jsdet-core 0.1.0

//! VulnIR producer implementation for jsdet.
//!
//! This module converts jsdet observations and execution results into
//! VulnIR graph representations for security analysis.
//!
//! # Example
//!
//! ```
//! use jsdet_core::{ExecutionResult, JsdetProducer};
//! use jsdet_core::vulnir_producer::to_vulnir_graph;
//!
//! let result = ExecutionResult {
//!     observations: vec![],
//!     scripts_executed: 1,
//!     errors: vec![],
//!     duration_us: 1000,
//!     timed_out: false,
//! };
//!
//! let producer = JsdetProducer::new("jsdet-core", "1.0.0");
//! let graph = to_vulnir_graph(&result, &producer);
//! ```

use petgraph::graph::NodeIndex;
use vulnir::{
    ConfidenceValue, Evidence, Producer, ProducerKind, Provenance, SourceLocation, VulnEdge,
    VulnIRGraph, VulnNode, VulnProducer,
};

use crate::observation::{Observation, Value};
use crate::sandbox::ExecutionResult;

/// Producer identity for jsdet VulnIR emission.
///
/// Implements the `VulnProducer` trait to provide stable identity
/// for all VulnIR graphs produced by jsdet.
#[derive(Debug, Clone)]
pub struct JsdetProducer {
    producer: Producer,
}

impl JsdetProducer {
    /// Creates a new jsdet producer with the given name and version.
    #[must_use]
    pub fn new(name: impl Into<String>, version: impl Into<String>) -> Self {
        Self {
            producer: Producer::new(name, ProducerKind::Dynamic).with_version(version),
        }
    }

    /// Creates a producer with default identity.
    #[must_use]
    pub fn default_producer() -> Self {
        Self::new("jsdet-core", env!("CARGO_PKG_VERSION"))
    }

    /// Creates a provenance record for a node or edge.
    fn create_provenance(&self, location: Option<SourceLocation>) -> Provenance {
        let mut prov = Provenance::new(self.producer.clone());
        prov.location = location;
        prov
    }

    /// Creates evidence from an observation.
    fn create_evidence(&self, details: impl Into<String>) -> Evidence {
        Evidence::new(
            self.producer.name.clone(),
            details,
            1.0, // High confidence for dynamic observations
            true,
        )
    }
}

impl VulnProducer for JsdetProducer {
    fn producer(&self) -> Producer {
        self.producer.clone()
    }
}

impl Default for JsdetProducer {
    fn default() -> Self {
        Self::default_producer()
    }
}

/// Converts an ExecutionResult into a VulnIR graph.
///
/// This function processes all observations in the execution result and
/// creates appropriate VulnIR nodes and edges:
///
/// - `DynamicCodeExec` (eval, Function) → `Capability` node with `code-execution` resource
/// - `ApiCall` for require/import → `TrustBoundary` node with `module-import` source_type
/// - `NetworkRequest` (fetch, XHR) → `Capability` node with `network` resource
/// - `ApiCall` for fs operations → `Capability` node with `filesystem` resource
/// - Taint flows → `TaintReach` edges between nodes
///
/// # Arguments
///
/// * `result` - The execution result containing observations
/// * `producer` - The producer identity for provenance
///
/// # Returns
///
/// A `VulnIRGraph` representing the security-relevant behavior
#[must_use]
pub fn to_vulnir_graph(
    result: &ExecutionResult,
    producer: &JsdetProducer,
) -> VulnIRGraph<VulnNode, VulnEdge> {
    let mut graph = VulnIRGraph::new();
    let mut node_indices: Vec<NodeIndex> = Vec::new();

    // First pass: create nodes for all observations
    for (idx, obs) in result.observations.iter().enumerate() {
        let node_idx = observation_to_node(&mut graph, obs, idx, producer);
        if let Some(idx) = node_idx {
            node_indices.push(idx);
        }
    }

    // Second pass: create edges for taint flows between nodes
    create_taint_edges(&mut graph, &result.observations, &node_indices, producer);

    graph
}

/// Converts a single observation into a VulnIR node.
///
/// Returns `Some(NodeIndex)` if the observation maps to a node,
/// `None` if the observation doesn't have a security-relevant representation.
fn observation_to_node(
    graph: &mut VulnIRGraph<VulnNode, VulnEdge>,
    obs: &Observation,
    idx: usize,
    producer: &JsdetProducer,
) -> Option<NodeIndex> {
    match obs {
        // eval, Function constructor → Capability node (code-execution)
        Observation::DynamicCodeExec {
            source,
            code_preview,
        } => {
            let source_type = match source {
                crate::observation::DynamicCodeSource::Eval => "eval",
                crate::observation::DynamicCodeSource::Function => "function-constructor",
                crate::observation::DynamicCodeSource::SetTimeoutString => "settimeout-string",
                crate::observation::DynamicCodeSource::SetIntervalString => "setinterval-string",
                crate::observation::DynamicCodeSource::ImportScripts => "importscripts",
            };

            let node = VulnNode::Capability {
                id: format!("dynamic-code-exec-{idx}"),
                resource: "code-execution".to_string(),
                permission: "execute".to_string(),
                target: Some(code_preview.chars().take(100).collect()),
                arguments: vec![source_type.to_string()],
                duration_ns: None,
                provenance: vec![producer.create_provenance(Some(SourceLocation {
                    file: None,
                    artifact: None,
                    line: None,
                    column: None,
                }))],
                metadata: Default::default(),
            };

            Some(graph.add_node(node))
        }

        // Network requests → Capability node (network)
        Observation::NetworkRequest {
            url,
            method,
            headers: _,
            body: _,
        } => {
            let node = VulnNode::Capability {
                id: format!("network-request-{idx}"),
                resource: "network".to_string(),
                permission: method.to_lowercase(),
                target: Some(url.clone()),
                arguments: vec![],
                duration_ns: None,
                provenance: vec![producer.create_provenance(Some(SourceLocation {
                    file: None,
                    artifact: None,
                    line: None,
                    column: None,
                }))],
                metadata: Default::default(),
            };

            Some(graph.add_node(node))
        }

        // API calls - may be module imports, filesystem operations, or code execution
        Observation::ApiCall {
            api,
            args,
            result: _,
        } => {
            if is_code_execution(api) {
                // eval, setTimeout with string, etc. → Capability node (code-execution)
                let code_preview = args
                    .first()
                    .and_then(|v| v.as_str())
                    .map(|s| s.chars().take(100).collect())
                    .unwrap_or_else(|| "<empty>".to_string());

                let node = VulnNode::Capability {
                    id: format!("dynamic-code-exec-{idx}"),
                    resource: "code-execution".to_string(),
                    permission: "execute".to_string(),
                    target: Some(code_preview),
                    arguments: vec![api.clone()],
                    duration_ns: None,
                    provenance: vec![producer.create_provenance(Some(SourceLocation {
                        file: None,
                        artifact: None,
                        line: None,
                        column: None,
                    }))],
                    metadata: Default::default(),
                };

                Some(graph.add_node(node))
            } else if is_module_import(api) {
                // require/import → TrustBoundary node
                let module_name = extract_module_name(api, args);

                let node = VulnNode::TrustBoundary {
                    id: format!("module-import-{idx}"),
                    description: format!("Module import: {module_name}"),
                    source_type: "module-import".to_string(),
                    confidence: ConfidenceValue::from(1.0),
                    taint_id: None,
                    created_ns: None,
                    provenance: vec![producer.create_provenance(Some(SourceLocation {
                        file: None,
                        artifact: None,
                        line: None,
                        column: None,
                    }))],
                    metadata: Default::default(),
                };

                Some(graph.add_node(node))
            } else if is_filesystem_operation(api) {
                // fs.readFile/writeFile → Capability node (filesystem)
                let permission = if api.contains("read") || api.contains("readdir") {
                    "read"
                } else if api.contains("write") {
                    "write"
                } else {
                    "access"
                };

                let target = args.first().and_then(|v| v.as_str()).map(String::from);

                let node = VulnNode::Capability {
                    id: format!("filesystem-{idx}"),
                    resource: "filesystem".to_string(),
                    permission: permission.to_string(),
                    target,
                    arguments: vec![api.clone()],
                    duration_ns: None,
                    provenance: vec![producer.create_provenance(Some(SourceLocation {
                        file: None,
                        artifact: None,
                        line: None,
                        column: None,
                    }))],
                    metadata: Default::default(),
                };

                Some(graph.add_node(node))
            } else {
                None
            }
        }

        // DOM mutations may indicate XSS or other injections
        Observation::DomMutation {
            kind,
            target,
            detail,
        } => {
            let _description = format!("DOM {kind:?} on {target}: {detail}");

            let node = VulnNode::Capability {
                id: format!("dom-mutation-{idx}"),
                resource: "dom-manipulation".to_string(),
                permission: "modify".to_string(),
                target: Some(target.clone()),
                arguments: vec![format!("{kind:?}"), detail.clone()],
                duration_ns: None,
                provenance: vec![producer.create_provenance(Some(SourceLocation {
                    file: None,
                    artifact: None,
                    line: None,
                    column: None,
                }))],
                metadata: Default::default(),
            };

            Some(graph.add_node(node))
        }

        // Cookie access → TrustBoundary (data crossing boundary)
        Observation::CookieAccess {
            operation,
            name,
            value: _,
        } => {
            let description = format!("Cookie {operation:?}: {name}");

            let node = VulnNode::TrustBoundary {
                id: format!("cookie-access-{idx}"),
                description,
                source_type: "cookie-access".to_string(),
                confidence: ConfidenceValue::from(1.0),
                taint_id: None,
                created_ns: None,
                provenance: vec![producer.create_provenance(Some(SourceLocation {
                    file: None,
                    artifact: None,
                    line: None,
                    column: None,
                }))],
                metadata: Default::default(),
            };

            Some(graph.add_node(node))
        }

        // WebAssembly instantiation
        Observation::WasmInstantiation {
            module_size,
            import_names,
            export_names,
        } => {
            let node = VulnNode::Capability {
                id: format!("wasm-instantiation-{idx}"),
                resource: "webassembly".to_string(),
                permission: "instantiate".to_string(),
                target: Some(format!("{module_size} bytes")),
                arguments: vec![
                    format!("imports: {:?}", import_names),
                    format!("exports: {:?}", export_names),
                ],
                duration_ns: None,
                provenance: vec![producer.create_provenance(Some(SourceLocation {
                    file: None,
                    artifact: None,
                    line: None,
                    column: None,
                }))],
                metadata: Default::default(),
            };

            Some(graph.add_node(node))
        }

        // Context messages indicate cross-context communication
        Observation::ContextMessage {
            from_context,
            to_context,
            payload,
        } => {
            let description = format!("Message from {from_context} to {to_context}: {payload}");

            let node = VulnNode::TrustBoundary {
                id: format!("context-message-{idx}"),
                description,
                source_type: "cross-context".to_string(),
                confidence: ConfidenceValue::from(1.0),
                taint_id: None,
                created_ns: None,
                provenance: vec![producer.create_provenance(Some(SourceLocation {
                    file: None,
                    artifact: None,
                    line: None,
                    column: None,
                }))],
                metadata: Default::default(),
            };

            Some(graph.add_node(node))
        }

        // Other observations don't map to VulnIR nodes directly
        _ => None,
    }
}

/// Creates TaintReach edges between nodes based on taint flow observations.
fn create_taint_edges(
    graph: &mut VulnIRGraph<VulnNode, VulnEdge>,
    observations: &[Observation],
    node_indices: &[NodeIndex],
    producer: &JsdetProducer,
) {
    for obs in observations {
        if let Observation::ApiCall { api, args, .. } = obs {
            // Check if any arguments are tainted
            let tainted_positions: Vec<usize> = args
                .iter()
                .enumerate()
                .filter(|(_, v)| is_value_tainted(v))
                .map(|(idx, _)| idx)
                .collect();

            if !tainted_positions.is_empty() && !node_indices.is_empty() {
                // Find or create a source node (first tainted argument source)
                // and a sink node (this API call)
                // For simplicity, we connect the last node to this observation's node
                // This is a simplified taint flow representation

                let evidence = vec![producer.create_evidence(format!(
                    "Tainted data reached sink '{api}' at argument positions {:?}",
                    tainted_positions
                ))];

                // Try to find a previous capability or trust boundary as source
                // and connect to a sink capability
                if node_indices.len() >= 2 {
                    let source_idx = node_indices[node_indices.len() - 2];
                    let sink_idx = node_indices[node_indices.len() - 1];

                    let edge = VulnEdge::TaintReach {
                        path: format!("{api}<-arg[{tainted_positions:?}]"),
                        confidence: ConfidenceValue::from(1.0),
                        observed_dynamically: true,
                        transform_chain: vec![],
                        evidence,
                    };

                    graph.add_edge(source_idx, sink_idx, edge);
                }
            }
        }
    }
}

/// Checks if a value is tainted.
fn is_value_tainted(value: &Value) -> bool {
    match value {
        Value::String(_, label) | Value::Json(_, label) => label.is_tainted(),
        _ => false,
    }
}

/// Checks if an API call is a code execution operation.
fn is_code_execution(api: &str) -> bool {
    api == "eval"
        || api == "Function"
        || api == "setTimeout"
        || api == "setInterval"
        || api == "importScripts"
        || api.contains("executeScript")
        || api.contains("execScript")
}

/// Checks if an API call is a module import operation.
fn is_module_import(api: &str) -> bool {
    api == "require"
        || api == "import"
        || api.starts_with("module.require")
        || api.contains("__webpack_require__")
        || api.contains("dynamicImport")
}

/// Extracts the module name from import arguments.
fn extract_module_name(api: &str, args: &[Value]) -> String {
    if let Some(first_arg) = args.first()
        && let Some(s) = first_arg.as_str()
    {
        return s.to_string();
    }
    api.to_string()
}

/// Checks if an API call is a filesystem operation.
fn is_filesystem_operation(api: &str) -> bool {
    api.starts_with("fs.")
        || api.starts_with("node:fs")
        || api.contains("readFile")
        || api.contains("writeFile")
        || api.contains("readdir")
        || api.contains("unlink")
        || api.contains("mkdir")
        || api.contains("rmdir")
}

/// Extension trait for ExecutionResult to provide VulnIR conversion.
pub trait ToVulnIR {
    /// Converts this execution result to a VulnIR graph.
    ///
    /// Uses the default jsdet producer identity.
    fn to_vulnir_graph(&self) -> VulnIRGraph<VulnNode, VulnEdge>;

    /// Converts this execution result to a VulnIR graph with a custom producer.
    fn to_vulnir_graph_with_producer(
        &self,
        producer: &JsdetProducer,
    ) -> VulnIRGraph<VulnNode, VulnEdge>;
}

impl ToVulnIR for ExecutionResult {
    fn to_vulnir_graph(&self) -> VulnIRGraph<VulnNode, VulnEdge> {
        let producer = JsdetProducer::default_producer();
        to_vulnir_graph(self, &producer)
    }

    fn to_vulnir_graph_with_producer(
        &self,
        producer: &JsdetProducer,
    ) -> VulnIRGraph<VulnNode, VulnEdge> {
        to_vulnir_graph(self, producer)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::observation::{DynamicCodeSource, Observation, TaintLabel, Value};
    use vulnir::VulnIRGraphExt;

    #[test]
    fn eval_produces_capability_node() {
        let result = ExecutionResult {
            observations: vec![Observation::DynamicCodeExec {
                source: DynamicCodeSource::Eval,
                code_preview: "console.log('test')".to_string(),
            }],
            scripts_executed: 1,
            errors: vec![],
            duration_us: 1000,
            timed_out: false,
        };

        let graph = result.to_vulnir_graph();

        assert_eq!(graph.node_count(), 1);
        assert_eq!(graph.edge_count(), 0);

        // Check it's a Capability node with code-execution resource
        let attack_surface = graph.attack_surface();
        assert!(attack_surface.is_empty()); // Capabilities are not attack surfaces
    }

    #[test]
    fn require_produces_trust_boundary_node() {
        let result = ExecutionResult {
            observations: vec![Observation::ApiCall {
                api: "require".to_string(),
                args: vec![Value::string("fs")],
                result: Value::Null,
            }],
            scripts_executed: 1,
            errors: vec![],
            duration_us: 1000,
            timed_out: false,
        };

        let graph = result.to_vulnir_graph();

        assert_eq!(graph.node_count(), 1);
        assert_eq!(graph.edge_count(), 0);

        // Check it's a TrustBoundary node (attack surface)
        let attack_surface = graph.attack_surface();
        assert_eq!(attack_surface.len(), 1);
    }

    #[test]
    fn network_and_eval_produces_taint_reach_edge() {
        let result = ExecutionResult {
            observations: vec![
                Observation::NetworkRequest {
                    url: "https://evil.com/payload".to_string(),
                    method: "GET".to_string(),
                    headers: vec![],
                    body: None,
                },
                Observation::ApiCall {
                    api: "eval".to_string(),
                    args: vec![Value::tainted_string(
                        "console.log('pwned')",
                        TaintLabel::new(1),
                    )],
                    result: Value::Null,
                },
            ],
            scripts_executed: 1,
            errors: vec![],
            duration_us: 1000,
            timed_out: false,
        };

        let graph = result.to_vulnir_graph();

        // Should have 2 nodes: network capability and the eval call
        assert_eq!(graph.node_count(), 2);

        // Should have 1 taint reach edge
        assert_eq!(graph.edge_count(), 1);
    }

    #[test]
    fn empty_result_produces_empty_graph() {
        let result = ExecutionResult {
            observations: vec![],
            scripts_executed: 0,
            errors: vec![],
            duration_us: 0,
            timed_out: false,
        };

        let graph = result.to_vulnir_graph();

        assert_eq!(graph.node_count(), 0);
        assert_eq!(graph.edge_count(), 0);
    }

    #[test]
    fn filesystem_operations_produce_capability_nodes() {
        let result = ExecutionResult {
            observations: vec![Observation::ApiCall {
                api: "fs.readFileSync".to_string(),
                args: vec![Value::string("/etc/passwd")],
                result: Value::Null,
            }],
            scripts_executed: 1,
            errors: vec![],
            duration_us: 1000,
            timed_out: false,
        };

        let graph = result.to_vulnir_graph();

        assert_eq!(graph.node_count(), 1);

        // Check the node is a filesystem capability
        let caps = graph.reachable_capabilities(NodeIndex::new(0));
        assert_eq!(caps.len(), 1);
    }

    #[test]
    fn jsdet_producer_trait_implementation() {
        let producer = JsdetProducer::new("test-producer", "1.0.0");
        let p = producer.producer();

        assert_eq!(p.name, "test-producer");
        assert_eq!(p.version, Some("1.0.0".to_string()));
        assert_eq!(p.kind, ProducerKind::Dynamic);
    }

    #[test]
    fn custom_producer_used_in_graph() {
        let result = ExecutionResult {
            observations: vec![Observation::DynamicCodeExec {
                source: DynamicCodeSource::Function,
                code_preview: "return 1".to_string(),
            }],
            scripts_executed: 1,
            errors: vec![],
            duration_us: 1000,
            timed_out: false,
        };

        let producer = JsdetProducer::new("custom-scanner", "2.0.0");
        let graph = result.to_vulnir_graph_with_producer(&producer);

        assert_eq!(graph.node_count(), 1);
    }
}