 128 bytes and
/// this enum stays under it, so a variant needing several owned strings boxes
/// them behind one payload struct rather than raising the threshold.
#[derive(Debug, Error)]
pub enum BenchError {
    /// The requested pack is not one this binary embeds.
    #[error("unknown bench pack {requested:?} (embedded: {known})")]
    UnknownPack {
        /// The token the caller asked for.
        requested: String,
        /// The embedded pack ids, comma-separated.
        known: String,
    },
    /// A token outside a closed vocabulary. Never a silent fallback: an
    /// unknown token in a conformance instrument manufactures a wrong row.
    #[error("unknown {vocabulary} token {token:?} (accepted: {accepted})")]
    UnknownToken {
        /// Which vocabulary rejected the token.
        vocabulary: &'static str,
        /// The token as written.
        token: String,
        /// The accepted tokens, comma-separated.
        accepted: String,
    },
    /// The requested posture profile is not one the pack defines.
    #[error("unknown posture profile {requested:?} for pack {pack} (defined: {known})")]
    UnknownProfile {
        /// The pack that was asked.
        pack: pack::PackId,
        /// The token the caller asked for.
        requested: String,
        /// The profile names the pack defines, comma-separated.
        known: String,
    },
    /// A pack defines no posture profile at all, so a run has nothing to
    /// declare.
    #[error("bench pack {pack} defines no posture profile, so a run has nothing to declare")]
    NoProfiles {
        /// The pack with no profile.
        pack: pack::PackId,
    },
    /// A posture canary observed something other than what the run declared.
    /// The run is refused: a published speed number never carries a footnote
    /// saying the disclosure was wrong.
    #[error(
        "posture canary contradicts the declaration: `{}` is declared `{}` and the \
         {} canary observed `{}` — {}",
        .0.item, .0.declared, .0.bracket, .0.observed, .0.evidence
    )]
    PostureContradiction(Box<posture::PostureDisagreement>),
    /// A posture canary read one thing before the measured window and another
    /// after it, so the numbers straddle two different systems.
    #[error(
        "posture canary flipped across the measured window: `{item}` read `{before}` before and \
         `{after}` after, so the measured window straddles two configurations"
    )]
    PostureFlip {
        /// The disclosed item that moved.
        item: String,
        /// The reading before the measured window.
        before: String,
        /// The reading after it.
        after: String,
    },
    /// A bracket did not produce a reading for one disclosed item.
    #[error("posture canary {bracket} bracket produced no reading for `{item}`")]
    PostureBracket {
        /// The item with no reading.
        item: String,
        /// The bracket that is short.
        bracket: String,
    },
    /// An embedded fixture's bytes do not hash to the pin the pack declares.
    #[error(
        "bench pack {pack}: fixture {fixture} is pinned at sha256 {expected} but the embedded bytes hash to {actual}"
    )]
    FixturePin {
        /// The pack carrying the fixture.
        pack: pack::PackId,
        /// The fixture key.
        fixture: pack::FixtureKey,
        /// The declared pin.
        expected: String,
        /// What the embedded bytes actually hash to.
        actual: String,
    },
    /// A composition fixture declares a root archetype its own template does
    /// not root at, so every commit the pack makes is a composition no server
    /// validating against that template may accept.
    #[error(
        "bench pack {}: fixture {} declares archetype_node_id {} and \
         archetype_details.archetype_id {}, but its template {} roots at {}",
        .0.pack, .0.fixture, .0.node_id, .0.archetype_id, .0.template, .0.root
    )]
    FixtureRoot(Box<pack::RootMismatch>),
    /// A composition fixture names a template the pack does not seed, so
    /// nothing in the pack says what root it should carry.
    #[error(
        "bench pack {pack}: fixture {fixture} declares template {template}, which the pack does \
         not seed (seeded: {seeded})"
    )]
    FixtureTemplate {
        /// The pack carrying the fixture.
        pack: pack::PackId,
        /// The composition fixture key.
        fixture: pack::FixtureKey,
        /// The template id the fixture declares.
        template: String,
        /// The template ids the pack does seed, comma-separated.
        seeded: String,
    },
    /// An embedded fixture could not be read well enough to check it.
    #[error("bench pack {pack}: fixture {fixture} cannot be read: {detail}")]
    FixtureUnreadable {
        /// The pack carrying the fixture.
        pack: pack::PackId,
        /// The fixture key.
        fixture: pack::FixtureKey,
        /// What the reader reported.
        detail: String,
    },
    /// `--auth basic` was selected without the user the header needs.
    #[error("--auth basic needs --user")]
    MissingUser,
    /// A credential environment variable is unset. Secrets never ride argv.
    #[error("credential environment variable {name} is unset: {source}")]
    Credential {
        /// The variable that was consulted.
        name: &'static str,
        /// The lookup failure.
        #[source]
        source: std::env::VarError,
    },
    /// The HTTP client could not be built.
    #[error("http client: {source}")]
    Client {
        /// The underlying failure.
        #[source]
        source: reqwest::Error,
    },
    /// A request never reached a response.
    #[error("{exchange}: transport: {source}")]
    Transport {
        /// The exchange that failed, named the way the preflight names it.
        exchange: String,
        /// The underlying failure.
        #[source]
        source: reqwest::Error,
    },
    /// The preflight refused the run. Nothing is measured after this.
    #[error("preflight refused the run at {exchange}: {detail}")]
    Preflight {
        /// The exchange that failed.
        exchange: String,
        /// What was wrong with it.
        detail: String,
    },
    /// A seed phase could not complete, so no measured phase may follow.
    #[error("seed phase {phase}: {detail}")]
    Seed {
        /// The phase name from the pack.
        phase: String,
        /// What went wrong.
        detail: String,
    },
    /// A measured phase could not be aggregated.
    #[error("measure phase {phase}: {detail}")]
    Measure {
        /// The phase name from the pack.
        phase: String,
        /// What went wrong.
        detail: String,
    },
    /// The repetition count is outside the engine's range.
    #[error("--repetitions must be at least 1 (got {0})")]
    Repetitions(u32),
    /// A histogram could not be created, recorded into, or encoded.
    #[error("histogram: {0}")]
    Histogram(String),
    /// A comparison was asked for with fewer than two result files.
    #[error("bench-compare needs at least two result files (got {0})")]
    TooFewResults(usize),
    /// `--with-baselines` was asked for on a host whose container runtime
    /// does not answer. The flag has one ground, and this names it.
    #[error(
        "--with-baselines needs the docker CLI, and {binary} does not answer: {detail}. \
         A run without the flag measures the target alone and needs no container runtime."
    )]
    DockerUnavailable {
        /// The binary that was invoked.
        binary: String,
        /// What the invocation reported.
        detail: String,
    },
    /// One reference baseline could not be composed, made ready, or torn
    /// down. Never a target failure: the target's own numbers stand.
    #[error("baseline {cdr}: {detail}")]
    Baseline {
        /// The reference CDR token.
        cdr: String,
        /// What went wrong.
        detail: String,
    },
    /// A file could not be written.
    #[error("cannot write {path}: {source}")]
    Write {
        /// The file that could not be written.
        path: PathBuf,
        /// The underlying filesystem error.
        #[source]
        source: std::io::Error,
    },
    /// A file could not be read.
    #[error("cannot read {path}: {source}")]
    Read {
        /// The file that could not be read.
        path: PathBuf,
        /// The underlying filesystem error.
        #[source]
        source: std::io::Error,
    },
    /// A document did not parse as a bench result.
    #[error("{path}: not a bench result: {message}")]
    Parse {
        /// The file that did not parse.
        path: PathBuf,
        /// The parser's own diagnostic.
        message: String,
    },
    /// A value could not be serialized back to JSON.
    #[error("serialize {context}: {source}")]
    Serialize {
        /// What was being serialized.
        context: &'static str,
        /// The serializer's own diagnostic.
        #[source]
        source: serde_json::Error,
    },
}