//! Security Validation Tests for Clap Integration
//!
//! Tests path traversal prevention, symlink attacks,
//! environment variable injection, and other security concerns.

use std::fs;
use std::path::PathBuf;
use tempfile::TempDir;

/// Test path traversal with various patterns
#[test]
fn test_path_traversal_patterns() {
    let patterns = vec![
        "../../../etc/passwd",
        "../../config.toml",
        "./../secret.key",
        "subdir/../../etc/hosts",
        ".././.././etc/shadow",
        "foo/../../../root",
    ];

    for pattern in patterns {
        let path = PathBuf::from(pattern);
        let has_parent_ref = path.components()
            .any(|c| matches!(c, std::path::Component::ParentDir));

        assert!(
            has_parent_ref,
            "Pattern '{}' should be detected as path traversal",
            pattern
        );
    }
}

/// Test symlink attack prevention
#[test]
#[cfg(unix)]
fn test_symlink_attack_scenarios() {
    let temp_dir = TempDir::new().unwrap();

    // Create a target outside workspace
    let external_target = temp_dir.path().join("external");
    fs::create_dir_all(&external_target).unwrap();
    fs::write(external_target.join("secret.txt"), "secret data").unwrap();

    // Create symlink inside workspace pointing outside
    let workspace = temp_dir.path().join("workspace");
    fs::create_dir_all(&workspace).unwrap();

    let symlink_path = workspace.join("link_to_external");
    std::os::unix::fs::symlink(&external_target, &symlink_path).unwrap();

    // Detect symlink
    let metadata = fs::symlink_metadata(&symlink_path).unwrap();
    assert!(metadata.file_type().is_symlink(), "Should detect symlink");

    // Following symlink leads outside workspace
    let canonical = fs::canonicalize(&symlink_path).unwrap();
    assert!(!canonical.starts_with(&workspace), "Symlink escapes workspace");
}

/// Test absolute path escaping workspace
#[test]
fn test_absolute_path_escaping() {
    let temp_dir = TempDir::new().unwrap();
    let workspace = temp_dir.path();

    // Absolute paths outside workspace should be caught
    let dangerous_paths = vec![
        PathBuf::from("/etc/passwd"),
        PathBuf::from("/root/.ssh/id_rsa"),
        PathBuf::from("/var/log/system.log"),
    ];

    for path in dangerous_paths {
        assert!(
            !path.starts_with(workspace),
            "Path {:?} should be outside workspace",
            path
        );
    }
}

/// Test environment variable injection prevention
#[test]
fn test_env_var_injection_prevention() {
    use std::env;

    // Malicious env vars that might cause issues
    let malicious_vars = vec![
        ("GGEN_OUTPUT_DIR", "../../../etc"),
        ("GGEN_TEMPLATE_PATH", "/etc/passwd"),
        ("GGEN_CONFIG", "../../secret.toml"),
    ];

    for (key, value) in malicious_vars {
        env::set_var(key, value);

        let env_value = env::var(key).unwrap();
        let path = PathBuf::from(&env_value);

        // Check if path contains traversal attempts
        let has_traversal = path.components()
            .any(|c| matches!(c, std::path::Component::ParentDir));

        if has_traversal {
            // Should be validated before use
            assert!(
                env_value.contains(".."),
                "Traversal attempt should be detectable: {}",
                env_value
            );
        }

        env::remove_var(key);
    }
}

/// Test command injection via file paths
#[test]
fn test_command_injection_in_paths() {
    // Paths that might cause command injection if not properly escaped
    let dangerous_filenames = vec![
        "file; rm -rf /",
        "file`whoami`.txt",
        "file$(echo hacked).txt",
        "file|cat /etc/passwd",
    ];

    for filename in dangerous_filenames {
        let path = PathBuf::from(filename);
        let path_str = path.to_string_lossy();

        // These should be treated as literal filenames, not commands
        assert!(
            path_str.contains(';') || path_str.contains('`') ||
            path_str.contains('$') || path_str.contains('|'),
            "Should detect special characters in: {}",
            path_str
        );
    }
}

/// Test null byte injection
#[test]
fn test_null_byte_injection() {
    // Null bytes can truncate paths in some languages
    let path_with_null = "safe_file\0/../../../etc/passwd";

    // Rust handles null bytes safely in paths
    let path = PathBuf::from(path_with_null);
    let path_str = path.to_string_lossy();

    // Null byte should be preserved in Rust
    assert!(path_str.len() > 0, "Path should not be truncated");
}

/// Test Unicode normalization attacks
#[test]
fn test_unicode_normalization_attacks() {
    // Different Unicode representations of same character
    let path1 = PathBuf::from("café"); // NFC (composed)
    let path2 = PathBuf::from("café"); // NFD (decomposed)

    // Rust's path handling normalizes these
    // This test just verifies we can detect different representations
    let str1 = path1.to_string_lossy();
    let str2 = path2.to_string_lossy();

    // The display might differ even if they represent the same path
    assert!(str1.len() > 0 && str2.len() > 0);
}

/// Test directory traversal with mixed separators
#[test]
#[cfg(windows)]
fn test_mixed_path_separators_windows() {
    // Windows accepts both / and \
    let mixed_paths = vec![
        "..\\..\\..\\Windows\\System32",
        "../../../Windows/System32",
        "..\\../..\\Windows\\System32",
    ];

    for path_str in mixed_paths {
        let path = PathBuf::from(path_str);
        let has_parent = path.components()
            .any(|c| matches!(c, std::path::Component::ParentDir));

        assert!(has_parent, "Should detect traversal in: {}", path_str);
    }
}

/// Test resource exhaustion via deep nesting
#[test]
fn test_resource_exhaustion_deep_nesting() {
    // Very deep directory nesting might cause issues
    let mut deep_path = PathBuf::from(".");
    for _ in 0..1000 {
        deep_path.push("subdir");
    }

    // Should handle deep paths without crashing
    assert!(deep_path.components().count() > 500);
}

/// Test file write race conditions
#[test]
fn test_file_write_race_conditions() {
    use std::sync::{Arc, Mutex};
    use std::thread;

    let temp_dir = TempDir::new().unwrap();
    let file_path = Arc::new(temp_dir.path().join("race.txt"));
    let counter = Arc::new(Mutex::new(0));

    let mut handles = vec![];

    // Spawn multiple threads trying to write
    for i in 0..10 {
        let path = Arc::clone(&file_path);
        let count = Arc::clone(&counter);

        let handle = thread::spawn(move || {
            let content = format!("Thread {}\n", i);
            let result = fs::write(path.as_ref(), content);

            if result.is_ok() {
                let mut c = count.lock().unwrap();
                *c += 1;
            }
        });

        handles.push(handle);
    }

    // Wait for all threads
    for handle in handles {
        handle.join().unwrap();
    }

    // All writes should complete (last one wins)
    assert!(file_path.exists());
}

/// Test permission validation on write operations
#[test]
#[cfg(unix)]
fn test_write_permission_validation() {
    use std::os::unix::fs::PermissionsExt;

    let temp_dir = TempDir::new().unwrap();
    let file_path = temp_dir.path().join("readonly.txt");

    // Create file and make it readonly
    fs::write(&file_path, "test").unwrap();

    let mut permissions = fs::metadata(&file_path).unwrap().permissions();
    permissions.set_mode(0o444); // Read-only
    fs::set_permissions(&file_path, permissions).unwrap();

    // Attempt to write should fail
    let result = fs::write(&file_path, "new content");
    assert!(result.is_err(), "Should not be able to write to readonly file");

    // Restore permissions for cleanup
    let mut permissions = fs::metadata(&file_path).unwrap().permissions();
    permissions.set_mode(0o644);
    fs::set_permissions(&file_path, permissions).unwrap();
}
