use std::path::PathBuf;
use sanctum::crypto::{
    derive_kek, generate_dek, generate_salt, wrap_dek, KdfParams, MIN_MEMORY_COST_KIB,
    MIN_TIME_COST,
};
use sanctum::storage::Database;

#[test]
fn test_reject_arbitrary_sqlite_database() {
    let temp_dir = std::env::temp_dir();
    let db_path: PathBuf = temp_dir.join(format!("test_foreign_sqlite_{}.db", std::process::id()));
    if db_path.exists() {
        let _ = std::fs::remove_file(&db_path);
    }

    // Erstelle eine fremde SQLite-Datenbank mit beliebigen Daten
    {
        let conn = rusqlite::Connection::open(&db_path).unwrap();
        conn.execute(
            "CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)",
            [],
        )
        .unwrap();
        conn.execute("INSERT INTO users (name) VALUES ('Alice')", []).unwrap();
    }

    // Sanctum Database::open muss die Datei sofort fail-closed ablehnen
    let res = Database::open(&db_path);
    match res {
        Err(err) => {
            let msg = err.to_string();
            assert!(
                msg.contains("kein gültiger Sanctum-Container"),
                "Fehler muss ungültigen Container abweisen: {msg}"
            );
        }
        Ok(_) => panic!("Fremde SQLite-DB ohne meta-Tabelle muss abgelehnt werden"),
    }

    let _ = std::fs::remove_file(&db_path);
}

#[test]
fn test_reject_sqlite_database_with_invalid_magic() {
    let temp_dir = std::env::temp_dir();
    let db_path: PathBuf = temp_dir.join(format!("test_invalid_magic_{}.db", std::process::id()));
    if db_path.exists() {
        let _ = std::fs::remove_file(&db_path);
    }

    // Erstelle SQLite DB mit 'meta' Tabelle, aber falscher Magic
    {
        let conn = rusqlite::Connection::open(&db_path).unwrap();
        conn.execute(
            "CREATE TABLE meta (
                slot_id INTEGER PRIMARY KEY,
                magic BLOB NOT NULL,
                version INTEGER NOT NULL,
                kdf_salt BLOB NOT NULL,
                kdf_params TEXT NOT NULL,
                wrapped_dek BLOB NOT NULL,
                header_nonce BLOB NOT NULL,
                header_tag BLOB NOT NULL
            );",
            [],
        )
        .unwrap();
        conn.execute(
            "INSERT INTO meta (slot_id, magic, version, kdf_salt, kdf_params, wrapped_dek, header_nonce, header_tag)
             VALUES (0, ?1, 2, ?2, '{}', ?3, ?4, ?5)",
            rusqlite::params![
                b"EVIL_MAGIC",
                &[0u8; 16][..],
                &[0u8; 40][..],
                &[0u8; 12][..],
                &[0u8; 16][..]
            ],
        )
        .unwrap();
    }

    let res = Database::open(&db_path);
    match res {
        Err(err) => {
            let msg = err.to_string();
            assert!(
                msg.contains("kein gültiger Sanctum-Container"),
                "Fehler muss ungültigen Magic-Header monieren: {msg}"
            );
        }
        Ok(_) => panic!("Container mit ungültigen Magic Bytes muss abgelehnt werden"),
    }

    let _ = std::fs::remove_file(&db_path);
}

#[test]
fn test_reject_out_of_bounds_kdf_params() {
    let temp_dir = std::env::temp_dir();
    let db_path: PathBuf = temp_dir.join(format!("test_oob_kdf_{}.sanctum", std::process::id()));
    if db_path.exists() {
        let _ = std::fs::remove_file(&db_path);
    }

    // 1. Initialisiere gültigen Container
    let salt = generate_salt();
    let kdf_params = KdfParams {
        memory_cost: MIN_MEMORY_COST_KIB,
        time_cost: MIN_TIME_COST,
        parallelism: 1,
    };
    let kek = derive_kek("ValidPassword2026!", &salt, &kdf_params).unwrap();
    let dek = generate_dek();
    let (wrapped_dek, nonce, tag) = wrap_dek(&kek, &dek).unwrap();

    let db = Database::open(&db_path).unwrap();
    db.init_schema(&salt, &kdf_params, &wrapped_dek, &nonce, &tag).unwrap();
    db.checkpoint().unwrap();
    drop(db);

    // 2. Manipuliere KDF-Parameter in der meta-Tabelle auf gefährliche Werte (DoS: 16 GiB Memory)
    {
        let conn = rusqlite::Connection::open(&db_path).unwrap();
        conn.execute(
            "UPDATE meta SET kdf_params = '{\"memory_cost\": 16777216, \"time_cost\": 3, \"parallelism\": 4}' WHERE slot_id = 0",
            [],
        )
        .unwrap();
    }

    // 3. Öffnen und read_slots() aufrufen: muss mit Kdf-Param-Fehler abbrechen
    let db_reopened = Database::open(&db_path).unwrap();
    let slots_res = db_reopened.read_slots();
    match slots_res {
        Err(err) => {
            let msg = err.to_string();
            assert!(
                msg.contains("KDF-Parameter"),
                "Fehler muss KDF-Parameter monieren: {msg}"
            );
        }
        Ok(_) => panic!("Überhöhte KDF-Parameter müssen fail-closed abgewehrt werden"),
    }

    // 4. Manipuliere KDF-Parameter auf zu schwache Werte (< MIN_MEMORY_COST_KIB)
    {
        let conn = rusqlite::Connection::open(&db_path).unwrap();
        conn.execute(
            "UPDATE meta SET kdf_params = '{\"memory_cost\": 1024, \"time_cost\": 3, \"parallelism\": 4}' WHERE slot_id = 0",
            [],
        )
        .unwrap();
    }
    let slots_res2 = db_reopened.read_slots();
    match slots_res2 {
        Err(err) => {
            let msg = err.to_string();
            assert!(
                msg.contains("KDF-Parameter"),
                "Fehler muss KDF-Parameter monieren: {msg}"
            );
        }
        Ok(_) => panic!("Zu schwache KDF-Parameter müssen fail-closed abgewehrt werden"),
    }

    let _ = std::fs::remove_file(&db_path);
}

#[test]
fn test_reject_corrupted_slot_lengths() {
    let temp_dir = std::env::temp_dir();
    let db_path: PathBuf = temp_dir.join(format!("test_slot_lengths_{}.sanctum", std::process::id()));
    if db_path.exists() {
        let _ = std::fs::remove_file(&db_path);
    }

    let salt = generate_salt();
    let kdf_params = KdfParams {
        memory_cost: MIN_MEMORY_COST_KIB,
        time_cost: MIN_TIME_COST,
        parallelism: 1,
    };
    let kek = derive_kek("ValidPassword2026!", &salt, &kdf_params).unwrap();
    let dek = generate_dek();
    let (wrapped_dek, nonce, tag) = wrap_dek(&kek, &dek).unwrap();

    let db = Database::open(&db_path).unwrap();
    db.init_schema(&salt, &kdf_params, &wrapped_dek, &nonce, &tag).unwrap();
    db.checkpoint().unwrap();
    drop(db);

    // Manipuliere Salt-Länge auf 8 Byte statt 16 Byte
    {
        let conn = rusqlite::Connection::open(&db_path).unwrap();
        conn.execute(
            "UPDATE meta SET kdf_salt = ?1 WHERE slot_id = 0",
            [&[0u8; 8][..]],
        )
        .unwrap();
    }

    let db_reopened = Database::open(&db_path).unwrap();
    let res = db_reopened.read_slots();
    match res {
        Err(err) => {
            let msg = err.to_string();
            assert!(
                msg.contains("Salt-Länge"),
                "Fehler muss fehlerhafte Salt-Länge monieren: {msg}"
            );
        }
        Ok(_) => panic!("Ungültige Salt-Länge muss abgewiesen werden"),
    }

    let _ = std::fs::remove_file(&db_path);
}