ic-testkit 0.7.6

use std::time::{Duration, Instant};

use super::transaction::{
    ArtifactBuildTransaction, ArtifactCacheError, ArtifactCacheOutcome, ArtifactCachePreparation,
    ArtifactCacheSpec, prepare_artifact_cache,
};

/// Successful outcomes from sequential independent artifact transactions.
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct ArtifactCacheBatchOutcome {
    outcomes: Vec<ArtifactCacheOutcome>,
    total: Duration,
}

/// Failure from a sequential independent artifact transaction batch.
#[derive(Debug)]
pub enum ArtifactCacheBatchError<E> {
    /// Cache preparation or commit failed.
    Cache {
        /// Zero-based position of the failed specification.
        failed_index: usize,
        /// Successful outcomes completed before the failure.
        completed: Vec<ArtifactCacheOutcome>,
        /// Wall-clock time through the failure.
        total: Duration,
        /// Cache preparation or commit failure.
        source: Box<ArtifactCacheError>,
    },
    /// The caller's population callback failed.
    Build {
        /// Zero-based position of the failed specification.
        failed_index: usize,
        /// Successful outcomes completed before the failure.
        completed: Vec<ArtifactCacheOutcome>,
        /// Wall-clock time through the failure.
        total: Duration,
        /// Caller population failure.
        source: Box<E>,
        /// Failure from synchronously aborting the active transaction.
        cleanup_error: Option<Box<ArtifactCacheError>>,
    },
}

impl ArtifactCacheBatchOutcome {
    /// Successful outcomes in specification order.
    #[must_use]
    pub fn outcomes(&self) -> &[ArtifactCacheOutcome] {
        &self.outcomes
    }

    /// Consume the report and return its ordered outcomes.
    #[must_use]
    pub fn into_outcomes(self) -> Vec<ArtifactCacheOutcome> {
        self.outcomes
    }

    /// Complete wall-clock time for the sequential batch.
    #[must_use]
    pub const fn total(&self) -> Duration {
        self.total
    }
}

impl<E> ArtifactCacheBatchError<E> {
    /// Zero-based index of the failed independent specification.
    #[must_use]
    pub const fn failed_index(&self) -> usize {
        match self {
            Self::Cache { failed_index, .. } | Self::Build { failed_index, .. } => *failed_index,
        }
    }

    /// Successful outcomes completed before the failure.
    #[must_use]
    pub fn completed(&self) -> &[ArtifactCacheOutcome] {
        match self {
            Self::Cache { completed, .. } | Self::Build { completed, .. } => completed,
        }
    }

    /// Wall-clock time through the failure.
    #[must_use]
    pub const fn total(&self) -> Duration {
        match self {
            Self::Cache { total, .. } | Self::Build { total, .. } => *total,
        }
    }

    /// Cleanup failure after a caller population error, when one occurred.
    #[must_use]
    pub fn cleanup_error(&self) -> Option<&ArtifactCacheError> {
        match self {
            Self::Build { cleanup_error, .. } => cleanup_error.as_deref(),
            Self::Cache { .. } => None,
        }
    }
}

impl std::fmt::Display for ArtifactCacheBatchOutcome {
    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let reused = self
            .outcomes
            .iter()
            .filter(|outcome| outcome.is_reused())
            .count();
        write!(
            formatter,
            "entries={} built={} reused={} total={:?}",
            self.outcomes.len(),
            self.outcomes.len().saturating_sub(reused),
            reused,
            self.total,
        )
    }
}

/// Build or reuse multiple independent transactional artifact sets.
///
/// The callback runs only for misses and receives one live transaction at a
/// time. Sequential acquisition avoids self-deadlock when entries share a
/// coordination scope. A callback error aborts and synchronously cleans that
/// transaction before returning. Completed entries remain valid when a later
/// entry fails.
///
/// This operation is not atomic across specifications. A caller requiring one
/// all-or-nothing multi-output publication should declare those outputs on one
/// [`ArtifactCacheSpec`] instead.
pub fn build_artifact_caches_batch<E, F>(
    specs: &[ArtifactCacheSpec],
    mut populate: F,
) -> Result<ArtifactCacheBatchOutcome, ArtifactCacheBatchError<E>>
where
    F: FnMut(usize, &ArtifactBuildTransaction) -> Result<(), E>,
{
    let started = Instant::now();
    let mut outcomes = Vec::with_capacity(specs.len());
    for (index, spec) in specs.iter().enumerate() {
        let preparation = match prepare_artifact_cache(spec) {
            Ok(preparation) => preparation,
            Err(source) => {
                return Err(ArtifactCacheBatchError::Cache {
                    failed_index: index,
                    completed: outcomes,
                    total: started.elapsed(),
                    source: Box::new(source),
                });
            }
        };
        let outcome = match preparation {
            ArtifactCachePreparation::Reused(record) => ArtifactCacheOutcome::Reused(record),
            ArtifactCachePreparation::Build(transaction) => {
                if let Err(source) = populate(index, &transaction) {
                    let cleanup_error = transaction.abort().err().map(Box::new);
                    return Err(ArtifactCacheBatchError::Build {
                        failed_index: index,
                        completed: outcomes,
                        total: started.elapsed(),
                        source: Box::new(source),
                        cleanup_error,
                    });
                }
                match transaction.commit() {
                    Ok(outcome) => outcome,
                    Err(source) => {
                        return Err(ArtifactCacheBatchError::Cache {
                            failed_index: index,
                            completed: outcomes,
                            total: started.elapsed(),
                            source: Box::new(source),
                        });
                    }
                }
            }
        };
        outcomes.push(outcome);
    }
    Ok(ArtifactCacheBatchOutcome {
        outcomes,
        total: started.elapsed(),
    })
}

impl<E: std::fmt::Display> std::fmt::Display for ArtifactCacheBatchError<E> {
    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Cache {
                failed_index,
                completed,
                source,
                ..
            } => write!(
                formatter,
                "artifact cache batch entry {failed_index} failed after {} successful entry/entries: {source}",
                completed.len(),
            ),
            Self::Build {
                failed_index,
                completed,
                source,
                cleanup_error,
                ..
            } => {
                write!(
                    formatter,
                    "artifact cache batch builder {failed_index} failed after {} successful entry/entries: {source}",
                    completed.len(),
                )?;
                if let Some(cleanup_error) = cleanup_error {
                    write!(formatter, "; cleanup also failed: {cleanup_error}")?;
                }
                Ok(())
            }
        }
    }
}

impl<E> std::error::Error for ArtifactCacheBatchError<E>
where
    E: std::error::Error + 'static,
{
    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        match self {
            Self::Cache { source, .. } => Some(source.as_ref()),
            Self::Build { source, .. } => Some(source.as_ref()),
        }
    }
}

#[cfg(test)]
mod tests;