perspt-agent 0.6.1

//! Artifact bundle parsing, transactional application, and path filtering.

use super::*;
use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};

impl SRBNOrchestrator {
    /// PSP-7: Typed parse pipeline returning structured state for every LLM response.
    ///
    /// Replaces the Option-based `parse_artifact_bundle` with a pipeline that
    /// classifies every response through Layers A→E and returns a typed result.
    ///
    /// - **Layer A**: Raw capture — fingerprints the response (hash + length).
    /// - **Layer B**: Path normalization via the hardened `normalize_artifact_path`.
    /// - **Layer C**: Strict JSON parse via `extract_and_deserialize`.
    /// - **Layer D**: Tolerant file-marker recovery via `extract_file_markers`.
    /// - **Layer E**: Semantic validation — declared paths, plugin support files, command policy.
    ///
    /// Returns `(Option<ArtifactBundle>, ParseResultState, Option<CorrectionAttemptRecord>)`.
    pub fn parse_artifact_bundle_typed(
        &self,
        content: &str,
        node_id: &str,
        attempt: u32,
    ) -> (
        Option<perspt_core::types::ArtifactBundle>,
        perspt_core::types::ParseResultState,
        Option<perspt_core::types::CorrectionAttemptRecord>,
    ) {
        use perspt_core::types::{
            ArtifactBundle, ArtifactOperation, CorrectionAttemptRecord, ParseResultState,
            RetryClassification,
        };

        // Layer A: raw capture — fingerprint the response
        let response_fingerprint = {
            let mut hasher = DefaultHasher::new();
            content.hash(&mut hasher);
            format!("{:016x}", hasher.finish())
        };
        let response_length = content.len();
        let created_at = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap_or_default()
            .as_secs() as i64;

        let classify_retry = |state: ParseResultState, rejection: Option<&str>| match state {
            ParseResultState::StrictJsonOk | ParseResultState::TolerantRecoveryOk => None,
            ParseResultState::NoStructuredPayload
            | ParseResultState::SchemaInvalid
            | ParseResultState::EmptyBundle => Some(RetryClassification::MalformedRetry),
            ParseResultState::SemanticallyRejected => {
                let reason = rejection.unwrap_or_default().to_ascii_lowercase();
                if reason.contains("all artifacts rejected")
                    || reason.contains("undeclared")
                    || reason.contains("target")
                {
                    Some(RetryClassification::Retarget)
                } else if reason.contains("support") {
                    Some(RetryClassification::SupportFileViolation)
                } else {
                    Some(RetryClassification::Replan)
                }
            }
        };

        let build_record = |state: ParseResultState, accepted: bool, rejection: Option<String>| {
            let retry_classification = classify_retry(state, rejection.as_deref());
            CorrectionAttemptRecord {
                attempt,
                parse_state: state,
                retry_classification,
                response_fingerprint: response_fingerprint.clone(),
                response_length,
                energy_after: None,
                accepted,
                rejection_reason: rejection,
                created_at,
            }
        };

        // Layer C: Strict JSON parse. Keep JSON extraction and schema
        // deserialization separate so malformed bundles are classified as
        // SchemaInvalid rather than collapsing to NoStructuredPayload.
        match perspt_core::normalize::extract_json(content) {
            Ok(output) => {
                let bundle = match serde_json::from_str::<ArtifactBundle>(&output.json_body) {
                    Ok(bundle) => {
                        log::info!(
                            "Parsed ArtifactBundle via normalization ({})",
                            output.method
                        );
                        bundle
                    }
                    Err(e) => {
                        let record = build_record(
                            ParseResultState::SchemaInvalid,
                            false,
                            Some(format!(
                                "JSON extracted via {} but bundle schema deserialization failed: {}",
                                output.method, e
                            )),
                        );
                        return (None, ParseResultState::SchemaInvalid, Some(record));
                    }
                };

                if bundle.validate().is_ok() {
                    // Layer B: normalize all paths in the bundle
                    let bundle = self.normalize_bundle_paths(bundle);

                    if bundle.artifacts.is_empty() {
                        let record = build_record(
                            ParseResultState::EmptyBundle,
                            false,
                            Some("Bundle is empty after path normalization".to_string()),
                        );
                        return (None, ParseResultState::EmptyBundle, Some(record));
                    }

                    // Layer E: semantic validation
                    match self.semantic_validate_bundle(&bundle, node_id) {
                        Ok(filtered) => {
                            if filtered.artifacts.is_empty() {
                                let record = build_record(
                                    ParseResultState::SemanticallyRejected,
                                    false,
                                    Some(
                                        "All artifacts rejected by semantic validation".to_string(),
                                    ),
                                );
                                return (
                                    None,
                                    ParseResultState::SemanticallyRejected,
                                    Some(record),
                                );
                            }
                            let record = build_record(ParseResultState::StrictJsonOk, true, None);
                            return (Some(filtered), ParseResultState::StrictJsonOk, Some(record));
                        }
                        Err(reason) => {
                            let record = build_record(
                                ParseResultState::SemanticallyRejected,
                                false,
                                Some(reason),
                            );
                            return (None, ParseResultState::SemanticallyRejected, Some(record));
                        }
                    }
                } else {
                    log::warn!("JSON bundle found but failed schema validation");
                    let record = build_record(
                        ParseResultState::SchemaInvalid,
                        false,
                        Some("JSON parsed but bundle schema validation failed".to_string()),
                    );
                    return (None, ParseResultState::SchemaInvalid, Some(record));
                }
            }
            Err(e) => {
                log::debug!("Normalization could not extract ArtifactBundle JSON: {}", e);
            }
        }

        // Layer D: Tolerant file-marker recovery
        let markers = perspt_core::normalize::extract_file_markers(content);
        if !markers.is_empty() {
            let artifacts: Vec<ArtifactOperation> = markers
                .into_iter()
                .filter_map(|m| {
                    let path = m.path?;
                    if m.content.is_empty() {
                        return None;
                    }
                    if m.is_diff {
                        Some(ArtifactOperation::Diff {
                            path,
                            patch: m.content,
                        })
                    } else {
                        Some(ArtifactOperation::Write {
                            path,
                            content: m.content,
                        })
                    }
                })
                .collect();

            if artifacts.is_empty() {
                let record = build_record(
                    ParseResultState::NoStructuredPayload,
                    false,
                    Some("File markers found but no named artifacts extracted".to_string()),
                );
                return (None, ParseResultState::NoStructuredPayload, Some(record));
            }

            let bundle = ArtifactBundle {
                artifacts,
                commands: vec![],
            };
            let bundle = self.normalize_bundle_paths(bundle);

            log::info!(
                "Tolerant recovery extracted {}-artifact bundle via file markers",
                bundle.len()
            );

            // Layer E: semantic validation
            match self.semantic_validate_bundle(&bundle, node_id) {
                Ok(filtered) => {
                    if filtered.artifacts.is_empty() {
                        let record = build_record(
                            ParseResultState::SemanticallyRejected,
                            false,
                            Some("All artifacts rejected by semantic validation".to_string()),
                        );
                        return (None, ParseResultState::SemanticallyRejected, Some(record));
                    }
                    let record = build_record(ParseResultState::TolerantRecoveryOk, true, None);
                    return (
                        Some(filtered),
                        ParseResultState::TolerantRecoveryOk,
                        Some(record),
                    );
                }
                Err(reason) => {
                    let record =
                        build_record(ParseResultState::SemanticallyRejected, false, Some(reason));
                    return (None, ParseResultState::SemanticallyRejected, Some(record));
                }
            }
        }

        // No structured payload at all
        let record = build_record(
            ParseResultState::NoStructuredPayload,
            false,
            Some("No JSON bundle or file markers found in response".to_string()),
        );
        (None, ParseResultState::NoStructuredPayload, Some(record))
    }

    /// Normalize all paths in a bundle through the hardened path normalizer.
    fn normalize_bundle_paths(
        &self,
        mut bundle: perspt_core::types::ArtifactBundle,
    ) -> perspt_core::types::ArtifactBundle {
        bundle.artifacts = bundle
            .artifacts
            .into_iter()
            .filter_map(|op| match op {
                perspt_core::types::ArtifactOperation::Write { path, content } => {
                    match perspt_core::path::normalize_artifact_path(&path) {
                        Ok(normalized) => Some(perspt_core::types::ArtifactOperation::Write {
                            path: normalized,
                            content,
                        }),
                        Err(e) => {
                            log::warn!("Dropping write artifact with bad path '{}': {}", path, e);
                            None
                        }
                    }
                }
                perspt_core::types::ArtifactOperation::Diff { path, patch } => {
                    match perspt_core::path::normalize_artifact_path(&path) {
                        Ok(normalized) => Some(perspt_core::types::ArtifactOperation::Diff {
                            path: normalized,
                            patch,
                        }),
                        Err(e) => {
                            log::warn!("Dropping diff artifact with bad path '{}': {}", path, e);
                            None
                        }
                    }
                }
                perspt_core::types::ArtifactOperation::Delete { path } => {
                    match perspt_core::path::normalize_artifact_path(&path) {
                        Ok(normalized) => {
                            Some(perspt_core::types::ArtifactOperation::Delete { path: normalized })
                        }
                        Err(e) => {
                            log::warn!("Dropping delete artifact with bad path '{}': {}", path, e);
                            None
                        }
                    }
                }
                perspt_core::types::ArtifactOperation::Move { from, to } => {
                    let from_norm = perspt_core::path::normalize_artifact_path(&from);
                    let to_norm = perspt_core::path::normalize_artifact_path(&to);
                    match (from_norm, to_norm) {
                        (Ok(f), Ok(t)) => {
                            Some(perspt_core::types::ArtifactOperation::Move { from: f, to: t })
                        }
                        _ => {
                            log::warn!("Dropping move artifact with bad paths '{}'→'{}'", from, to);
                            None
                        }
                    }
                }
            })
            .collect();
        bundle
    }

    /// PSP-7 Layer E: Semantic validation of a parsed bundle.
    ///
    /// Extends `filter_bundle_to_declared_paths` with plugin-driven checks:
    /// - Legal support files (from plugin `legal_support_files()`)
    /// - Dependency command policy (from plugin `dependency_command_policy()`)
    ///
    /// Returns `Ok(filtered_bundle)` or `Err(reason)` if validation fails hard.
    fn semantic_validate_bundle(
        &self,
        bundle: &perspt_core::types::ArtifactBundle,
        node_id: &str,
    ) -> Result<perspt_core::types::ArtifactBundle, String> {
        let allowed_paths = self.allowed_bundle_paths(node_id);

        // If no output targets declared, pass everything through
        if allowed_paths.is_empty() {
            return Ok(bundle.clone());
        }

        // Get legal support files from the plugin
        let registry = perspt_core::plugin::PluginRegistry::new();
        let plugin_name = self
            .node_indices
            .get(node_id)
            .map(|idx| self.graph[*idx].owner_plugin.as_str())
            .unwrap_or("");
        let plugin = registry.get(plugin_name);
        let legal_support: std::collections::HashSet<String> = plugin
            .map(|p| {
                p.legal_support_files()
                    .iter()
                    .map(|s| s.to_string())
                    .collect()
            })
            .unwrap_or_default();

        let (kept, dropped): (Vec<_>, Vec<_>) = bundle.artifacts.iter().cloned().partition(|a| {
            let normalized = perspt_core::path::normalize_artifact_path(a.path())
                .unwrap_or_else(|_| a.path().to_string());

            if let Some(plugin) = plugin {
                if Self::is_manifest_path(&normalized)
                    && plugin.manifest_mutation_policy(&normalized)
                        == perspt_core::types::ManifestMutationPolicy::Deny
                {
                    log::warn!(
                        "Rejecting manifest mutation '{}' by plugin policy for '{}'",
                        normalized,
                        plugin_name
                    );
                    return false;
                }
            }

            // Accept if in declared output targets
            if allowed_paths.contains(&normalized) {
                return true;
            }

            // Accept if it's a legal support file
            let filename = std::path::Path::new(&normalized)
                .file_name()
                .map(|f| f.to_string_lossy().to_string())
                .unwrap_or_default();
            if legal_support.contains(&filename) {
                log::info!(
                    "Accepting support file '{}' via plugin legal_support_files",
                    normalized
                );
                return true;
            }

            false
        });

        if !dropped.is_empty() {
            let dropped_paths: Vec<String> = dropped.iter().map(|a| a.path().to_string()).collect();
            log::warn!(
                "Semantic validation stripped {} artifact(s) from node '{}': {}",
                dropped.len(),
                node_id,
                dropped_paths.join(", ")
            );
        }

        // Validate commands via plugin dependency_command_policy
        let mut validated_commands = Vec::new();
        for cmd in &bundle.commands {
            let decision = self
                .node_indices
                .get(node_id)
                .and_then(|idx| {
                    let plugin_name = &self.graph[*idx].owner_plugin;
                    let registry = perspt_core::plugin::PluginRegistry::new();
                    registry
                        .get(plugin_name)
                        .map(|p| p.dependency_command_policy(cmd))
                })
                .unwrap_or(perspt_core::types::CommandPolicyDecision::Allow);

            match decision {
                perspt_core::types::CommandPolicyDecision::Allow => {
                    validated_commands.push(cmd.clone());
                }
                perspt_core::types::CommandPolicyDecision::RequireApproval => {
                    log::info!("Command '{}' requires approval — including with flag", cmd);
                    validated_commands.push(cmd.clone());
                }
                perspt_core::types::CommandPolicyDecision::Deny => {
                    log::warn!("Command '{}' denied by plugin policy", cmd);
                }
            }
        }

        Ok(perspt_core::types::ArtifactBundle {
            artifacts: kept,
            commands: validated_commands,
        })
    }

    /// PSP-5: Apply an artifact bundle transactionally
    ///
    /// All file operations are validated first, then applied.
    /// PSP-5 Phase 2: Validates ownership boundaries before applying.
    /// If any operation fails, the method returns an error describing which operation
    /// failed, and previous successful operations are logged for manual review.
    pub async fn apply_bundle_transactionally(
        &mut self,
        bundle: &perspt_core::types::ArtifactBundle,
        node_id: &str,
        node_class: perspt_core::types::NodeClass,
    ) -> Result<()> {
        let idx =
            self.node_indices.get(node_id).copied().ok_or_else(|| {
                anyhow::anyhow!("Unknown node '{}' for bundle application", node_id)
            })?;
        let node_workdir = self.effective_working_dir(idx);

        // Validate structural integrity first
        bundle.validate().map_err(|e| {
            eprintln!(
                "[SRBN-DIAG] Bundle validation failed for '{}': {}",
                node_id, e
            );
            anyhow::anyhow!(e)
        })?;

        // Filter out undeclared paths instead of failing the entire session
        let filtered = self
            .semantic_validate_bundle(bundle, node_id)
            .map_err(|reason| {
                anyhow::anyhow!(
                    "Bundle semantic validation failed for '{}': {}",
                    node_id,
                    reason
                )
            })?;

        // If filtering removed ALL artifacts, fail so the correction loop can
        // retry with proper paths.  The old fallback applied the *unfiltered*
        // bundle, causing cross-node file pollution (e.g., overwriting root
        // Cargo.toml with a crate-level manifest).
        if filtered.artifacts.is_empty() && !bundle.artifacts.is_empty() {
            let dropped_paths: Vec<String> = bundle
                .artifacts
                .iter()
                .map(|a| a.path().to_string())
                .collect();
            eprintln!(
                "[SRBN-DIAG] All artifacts stripped for '{}': {:?}",
                node_id, dropped_paths
            );
            log::warn!(
                "All artifacts stripped for node '{}' — skipping bundle application. \
                 Dropped paths: {}",
                node_id,
                dropped_paths.join(", ")
            );
            self.emit_log(format!(
                "⚠️ All artifacts for '{}' targeted undeclared paths — bundle skipped. \
                 The actuator's output_files don't match the plan.",
                node_id
            ));
            return Err(anyhow::anyhow!(
                "All {} artifact(s) targeted undeclared paths for node '{}': [{}]. \
                 Expected paths: {:?}",
                bundle.artifacts.len(),
                node_id,
                dropped_paths.join(", "),
                self.node_indices
                    .get(node_id)
                    .map(|idx| self.graph[*idx]
                        .output_targets
                        .iter()
                        .map(|p| p.to_string_lossy().to_string())
                        .collect::<Vec<_>>())
                    .unwrap_or_default()
            ));
        }
        let bundle = filtered;

        // PSP-5 Phase 2: Validate ownership boundaries (soft failure)
        // Instead of crashing the session, log ownership conflicts and
        // continue — the LLM often generates shared files (e.g. config.json)
        // from multiple nodes.
        if let Err(e) = self
            .context
            .ownership_manifest
            .validate_bundle(&bundle, node_id, node_class)
        {
            log::warn!("Ownership validation warning for node '{}': {}", node_id, e);
            self.emit_log(format!("⚠️ Ownership warning: {}", e));
        }

        // PSP-5 Phase 2: Determine owner_plugin for new path assignment
        let owner_plugin = self
            .node_indices
            .get(node_id)
            .and_then(|idx| {
                let plugin = &self.graph[*idx].owner_plugin;
                if plugin.is_empty() {
                    None
                } else {
                    Some(plugin.clone())
                }
            })
            .unwrap_or_else(|| "unknown".to_string());

        let mut files_created: Vec<String> = Vec::new();
        let mut files_modified: Vec<String> = Vec::new();
        let mut files_deleted: Vec<String> = Vec::new();

        for op in &bundle.artifacts {
            let mut args = HashMap::new();
            let resolved_path = node_workdir.join(op.path());
            args.insert(
                "path".to_string(),
                resolved_path.to_string_lossy().to_string(),
            );

            let call = match op {
                perspt_core::types::ArtifactOperation::Write { content, .. } => {
                    args.insert("content".to_string(), content.clone());
                    ToolCall {
                        name: "write_file".to_string(),
                        arguments: args,
                    }
                }
                perspt_core::types::ArtifactOperation::Diff { patch, .. } => {
                    args.insert("diff".to_string(), patch.clone());
                    ToolCall {
                        name: "apply_diff".to_string(),
                        arguments: args,
                    }
                }
                perspt_core::types::ArtifactOperation::Delete { path } => {
                    // Validate delete through policy layer
                    if let Err(e) = perspt_policy::sanitize::validate_artifact_mutation(
                        path,
                        &self.context.working_dir,
                        "Delete",
                    ) {
                        log::warn!("Delete blocked by policy: {}", e);
                        self.emit_log(format!("⚠️ Delete blocked: {}", e));
                        continue;
                    }
                    ToolCall {
                        name: "delete_file".to_string(),
                        arguments: args,
                    }
                }
                perspt_core::types::ArtifactOperation::Move { from, to } => {
                    // Validate both source and destination through policy
                    if let Err(e) = perspt_policy::sanitize::validate_artifact_mutation(
                        from,
                        &self.context.working_dir,
                        "Move",
                    ) {
                        log::warn!("Move source blocked by policy: {}", e);
                        self.emit_log(format!("⚠️ Move blocked: {}", e));
                        continue;
                    }
                    if let Err(e) = perspt_policy::sanitize::validate_artifact_mutation(
                        to,
                        &self.context.working_dir,
                        "Move",
                    ) {
                        log::warn!("Move destination blocked by policy: {}", e);
                        self.emit_log(format!("⚠️ Move blocked: {}", e));
                        continue;
                    }
                    let resolved_to = node_workdir.join(to);
                    args.insert("from".to_string(), args["path"].clone());
                    args.insert("to".to_string(), resolved_to.to_string_lossy().to_string());
                    ToolCall {
                        name: "move_file".to_string(),
                        arguments: args,
                    }
                }
            };

            let result = self.tools.execute(&call).await;
            if result.success {
                let full_path = resolved_path.clone();

                if op.is_write() {
                    files_created.push(op.path().to_string());
                } else if op.is_delete() {
                    files_deleted.push(op.path().to_string());
                    self.emit_event(perspt_core::AgentEvent::FileDeleted {
                        node_id: self.graph[idx].node_id.clone(),
                        path: op.path().to_string(),
                    });
                } else if op.is_move() {
                    if let perspt_core::types::ArtifactOperation::Move { to, .. } = op {
                        files_modified.push(format!("{} -> {}", op.path(), to));
                        self.emit_event(perspt_core::AgentEvent::FileMoved {
                            node_id: self.graph[idx].node_id.clone(),
                            from: op.path().to_string(),
                            to: to.to_string(),
                        });
                    }
                } else {
                    files_modified.push(op.path().to_string());
                }

                // Track for LSP notification (skip for deleted files)
                if !op.is_delete() {
                    self.last_written_file = Some(full_path.clone());
                    self.file_version += 1;

                    // Notify LSP of file change
                    let registry = perspt_core::plugin::PluginRegistry::new();
                    for (lang, client) in self.lsp_clients.iter_mut() {
                        // Only notify if the plugin owns this file
                        let should_notify = match registry.get(lang) {
                            Some(plugin) => plugin.owns_file(op.path()),
                            None => true,
                        };
                        if should_notify {
                            if let Ok(content) = std::fs::read_to_string(&full_path) {
                                let _ = client
                                    .did_change(&full_path, &content, self.file_version)
                                    .await;
                            }
                        }
                    }
                }

                log::info!("✓ Applied: {}", op.path());
                self.emit_log(format!("✅ Applied: {}", op.path()));
            } else {
                log::warn!("Failed to apply {}: {:?}", op.path(), result.error);
                self.emit_log(format!("❌ Failed: {} - {:?}", op.path(), result.error));
                self.last_tool_failure = result.error.clone();
                return Err(anyhow::anyhow!(
                    "Bundle application failed at {}: {:?}",
                    op.path(),
                    result.error
                ));
            }
        }

        // PSP-5 Phase 2: Auto-assign unregistered paths to this node
        self.context.ownership_manifest.assign_new_paths(
            &bundle,
            node_id,
            &owner_plugin,
            node_class,
        );

        // Emit BundleApplied event
        self.emit_event(perspt_core::AgentEvent::BundleApplied {
            node_id: node_id.to_string(),
            files_created,
            files_modified,
            writes_count: bundle.writes_count(),
            diffs_count: bundle.diffs_count(),
            node_class: node_class.to_string(),
        });

        self.last_tool_failure = None;
        Ok(())
    }

    fn allowed_bundle_paths(&self, node_id: &str) -> std::collections::HashSet<String> {
        self.node_indices
            .get(node_id)
            .map(|idx| {
                self.graph[*idx]
                    .output_targets
                    .iter()
                    .map(|p| {
                        let raw = p.to_string_lossy();
                        perspt_core::path::normalize_artifact_path(&raw)
                            .unwrap_or_else(|_| raw.to_string())
                    })
                    .collect()
            })
            .unwrap_or_default()
    }

    fn is_manifest_path(path: &str) -> bool {
        matches!(
            std::path::Path::new(path)
                .file_name()
                .and_then(|name| name.to_str()),
            Some("Cargo.toml" | "package.json" | "pyproject.toml" | "setup.py" | "setup.cfg")
        )
    }
}

#[cfg(test)]
mod tests {
    use perspt_core::types::{ArtifactBundle, ArtifactOperation, ParseResultState};

    #[test]
    fn test_parse_result_state_is_ok() {
        assert!(ParseResultState::StrictJsonOk.is_ok());
        assert!(ParseResultState::TolerantRecoveryOk.is_ok());
        assert!(!ParseResultState::NoStructuredPayload.is_ok());
        assert!(!ParseResultState::SchemaInvalid.is_ok());
        assert!(!ParseResultState::SemanticallyRejected.is_ok());
        assert!(!ParseResultState::EmptyBundle.is_ok());
    }

    #[test]
    fn test_strict_json_layer_c_valid_bundle() {
        // Layer C: strict JSON parse succeeds for a well-formed bundle
        let json = r#"{"artifacts":[{"operation":"write","path":"src/main.rs","content":"fn main() {}"}],"commands":[]}"#;
        let result = perspt_core::normalize::extract_and_deserialize::<ArtifactBundle>(json);
        assert!(result.is_ok());
        let (bundle, _method) = result.unwrap();
        assert_eq!(bundle.artifacts.len(), 1);
        assert!(bundle.validate().is_ok());
    }

    #[test]
    fn test_strict_json_layer_c_invalid_schema() {
        // Layer C: JSON parses but doesn't match ArtifactBundle schema
        let json = r#"{"foo": "bar"}"#;
        let result = perspt_core::normalize::extract_and_deserialize::<ArtifactBundle>(json);
        // extract_and_deserialize may fail at deserialization
        assert!(result.is_err());
    }

    #[test]
    fn test_tolerant_recovery_layer_d_file_markers() {
        // Layer D: extract_file_markers recovers artifacts from markdown
        let response = r#"
Here is the implementation:

### File: src/main.rs
```rust
fn main() {
    println!("Hello");
}
```

### File: src/lib.rs
```rust
pub fn greet() -> &'static str { "Hello" }
```
"#;
        let markers = perspt_core::normalize::extract_file_markers(response);
        assert_eq!(markers.len(), 2);
        assert_eq!(markers[0].path, Some("src/main.rs".to_string()));
        assert_eq!(markers[1].path, Some("src/lib.rs".to_string()));
        assert!(!markers[0].is_diff);
    }

    #[test]
    fn test_tolerant_recovery_layer_d_no_named_blocks() {
        // Layer D: unnamed code blocks produce None path (never invented)
        let response = "Here is some code:\n```rust\nfn foo() {}\n```\n";
        let markers = perspt_core::normalize::extract_file_markers(response);
        // Unnamed blocks don't produce markers with paths
        let named = markers.iter().filter(|m| m.path.is_some()).count();
        assert_eq!(named, 0);
    }

    #[test]
    fn test_path_normalization_layer_b() {
        // Layer B: path normalization strips backticks, quotes, markdown
        let normalized = perspt_core::path::normalize_artifact_path("`src/main.rs`").unwrap();
        assert_eq!(normalized, "src/main.rs");

        let normalized = perspt_core::path::normalize_artifact_path("'src/lib.rs'").unwrap();
        assert_eq!(normalized, "src/lib.rs");

        let normalized = perspt_core::path::normalize_artifact_path("**src/utils.rs**").unwrap();
        assert_eq!(normalized, "src/utils.rs");
    }

    #[test]
    fn test_empty_bundle_detection() {
        let bundle = ArtifactBundle {
            artifacts: vec![],
            commands: vec![],
        };
        assert!(bundle.artifacts.is_empty());
    }

    #[test]
    fn test_bundle_with_commands() {
        let json = r#"{"artifacts":[{"operation":"write","path":"src/main.rs","content":"fn main() {}"}],"commands":["cargo add serde"]}"#;
        let result = perspt_core::normalize::extract_and_deserialize::<ArtifactBundle>(json);
        assert!(result.is_ok());
        let (bundle, _) = result.unwrap();
        assert_eq!(bundle.commands.len(), 1);
        assert_eq!(bundle.commands[0], "cargo add serde");
    }

    #[test]
    fn test_layer_d_diff_markers() {
        let response = r#"
### Diff: src/main.rs
```diff
--- a/src/main.rs
+++ b/src/main.rs
@@ -1 +1 @@
-fn main() {}
+fn main() { println!("hello"); }
```
"#;
        let markers = perspt_core::normalize::extract_file_markers(response);
        assert!(!markers.is_empty());
        let first = &markers[0];
        assert_eq!(first.path, Some("src/main.rs".to_string()));
        assert!(first.is_diff);
    }

    #[test]
    fn test_no_structured_payload() {
        // A response with no JSON and no file markers
        let response = "I'm sorry, I can't help with that. Please try again.";
        let json_result =
            perspt_core::normalize::extract_and_deserialize::<ArtifactBundle>(response);
        assert!(json_result.is_err());
        let markers = perspt_core::normalize::extract_file_markers(response);
        assert!(markers.is_empty());
    }

    #[test]
    fn test_fenced_json_bundle_extraction() {
        // JSON bundle wrapped in markdown code fence
        let response = r#"Here is the bundle:
```json
{"artifacts":[{"operation":"write","path":"src/main.rs","content":"fn main() {}"}],"commands":[]}
```
"#;
        let result = perspt_core::normalize::extract_and_deserialize::<ArtifactBundle>(response);
        assert!(result.is_ok());
    }

    #[test]
    fn test_artifact_operation_paths() {
        let write = ArtifactOperation::Write {
            path: "src/main.rs".to_string(),
            content: "fn main() {}".to_string(),
        };
        assert_eq!(write.path(), "src/main.rs");

        let diff = ArtifactOperation::Diff {
            path: "src/lib.rs".to_string(),
            patch: "...".to_string(),
        };
        assert_eq!(diff.path(), "src/lib.rs");
    }
}