ostraka-runtime 1.0.0

//! One task, start to finish.
//!
//! Isolate, execute, gate, review, record. The orchestrator drives every step
//! and can approve none of them: the only thing that ends a run favourably is a
//! [`crate::gate::MergeToken`], which this module cannot construct.

use crate::author;
use crate::gate::{self, MergeToken, Refusal};
use crate::progress::{Phase, Watcher};
use crate::record::RunLog;
use crate::review;
use crate::route::Routing;
use crate::worktree;
use crate::{Error, Result};
use ostraka_adapter::{AdapterOutcome, VendorAdapter};
use ostraka_core::clock::now_rfc3339;
use ostraka_core::config::Config;
use ostraka_core::gate::{Approval, Verdict};
use ostraka_core::identity::ActorId;
use ostraka_core::record::{Event, Outcome, RunRecord};
use ostraka_core::task::TaskSpec;
use std::path::Path;

/// What a finished run produced.
pub struct RunReport {
    pub record: RunRecord,
    /// Present only when the gate minted one. Its absence is the refusal.
    pub token: Option<MergeToken>,
    pub refusal: Option<Refusal>,
    pub diff: String,
}

impl RunReport {
    pub fn approved(&self) -> bool {
        self.token.is_some()
    }
}

/// Where the parts of a run live.
///
/// Three directories that used to be one: a run is made *in* a repository,
/// *beside* a set of worktrees, and *recorded* somewhere that may be neither.
/// Deriving the second two from the first assumed a workspace holding exactly
/// one repository, which is the assumption this replaces — and passing them
/// explicitly means the layout is decided by whoever knows it rather than
/// rebuilt from a convention in here.
pub struct Places<'a> {
    /// The repository the change is made in.
    pub repo: &'a Path,
    /// Where worktrees are created.
    pub worktrees: &'a Path,
    /// Where run records are written.
    pub records: &'a Path,
    /// The name this repository is known by, for the record.
    pub name: &'a str,
    /// The workspace's notes, linked into the worktree so what an agent works
    /// out survives the run. `None` where there are none.
    pub notes: Option<&'a Path>,
    /// The workspace's skills, linked in the same way and for the mirror
    /// reason: what people wrote down for a run to follow. `None` where there
    /// are none.
    pub skills: Option<&'a Path>,
}

/// Runs one task through the whole pipeline.
///
/// The worktree is left in place on completion so the diff can be inspected;
/// removing it is the caller's decision, not this function's.
///
/// `watcher` is told what is happening while it happens, for a caller that has
/// a screen to keep up to date. It cannot change any of it: see
/// [`crate::progress`]. `None` behaves exactly as this function always has.
pub fn run_task(
    places: &Places<'_>,
    config: &Config,
    routing: &Routing,
    task: &TaskSpec,
    reviewer_identity: &ActorId,
    watcher: Option<Box<dyn Watcher>>,
) -> Result<RunReport> {
    let repo = places.repo;
    let run_id = format!("{}-{}", task.id, now_rfc3339().replace([':', '-'], ""));
    let mut log = RunLog::create(places.records, &run_id)?.watched_by(watcher);
    log.enter(Phase::Isolating);

    let mut record = RunRecord {
        run_id: run_id.clone(),
        task_id: task.id.clone(),
        prompt: task.prompt.clone(),
        author: task.author.clone(),
        adapter: routing.author.id().to_string(),
        repository: places.name.to_string(),
        started_at: now_rfc3339(),
        finished_at: None,
        checks: Vec::new(),
        approval: None,
        usage: Vec::new(),
        outcome: None,
    };

    // 1. Isolate. Work is a diff on disk before it is anything else.
    let wt = worktree::create(repo, places.worktrees, &run_id, &task.base_ref)?;

    // 2. Make the checkout usable. A worktree is a fresh checkout, so whatever
    //    git ignores is missing from it — and the agent needs the project's
    //    tools as much as the gate does.
    log.enter(Phase::Preparing);
    match worktree::prepare(
        repo,
        wt.path(),
        &config.worktree,
        places.notes,
        places.skills,
        config.gate.timeout_secs.map(std::time::Duration::from_secs),
    ) {
        Ok(steps) => {
            for step in steps {
                log.append(&Event::Message {
                    text: format!("prepared: {step}"),
                    raw: None,
                })?;
            }
        }
        Err(problem) => {
            return finish(
                log,
                record,
                Outcome::Failed,
                None,
                Some(Refusal::SetupFailed {
                    step: problem.step,
                    reason: problem.reason,
                }),
                String::new(),
            );
        }
    }

    // 3. Execute, streaming events into the log as they arrive so an
    //    interrupted run still leaves an account of how far it got.
    log.enter(Phase::Authoring);
    // A separate spec, the way review builds one. `task.prompt` is the
    // operator's sentence and it is read again further down — by the record and
    // by the commit message — so composing in place would put this preamble in
    // both, where it is neither what was asked nor part of the audit trail.
    // Read off the worktree rather than off the configuration. Naming notes in
    // `[worktree]` is an intention; a repository that tracks its own `notes/`
    // keeps it, and telling an agent otherwise would point it at the diff.
    let authoring = TaskSpec {
        prompt: author::author_prompt(
            &task.prompt,
            worktree::linked(wt.path(), "notes"),
            worktree::linked(wt.path(), "skills"),
        ),
        ..task.clone()
    };
    let author = drive(routing.author.as_ref(), &authoring, wt.path(), &mut log)?;
    record.usage.extend(author.usage.clone());

    // 3. Read what was actually touched, from git rather than from the agent.
    let touched = worktree::touched_paths(wt.path())?;
    log.append(&Event::Finished {
        exit_code: author.exit_code,
        files_touched: touched.clone(),
    })?;

    // Nothing was written, so there is nothing a reviewer can rule on: it would
    // be handed an empty diff and asked what it thinks of it, which spends a
    // second vendor to produce a confused answer and then reports that answer
    // as the reason. Why it is empty is the reason, and it is known here.
    // A killed author is refused whether or not it left something behind: what
    // is on disk is half of whatever it was doing, and half a change is not a
    // change anybody should be asked to review.
    if author.interrupted {
        return finish(
            log,
            record,
            Outcome::Rejected,
            None,
            Some(Refusal::Interrupted),
            String::new(),
        );
    }

    if author.timed_out {
        return finish(
            log,
            record,
            Outcome::Rejected,
            None,
            Some(Refusal::TimedOut {
                after_secs: config.policy.timeout_secs.unwrap_or_default(),
            }),
            String::new(),
        );
    }

    // An author that did not exit cleanly did not finish, and what is on disk
    // is half of whatever it was doing. Half a change is not a change anybody
    // should be asked to review — the same reasoning that refuses a killed
    // author, and the same situation: a context window running out is a stop
    // like any other, and only who stopped it differs.
    //
    // Being this strict costs something, and it is worth naming: a vendor that
    // exits non-zero for a harmless reason now has finished work refused
    // rather than reviewed. That is the safe direction and it is recoverable —
    // a refused run keeps its worktree, the record carries the vendor's own
    // words, and running it again is one command. The unsafe direction is not:
    // a half-written change that happened to compile was gated, reviewed and
    // approved, which is what this used to do.
    if author.exit_code != Some(0) {
        let refusal = Refusal::AuthorFailed {
            code: author
                .exit_code
                .map(|c| c.to_string())
                .unwrap_or_else(|| "no exit code".to_string()),
            diagnostics: author.diagnostics.clone(),
        };
        return finish(
            log,
            record,
            Outcome::Rejected,
            None,
            Some(refusal),
            String::new(),
        );
    }

    if touched.is_empty() {
        return finish(
            log,
            record,
            Outcome::Rejected,
            None,
            Some(Refusal::NoChange),
            String::new(),
        );
    }

    if !config.policy.permits(&touched) {
        return finish(
            log,
            record,
            Outcome::Rejected,
            None,
            Some(Refusal::PolicyViolation {
                reason: format!("policy forbids writing outside declared paths: {touched:?}"),
            }),
            String::new(),
        );
    }

    // 4. Gate. These commands actually run; their output is captured.
    log.enter(Phase::Gating);
    let passed = match gate::run_checks(&config.gate, wt.path(), &mut |record| {
        log_checked(&mut log, record)
    }) {
        Ok(p) => p,
        Err(refusal) => {
            // Keep the evidence. A failed run is the one someone will need to
            // read afterwards, so the records travel from the refusal into the
            // record before anything returns.
            if let Refusal::ChecksFailed { records, .. } = &refusal {
                record.checks.clone_from(records);
            }
            return finish(
                log,
                record,
                Outcome::Rejected,
                None,
                Some(refusal),
                String::new(),
            );
        }
    };
    record.checks = passed.records().to_vec();

    // 5. Review, by an adapter that is not the one that wrote the change.
    log.enter(Phase::Reviewing);
    let diff = worktree::diff(wt.path())?;
    let (verdict, reviewer_usage) =
        collect_verdict(routing.reviewer.as_ref(), task, &diff, wt.path(), &mut log)?;
    record.usage.extend(reviewer_usage);
    let approval = Approval {
        reviewer: reviewer_identity.clone(),
        verdict: verdict.clone(),
    };
    record.approval = Some(approval.clone());

    // 6. The gate decides. Nothing above this line can mint a token.
    match gate::evaluate(
        passed,
        &task.author,
        &approval,
        config.gate.review.must_differ_from_author,
    ) {
        Ok(token) => {
            // The trailers are the audit trail in the place it survives longest:
            // a commit outlives the run directory it came from.
            let message = format!(
                "{}\n\nRun: {run_id}\nAuthored-by: {} ({})\nReviewed-by: {} ({})",
                task.prompt,
                task.author,
                routing.author.id(),
                reviewer_identity,
                routing.reviewer.id(),
            );
            worktree::commit(wt.path(), &message, &task.author)?;
            // The commit is on the run's branch now, and everything downstream
            // reads it from there: the diff pane, `replay`, and promotion. The
            // checkout is redundant, and a directory per run is how a busy
            // repository fills a disk with copies of itself.
            //
            // Only on success. A refused run's worktree is the evidence someone
            // needs to see what went wrong, and deleting it would take that
            // away at exactly the moment it matters.
            if let Err(e) = worktree::release(repo, &wt) {
                log.append(&Event::Error {
                    message: format!("the worktree could not be removed: {e}"),
                    raw: None,
                })?;
            }
            finish(log, record, Outcome::Approved, Some(token), None, diff)
        }
        Err(refusal) => finish(log, record, Outcome::Rejected, None, Some(refusal), diff),
    }
}

/// Reports one finished check.
///
/// A free function rather than a closure body so the borrow of the log inside
/// `run_checks` stays a single obvious line.
fn log_checked(log: &mut RunLog, record: &ostraka_core::gate::CheckRecord) {
    log.checked(record);
}

/// Runs an adapter to completion, logging every event.
fn drive(
    adapter: &dyn VendorAdapter,
    task: &TaskSpec,
    worktree: &Path,
    log: &mut RunLog,
) -> Result<AdapterOutcome> {
    let mut session = adapter.launch(task, worktree)?;
    while let Some(event) = session.next_event() {
        log.append(&event)?;
    }
    let outcome = session.finish();
    // Recorded whether or not anything else reads it. A run that ended badly
    // and whose cause was discarded looks like an agent that simply did
    // nothing, and the transcript is where somebody goes to find out which.
    if let Some(diagnostics) = &outcome.diagnostics {
        log.append(&Event::Error {
            message: format!("author exited abnormally: {diagnostics}"),
            raw: None,
        })?;
    }
    Ok(outcome)
}

/// Runs the reviewer and reads its answer.
///
/// Fail-safe throughout: a reviewer that cannot be launched, or that says
/// nothing usable, has not approved anything.
type Reviewed = (Verdict, Option<ostraka_core::record::TokenUsage>);

fn collect_verdict(
    reviewer: &dyn VendorAdapter,
    task: &TaskSpec,
    diff: &str,
    worktree: &Path,
    log: &mut RunLog,
) -> Result<Reviewed> {
    // Derived here, after the author has finished, and handed only to the
    // reviewer: it is what lets the verdict be read from anywhere in the answer
    // without an author being able to plant one in the diff.
    let marker = review::verdict_marker(&task.id);
    let review_task = TaskSpec {
        id: format!("{}-review", task.id),
        prompt: review::review_prompt(&task.prompt, diff, &marker),
        adapter: reviewer.id().to_string(),
        author: task.author.clone(),
        base_ref: task.base_ref.clone(),
        model: None,
    };

    let mut session = match reviewer.launch(&review_task, worktree) {
        Ok(s) => s,
        Err(e) => {
            return Ok((
                Verdict::Reject {
                    reason: format!("reviewer could not be launched: {e}"),
                },
                None,
            ));
        }
    };

    let mut spoken = String::new();
    while let Some(event) = session.next_event() {
        if let Event::Message { text, .. } = &event {
            spoken.push_str(text);
            spoken.push('\n');
        }
        log.append(&event)?;
    }
    let outcome = session.finish();
    if outcome.exit_code != Some(0) {
        let code = outcome
            .exit_code
            .map(|c| c.to_string())
            .unwrap_or_else(|| "no exit code".to_string());
        // Say why. A reviewer that failed because a credential expired and one
        // that failed because it disagreed are the same exit code, and only one
        // of them is about the change.
        let reason = match &outcome.diagnostics {
            Some(d) => format!("reviewer could not run (exit {code}): {d}"),
            None => format!("reviewer could not run (exit {code}), and said nothing"),
        };
        log.append(&Event::Error {
            message: reason.clone(),
            raw: None,
        })?;
        return Ok((Verdict::Reject { reason }, outcome.usage));
    }

    Ok((review::parse_verdict(&spoken, &marker), outcome.usage))
}

fn finish(
    log: RunLog,
    mut record: RunRecord,
    outcome: Outcome,
    token: Option<MergeToken>,
    refusal: Option<Refusal>,
    diff: String,
) -> Result<RunReport> {
    record.finished_at = Some(now_rfc3339());
    record.outcome = Some(outcome);
    log.write_record(&record)?;
    Ok(RunReport {
        record,
        token,
        refusal,
        diff,
    })
}

/// Reads a previous run back for replay.
pub fn replay(records_root: &Path, run_id: &str) -> Result<(RunRecord, Vec<Event>)> {
    let dir = records_root.join("runs").join(run_id);
    let record_text = std::fs::read_to_string(dir.join("record.json"))
        .map_err(|e| Error::Other(format!("no run {run_id:?}: {e}")))?;
    let record: RunRecord = serde_json::from_str(&record_text)
        .map_err(|e| Error::Other(format!("run record is unreadable: {e}")))?;
    let events = crate::record::read_events(&dir)?;
    Ok((record, events))
}