csaf-core 0.3.4

// SPDX-License-Identifier: Apache-2.0
// Copyright (c) 2026 Pierre Gronau, ndaal in Cologne

//! Export the `audit_log` `SQLite` table in four formats with matching
//! hash sidecars.
//!
//! Produces four files under a caller-chosen directory, each named
//! `audit-<UTC>.ext` where `<UTC>` is `%Y-%m-%dT%H-%M-%SZ`:
//!
//! | Format | Extension | Builder                           |
//! |--------|-----------|-----------------------------------|
//! | JSON   | `.json`   | `serde_json::to_vec_pretty`       |
//! | CSV    | `.csv`    | hand-rolled RFC 4180 writer       |
//! | SARIF  | `.sarif`  | hand-rolled SARIF 2.1.0 via serde |
//! | Markdown | `.md`   | hand-rolled GFM table             |
//!
//! For each payload the three hash sidecars mandated by `CLAUDE.md`
//! (`.sha-256`, `.sha-512`, `.sha3-512`) are emitted via
//! [`crate::sidecar::write_sidecar_files_for`], controlled by the
//! matching `Settings.sidecar_*` toggles.

use std::path::{Path, PathBuf};

use chrono::Utc;
use csaf_models::audit_log::{self, AuditLogEntry};
use csaf_models::db::DbPool;
use csaf_models::settings::Settings;

use crate::error::{CsafError, Result};
use crate::fs::DataDir;
use crate::sidecar;

/// Maximum number of audit rows an export ever pulls in one pass.
///
/// Ten million is three orders of magnitude above any realistic CSAF CRUD
/// deployment's audit history and still fits comfortably in memory as
/// JSON/CSV/SARIF/MD. Hard cap rather than streaming for simplicity.
const MAX_AUDIT_ROWS: usize = 10_000_000;

/// Tool name written into the SARIF `tool.driver.name` field.
const SARIF_DRIVER_NAME: &str = "csaf-crud";

/// SARIF 2.1.0 standard schema URI.
const SARIF_SCHEMA: &str = "https://raw.githubusercontent.com/oasis-tcs/sarif-spec/master/Schemata/sarif-schema-2.1.0.json";

/// Which formats to emit on an audit-log export.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
// Four independent boolean flags is the natural shape here — each
// format is orthogonal, and collapsing to a bitflag type would make the
// HTML form plumbing in `routes::admin` considerably noisier.
#[allow(clippy::struct_excessive_bools)]
pub struct AuditExportOptions {
    /// Emit `audit-<ts>.md` (GitHub-flavoured Markdown table).
    pub markdown: bool,
    /// Emit `audit-<ts>.csv` (RFC 4180).
    pub csv: bool,
    /// Emit `audit-<ts>.json` (pretty-printed JSON array).
    pub json: bool,
    /// Emit `audit-<ts>.sarif` (SARIF 2.1.0).
    pub sarif: bool,
}

impl Default for AuditExportOptions {
    fn default() -> Self {
        Self {
            markdown: true,
            csv: true,
            json: true,
            sarif: true,
        }
    }
}

/// Result of an `export_audit_log` call.
#[derive(Debug, Clone)]
pub struct AuditExportResult {
    /// Filename-safe UTC timestamp used for every written artefact.
    pub timestamp: String,
    /// Number of audit-log rows exported.
    pub rows: usize,
    /// Paths to the payload files (md, csv, json, sarif in that order
    /// when enabled).
    pub written: Vec<PathBuf>,
    /// Paths to every hash sidecar written.
    pub sidecars: Vec<PathBuf>,
}

/// Export the audit log from the supplied sqlite pool.
///
/// `out_dir` is created if missing. The four payload filenames share a
/// single timestamp so operators can group them on disk at a glance.
///
/// # Errors
///
/// - [`CsafError::Database`] if the `audit_log` query fails.
/// - [`CsafError::Io`] if the output directory or any payload cannot be
///   written.
/// - [`CsafError::Config`] if the SARIF payload fails self-validation
///   (invariant: we never ship malformed SARIF).
pub fn export_audit_log(
    pool: &DbPool,
    out_dir: impl AsRef<Path>,
    settings: &Settings,
    opts: &AuditExportOptions,
) -> Result<AuditExportResult> {
    // Capability handle for the output directory: creates it if missing
    // and confines every payload + sidecar write to it.
    let dir = crate::fs::DataDir::open_or_create(out_dir.as_ref())?;

    // Timestamp-safe filename stem — ":" and "." are illegal on Windows
    // filesystems, so we use "-" throughout.
    let timestamp = Utc::now().format("%Y-%m-%dT%H-%M-%SZ").to_string();

    let entries: Vec<AuditLogEntry> =
        pool.with_conn(|conn| audit_log::list(conn, None, MAX_AUDIT_ROWS, 0))?;

    let rows = entries.len();
    let mut written: Vec<PathBuf> = Vec::new();
    let mut sidecars: Vec<PathBuf> = Vec::new();

    if opts.markdown {
        let rel = format!("audit-{timestamp}.md");
        let body = to_markdown(&entries);
        dir.write(&rel, body.as_bytes())?;
        record_sidecars(&dir, &rel, body.as_bytes(), settings, &mut sidecars)?;
        written.push(dir.resolve(&rel));
    }

    if opts.csv {
        let rel = format!("audit-{timestamp}.csv");
        let body = to_csv(&entries);
        dir.write(&rel, body.as_bytes())?;
        record_sidecars(&dir, &rel, body.as_bytes(), settings, &mut sidecars)?;
        written.push(dir.resolve(&rel));
    }

    if opts.json {
        let rel = format!("audit-{timestamp}.json");
        let body = serde_json::to_vec_pretty(&entries)?;
        dir.write(&rel, &body)?;
        record_sidecars(&dir, &rel, &body, settings, &mut sidecars)?;
        written.push(dir.resolve(&rel));
    }

    if opts.sarif {
        let rel = format!("audit-{timestamp}.sarif");
        let sarif_value = to_sarif(&entries);
        // Self-validate before write — cheap sanity guard against schema
        // drift in `to_sarif`. See `validate_sarif` for the full list of
        // invariants enforced.
        validate_sarif(&sarif_value)?;
        let body = serde_json::to_vec_pretty(&sarif_value)?;
        dir.write(&rel, &body)?;
        record_sidecars(&dir, &rel, &body, settings, &mut sidecars)?;
        written.push(dir.resolve(&rel));
    }

    Ok(AuditExportResult {
        timestamp,
        rows,
        written,
        sidecars,
    })
}

/// Write the three hash sidecars for the payload at confined relative
/// path `rel` inside `dir` and push the resolved paths into `sidecars`.
fn record_sidecars(
    dir: &DataDir,
    rel: &str,
    bytes: &[u8],
    settings: &Settings,
    sidecars: &mut Vec<PathBuf>,
) -> Result<()> {
    for sidecar_rel in sidecar::write_sidecar_files_for(
        dir,
        rel,
        bytes,
        sidecar::SidecarHashes::from_settings(settings),
    )? {
        sidecars.push(dir.resolve(&sidecar_rel));
    }
    Ok(())
}

/// Render audit entries as a GitHub Flavoured Markdown table.
fn to_markdown(entries: &[AuditLogEntry]) -> String {
    use std::fmt::Write as _;

    let mut out = String::with_capacity(256 + entries.len() * 120);
    out.push_str("# Audit Log Export\n\n");
    let _ = writeln!(
        out,
        "Generated: `{}`\n",
        Utc::now().format("%Y-%m-%dT%H:%M:%SZ")
    );
    let _ = writeln!(out, "Total rows: **{}**\n", entries.len());
    out.push_str("| id | timestamp | action | tracking_id | user_id | details |\n");
    out.push_str("|----|-----------|--------|-------------|---------|---------|\n");
    for e in entries {
        let _ = writeln!(
            out,
            "| {} | {} | {} | {} | {} | {} |",
            e.id,
            md_escape(&e.timestamp),
            md_escape(&e.action),
            md_escape(&e.tracking_id),
            e.user_id
                .map_or_else(|| "—".to_owned(), |id| id.to_string()),
            md_escape(e.details.as_deref().unwrap_or("")),
        );
    }
    out
}

/// Escape characters that would break a GFM table row.
fn md_escape(value: &str) -> String {
    value
        .replace('\\', r"\\")
        .replace('|', r"\|")
        .replace('\n', " ")
        .replace('\r', "")
}

/// Render audit entries as RFC 4180 CSV (UTF-8, CRLF terminated).
fn to_csv(entries: &[AuditLogEntry]) -> String {
    use std::fmt::Write as _;

    let mut out = String::with_capacity(128 + entries.len() * 100);
    out.push_str("id,timestamp,action,tracking_id,user_id,details\r\n");
    for e in entries {
        let _ = write!(
            out,
            "{},{},{},{},{},{}\r\n",
            e.id,
            csv_quote(&e.timestamp),
            csv_quote(&e.action),
            csv_quote(&e.tracking_id),
            e.user_id.map_or(String::new(), |id| id.to_string()),
            csv_quote(e.details.as_deref().unwrap_or("")),
        );
    }
    out
}

/// RFC 4180 quoting: wrap in double-quotes and escape inner quotes by
/// doubling them. Only wrap if the value contains `,`, `"`, `\r`, or `\n`.
fn csv_quote(value: &str) -> String {
    let needs_quoting = value.chars().any(|c| matches!(c, ',' | '"' | '\r' | '\n'));
    if needs_quoting {
        format!("\"{}\"", value.replace('"', "\"\""))
    } else {
        value.to_owned()
    }
}

/// Build a SARIF 2.1.0 log (as a `serde_json::Value`) from audit entries.
///
/// One `Run` with `tool.driver.name = "csaf-crud"`, one `Result` per
/// entry. `rule_id` mirrors the audit `action`; severity `Level` is
/// `note` for routine read/create/import/export, `warning` for any
/// mutation or reset.
fn to_sarif(entries: &[AuditLogEntry]) -> serde_json::Value {
    use serde_json::json;

    // Unique rule definitions, one per observed action, so downstream
    // SARIF consumers can cite a rule by ID.
    let mut rule_ids: Vec<&str> = entries.iter().map(|e| e.action.as_str()).collect();
    rule_ids.sort_unstable();
    rule_ids.dedup();

    let rules: Vec<serde_json::Value> = rule_ids
        .iter()
        .map(|rule_id| {
            json!({
                "id": rule_id,
                "name": rule_id,
                "shortDescription": { "text": format!("Audit event: {rule_id}") },
                "fullDescription":  { "text": format!("CSAF CRUD audit-log action '{rule_id}'.") },
                "defaultConfiguration": { "level": default_level_for_action(rule_id) },
            })
        })
        .collect();

    let results: Vec<serde_json::Value> = entries
        .iter()
        .map(|e| {
            let mut props = serde_json::Map::new();
            props.insert("timestamp".to_owned(), json!(e.timestamp));
            props.insert("audit_id".to_owned(), json!(e.id));
            if let Some(uid) = e.user_id {
                props.insert("user_id".to_owned(), json!(uid));
            }
            if let Some(details) = &e.details {
                props.insert("details".to_owned(), json!(details));
            }

            json!({
                "ruleId": e.action,
                "level":  default_level_for_action(&e.action),
                "message": {
                    "text": format!(
                        "{action} {tracking} at {ts}",
                        action = e.action,
                        tracking = e.tracking_id,
                        ts = e.timestamp,
                    )
                },
                "properties": props,
            })
        })
        .collect();

    json!({
        "$schema": SARIF_SCHEMA,
        "version": "2.1.0",
        "runs": [{
            "tool": {
                "driver": {
                    "name": SARIF_DRIVER_NAME,
                    "version": env!("CARGO_PKG_VERSION"),
                    "informationUri": "https://gitlab.com/vPierre/ndaal_public_csaf_crud",
                    "rules": rules,
                }
            },
            "results": results,
        }]
    })
}

/// SARIF severity for an audit-log action.
///
/// Any mutation ('update', 'delete') or state reset ('`settings_reset`')
/// is `warning`. Everything else (create / import / export / read) is
/// `note`.
fn default_level_for_action(action: &str) -> &'static str {
    match action {
        "delete" | "update" | "settings_reset" => "warning",
        _ => "note",
    }
}

/// Cheap structural SARIF 2.1.0 validator.
///
/// Asserts the invariants we care about: top-level `version = "2.1.0"`,
/// `$schema` present, exactly one run, every result has `ruleId`, a
/// `message.text`, and a recognised `level`. A full JSON-Schema
/// validation would pull in a heavy dep; these checks catch every real
/// regression we have observed.
fn validate_sarif(log: &serde_json::Value) -> Result<()> {
    let invalid = |msg: &str| -> CsafError { CsafError::Config(format!("SARIF invalid: {msg}")) };

    let Some(version) = log.get("version").and_then(|v| v.as_str()) else {
        return Err(invalid("missing `version`"));
    };
    if version != "2.1.0" {
        return Err(invalid("version must be '2.1.0'"));
    }
    if log.get("$schema").and_then(|v| v.as_str()).is_none() {
        return Err(invalid("missing `$schema`"));
    }

    let Some(runs) = log.get("runs").and_then(|v| v.as_array()) else {
        return Err(invalid("`runs` must be an array"));
    };
    let [run] = runs.as_slice() else {
        return Err(invalid("exactly one run expected"));
    };
    if run.pointer("/tool/driver/name").is_none() {
        return Err(invalid("missing `tool.driver.name`"));
    }

    if let Some(results) = run.get("results").and_then(|v| v.as_array()) {
        for (idx, r) in results.iter().enumerate() {
            if r.get("ruleId").and_then(|v| v.as_str()).is_none() {
                return Err(invalid(&format!("result[{idx}] missing ruleId")));
            }
            if r.pointer("/message/text")
                .and_then(|v| v.as_str())
                .is_none()
            {
                return Err(invalid(&format!("result[{idx}] missing message.text")));
            }
            let level = r.get("level").and_then(|v| v.as_str()).unwrap_or("");
            if !matches!(level, "none" | "note" | "warning" | "error") {
                return Err(invalid(&format!(
                    "result[{idx}] has unknown level `{level}`"
                )));
            }
        }
    }
    Ok(())
}

#[cfg(test)]
// Extension comparisons in these tests are intentionally case-sensitive:
// every filename is produced by our own code, so the deterministic
// lowercase form is both necessary and sufficient.
#[allow(clippy::case_sensitive_file_extension_comparisons)]
mod tests {
    use super::*;

    fn seed_entries(count: usize) -> Vec<AuditLogEntry> {
        (0..count)
            .map(|i| {
                // `i` is a small loop counter bounded by `count` at the
                // call site — go through `try_from` so the cast can
                // never wrap on any 64-bit target and so rust-doctor's
                // `cast_possible_wrap` stays quiet.
                let id = i64::try_from(i).unwrap_or(i64::MAX);
                AuditLogEntry {
                    id,
                    timestamp: format!("2026-04-23T00:00:{i:02}Z"),
                    action: if i % 3 == 0 {
                        "create".to_owned()
                    } else if i % 3 == 1 {
                        "update".to_owned()
                    } else {
                        "delete".to_owned()
                    },
                    tracking_id: format!("ndaal-sa-2026-{i:03}"),
                    user_id: if i % 2 == 0 { Some(id) } else { None },
                    details: if i % 4 == 0 {
                        Some(format!("row {i}"))
                    } else {
                        None
                    },
                }
            })
            .collect()
    }

    #[test]
    fn test_to_markdown_header_and_rows() {
        let entries = seed_entries(3);
        let md = to_markdown(&entries);
        assert!(md.starts_with("# Audit Log Export"));
        assert!(md.contains("Total rows: **3**"));
        assert!(md.contains("| id | timestamp | action | tracking_id | user_id | details |"));
        assert!(md.contains("ndaal-sa-2026-000"));
        assert!(md.contains("ndaal-sa-2026-002"));
    }

    #[test]
    fn test_to_markdown_escapes_pipe_and_newline() {
        let e = AuditLogEntry {
            id: 1,
            timestamp: "2026-04-23T00:00:00Z".to_owned(),
            action: "create".to_owned(),
            tracking_id: "ndaal-sa-2026-001".to_owned(),
            user_id: None,
            details: Some("a | b\nc".to_owned()),
        };
        let md = to_markdown(std::slice::from_ref(&e));
        // Pipe escaped, newline flattened.
        assert!(md.contains(r"a \| b c"));
        assert!(!md.contains("a | b\nc"));
    }

    #[test]
    fn test_to_csv_rfc4180_quoting() {
        let e = AuditLogEntry {
            id: 1,
            timestamp: "2026-04-23T00:00:00Z".to_owned(),
            action: "create".to_owned(),
            tracking_id: "ndaal-sa-2026-001".to_owned(),
            user_id: Some(42),
            details: Some(r#"has,comma and "quote""#.to_owned()),
        };
        let csv = to_csv(std::slice::from_ref(&e));
        assert!(csv.starts_with("id,timestamp,action,tracking_id,user_id,details\r\n"));
        // RFC 4180: quote-wrap + double the inner quotes.
        assert!(csv.contains(r#""has,comma and ""quote"""#));
        // Rows must be CRLF-terminated.
        assert!(csv.ends_with("\r\n"));
    }

    #[test]
    fn test_to_sarif_passes_self_validation() {
        let entries = seed_entries(5);
        let sarif = to_sarif(&entries);
        validate_sarif(&sarif).expect("self-produced SARIF must validate");

        assert_eq!(sarif["version"], "2.1.0");
        assert!(sarif["$schema"].is_string());
        assert_eq!(sarif["runs"][0]["tool"]["driver"]["name"], "csaf-crud");
        assert_eq!(sarif["runs"][0]["results"].as_array().unwrap().len(), 5);
    }

    #[test]
    fn test_to_sarif_levels() {
        let entries = vec![
            AuditLogEntry {
                id: 1,
                timestamp: "t".to_owned(),
                action: "create".to_owned(),
                tracking_id: "x".to_owned(),
                user_id: None,
                details: None,
            },
            AuditLogEntry {
                id: 2,
                timestamp: "t".to_owned(),
                action: "delete".to_owned(),
                tracking_id: "x".to_owned(),
                user_id: None,
                details: None,
            },
            AuditLogEntry {
                id: 3,
                timestamp: "t".to_owned(),
                action: "settings_reset".to_owned(),
                tracking_id: "all".to_owned(),
                user_id: None,
                details: None,
            },
        ];
        let sarif = to_sarif(&entries);
        assert_eq!(sarif["runs"][0]["results"][0]["level"], "note");
        assert_eq!(sarif["runs"][0]["results"][1]["level"], "warning");
        assert_eq!(sarif["runs"][0]["results"][2]["level"], "warning");
    }

    #[test]
    fn test_validate_sarif_rejects_bad_version() {
        let bad = serde_json::json!({
            "version": "1.0",
            "$schema": "https://example/sarif",
            "runs": [{ "tool": { "driver": { "name": "x" } } }],
        });
        assert!(validate_sarif(&bad).is_err());
    }

    #[test]
    fn test_validate_sarif_rejects_missing_rule_id() {
        let bad = serde_json::json!({
            "version": "2.1.0",
            "$schema": "https://example/sarif",
            "runs": [{
                "tool": { "driver": { "name": "x" } },
                "results": [{ "message": { "text": "m" }, "level": "note" }],
            }],
        });
        assert!(validate_sarif(&bad).is_err());
    }

    #[test]
    fn test_export_audit_log_writes_four_payloads_and_sidecars() {
        let pool = DbPool::open_in_memory().expect("db open");
        pool.with_conn(|conn| {
            audit_log::record(conn, "create", "ndaal-sa-2026-001", None, None)?;
            audit_log::record(conn, "delete", "ndaal-sa-2026-002", None, None)?;
            audit_log::record(conn, "settings_reset", "all", None, None)
        })
        .expect("seed audit_log");

        let out = tempfile::tempdir().expect("tmp");
        let settings = Settings::default(); // all sidecars ON
        let res = export_audit_log(&pool, out.path(), &settings, &AuditExportOptions::default())
            .expect("export ok");

        assert_eq!(res.rows, 3);
        assert_eq!(res.written.len(), 4);
        // 5 sidecars per payload × 4 payloads = 20.
        assert_eq!(res.sidecars.len(), 20);

        for path in &res.written {
            assert!(path.exists(), "missing payload {}", path.display());
        }
        for side in &res.sidecars {
            assert!(side.exists(), "missing sidecar {}", side.display());
            let name = side.file_name().unwrap().to_string_lossy();
            assert!(
                name.ends_with(".sha-256")
                    || name.ends_with(".sha-512")
                    || name.ends_with(".sha3-512")
                    || name.ends_with(".blake3-512")
                    || name.ends_with(".shake256-512"),
                "unexpected sidecar extension: {name}"
            );
            assert!(!name.ends_with(".sha256"));
            assert!(!name.ends_with(".sha512"));
        }
    }

    #[test]
    fn test_export_audit_log_respects_format_opts() {
        let pool = DbPool::open_in_memory().expect("db open");
        pool.with_conn(|conn| audit_log::record(conn, "create", "t", None, None))
            .expect("seed");

        let out = tempfile::tempdir().expect("tmp");
        let opts = AuditExportOptions {
            markdown: false,
            csv: true,
            json: false,
            sarif: true,
        };
        let res = export_audit_log(&pool, out.path(), &Settings::default(), &opts).expect("ok");
        assert_eq!(res.written.len(), 2);
        let names: Vec<String> = res
            .written
            .iter()
            .map(|p| p.file_name().unwrap().to_string_lossy().to_string())
            .collect();
        assert!(names.iter().any(|n| n.ends_with(".csv")));
        assert!(names.iter().any(|n| n.ends_with(".sarif")));
        assert!(!names.iter().any(|n| n.ends_with(".md")));
        assert!(!names.iter().any(|n| n.ends_with(".json")));
    }

    #[test]
    fn test_export_audit_log_respects_sidecar_toggles() {
        let pool = DbPool::open_in_memory().expect("db open");
        pool.with_conn(|conn| audit_log::record(conn, "create", "t", None, None))
            .expect("seed");

        let out = tempfile::tempdir().expect("tmp");
        let settings = Settings {
            sidecar_sha256: true,
            sidecar_sha512: false,
            sidecar_sha3_512: true,
            sidecar_blake3_512: false,
            sidecar_shake256_512: false,
            ..Settings::default()
        };
        let res = export_audit_log(&pool, out.path(), &settings, &AuditExportOptions::default())
            .expect("ok");

        // 4 payloads × 2 sidecars (sha-256 + sha3-512) = 8.
        assert_eq!(res.sidecars.len(), 8);
        for side in &res.sidecars {
            let name = side.file_name().unwrap().to_string_lossy();
            assert!(
                name.ends_with(".sha-256") || name.ends_with(".sha3-512"),
                "sha-512 must be skipped: {name}"
            );
        }
    }

    #[test]
    fn test_export_audit_log_creates_missing_dir() {
        let pool = DbPool::open_in_memory().expect("db open");
        let tmp = tempfile::tempdir().expect("tmp");
        let nested = tmp.path().join("a/b/c");
        assert!(!nested.exists());

        export_audit_log(
            &pool,
            &nested,
            &Settings::default(),
            &AuditExportOptions::default(),
        )
        .expect("ok");
        assert!(nested.exists());
    }

    #[test]
    fn test_export_audit_log_empty_table() {
        let pool = DbPool::open_in_memory().expect("db open");
        let out = tempfile::tempdir().expect("tmp");
        let res = export_audit_log(
            &pool,
            out.path(),
            &Settings::default(),
            &AuditExportOptions::default(),
        )
        .expect("ok");
        assert_eq!(res.rows, 0);
        assert_eq!(res.written.len(), 4);
        // Each payload still gets its five sidecars (4 × 5 = 20).
        assert_eq!(res.sidecars.len(), 20);
    }

    #[test]
    fn test_export_audit_log_json_roundtrip() {
        let pool = DbPool::open_in_memory().expect("db open");
        pool.with_conn(|conn| audit_log::record(conn, "create", "t", None, Some("x")))
            .expect("seed");

        let out = tempfile::tempdir().expect("tmp");
        let opts = AuditExportOptions {
            markdown: false,
            csv: false,
            json: true,
            sarif: false,
        };
        let res = export_audit_log(&pool, out.path(), &Settings::default(), &opts).expect("ok");

        let bytes = std::fs::read(&res.written[0]).expect("read");
        let parsed: Vec<AuditLogEntry> = serde_json::from_slice(&bytes).expect("parse");
        assert_eq!(parsed.len(), 1);
        assert_eq!(parsed[0].action, "create");
    }
}