csaf-core 0.1.0

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

//! Embedded storage abstraction layer using redb.
//!
//! Provides the [`CsafStorage`] struct that wraps an embedded redb database
//! for storing CSAF documents, metadata, settings, and provider metadata.

use std::path::Path;
use std::sync::Arc;

use redb::{
    Database, MultimapTableDefinition, ReadableTable, ReadableTableMetadata, TableDefinition,
};
use serde_json::Value;

use csaf_models::csaf_document::{CsafDocument, CsafMeta};
use csaf_models::provider_meta::ProviderMetadata;
use csaf_models::settings::Settings;

use crate::error::Result;

// ---------------------------------------------------------------------------
// Table definitions
// ---------------------------------------------------------------------------

/// CSAF document store: tracking_id -> JSON bytes.
const CSAF_DOCUMENTS: TableDefinition<&str, &[u8]> = TableDefinition::new("csaf_documents");

/// Document metadata for listing/search: tracking_id -> serialized CsafMeta.
const CSAF_META: TableDefinition<&str, &[u8]> = TableDefinition::new("csaf_meta");

/// Sorted index: big-endian timestamp bytes + tracking_id -> tracking_id.
const CSAF_DATE_INDEX: TableDefinition<&[u8], &str> = TableDefinition::new("csaf_date_index");

/// Category index: category -> tracking_ids (multimap).
const CSAF_CATEGORY_INDEX: MultimapTableDefinition<&str, &str> =
    MultimapTableDefinition::new("csaf_category_index");

/// Application settings: key -> JSON bytes.
const SETTINGS: TableDefinition<&str, &[u8]> = TableDefinition::new("settings");

/// Provider metadata: "default" -> JSON bytes.
const PROVIDER_METADATA: TableDefinition<&str, &[u8]> = TableDefinition::new("provider_metadata");

// ---------------------------------------------------------------------------
// Helper: composite index key
// ---------------------------------------------------------------------------

/// Build a composite key for sorted index: 8-byte big-endian timestamp + tracking_id.
fn index_key(timestamp_millis: i64, tracking_id: &str) -> Vec<u8> {
    let mut key = Vec::with_capacity(8 + tracking_id.len());
    key.extend_from_slice(&timestamp_millis.to_be_bytes());
    key.extend_from_slice(tracking_id.as_bytes());
    key
}

// ---------------------------------------------------------------------------
// CsafStorage
// ---------------------------------------------------------------------------

/// Embedded CSAF document storage backed by redb.
#[derive(Clone)]
pub struct CsafStorage {
    db: Arc<Database>,
}

impl CsafStorage {
    /// Open or create the redb database at the given path.
    ///
    /// # Errors
    ///
    /// Returns an error if the database cannot be opened.
    pub fn open(path: &Path) -> Result<Self> {
        if let Some(parent) = path.parent() {
            std::fs::create_dir_all(parent).ok();
        }
        let db = Database::create(path)?;

        // Create tables on first use.
        let txn = db.begin_write()?;
        {
            let _ = txn.open_table(CSAF_DOCUMENTS)?;
            let _ = txn.open_table(CSAF_META)?;
            let _ = txn.open_table(CSAF_DATE_INDEX)?;
            let _ = txn.open_multimap_table(CSAF_CATEGORY_INDEX)?;
            let _ = txn.open_table(SETTINGS)?;
            let _ = txn.open_table(PROVIDER_METADATA)?;
        }
        txn.commit()?;

        Ok(Self { db: Arc::new(db) })
    }

    /// Open a temporary in-memory-like database (for tests).
    ///
    /// # Errors
    ///
    /// Returns an error if the temporary database cannot be created.
    pub fn open_temp() -> Result<Self> {
        let tmp = tempfile::NamedTempFile::new()?;
        Self::open(tmp.path())
    }

    /// Copy the on-disk redb file at `src` to `dst` while holding a read
    /// transaction on the live handle to pin an MVCC snapshot. This
    /// avoids the "Database already open" lock collision that a
    /// second `redb::Database::open` would trigger when the server is
    /// running against the same file.
    ///
    /// The destination is then re-opened to verify the copy is a valid
    /// redb file; the file is deleted and an error returned if the
    /// verification fails.
    ///
    /// # Errors
    ///
    /// Returns an error if the read txn can't be acquired, the file
    /// can't be copied, or the copy fails integrity verification.
    pub fn copy_file_with_snapshot(&self, src: &Path, dst: &Path) -> Result<()> {
        if !src.exists() {
            return Err(crate::error::CsafError::Storage(format!(
                "redb source file missing: {}",
                src.display()
            )));
        }
        // Pin the snapshot on the LIVE handle (no second open).
        let read_txn = self.db.begin_read()?;
        std::fs::copy(src, dst)?;
        drop(read_txn);

        // Verify — reopening the freshly-written copy must succeed.
        match redb::Database::open(dst) {
            Ok(_verified) => Ok(()),
            Err(e) => {
                let _ = std::fs::remove_file(dst);
                Err(crate::error::CsafError::Storage(format!(
                    "redb dump verification failed: {e}"
                )))
            },
        }
    }

    // -----------------------------------------------------------------------
    // CSAF document CRUD
    // -----------------------------------------------------------------------

    /// Store a CSAF document (create or overwrite).
    ///
    /// # Errors
    ///
    /// Returns an error if serialization or storage fails.
    pub fn put_document(&self, doc: &CsafDocument) -> Result<()> {
        let tracking_id = doc.tracking_id();
        let json_bytes = serde_json::to_vec(doc)?;
        let meta = CsafMeta::from_document(doc);
        let meta_bytes = serde_json::to_vec(&meta)?;

        let timestamp = chrono::Utc::now().timestamp_millis();
        let idx_key = index_key(timestamp, tracking_id);

        let txn = self.db.begin_write()?;
        {
            let mut docs_table = txn.open_table(CSAF_DOCUMENTS)?;
            docs_table.insert(tracking_id, json_bytes.as_slice())?;

            let mut meta_table = txn.open_table(CSAF_META)?;
            meta_table.insert(tracking_id, meta_bytes.as_slice())?;

            let mut date_index = txn.open_table(CSAF_DATE_INDEX)?;
            date_index.insert(idx_key.as_slice(), tracking_id)?;

            let mut cat_index = txn.open_multimap_table(CSAF_CATEGORY_INDEX)?;
            cat_index.insert(doc.category(), tracking_id)?;
        }
        txn.commit()?;

        Ok(())
    }

    /// Retrieve a CSAF document by tracking ID.
    ///
    /// # Errors
    ///
    /// Returns an error if the read fails.
    pub fn get_document(&self, tracking_id: &str) -> Result<Option<CsafDocument>> {
        let txn = self.db.begin_read()?;
        let table = txn.open_table(CSAF_DOCUMENTS)?;

        match table.get(tracking_id)? {
            Some(value) => {
                let doc: CsafDocument = serde_json::from_slice(value.value())?;
                Ok(Some(doc))
            },
            None => Ok(None),
        }
    }

    /// Retrieve a CSAF document as raw JSON value.
    ///
    /// # Errors
    ///
    /// Returns an error if the read fails.
    pub fn get_document_json(&self, tracking_id: &str) -> Result<Option<Value>> {
        let txn = self.db.begin_read()?;
        let table = txn.open_table(CSAF_DOCUMENTS)?;

        match table.get(tracking_id)? {
            Some(value) => {
                let json: Value = serde_json::from_slice(value.value())?;
                Ok(Some(json))
            },
            None => Ok(None),
        }
    }

    /// Delete a CSAF document by tracking ID.
    ///
    /// # Errors
    ///
    /// Returns an error if the delete fails.
    pub fn delete_document(&self, tracking_id: &str) -> Result<bool> {
        let txn = self.db.begin_write()?;
        let existed;
        {
            let mut docs_table = txn.open_table(CSAF_DOCUMENTS)?;
            existed = docs_table.remove(tracking_id)?.is_some();

            let mut meta_table = txn.open_table(CSAF_META)?;
            meta_table.remove(tracking_id)?;

            // Remove from category index (all categories).
            let mut cat_index = txn.open_multimap_table(CSAF_CATEGORY_INDEX)?;
            for cat in &[
                "csaf_security_advisory",
                "csaf_vex",
                "csaf_informational_advisory",
            ] {
                cat_index.remove(cat, tracking_id)?;
            }
        }
        txn.commit()?;

        Ok(existed)
    }

    /// List all CSAF document metadata, ordered by tracking ID.
    ///
    /// # Errors
    ///
    /// Returns an error if the read fails.
    pub fn list_meta(&self, limit: usize, offset: usize) -> Result<Vec<CsafMeta>> {
        let txn = self.db.begin_read()?;
        let table = txn.open_table(CSAF_META)?;

        let mut results = Vec::new();
        let mut skipped = 0;

        let iter = table.iter()?;
        for entry in iter {
            let (_key, value) = entry?;
            if skipped < offset {
                skipped += 1;
                continue;
            }
            if results.len() >= limit {
                break;
            }
            let meta: CsafMeta = serde_json::from_slice(value.value())?;
            results.push(meta);
        }

        Ok(results)
    }

    /// Count total number of stored documents.
    ///
    /// # Errors
    ///
    /// Returns an error if the read fails.
    pub fn count_documents(&self) -> Result<usize> {
        let txn = self.db.begin_read()?;
        let table = txn.open_table(CSAF_DOCUMENTS)?;
        // `table.len()` returns `u64`; on 32-bit targets it may be
        // wider than `usize`. Saturate to the platform `usize::MAX`
        // instead of silently truncating.
        let count = usize::try_from(table.len()?).unwrap_or(usize::MAX);
        Ok(count)
    }

    /// Check if a document exists.
    ///
    /// # Errors
    ///
    /// Returns an error if the read fails.
    pub fn document_exists(&self, tracking_id: &str) -> Result<bool> {
        let txn = self.db.begin_read()?;
        let table = txn.open_table(CSAF_DOCUMENTS)?;
        Ok(table.get(tracking_id)?.is_some())
    }

    /// List tracking IDs for a given category.
    ///
    /// # Errors
    ///
    /// Returns an error if the read fails.
    pub fn list_by_category(&self, category: &str) -> Result<Vec<String>> {
        let txn = self.db.begin_read()?;
        let table = txn.open_multimap_table(CSAF_CATEGORY_INDEX)?;

        let mut ids = Vec::new();
        if let Ok(iter) = table.get(category) {
            for entry in iter {
                let value = entry?;
                ids.push(value.value().to_owned());
            }
        }

        Ok(ids)
    }

    // -----------------------------------------------------------------------
    // Settings
    // -----------------------------------------------------------------------

    /// Load application settings from storage.
    ///
    /// # Errors
    ///
    /// Returns an error if the read fails.
    pub fn get_settings(&self) -> Result<Settings> {
        let txn = self.db.begin_read()?;
        let table = txn.open_table(SETTINGS)?;

        match table.get("settings")? {
            Some(value) => {
                let settings: Settings = serde_json::from_slice(value.value())?;
                Ok(settings)
            },
            None => Ok(Settings::default()),
        }
    }

    /// Save application settings to storage.
    ///
    /// # Errors
    ///
    /// Returns an error if serialization or storage fails.
    pub fn put_settings(&self, settings: &Settings) -> Result<()> {
        let bytes = serde_json::to_vec(settings)?;
        let txn = self.db.begin_write()?;
        {
            let mut table = txn.open_table(SETTINGS)?;
            table.insert("settings", bytes.as_slice())?;
        }
        txn.commit()?;
        Ok(())
    }

    // -----------------------------------------------------------------------
    // Provider metadata
    // -----------------------------------------------------------------------

    /// Load provider metadata from storage.
    ///
    /// # Errors
    ///
    /// Returns an error if the read fails.
    pub fn get_provider_metadata(&self) -> Result<Option<ProviderMetadata>> {
        let txn = self.db.begin_read()?;
        let table = txn.open_table(PROVIDER_METADATA)?;

        match table.get("default")? {
            Some(value) => {
                let meta: ProviderMetadata = serde_json::from_slice(value.value())?;
                Ok(Some(meta))
            },
            None => Ok(None),
        }
    }

    /// Save provider metadata to storage.
    ///
    /// # Errors
    ///
    /// Returns an error if serialization or storage fails.
    pub fn put_provider_metadata(&self, meta: &ProviderMetadata) -> Result<()> {
        let bytes = serde_json::to_vec(meta)?;
        let txn = self.db.begin_write()?;
        {
            let mut table = txn.open_table(PROVIDER_METADATA)?;
            table.insert("default", bytes.as_slice())?;
        }
        txn.commit()?;
        Ok(())
    }

    // -----------------------------------------------------------------------
    // Health check
    // -----------------------------------------------------------------------

    /// Check if storage is operational.
    ///
    /// # Errors
    ///
    /// Returns an error if the check fails.
    pub fn check_storage_up(&self) -> Result<bool> {
        let txn = self.db.begin_read()?;
        let _ = txn.open_table(CSAF_DOCUMENTS)?;
        Ok(true)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    fn test_doc() -> CsafDocument {
        let json = include_str!("../../../test/csaf/2026/003/ndaal-sa-2026-003.json");
        serde_json::from_str(json).expect("parse error")
    }

    #[test]
    fn test_put_and_get_document() {
        let storage = CsafStorage::open_temp().expect("open failed");
        let doc = test_doc();

        storage.put_document(&doc).expect("put failed");

        let retrieved = storage
            .get_document("ndaal-sa-2026-003")
            .expect("get failed")
            .expect("doc not found");

        assert_eq!(retrieved.document.tracking.id, "ndaal-sa-2026-003");
        assert_eq!(retrieved.document.category, "csaf_security_advisory");
    }

    #[test]
    fn test_delete_document() {
        let storage = CsafStorage::open_temp().expect("open failed");
        let doc = test_doc();

        storage.put_document(&doc).expect("put failed");
        assert!(
            storage
                .document_exists("ndaal-sa-2026-003")
                .expect("exists check failed")
        );

        let deleted = storage
            .delete_document("ndaal-sa-2026-003")
            .expect("delete failed");
        assert!(deleted);

        assert!(
            !storage
                .document_exists("ndaal-sa-2026-003")
                .expect("exists check failed")
        );
    }

    #[test]
    fn test_delete_nonexistent() {
        let storage = CsafStorage::open_temp().expect("open failed");
        let deleted = storage
            .delete_document("nonexistent")
            .expect("delete failed");
        assert!(!deleted);
    }

    #[test]
    fn test_list_meta() {
        let storage = CsafStorage::open_temp().expect("open failed");
        let doc = test_doc();
        storage.put_document(&doc).expect("put failed");

        let meta_list = storage.list_meta(100, 0).expect("list failed");
        assert_eq!(meta_list.len(), 1);
        assert_eq!(meta_list[0].tracking_id, "ndaal-sa-2026-003");
    }

    #[test]
    fn test_count_documents() {
        let storage = CsafStorage::open_temp().expect("open failed");
        assert_eq!(storage.count_documents().expect("count failed"), 0);

        let doc = test_doc();
        storage.put_document(&doc).expect("put failed");
        assert_eq!(storage.count_documents().expect("count failed"), 1);
    }

    #[test]
    fn test_list_by_category() {
        let storage = CsafStorage::open_temp().expect("open failed");
        let doc = test_doc();
        storage.put_document(&doc).expect("put failed");

        let ids = storage
            .list_by_category("csaf_security_advisory")
            .expect("list failed");
        assert!(ids.contains(&"ndaal-sa-2026-003".to_owned()));

        let empty = storage.list_by_category("csaf_vex").expect("list failed");
        assert!(empty.is_empty());
    }

    #[test]
    fn test_settings_roundtrip() {
        let storage = CsafStorage::open_temp().expect("open failed");

        let settings = storage.get_settings().expect("get failed");
        assert_eq!(settings.csaf_mode, "2.1"); // default

        let mut custom = settings;
        custom.csaf_mode = "2.0".to_owned();
        custom.theme = "dark".to_owned();
        storage.put_settings(&custom).expect("put failed");

        let loaded = storage.get_settings().expect("get failed");
        assert_eq!(loaded.csaf_mode, "2.0");
        assert_eq!(loaded.theme, "dark");
    }

    #[test]
    fn test_provider_metadata_roundtrip() {
        let storage = CsafStorage::open_temp().expect("open failed");

        assert!(
            storage
                .get_provider_metadata()
                .expect("get failed")
                .is_none()
        );

        let json = include_str!("../../../test/csaf/provider-metadata.json");
        let meta: ProviderMetadata = serde_json::from_str(json).expect("parse error");
        storage.put_provider_metadata(&meta).expect("put failed");

        let loaded = storage
            .get_provider_metadata()
            .expect("get failed")
            .expect("meta not found");
        assert_eq!(loaded.role, "csaf_publisher");
    }

    #[test]
    fn test_health_check() {
        let storage = CsafStorage::open_temp().expect("open failed");
        assert!(storage.check_storage_up().expect("health check failed"));
    }

    #[test]
    fn test_store_all_test_files() {
        let storage = CsafStorage::open_temp().expect("open failed");
        let test_dir =
            std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../test/csaf/2026");

        let mut count = 0;
        for entry in std::fs::read_dir(&test_dir).expect("test dir missing") {
            let entry = entry.expect("dir entry error");
            if !entry.file_type().expect("type error").is_dir() {
                continue;
            }
            for file in std::fs::read_dir(entry.path()).expect("subdir error") {
                let file = file.expect("file error");
                let path = file.path();
                if path.extension().is_some_and(|e| e == "json") {
                    let content = std::fs::read_to_string(&path).expect("read error");
                    let doc: CsafDocument = serde_json::from_str(&content).expect("parse error");
                    storage.put_document(&doc).expect("put failed");
                    count += 1;
                }
            }
        }

        assert!(count >= 15, "Expected at least 15 test files, got {count}");
        assert_eq!(storage.count_documents().expect("count failed"), count);
    }
}