forge-guard 0.3.6

//! Historical trend tracking — M16.
//!
//! Persists audit results in a local SQLite database (default
//! `~/.forge-guard/history.db`) so teams can track their security posture
//! over time:
//!
//! * `forge-guard report --history` — score trends over time
//! * `forge-guard report --regression` — new findings since the last audit
//!
//! Recording is opt-in (`--enable-history` or `[history] enabled = true`) and
//! best-effort — a failed write is logged as a warning and never fails the
//! audit itself.

use crate::core::{AuditResult, Finding, ForgeGuardError, ProjectConfig};
use rusqlite::{params, Connection};
use std::path::PathBuf;

/// One stored audit record.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct HistoryEntry {
    /// Row id in the database.
    pub id: i64,
    /// RFC3339 timestamp of the audit.
    pub timestamp: String,
    /// Project name (project root path as reported by the audit).
    pub project: String,
    /// Target chain (or "all" for `--all-chains` audits).
    pub chain: String,
    /// Overall security score (0-100).
    pub overall_score: u8,
    /// Risk level label.
    pub risk_level: String,
    /// Total number of findings.
    pub total_findings: usize,
    pub critical_count: usize,
    pub high_count: usize,
    pub medium_count: usize,
    pub low_count: usize,
    pub info_count: usize,
    /// Finding signatures present in this audit (for regression detection).
    pub finding_signatures: Vec<String>,
}

/// A stable signature identifying a finding across audits. Line numbers are
/// intentionally excluded so that code edits which shift lines don't turn a
/// pre-existing issue into a false "new finding".
pub fn finding_signature(f: &Finding) -> String {
    format!(
        "{}|{}|{}",
        f.severity.label(),
        f.file.as_deref().unwrap_or(""),
        f.title.to_lowercase()
    )
}

/// Result of comparing the current audit against the previous snapshot.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Regression {
    /// Signatures of findings present now but not in the previous audit.
    pub new_signatures: Vec<String>,
    /// Signatures present in the previous audit but gone now.
    pub resolved_signatures: Vec<String>,
}

/// Compute new/resolved findings between two audits.
///
/// `previous` is the set of signatures from the earlier audit (e.g.
/// [`HistoryEntry::finding_signatures`]); `current` is the live findings of
/// the latest audit. Signatures are matched set-wise, so findings are stable
/// across line-number shifts.
pub fn regression(current: &[Finding], previous: &[String]) -> Regression {
    let current_set: std::collections::HashSet<String> =
        current.iter().map(finding_signature).collect();
    let previous_set: std::collections::HashSet<String> = previous.iter().cloned().collect();

    let mut new_signatures: Vec<String> = current_set.difference(&previous_set).cloned().collect();
    new_signatures.sort();

    let mut resolved_signatures: Vec<String> =
        previous_set.difference(&current_set).cloned().collect();
    resolved_signatures.sort();

    Regression {
        new_signatures,
        resolved_signatures,
    }
}

/// Handle to the local history SQLite database.
pub struct HistoryStore {
    conn: Connection,
}

impl HistoryStore {
    /// Open (creating if needed) the history database configured for the
    /// given project. Creates the parent directory and the schema.
    pub fn open(config: &ProjectConfig) -> Result<Self, ForgeGuardError> {
        let path = db_path(config);
        if let Some(parent) = path.parent() {
            std::fs::create_dir_all(parent)?;
        }
        let conn = Connection::open(&path)?;
        conn.execute_batch(
            "CREATE TABLE IF NOT EXISTS audit_history (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                timestamp TEXT NOT NULL,
                project TEXT NOT NULL,
                chain TEXT NOT NULL,
                overall_score INTEGER NOT NULL,
                risk_level TEXT NOT NULL,
                total_findings INTEGER NOT NULL,
                critical_count INTEGER NOT NULL,
                high_count INTEGER NOT NULL,
                medium_count INTEGER NOT NULL,
                low_count INTEGER NOT NULL,
                info_count INTEGER NOT NULL,
                finding_signatures TEXT NOT NULL
            );
            CREATE INDEX IF NOT EXISTS idx_history_project
                ON audit_history(project, timestamp);",
        )?;
        Ok(Self { conn })
    }

    /// Persist an audit result as a history entry.
    pub fn record(&self, result: &AuditResult) -> Result<(), ForgeGuardError> {
        let signatures: Vec<String> = result.findings.iter().map(finding_signature).collect();
        self.conn.execute(
            "INSERT INTO audit_history (
                timestamp, project, chain, overall_score, risk_level,
                total_findings, critical_count, high_count, medium_count,
                low_count, info_count, finding_signatures
            ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12)",
            params![
                result.timestamp,
                result.project_name,
                result.chain,
                i64::from(result.overall_score),
                result.risk_level.to_string(),
                result.summary.total_findings as i64,
                result.summary.critical_count as i64,
                result.summary.high_count as i64,
                result.summary.medium_count as i64,
                result.summary.low_count as i64,
                result.summary.info_count as i64,
                serde_json::to_string(&signatures).unwrap_or_else(|_| "[]".into()),
            ],
        )?;
        Ok(())
    }

    /// Most recent history entries for a project, newest first.
    pub fn trends(
        &self,
        project: &str,
        limit: usize,
    ) -> Result<Vec<HistoryEntry>, ForgeGuardError> {
        let limit = limit.max(1) as i64;
        let mut stmt = self.conn.prepare(
            "SELECT id, timestamp, project, chain, overall_score, risk_level,
                    total_findings, critical_count, high_count, medium_count,
                    low_count, info_count, finding_signatures
             FROM audit_history
             WHERE project = ?1
             ORDER BY timestamp DESC, id DESC
             LIMIT ?2",
        )?;
        let rows = stmt.query_map(params![project, limit], row_to_entry)?;
        let mut entries = Vec::new();
        for row in rows {
            entries.push(row?);
        }
        Ok(entries)
    }

    /// Latest history entry for a project + chain (used for regression).
    pub fn latest(
        &self,
        project: &str,
        chain: &str,
    ) -> Result<Option<HistoryEntry>, ForgeGuardError> {
        let mut stmt = self.conn.prepare(
            "SELECT id, timestamp, project, chain, overall_score, risk_level,
                    total_findings, critical_count, high_count, medium_count,
                    low_count, info_count, finding_signatures
             FROM audit_history
             WHERE project = ?1 AND chain = ?2
             ORDER BY timestamp DESC, id DESC
             LIMIT 1",
        )?;
        let mut rows = stmt.query_map(params![project, chain], row_to_entry)?;
        Ok(rows.next().transpose()?)
    }
}

fn row_to_entry(row: &rusqlite::Row<'_>) -> rusqlite::Result<HistoryEntry> {
    let signatures_json: String = row.get(12)?;
    let finding_signatures: Vec<String> =
        serde_json::from_str(&signatures_json).unwrap_or_default();
    Ok(HistoryEntry {
        id: row.get(0)?,
        timestamp: row.get(1)?,
        project: row.get(2)?,
        chain: row.get(3)?,
        overall_score: row.get::<_, i64>(4)? as u8,
        risk_level: row.get(5)?,
        total_findings: row.get::<_, i64>(6)? as usize,
        critical_count: row.get::<_, i64>(7)? as usize,
        high_count: row.get::<_, i64>(8)? as usize,
        medium_count: row.get::<_, i64>(9)? as usize,
        low_count: row.get::<_, i64>(10)? as usize,
        info_count: row.get::<_, i64>(11)? as usize,
        finding_signatures,
    })
}

/// Resolve the history database path from configuration.
///
/// * `[history] db_path` set and absolute → used directly
/// * `[history] db_path` set and relative → resolved against the project root
/// * `~` prefix → expanded to the user's home directory
/// * unset → `~/.forge-guard/history.db`
pub fn db_path(config: &ProjectConfig) -> PathBuf {
    if let Some(p) = &config.history.db_path {
        let expanded = expand_tilde(p);
        let path = PathBuf::from(expanded);
        if path.is_absolute() {
            path
        } else {
            config.project_root.join(path)
        }
    } else {
        default_db_path()
    }
}

/// `~/.forge-guard/history.db`, falling back to `$USERPROFILE` on Windows and
/// finally to `.forge-guard/history.db` relative to the current directory.
pub fn default_db_path() -> PathBuf {
    if let Some(home) = home_dir() {
        PathBuf::from(home).join(".forge-guard").join("history.db")
    } else {
        PathBuf::from(".forge-guard").join("history.db")
    }
}

fn expand_tilde(path: &str) -> String {
    if let Some(rest) = path.strip_prefix("~/") {
        if let Some(home) = home_dir() {
            return format!("{}/{}", home, rest);
        }
    }
    path.to_string()
}

fn home_dir() -> Option<String> {
    std::env::var("HOME")
        .ok()
        .or_else(|| std::env::var("USERPROFILE").ok())
}

/// Truncate an RFC3339 timestamp to second precision for display.
pub fn format_timestamp(ts: &str) -> &str {
    &ts[..ts.len().min(19)]
}

/// Format a history entry for the `report --history` table:
/// `date, chain, score, risk, findings summary`.
pub fn format_trend_row(entry: &HistoryEntry) -> String {
    format!(
        "  {:<19} {:<12} {:>9} {:<9} {} (🛑{} 🔴{} 🟡{} 🔵{} ⚪{})",
        format_timestamp(&entry.timestamp),
        entry.chain,
        format!("{}/100", entry.overall_score),
        entry.risk_level,
        entry.total_findings,
        entry.critical_count,
        entry.high_count,
        entry.medium_count,
        entry.low_count,
        entry.info_count,
    )
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::core::{AuditSummary, RiskLevel, SecurityScores, Severity};

    fn finding(sev: Severity, title: &str, file: &str) -> Finding {
        Finding::builder()
            .id(&format!("FA-{}-1", sev.label()))
            .title(title)
            .description("desc")
            .severity(sev)
            .file(file)
            .location(1, 0)
            .recommendation("fix")
            .category("Security")
            .build()
    }

    fn sample_result(score: u8, findings: Vec<Finding>) -> AuditResult {
        let mut summary = AuditSummary {
            total_findings: findings.len(),
            critical_count: 0,
            high_count: 0,
            medium_count: 0,
            low_count: 0,
            info_count: 0,
            files_analyzed: 1,
            lines_analyzed: 10,
            contracts_analyzed: 1,
        };
        for f in &findings {
            match f.severity {
                Severity::Critical => summary.critical_count += 1,
                Severity::High => summary.high_count += 1,
                Severity::Medium => summary.medium_count += 1,
                Severity::Low => summary.low_count += 1,
                Severity::Informational => summary.info_count += 1,
            }
        }
        AuditResult {
            project_name: "demo".into(),
            chain: "ethereum".into(),
            chains: vec!["ethereum".into()],
            timestamp: "2026-08-17T10:00:00Z".into(),
            duration_seconds: 1.0,
            findings,
            scores: SecurityScores::perfect(),
            overall_score: score,
            risk_level: RiskLevel::Low,
            production_ready: true,
            deployment_approved: true,
            summary,
        }
    }

    #[test]
    fn test_finding_signature_is_stable_across_lines() {
        let a = finding(Severity::High, "Reentrancy", "Vault.sol");
        let mut b = finding(Severity::High, "Reentrancy", "Vault.sol");
        b.line = Some(999);
        assert_eq!(finding_signature(&a), finding_signature(&b));

        let c = finding(Severity::High, "Access Control", "Vault.sol");
        assert_ne!(finding_signature(&a), finding_signature(&c));
        assert_eq!(
            finding_signature(&a),
            "HIGH|Vault.sol|reentrancy".to_string()
        );
    }

    #[test]
    fn test_regression_detects_new_and_resolved() {
        let current = vec![
            finding(Severity::High, "Reentrancy", "Vault.sol"),
            finding(Severity::Medium, "Gas", "Vault.sol"),
        ];
        let previous = vec![finding_signature(&finding(
            Severity::High,
            "Reentrancy",
            "Vault.sol",
        ))];

        let diff = regression(&current, &previous);
        assert_eq!(diff.new_signatures, vec!["MEDIUM|Vault.sol|gas"]);
        assert!(diff.resolved_signatures.is_empty());

        // A finding fixed in the current audit shows up as resolved
        let diff2 = regression(&[], &previous);
        assert!(diff2.new_signatures.is_empty());
        assert_eq!(diff2.resolved_signatures, previous);
    }

    #[test]
    fn test_regression_ignores_line_shifts() {
        let mut before = finding(Severity::High, "Reentrancy", "Vault.sol");
        before.line = Some(10);
        let after = finding(Severity::High, "Reentrancy", "Vault.sol");
        let diff = regression(&[after], &[finding_signature(&before)]);
        assert!(
            diff.new_signatures.is_empty(),
            "line shifts must not regress"
        );
    }

    #[test]
    fn test_record_and_trends_roundtrip() {
        let dir = tempfile::tempdir().unwrap();
        let config = ProjectConfig {
            history: crate::core::config::HistoryConfig {
                enabled: true,
                db_path: Some(dir.path().join("history.db").to_string_lossy().into()),
            },
            ..ProjectConfig::default()
        };

        let store = HistoryStore::open(&config).unwrap();
        let mut result = sample_result(80, vec![finding(Severity::High, "Reentrancy", "V.sol")]);
        result.timestamp = "2026-08-17T10:00:00Z".into();
        store.record(&result).unwrap();
        let mut result2 = sample_result(90, vec![]);
        result2.timestamp = "2026-08-18T10:00:00Z".into();
        store.record(&result2).unwrap();

        let trends = store.trends("demo", 10).unwrap();
        assert_eq!(trends.len(), 2);
        // Newest first
        assert_eq!(trends[0].overall_score, 90);
        assert_eq!(trends[0].finding_signatures.len(), 0);
        assert_eq!(trends[1].overall_score, 80);
        assert_eq!(
            trends[1].finding_signatures,
            vec!["HIGH|V.sol|reentrancy".to_string()]
        );

        let latest = store.latest("demo", "ethereum").unwrap().unwrap();
        assert_eq!(latest.overall_score, 90);
    }

    #[test]
    fn test_latest_filters_by_chain_and_project() {
        let dir = tempfile::tempdir().unwrap();
        let config = ProjectConfig {
            history: crate::core::config::HistoryConfig {
                enabled: true,
                db_path: Some(dir.path().join("history.db").to_string_lossy().into()),
            },
            ..ProjectConfig::default()
        };
        let store = HistoryStore::open(&config).unwrap();
        store.record(&sample_result(80, vec![])).unwrap();
        assert!(store.latest("other-project", "ethereum").unwrap().is_none());
        assert!(store.latest("demo", "base").unwrap().is_none());
        assert!(store.latest("demo", "ethereum").unwrap().is_some());
    }

    #[test]
    fn test_db_path_resolution() {
        // Explicit absolute path is used directly
        let config = ProjectConfig {
            history: crate::core::config::HistoryConfig {
                enabled: true,
                db_path: Some("/tmp/custom/history.db".into()),
            },
            ..ProjectConfig::default()
        };
        assert_eq!(db_path(&config), PathBuf::from("/tmp/custom/history.db"));

        // Relative path resolves against the project root
        let config = ProjectConfig {
            project_root: "/home/user/proj".into(),
            history: crate::core::config::HistoryConfig {
                enabled: true,
                db_path: Some("history.db".into()),
            },
            ..ProjectConfig::default()
        };
        assert_eq!(
            db_path(&config),
            PathBuf::from("/home/user/proj/history.db")
        );

        // Tilde expands to the home directory
        let config = ProjectConfig {
            history: crate::core::config::HistoryConfig {
                enabled: true,
                db_path: Some("~/.forge-guard/history.db".into()),
            },
            ..ProjectConfig::default()
        };
        let path = db_path(&config);
        assert!(path.is_absolute());

        // Default resolves to ~/.forge-guard/history.db
        let config = ProjectConfig::default();
        let path = default_db_path();
        assert!(path.to_string_lossy().contains(".forge-guard"));
        let _ = &config;
    }
}