knowledge-runtime 0.1.0

use crate::error::RuntimeError;
use crate::ids::{EntityId, Scope, ScopeKey};
use crate::obs::trace::{RuntimeDerivedCandidateTraceV1, RuntimeQueryProvenanceV1, RuntimeView};
use semantic_memory::{
    ExplainedResult, MemoryStore, ProjectionClaimVersion, ProjectionEntityAlias, ProjectionEpisode,
    ProjectionEvidenceRef, ProjectionImportLogEntry, ProjectionQuery, ProjectionRelationVersion,
    ReceiptMode, SearchContext, SearchResult, SearchSource, SearchSourceType,
    VectorSearchReceiptV1,
};
use stack_ids::{ClaimId, ClaimVersionId, TraceCtx};

/// Read-only adapter over a `semantic_memory::MemoryStore`.
///
/// This adapter exposes only the query surface of `MemoryStore`. It
/// intentionally does NOT expose mutation methods — the runtime owns
/// derived projections, never source truth.
#[derive(Clone)]
pub struct SemanticMemoryAdapter {
    store: MemoryStore,
}

#[derive(Debug, Clone)]
pub struct ExplainedSearchArtifacts {
    pub explained_results: Vec<ExplainedResult>,
    pub provenance: RuntimeQueryProvenanceV1,
}

impl SemanticMemoryAdapter {
    /// Wrap an existing `MemoryStore`.
    pub fn new(store: MemoryStore) -> Self {
        Self { store }
    }

    /// Hybrid search with scope applied as namespace filter.
    pub async fn search(
        &self,
        query: &str,
        scope: &Scope,
        limit: Option<usize>,
        source_types: Option<&[SearchSourceType]>,
    ) -> Result<Vec<SearchResult>, RuntimeError> {
        let ns = scope.namespace.as_str();
        let ns_slice: &[&str] = &[ns];
        let scope_key = scope.key();
        let filterable_scope =
            scope.domain.is_some() || scope.workspace_id.is_some() || scope.repo_id.is_some();
        let scoped_source_types = if filterable_scope {
            Some(filterable_search_source_types(source_types))
        } else {
            source_types.map(|types| types.to_vec())
        };
        let requested_limit = limit.unwrap_or(10);
        let candidate_limit = if filterable_scope {
            Some(requested_limit.saturating_mul(3).max(requested_limit))
        } else {
            limit
        };

        let results = self
            .store
            .search(
                query,
                candidate_limit,
                Some(ns_slice),
                scoped_source_types.as_deref(),
            )
            .await
            .map_err(RuntimeError::Memory)?;

        if filterable_scope {
            let filtered = self
                .store
                .filter_search_results_by_scope(results, &scope_key)
                .await
                .map_err(RuntimeError::Memory)?;
            Ok(filtered.into_iter().take(requested_limit).collect())
        } else {
            Ok(results)
        }
    }

    /// Hybrid search that requests semantic-memory receipt metadata and returns
    /// a runtime-safe derived candidate summary when available.
    pub async fn search_with_receipt(
        &self,
        query: &str,
        scope: &Scope,
        limit: Option<usize>,
        source_types: Option<&[SearchSourceType]>,
    ) -> Result<(Vec<SearchResult>, Option<RuntimeDerivedCandidateTraceV1>), RuntimeError> {
        let ns = scope.namespace.as_str();
        let ns_slice: &[&str] = &[ns];
        let scope_key = scope.key();
        let filterable_scope =
            scope.domain.is_some() || scope.workspace_id.is_some() || scope.repo_id.is_some();
        let scoped_source_types = if filterable_scope {
            Some(filterable_search_source_types(source_types))
        } else {
            source_types.map(|types| types.to_vec())
        };
        let requested_limit = limit.unwrap_or(10);
        let candidate_limit = if filterable_scope {
            requested_limit.saturating_mul(3).max(requested_limit)
        } else {
            requested_limit
        };
        let mut context = SearchContext::default_now();
        context.receipt_mode = ReceiptMode::ReturnReceipt;

        let response = self
            .store
            .search_explained_with_context(
                query,
                Some(candidate_limit),
                Some(ns_slice),
                scoped_source_types.as_deref(),
                context,
            )
            .await
            .map_err(RuntimeError::Memory)?;
        let receipt = response.receipt.as_ref().map(runtime_trace_from_receipt);

        let explained_results = if filterable_scope {
            let filtered = self
                .store
                .filter_search_results_by_scope(
                    response
                        .results
                        .iter()
                        .map(|item| item.result.clone())
                        .collect(),
                    &scope_key,
                )
                .await
                .map_err(RuntimeError::Memory)?;
            let allowed: std::collections::BTreeSet<String> =
                filtered.iter().map(search_identity).collect();
            response
                .results
                .into_iter()
                .filter(|item| allowed.contains(&search_identity(&item.result)))
                .take(requested_limit)
                .collect::<Vec<_>>()
        } else {
            response.results.into_iter().take(requested_limit).collect()
        };

        Ok((
            explained_results
                .into_iter()
                .map(|item| item.result)
                .collect(),
            receipt,
        ))
    }

    /// Hybrid search with explicit explained-score payloads and runtime-owned provenance.
    pub async fn search_explained(
        &self,
        query: &str,
        scope: &Scope,
        limit: usize,
        relevance_threshold: f64,
    ) -> Result<ExplainedSearchArtifacts, RuntimeError> {
        let ns = scope.namespace.as_str();
        let ns_slice: &[&str] = &[ns];
        let scope_key = scope.key();
        let filterable_scope =
            scope.domain.is_some() || scope.workspace_id.is_some() || scope.repo_id.is_some();
        let candidate_limit = if filterable_scope {
            limit.saturating_mul(3).max(limit)
        } else {
            limit
        };

        let explained_results = self
            .store
            .search_explained(query, Some(candidate_limit), Some(ns_slice), None)
            .await
            .map_err(RuntimeError::Memory)?;
        let pre_filter_count = explained_results.len();

        let scoped_results = if filterable_scope {
            let filtered = self
                .store
                .filter_search_results_by_scope(
                    explained_results
                        .iter()
                        .map(|item| item.result.clone())
                        .collect(),
                    &scope_key,
                )
                .await
                .map_err(RuntimeError::Memory)?;
            let allowed: std::collections::BTreeSet<String> =
                filtered.iter().map(search_identity).collect();
            explained_results
                .into_iter()
                .filter(|item| allowed.contains(&search_identity(&item.result)))
                .collect::<Vec<_>>()
        } else {
            explained_results
        };
        let post_filter_count = scoped_results.len();

        let filtered: Vec<_> = scoped_results
            .iter()
            .filter(|item| item.result.score >= relevance_threshold)
            .take(limit)
            .cloned()
            .collect();

        let mut adaptive_threshold_used = false;
        let mut fallback_threshold_val = None;
        let final_results = if filtered.len() < 2 {
            let fallback_threshold = relevance_threshold / 2.0;
            let fallback: Vec<_> = scoped_results
                .iter()
                .filter(|item| item.result.score >= fallback_threshold)
                .take(limit)
                .cloned()
                .collect();
            if fallback.len() > filtered.len() {
                adaptive_threshold_used = true;
                fallback_threshold_val = Some(fallback_threshold);
                fallback
            } else {
                filtered
            }
        } else {
            filtered
        };

        let kernel_degraded_reason = if adaptive_threshold_used {
            Some(format!(
                "adaptive_threshold: primary {:.3} fell back to {:.3}",
                relevance_threshold,
                fallback_threshold_val.unwrap_or(0.0)
            ))
        } else if final_results.is_empty() {
            Some("zero_results: no relevant chunks found".into())
        } else {
            None
        };

        Ok(ExplainedSearchArtifacts {
            explained_results: final_results,
            provenance: RuntimeQueryProvenanceV1 {
                schema_version: "runtime_query_provenance_v1".into(),
                trace_ctx: TraceCtx::generate(),
                scope: scope_key,
                classification_mode: "search".into(),
                classification_reason: None,
                query: query.to_string(),
                requested_views: vec![RuntimeView::Semantic],
                executed_views: vec![RuntimeView::Semantic],
                widenings: Vec::new(),
                warnings: Vec::new(),
                kernel_degraded_reason,
                leg_strategies: vec!["semantic_memory.search_explained".into()],
                leg_timings_ms: Vec::new(),
                total_duration_ms: 0,
                raw_result_count: pre_filter_count,
                merged_result_count: post_filter_count,
                duplicates_fused: 0,
                valid_as_of: None,
                recorded_as_of: None,
                temporal_mode: None,
            },
        })
    }

    /// Query imported projection rows by free-text content.
    pub async fn search_projection_text(
        &self,
        query: &str,
        scope: &Scope,
        limit: usize,
    ) -> Result<Vec<SearchResult>, RuntimeError> {
        let mut projection_query = ProjectionQuery::new(scope.key());
        projection_query.text_query = Some(query.to_string());
        projection_query.limit = limit;

        let claims = self
            .store
            .query_claim_versions(projection_query.clone())
            .await
            .map_err(RuntimeError::Memory)?;
        let relations = self
            .store
            .query_relation_versions(projection_query.clone())
            .await
            .map_err(RuntimeError::Memory)?;
        let episodes = self
            .store
            .query_episodes(projection_query)
            .await
            .map_err(RuntimeError::Memory)?;

        Ok(merge_projection_results(claims, relations, episodes, limit))
    }

    /// Query imported projection rows with explicit bitemporal filters.
    ///
    /// This is the explicit form used by callers that need independent
    /// `valid_at` and `recorded_at_or_before` semantics.
    pub async fn search_projection_temporal_with_recorded_at(
        &self,
        query: &str,
        scope: &Scope,
        valid_at: &str,
        recorded_at_or_before: &str,
        limit: usize,
    ) -> Result<Vec<SearchResult>, RuntimeError> {
        let mut projection_query = ProjectionQuery::new(scope.key());
        projection_query.text_query = Some(query.to_string());
        projection_query.valid_at = Some(valid_at.to_string());
        projection_query.recorded_at_or_before = Some(recorded_at_or_before.to_string());
        projection_query.limit = limit;

        let claims = self
            .store
            .query_claim_versions(projection_query.clone())
            .await
            .map_err(RuntimeError::Memory)?;
        let relations = self
            .store
            .query_relation_versions(projection_query.clone())
            .await
            .map_err(RuntimeError::Memory)?;
        let episodes = self
            .store
            .query_episodes(projection_query)
            .await
            .map_err(RuntimeError::Memory)?;

        Ok(merge_projection_results(claims, relations, episodes, limit))
    }

    /// Query imported projection rows with temporal filters.
    ///
    /// This convenience form keeps the existing route behavior by using
    /// the same `valid_at` value for both valid-time and transaction-time
    /// cutoffs.
    pub async fn search_projection_temporal(
        &self,
        query: &str,
        scope: &Scope,
        valid_at: &str,
        limit: usize,
    ) -> Result<Vec<SearchResult>, RuntimeError> {
        self.search_projection_temporal_with_recorded_at(query, scope, valid_at, valid_at, limit)
            .await
    }

    /// Query imported claim/relation rows for a bounded set of entity candidates.
    pub async fn search_projection_by_entity_ids(
        &self,
        scope: &Scope,
        entity_ids: &[EntityId],
        limit: usize,
    ) -> Result<Vec<SearchResult>, RuntimeError> {
        let mut all_claims = Vec::new();
        let mut all_relations = Vec::new();

        for entity_id in entity_ids.iter().take(limit.max(1)) {
            let mut projection_query = ProjectionQuery::new(scope.key());
            projection_query.subject_entity_id = Some(entity_id.clone());
            projection_query.limit = limit;

            all_claims.extend(
                self.store
                    .query_claim_versions(projection_query.clone())
                    .await
                    .map_err(RuntimeError::Memory)?,
            );
            all_relations.extend(
                self.store
                    .query_relation_versions(projection_query)
                    .await
                    .map_err(RuntimeError::Memory)?,
            );
        }

        Ok(merge_projection_results(
            all_claims,
            all_relations,
            Vec::new(),
            limit,
        ))
    }

    /// Query imported claim/relation rows for a bounded set of entity candidates
    /// with explicit bitemporal filters.
    pub async fn search_projection_by_entity_ids_with_recorded_at(
        &self,
        scope: &Scope,
        entity_ids: &[EntityId],
        valid_at: &str,
        recorded_at_or_before: &str,
        limit: usize,
    ) -> Result<Vec<SearchResult>, RuntimeError> {
        let mut all_claims = Vec::new();
        let mut all_relations = Vec::new();

        for entity_id in entity_ids.iter().take(limit.max(1)) {
            let mut projection_query = ProjectionQuery::new(scope.key());
            projection_query.subject_entity_id = Some(entity_id.clone());
            projection_query.valid_at = Some(valid_at.to_string());
            projection_query.recorded_at_or_before = Some(recorded_at_or_before.to_string());
            projection_query.limit = limit;

            all_claims.extend(
                self.store
                    .query_claim_versions(projection_query.clone())
                    .await
                    .map_err(RuntimeError::Memory)?,
            );
            all_relations.extend(
                self.store
                    .query_relation_versions(projection_query)
                    .await
                    .map_err(RuntimeError::Memory)?,
            );
        }

        Ok(merge_projection_results(
            all_claims,
            all_relations,
            Vec::new(),
            limit,
        ))
    }

    /// Query bounded alias candidates from imported projection rows.
    pub async fn query_alias_candidates(
        &self,
        mention: &str,
        scope: &Scope,
        limit: usize,
    ) -> Result<Vec<ProjectionEntityAlias>, RuntimeError> {
        let mut projection_query = ProjectionQuery::new(scope.key());
        projection_query.limit = limit.max(8).saturating_mul(8).min(64);

        let mut aliases = self
            .store
            .query_entity_aliases(projection_query)
            .await
            .map_err(RuntimeError::Memory)?;
        aliases.sort_by(|a, b| {
            alias_candidate_score(mention, b)
                .cmp(&alias_candidate_score(mention, a))
                .then_with(|| b.is_human_confirmed_final.cmp(&a.is_human_confirmed_final))
                .then_with(|| b.recorded_at.cmp(&a.recorded_at))
        });
        aliases.retain(|alias| alias_candidate_score(mention, alias) > 0);
        aliases.truncate(limit);
        Ok(aliases)
    }

    /// Query bounded alias candidates from imported projection rows with explicit
    /// temporal filters.
    pub async fn query_alias_candidates_with_recorded_at(
        &self,
        mention: &str,
        scope: &Scope,
        valid_at: &str,
        recorded_at_or_before: &str,
        limit: usize,
    ) -> Result<Vec<ProjectionEntityAlias>, RuntimeError> {
        let mut projection_query = ProjectionQuery::new(scope.key());
        projection_query.valid_at = Some(valid_at.to_string());
        projection_query.recorded_at_or_before = Some(recorded_at_or_before.to_string());
        projection_query.limit = limit.max(8).saturating_mul(8).min(64);

        let mut aliases = self
            .store
            .query_entity_aliases(projection_query)
            .await
            .map_err(RuntimeError::Memory)?;
        aliases.sort_by(|a, b| {
            alias_candidate_score(mention, b)
                .cmp(&alias_candidate_score(mention, a))
                .then_with(|| b.is_human_confirmed_final.cmp(&a.is_human_confirmed_final))
                .then_with(|| b.recorded_at.cmp(&a.recorded_at))
        });
        aliases.retain(|alias| alias_candidate_score(mention, alias) > 0);
        aliases.truncate(limit);
        Ok(aliases)
    }

    /// Query imported evidence-reference rows for a specific claim.
    ///
    /// This is an explicit explain/audit entrypoint: raw evidence handles are
    /// returned as opaque `ProjectionEvidenceRef` rows and are not merged into
    /// normal search payloads.
    pub async fn query_evidence_refs_for_claim(
        &self,
        claim_id: &str,
        claim_version_id: Option<&str>,
        scope: &Scope,
        recorded_at_or_before: Option<&str>,
        limit: usize,
    ) -> Result<Vec<ProjectionEvidenceRef>, RuntimeError> {
        let mut projection_query = ProjectionQuery::new(scope.key());
        projection_query.limit = limit.max(1);
        projection_query.claim_id = Some(ClaimId::new(claim_id));
        projection_query.claim_version_id = claim_version_id.map(ClaimVersionId::new);
        projection_query.recorded_at_or_before = recorded_at_or_before.map(str::to_string);

        self.store
            .query_evidence_refs(projection_query)
            .await
            .map_err(RuntimeError::Memory)
    }

    /// Query imported claim rows for a specific claim or claim version.
    pub async fn query_claim_versions_for_claim(
        &self,
        claim_id: &str,
        claim_version_id: Option<&str>,
        scope: &Scope,
        recorded_at_or_before: Option<&str>,
        limit: usize,
    ) -> Result<Vec<ProjectionClaimVersion>, RuntimeError> {
        let mut projection_query = ProjectionQuery::new(scope.key());
        projection_query.limit = limit.max(1);
        projection_query.claim_id = Some(ClaimId::new(claim_id));
        projection_query.claim_version_id = claim_version_id.map(ClaimVersionId::new);
        projection_query.recorded_at_or_before = recorded_at_or_before.map(str::to_string);

        self.store
            .query_claim_versions(projection_query)
            .await
            .map_err(RuntimeError::Memory)
    }

    /// Get the underlying store reference for advanced read operations
    /// (graph traversal, explained search, etc.).
    pub fn store(&self) -> &MemoryStore {
        &self.store
    }

    /// Query the last successful import timestamp for a namespace.
    ///
    /// Returns `None` if no imports have ever been recorded for this namespace.
    /// Used by the runtime to detect import staleness and emit warnings.
    pub async fn last_import_at(&self, namespace: &str) -> Result<Option<String>, RuntimeError> {
        self.store
            .last_import_at(namespace)
            .await
            .map_err(RuntimeError::Memory)
    }

    /// Return the most recent import receipt carrying a rebuildable kernel payload.
    pub async fn latest_kernel_projection_import(
        &self,
        scope_key: &ScopeKey,
    ) -> Result<Option<ProjectionImportLogEntry>, RuntimeError> {
        self.store
            .latest_rebuildable_kernel_projection_import_for_scope(scope_key)
            .await
            .map_err(RuntimeError::Memory)
    }
}

fn filterable_search_source_types(
    source_types: Option<&[SearchSourceType]>,
) -> Vec<SearchSourceType> {
    let mut filtered = source_types
        .map(|types| {
            types
                .iter()
                .filter(|source_type| {
                    matches!(
                        source_type,
                        SearchSourceType::Chunks | SearchSourceType::Episodes
                    )
                })
                .cloned()
                .collect::<Vec<_>>()
        })
        .unwrap_or_else(|| vec![SearchSourceType::Chunks, SearchSourceType::Episodes]);
    if filtered.is_empty() {
        filtered = vec![SearchSourceType::Chunks, SearchSourceType::Episodes];
    }
    filtered
}

fn merge_projection_results(
    claims: Vec<ProjectionClaimVersion>,
    relations: Vec<ProjectionRelationVersion>,
    episodes: Vec<ProjectionEpisode>,
    limit: usize,
) -> Vec<SearchResult> {
    let mut results = Vec::new();
    let total = claims.len() + relations.len() + episodes.len();
    if total == 0 {
        return results;
    }

    for (idx, claim) in claims.into_iter().enumerate() {
        results.push(SearchResult {
            content: claim.content.clone(),
            source: SearchSource::Projection {
                projection_kind: "claim_version".into(),
                projection_id: claim.claim_version_id.as_str().to_string(),
                scope_key: claim.scope_key.clone(),
                valid_from: claim.valid_from.clone(),
                valid_to: claim.valid_to.clone(),
                recorded_at: claim.recorded_at.clone(),
                source_envelope_id: claim.source_envelope_id.as_str().to_string(),
                source_authority: claim.source_authority.clone(),
            },
            score: projection_rank_score(idx, total),
            bm25_rank: None,
            vector_rank: None,
            cosine_similarity: None,
        });
    }

    for (idx, relation) in relations.into_iter().enumerate() {
        results.push(SearchResult {
            content: format!(
                "{} {} {}",
                relation.subject_entity_id.as_str(),
                relation.predicate,
                relation.object_anchor
            ),
            source: SearchSource::Projection {
                projection_kind: "relation_version".into(),
                projection_id: relation.relation_version_id.as_str().to_string(),
                scope_key: relation.scope_key.clone(),
                valid_from: relation.valid_from.clone(),
                valid_to: relation.valid_to.clone(),
                recorded_at: relation.recorded_at.clone(),
                source_envelope_id: relation.source_envelope_id.as_str().to_string(),
                source_authority: relation.source_authority.clone(),
            },
            score: projection_rank_score(idx, total),
            bm25_rank: None,
            vector_rank: None,
            cosine_similarity: None,
        });
    }

    for (idx, episode) in episodes.into_iter().enumerate() {
        results.push(SearchResult {
            content: format!(
                "{} {} {}",
                episode.document_id, episode.effect_type, episode.outcome
            ),
            source: SearchSource::Projection {
                projection_kind: "episode".into(),
                projection_id: episode.episode_id.as_str().to_string(),
                scope_key: episode.scope_key.clone(),
                valid_from: None,
                valid_to: None,
                recorded_at: episode.recorded_at.clone(),
                source_envelope_id: episode.source_envelope_id.as_str().to_string(),
                source_authority: episode.source_authority.clone(),
            },
            score: projection_rank_score(idx, total),
            bm25_rank: None,
            vector_rank: None,
            cosine_similarity: None,
        });
    }

    results.sort_by(|a, b| {
        b.score
            .partial_cmp(&a.score)
            .unwrap_or(std::cmp::Ordering::Equal)
    });
    results.truncate(limit);
    results
}

fn projection_rank_score(index: usize, total: usize) -> f64 {
    let denom = total.max(1) as f64;
    (denom - index as f64) / denom
}

fn alias_candidate_score(mention: &str, alias: &ProjectionEntityAlias) -> usize {
    let mention = mention.trim().to_lowercase();
    if mention.is_empty() {
        return 0;
    }

    let alias_text = alias.alias_text.to_lowercase();
    let canonical = alias.canonical_entity_id.as_str().to_lowercase();
    if alias_text == mention {
        return 400;
    }
    if alias_text.starts_with(&mention) || alias_text.contains(&mention) {
        return 300;
    }
    if canonical == mention || canonical.starts_with(&mention) {
        return 200;
    }

    let alias_distance = levenshtein_distance(&mention, &alias_text);
    if alias_distance <= 2 {
        return 100usize.saturating_sub(alias_distance * 20);
    }

    0
}

fn levenshtein_distance(left: &str, right: &str) -> usize {
    let left: Vec<char> = left.chars().collect();
    let right: Vec<char> = right.chars().collect();
    let mut costs: Vec<usize> = (0..=right.len()).collect();

    for (i, left_char) in left.iter().enumerate() {
        let mut last_cost = i;
        costs[0] = i + 1;
        for (j, right_char) in right.iter().enumerate() {
            let new_cost = if left_char == right_char {
                last_cost
            } else {
                1 + last_cost.min(costs[j]).min(costs[j + 1])
            };
            last_cost = costs[j + 1];
            costs[j + 1] = new_cost;
        }
    }

    costs[right.len()]
}

impl std::fmt::Debug for SemanticMemoryAdapter {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("SemanticMemoryAdapter")
            .field("store", &"<MemoryStore>")
            .finish()
    }
}

fn search_identity(result: &SearchResult) -> String {
    serde_json::to_string(&result.source).unwrap_or_else(|_| format!("{:?}", result.source))
}

fn runtime_trace_from_receipt(receipt: &VectorSearchReceiptV1) -> RuntimeDerivedCandidateTraceV1 {
    RuntimeDerivedCandidateTraceV1 {
        candidate_backend: receipt.candidate_backend.clone(),
        codec_family: receipt.codec_family.clone(),
        generation_id: receipt.artifact_generation_id.clone(),
        embedding_snapshot_digest: None,
        pool_manifest_digest: receipt.vector_artifact_manifest_digest.clone(),
        exact_rerank: receipt.exact_rerank,
        approximate: receipt.approximate,
        fallback: receipt.fallback.clone(),
        raw_candidate_count: receipt.returned_candidates,
        post_filter_count: receipt.post_filter_candidates,
        final_result_count: receipt.result_ids.len(),
    }
}