torsh-package 0.1.2

//! Package vulnerability scanning and security auditing
//!
//! This module provides comprehensive security scanning capabilities for packages,
//! including:
//! - Dependency vulnerability detection
//! - Known CVE checking
//! - Security policy enforcement
//! - Package integrity verification
//! - Malicious code pattern detection
//!
//! # Security Scanning Workflow
//!
//! 1. **Dependency Analysis**: Check all dependencies against vulnerability databases
//! 2. **Pattern Detection**: Scan package contents for suspicious patterns
//! 3. **Policy Enforcement**: Verify package meets security requirements
//! 4. **Report Generation**: Generate detailed security audit reports
//!
//! # Example
//!
//! ```rust,no_run
//! use torsh_package::vulnerability::{VulnerabilityScanner, ScanPolicy};
//! use torsh_package::Package;
//!
//! # fn main() -> Result<(), Box<dyn std::error::Error>> {
//! let package = Package::load("model.torshpkg")?;
//!
//! let scanner = VulnerabilityScanner::new()
//!     .with_policy(ScanPolicy::strict());
//!
//! let report = scanner.scan(&package)?;
//!
//! if report.has_critical_issues() {
//!     eprintln!("Critical security issues found!");
//!     for issue in report.critical_issues() {
//!         eprintln!("  - {}: {}", issue.severity, issue.description);
//!     }
//! }
//! # Ok(())
//! # }
//! ```

use crate::package::Package;
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use torsh_core::error::Result;

/// Vulnerability severity levels
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
pub enum Severity {
    /// Low severity - informational
    Low,
    /// Medium severity - should be addressed
    Medium,
    /// High severity - should be fixed soon
    High,
    /// Critical severity - immediate action required
    Critical,
}

impl std::fmt::Display for Severity {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Severity::Low => write!(f, "LOW"),
            Severity::Medium => write!(f, "MEDIUM"),
            Severity::High => write!(f, "HIGH"),
            Severity::Critical => write!(f, "CRITICAL"),
        }
    }
}

/// Security issue types
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum IssueType {
    /// Known CVE (Common Vulnerabilities and Exposures)
    KnownCVE,
    /// Dependency vulnerability
    DependencyVulnerability,
    /// Suspicious code pattern
    SuspiciousPattern,
    /// Missing security feature
    MissingSecurityFeature,
    /// Weak cryptography
    WeakCryptography,
    /// Insecure configuration
    InsecureConfiguration,
    /// Supply chain risk
    SupplyChainRisk,
}

/// A single security issue found during scanning
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SecurityIssue {
    /// Issue type
    pub issue_type: IssueType,
    /// Severity level
    pub severity: Severity,
    /// Issue title
    pub title: String,
    /// Detailed description
    pub description: String,
    /// Affected component (dependency, resource, etc.)
    pub affected_component: Option<String>,
    /// CVE ID if applicable
    pub cve_id: Option<String>,
    /// Recommended fix
    pub recommendation: Option<String>,
    /// Additional metadata
    pub metadata: HashMap<String, String>,
}

impl SecurityIssue {
    /// Create a new security issue
    pub fn new(
        issue_type: IssueType,
        severity: Severity,
        title: String,
        description: String,
    ) -> Self {
        Self {
            issue_type,
            severity,
            title,
            description,
            affected_component: None,
            cve_id: None,
            recommendation: None,
            metadata: HashMap::new(),
        }
    }

    /// Set affected component
    pub fn with_affected_component(mut self, component: String) -> Self {
        self.affected_component = Some(component);
        self
    }

    /// Set CVE ID
    pub fn with_cve_id(mut self, cve_id: String) -> Self {
        self.cve_id = Some(cve_id);
        self
    }

    /// Set recommendation
    pub fn with_recommendation(mut self, recommendation: String) -> Self {
        self.recommendation = Some(recommendation);
        self
    }

    /// Add metadata
    pub fn with_metadata(mut self, key: String, value: String) -> Self {
        self.metadata.insert(key, value);
        self
    }
}

/// Vulnerability scan report
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ScanReport {
    /// Package name
    pub package_name: String,
    /// Package version
    pub package_version: String,
    /// Scan timestamp
    pub scan_timestamp: chrono::DateTime<chrono::Utc>,
    /// All issues found
    pub issues: Vec<SecurityIssue>,
    /// Scan policy used
    pub policy_name: String,
    /// Scan duration in milliseconds
    pub scan_duration_ms: u64,
    /// Scanner version
    pub scanner_version: String,
}

impl ScanReport {
    /// Get critical issues
    pub fn critical_issues(&self) -> Vec<&SecurityIssue> {
        self.issues
            .iter()
            .filter(|i| i.severity == Severity::Critical)
            .collect()
    }

    /// Get high severity issues
    pub fn high_issues(&self) -> Vec<&SecurityIssue> {
        self.issues
            .iter()
            .filter(|i| i.severity == Severity::High)
            .collect()
    }

    /// Get medium severity issues
    pub fn medium_issues(&self) -> Vec<&SecurityIssue> {
        self.issues
            .iter()
            .filter(|i| i.severity == Severity::Medium)
            .collect()
    }

    /// Get low severity issues
    pub fn low_issues(&self) -> Vec<&SecurityIssue> {
        self.issues
            .iter()
            .filter(|i| i.severity == Severity::Low)
            .collect()
    }

    /// Check if there are critical issues
    pub fn has_critical_issues(&self) -> bool {
        self.issues.iter().any(|i| i.severity == Severity::Critical)
    }

    /// Check if there are high severity issues
    pub fn has_high_issues(&self) -> bool {
        self.issues.iter().any(|i| i.severity == Severity::High)
    }

    /// Get total issue count
    pub fn total_issues(&self) -> usize {
        self.issues.len()
    }

    /// Calculate risk score (0-100)
    pub fn risk_score(&self) -> u32 {
        let critical_weight = 25;
        let high_weight = 10;
        let medium_weight = 3;
        let low_weight = 1;

        let score = self.critical_issues().len() * critical_weight
            + self.high_issues().len() * high_weight
            + self.medium_issues().len() * medium_weight
            + self.low_issues().len() * low_weight;

        std::cmp::min(score as u32, 100)
    }
}

/// Security scan policy
#[derive(Debug, Clone)]
pub struct ScanPolicy {
    /// Policy name
    pub name: String,
    /// Check for known CVEs
    pub check_cves: bool,
    /// Scan dependencies
    pub scan_dependencies: bool,
    /// Detect suspicious patterns
    pub detect_patterns: bool,
    /// Check cryptography
    pub check_cryptography: bool,
    /// Verify signatures
    pub verify_signatures: bool,
    /// Maximum allowed risk score
    pub max_risk_score: u32,
    /// Fail on critical issues
    pub fail_on_critical: bool,
}

impl Default for ScanPolicy {
    fn default() -> Self {
        Self::standard()
    }
}

impl ScanPolicy {
    /// Create a lenient policy (minimal checks)
    pub fn lenient() -> Self {
        Self {
            name: "lenient".to_string(),
            check_cves: false,
            scan_dependencies: true,
            detect_patterns: false,
            check_cryptography: false,
            verify_signatures: false,
            max_risk_score: 75,
            fail_on_critical: false,
        }
    }

    /// Create a standard policy (balanced security)
    pub fn standard() -> Self {
        Self {
            name: "standard".to_string(),
            check_cves: true,
            scan_dependencies: true,
            detect_patterns: true,
            check_cryptography: true,
            verify_signatures: true,
            max_risk_score: 50,
            fail_on_critical: false,
        }
    }

    /// Create a strict policy (maximum security)
    pub fn strict() -> Self {
        Self {
            name: "strict".to_string(),
            check_cves: true,
            scan_dependencies: true,
            detect_patterns: true,
            check_cryptography: true,
            verify_signatures: true,
            max_risk_score: 20,
            fail_on_critical: true,
        }
    }
}

/// Vulnerability scanner
pub struct VulnerabilityScanner {
    policy: ScanPolicy,
    cve_database: HashMap<String, Vec<String>>, // package -> CVEs
}

impl VulnerabilityScanner {
    /// Create a new vulnerability scanner with default policy
    pub fn new() -> Self {
        Self {
            policy: ScanPolicy::default(),
            cve_database: Self::load_cve_database(),
        }
    }

    /// Set scan policy
    pub fn with_policy(mut self, policy: ScanPolicy) -> Self {
        self.policy = policy;
        self
    }

    /// Scan a package for vulnerabilities
    pub fn scan(&self, package: &Package) -> Result<ScanReport> {
        let start_time = std::time::Instant::now();
        let mut issues = Vec::new();

        // Check package signature if policy requires
        if self.policy.verify_signatures {
            if let Err(e) = package.verify() {
                issues.push(
                    SecurityIssue::new(
                        IssueType::MissingSecurityFeature,
                        Severity::High,
                        "Package signature verification failed".to_string(),
                        format!("Package signature could not be verified: {}", e),
                    )
                    .with_recommendation("Sign the package with a trusted key".to_string()),
                );
            }
        }

        // Scan dependencies for vulnerabilities
        if self.policy.scan_dependencies {
            issues.extend(self.scan_dependencies(package));
        }

        // Check for known CVEs
        if self.policy.check_cves {
            issues.extend(self.check_cves(package));
        }

        // Detect suspicious patterns
        if self.policy.detect_patterns {
            issues.extend(self.detect_patterns(package));
        }

        // Check cryptography
        if self.policy.check_cryptography {
            issues.extend(self.check_cryptography(package));
        }

        let scan_duration_ms = start_time.elapsed().as_millis() as u64;

        Ok(ScanReport {
            package_name: package.name().to_string(),
            package_version: package.get_version().to_string(),
            scan_timestamp: chrono::Utc::now(),
            issues,
            policy_name: self.policy.name.clone(),
            scan_duration_ms,
            scanner_version: env!("CARGO_PKG_VERSION").to_string(),
        })
    }

    /// Scan dependencies for known vulnerabilities
    fn scan_dependencies(&self, package: &Package) -> Vec<SecurityIssue> {
        let mut issues = Vec::new();

        for (dep_name, dep_version) in &package.metadata().dependencies {
            // Check against known vulnerable versions
            // In production, this would query a real vulnerability database
            if dep_name.contains("vulnerable") {
                issues.push(
                    SecurityIssue::new(
                        IssueType::DependencyVulnerability,
                        Severity::High,
                        format!("Vulnerable dependency: {}", dep_name),
                        format!(
                            "Dependency {} version {} has known vulnerabilities",
                            dep_name, dep_version
                        ),
                    )
                    .with_affected_component(dep_name.clone())
                    .with_recommendation(format!(
                        "Update {} to the latest secure version",
                        dep_name
                    )),
                );
            }
        }

        issues
    }

    /// Check for known CVEs
    fn check_cves(&self, package: &Package) -> Vec<SecurityIssue> {
        let mut issues = Vec::new();

        for (dep_name, _dep_version) in &package.metadata().dependencies {
            if let Some(cves) = self.cve_database.get(dep_name) {
                for cve in cves {
                    issues.push(
                        SecurityIssue::new(
                            IssueType::KnownCVE,
                            Severity::Critical,
                            format!("Known CVE in dependency: {}", dep_name),
                            format!("Dependency {} is affected by {}", dep_name, cve),
                        )
                        .with_affected_component(dep_name.clone())
                        .with_cve_id(cve.clone())
                        .with_recommendation("Update to a patched version".to_string()),
                    );
                }
            }
        }

        issues
    }

    /// Detect suspicious code patterns
    fn detect_patterns(&self, package: &Package) -> Vec<SecurityIssue> {
        let mut issues = Vec::new();

        // Patterns that might indicate malicious code
        let suspicious_patterns = vec![
            ("eval(", "Dynamic code evaluation"),
            ("exec(", "Command execution"),
            ("__import__", "Dynamic imports"),
            ("os.system", "System command execution"),
            ("subprocess", "Subprocess execution"),
            ("/etc/passwd", "System file access"),
            ("rm -rf", "Destructive command"),
        ];

        for (_, resource) in package.resources() {
            let content = String::from_utf8_lossy(&resource.data);

            for (pattern, description) in &suspicious_patterns {
                if content.contains(pattern) {
                    issues.push(
                        SecurityIssue::new(
                            IssueType::SuspiciousPattern,
                            Severity::Medium,
                            format!("Suspicious pattern detected: {}", pattern),
                            format!(
                                "Resource contains potentially dangerous pattern: {}",
                                description
                            ),
                        )
                        .with_affected_component(resource.name.clone())
                        .with_recommendation("Review the code and ensure it's safe".to_string()),
                    );
                }
            }
        }

        issues
    }

    /// Check cryptography usage
    fn check_cryptography(&self, _package: &Package) -> Vec<SecurityIssue> {
        let issues = Vec::new();

        // Check for weak cryptographic algorithms
        // This is a simplified check - production systems would be more sophisticated

        // Example: Check if package uses weak hashing
        // In a real implementation, this would scan the actual code

        issues
    }

    /// Load CVE database (in production, this would load from a real database)
    fn load_cve_database() -> HashMap<String, Vec<String>> {
        let mut db = HashMap::new();

        // Mock CVE data for demonstration
        db.insert(
            "example-vulnerable-lib".to_string(),
            vec!["CVE-2024-1234".to_string(), "CVE-2024-5678".to_string()],
        );

        db
    }
}

impl Default for VulnerabilityScanner {
    fn default() -> Self {
        Self::new()
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::resources::{Resource, ResourceType};

    #[test]
    fn test_severity_ordering() {
        assert!(Severity::Critical > Severity::High);
        assert!(Severity::High > Severity::Medium);
        assert!(Severity::Medium > Severity::Low);
    }

    #[test]
    fn test_security_issue_creation() {
        let issue = SecurityIssue::new(
            IssueType::KnownCVE,
            Severity::High,
            "Test Issue".to_string(),
            "Test Description".to_string(),
        )
        .with_cve_id("CVE-2024-1234".to_string())
        .with_affected_component("test-component".to_string())
        .with_recommendation("Fix it".to_string());

        assert_eq!(issue.severity, Severity::High);
        assert_eq!(issue.cve_id, Some("CVE-2024-1234".to_string()));
        assert!(issue.recommendation.is_some());
    }

    #[test]
    fn test_scan_report_risk_score() {
        let mut report = ScanReport {
            package_name: "test".to_string(),
            package_version: "1.0.0".to_string(),
            scan_timestamp: chrono::Utc::now(),
            issues: vec![],
            policy_name: "test".to_string(),
            scan_duration_ms: 100,
            scanner_version: "1.0.0".to_string(),
        };

        // No issues = 0 score
        assert_eq!(report.risk_score(), 0);

        // Add critical issue
        report.issues.push(SecurityIssue::new(
            IssueType::KnownCVE,
            Severity::Critical,
            "Critical".to_string(),
            "Test".to_string(),
        ));
        assert_eq!(report.risk_score(), 25);

        // Add high issue
        report.issues.push(SecurityIssue::new(
            IssueType::DependencyVulnerability,
            Severity::High,
            "High".to_string(),
            "Test".to_string(),
        ));
        assert_eq!(report.risk_score(), 35);
    }

    #[test]
    fn test_scan_report_filtering() {
        let report = ScanReport {
            package_name: "test".to_string(),
            package_version: "1.0.0".to_string(),
            scan_timestamp: chrono::Utc::now(),
            issues: vec![
                SecurityIssue::new(
                    IssueType::KnownCVE,
                    Severity::Critical,
                    "Critical".to_string(),
                    "Test".to_string(),
                ),
                SecurityIssue::new(
                    IssueType::DependencyVulnerability,
                    Severity::High,
                    "High".to_string(),
                    "Test".to_string(),
                ),
                SecurityIssue::new(
                    IssueType::SuspiciousPattern,
                    Severity::Medium,
                    "Medium".to_string(),
                    "Test".to_string(),
                ),
            ],
            policy_name: "test".to_string(),
            scan_duration_ms: 100,
            scanner_version: "1.0.0".to_string(),
        };

        assert_eq!(report.critical_issues().len(), 1);
        assert_eq!(report.high_issues().len(), 1);
        assert_eq!(report.medium_issues().len(), 1);
        assert_eq!(report.total_issues(), 3);
        assert!(report.has_critical_issues());
        assert!(report.has_high_issues());
    }

    #[test]
    fn test_scan_policy_presets() {
        let lenient = ScanPolicy::lenient();
        let standard = ScanPolicy::standard();
        let strict = ScanPolicy::strict();

        assert!(!lenient.fail_on_critical);
        assert!(standard.scan_dependencies);
        assert!(strict.fail_on_critical);
        assert!(strict.max_risk_score < standard.max_risk_score);
    }

    #[test]
    fn test_vulnerability_scanner_basic() {
        let scanner = VulnerabilityScanner::new();
        let package = Package::new("test-package".to_string(), "1.0.0".to_string());

        let report = scanner.scan(&package).unwrap();
        assert_eq!(report.package_name, "test-package");
        assert_eq!(report.package_version, "1.0.0");
    }

    #[test]
    fn test_pattern_detection() {
        let scanner = VulnerabilityScanner::new();
        let mut package = Package::new("test-package".to_string(), "1.0.0".to_string());

        // Add resource with suspicious pattern
        let suspicious_code = b"import os\nos.system('rm -rf /')";
        let resource = Resource::new(
            "suspicious.py".to_string(),
            ResourceType::Source,
            suspicious_code.to_vec(),
        );
        package.add_resource(resource);

        let report = scanner.scan(&package).unwrap();
        assert!(report.total_issues() > 0);
        assert!(report
            .issues
            .iter()
            .any(|i| i.issue_type == IssueType::SuspiciousPattern));
    }

    #[test]
    fn test_scanner_with_policy() {
        let scanner = VulnerabilityScanner::new().with_policy(ScanPolicy::strict());
        let package = Package::new("test".to_string(), "1.0.0".to_string());

        let report = scanner.scan(&package).unwrap();
        assert_eq!(report.policy_name, "strict");
    }
}