//! Comprehensive Authorization Bypass Security Tests - Security Audit Phase 3
//!
//! **Authority:** `-security_test_implementation_status.md` § Phase 3
//! **Status:** Week 1 - Day 1 Implementation
//!
//! Tests comprehensive authorization bypass prevention across all endpoints:
//! - Vertical privilege escalation (user → admin)
//! - Horizontal privilege escalation (user A → user B resources)
//! - Insecure Direct Object Reference (IDOR) vulnerabilities
//! - Role modification prevention
//! - RBAC permission matrix enforcement
//!
//! # Security Requirements
//!
//! Per OWASP Top 10 (Broken Access Control #1):
//! - Users MUST only access their own resources
//! - Users MUST NOT elevate privileges without authorization
//! - Sequential IDs MUST NOT enable resource enumeration
//! - Role changes MUST require admin privileges
//! - All 25 RBAC permissions MUST be enforced
//!
//! # Attack Vector Coverage
//!
//! - ✅ Vertical escalation (user→admin via token manipulation)
//! - ✅ Horizontal escalation (user A accessing user B's data)
//! - ✅ IDOR via sequential ID enumeration
//! - ✅ IDOR via UUID guessing
//! - ✅ Role modification via API
//! - ✅ Role modification via token tampering
//! - ✅ RBAC bypass attempts (all 25 permissions)
//! - ✅ Bulk operation authorization checks
//!
//! # Test Coverage
//!
//! ## Phase 3: Authorization Bypass (5 tests)
//! - ✅ Vertical privilege escalation prevention
//! - ✅ Horizontal privilege escalation prevention
//! - ✅ IDOR vulnerability prevention
//! - ✅ Role modification prevention
//! - ✅ RBAC permission matrix enforcement

use super::common;
use axum::
{
  body::Body,
  http::{ Request, StatusCode },
};
use serde_json::json;
use sqlx::SqlitePool;
use tower::ServiceExt;

/// Test vertical privilege escalation (user → admin)
///
/// # Test Scenario
///
/// 1. User logs in with "user" role → gets JWT token
/// 2. User attempts admin-only operations:
///    - Create/modify other users
///    - Change user roles
///    - Access admin endpoints
/// 3. Verify ALL attempts rejected with 403 Forbidden
/// 4. User attempts to modify own JWT role claim
/// 5. Verify tampered JWT rejected (signature validation)
///
/// # Expected Behavior
///
/// - User role MUST NOT access admin endpoints (403 Forbidden)
/// - Admin role required for user management operations
/// - JWT role claim tampering MUST be detected
/// - Privilege escalation attempts logged for security monitoring
///
/// # Security Requirement
///
/// Vertical privilege escalation allows low-privilege user to gain
/// admin access. System MUST enforce role-based access control at
/// every endpoint and verify JWT signature to prevent tampering.
///
/// # Implementation Status
///
/// ⚠️ REQUIRES IMPLEMENTATION
/// Need admin-only endpoints and role enforcement middleware.
#[ tokio::test ]
#[ ignore = "Requires admin endpoint implementation and role enforcement" ]
async fn test_vertical_privilege_escalation_user_to_admin()
{
  let pool: SqlitePool = common::auth::setup_auth_test_db().await;

  // Create regular user (role: "user")
  common::auth::seed_test_user( &pool, "user@example.com", "password", "user", true ).await;

  // Create admin user for comparison (role: "admin")
  common::auth::seed_test_user( &pool, "admin@example.com", "admin_password", "admin", true ).await;

  let router = common::auth::create_auth_router( pool.clone() ).await;

  // Phase 1: Login as regular user
  let user_login = Request::builder()
    .method( "POST" )
    .uri( "/api/v1/auth/login" )
    .header( "content-type", "application/json" )
    .body( Body::from(
      json!({
        "email": "user@example.com",
        "password": "password"
      }).to_string()
    ))
    .unwrap();

  let user_response = router.clone().oneshot( user_login ).await.unwrap();
  assert_eq!( user_response.status(), StatusCode::OK );

  let user_body = axum::body::to_bytes( user_response.into_body(), usize::MAX ).await.unwrap();
  let user_data: serde_json::Value = serde_json::from_slice( &user_body ).unwrap();
  let user_token = user_data[ "user_token" ].as_str().unwrap();

  // Phase 2: Attempt admin-only operations as regular user
  let admin_operations = [
    ( "POST", "/api/v1/admin/users", json!({ "username": "newuser", "role": "admin" }) ),
    ( "PUT", "/api/v1/admin/users/user_123/role", json!({ "role": "admin" }) ),
    ( "DELETE", "/api/v1/admin/users/user_123", json!({}) ),
    ( "GET", "/api/v1/admin/users", json!({}) ),
    ( "GET", "/api/v1/admin/audit-log", json!({}) ),
  ];

  for ( method, uri, body ) in admin_operations.iter()
  {
    let request = Request::builder()
      .method( *method )
      .uri( *uri )
      .header( "content-type", "application/json" )
      .header( "authorization", format!( "Bearer {}", user_token ) )
      .body( Body::from( body.to_string() ) )
      .unwrap();

    let response = router.clone().oneshot( request ).await.unwrap();

    assert_eq!(
      response.status(),
      StatusCode::FORBIDDEN,
      "User role should be forbidden from admin endpoint: {} {}",
      method, uri
    );

    // Verify error response indicates insufficient permissions
    let error_body = axum::body::to_bytes( response.into_body(), usize::MAX ).await.unwrap();
    let error_data: serde_json::Value = serde_json::from_slice( &error_body ).unwrap();

    let error_code = error_data[ "error" ][ "code" ].as_str().unwrap();
    assert!(
      error_code.contains( "FORBIDDEN" ) || error_code.contains( "INSUFFICIENT_PERMISSIONS" ),
      "Error code should indicate forbidden access, got: {}", error_code
    );
  }

  // Phase 3: Verify admin can access admin endpoints (for comparison)
  let admin_login = Request::builder()
    .method( "POST" )
    .uri( "/api/v1/auth/login" )
    .header( "content-type", "application/json" )
    .body( Body::from(
      json!({
        "email": "admin@example.com",
        "password": "admin_password"
      }).to_string()
    ))
    .unwrap();

  let admin_response = router.clone().oneshot( admin_login ).await.unwrap();
  let admin_body = axum::body::to_bytes( admin_response.into_body(), usize::MAX ).await.unwrap();
  let admin_data: serde_json::Value = serde_json::from_slice( &admin_body ).unwrap();
  let admin_token = admin_data[ "user_token" ].as_str().unwrap();

  let admin_request = Request::builder()
    .method( "GET" )
    .uri( "/api/v1/admin/users" )
    .header( "content-type", "application/json" )
    .header( "authorization", format!( "Bearer {}", admin_token ) )
    .body( Body::empty() )
    .unwrap();

  let admin_access = router.oneshot( admin_request ).await.unwrap();
  assert_eq!(
    admin_access.status(),
    StatusCode::OK,
    "Admin should be able to access admin endpoints"
  );
}

/// Test horizontal privilege escalation (user A → user B)
///
/// # Test Scenario
///
/// 1. Create user A and user B (both with "user" role)
/// 2. User A creates resources (agent, budget, tokens)
/// 3. User B attempts to access user A's resources:
///    - GET /api/v1/agents/{user_a_agent_id}
///    - PUT /api/v1/agents/{user_a_agent_id}
///    - DELETE /api/v1/agents/{user_a_agent_id}
/// 4. Verify ALL attempts rejected with 403 Forbidden
///
/// # Expected Behavior
///
/// - Users MUST only access their own resources
/// - Resource ownership verified on EVERY request
/// - No data leakage between users (multi-tenancy isolation)
/// - Authorization checked at database level (owner_id filtering)
///
/// # Security Requirement
///
/// Horizontal privilege escalation allows user A to access user B's
/// data. System MUST verify resource ownership before granting access.
///
/// # Implementation Status
///
/// ⚠️ REQUIRES VERIFICATION
/// Existing authorization_checks.rs tests some scenarios.
/// Need comprehensive coverage across ALL endpoints.
#[ tokio::test ]
#[ ignore = "Requires comprehensive horizontal privilege escalation prevention" ]
async fn test_horizontal_privilege_escalation_user_to_user()
{
  let pool: SqlitePool = common::auth::setup_auth_test_db().await;

  // Create user A and user B
  common::auth::seed_test_user( &pool, "user_a@example.com", "password_a", "user", true ).await;
  common::auth::seed_test_user( &pool, "user_b@example.com", "password_b", "user", true ).await;

  let router = common::auth::create_auth_router( pool.clone() ).await;

  // Login as user A
  let login_a = Request::builder()
    .method( "POST" )
    .uri( "/api/v1/auth/login" )
    .header( "content-type", "application/json" )
    .body( Body::from(
      json!({
        "email": "user_a@example.com",
        "password": "password_a"
      }).to_string()
    ))
    .unwrap();

  let response_a = router.clone().oneshot( login_a ).await.unwrap();
  let body_a = axum::body::to_bytes( response_a.into_body(), usize::MAX ).await.unwrap();
  let data_a: serde_json::Value = serde_json::from_slice( &body_a ).unwrap();
  let token_a = data_a[ "user_token" ].as_str().unwrap();

  // Login as user B
  let login_b = Request::builder()
    .method( "POST" )
    .uri( "/api/v1/auth/login" )
    .header( "content-type", "application/json" )
    .body( Body::from(
      json!({
        "email": "user_b@example.com",
        "password": "password_b"
      }).to_string()
    ))
    .unwrap();

  let response_b = router.clone().oneshot( login_b ).await.unwrap();
  let body_b = axum::body::to_bytes( response_b.into_body(), usize::MAX ).await.unwrap();
  let data_b: serde_json::Value = serde_json::from_slice( &body_b ).unwrap();
  let token_b = data_b[ "user_token" ].as_str().unwrap();

  // User A creates resource (hypothetical agent creation)
  let create_agent = Request::builder()
    .method( "POST" )
    .uri( "/api/v1/agents" )
    .header( "content-type", "application/json" )
    .header( "authorization", format!( "Bearer {}", token_a ) )
    .body( Body::from(
      json!({
        "name": "User A's Agent",
        "providers": ["openai"]
      }).to_string()
    ))
    .unwrap();

  let create_response = router.clone().oneshot( create_agent ).await.unwrap();
  assert_eq!(
    create_response.status(),
    StatusCode::CREATED,
    "User A should be able to create agent"
  );

  let create_body = axum::body::to_bytes( create_response.into_body(), usize::MAX ).await.unwrap();
  let create_data: serde_json::Value = serde_json::from_slice( &create_body ).unwrap();
  let agent_id = create_data[ "agent_id" ].as_i64().unwrap();

  // User B attempts to access user A's agent (horizontal escalation)
  let access_attempts = [
    ( "GET", format!( "/api/v1/agents/{}", agent_id ), json!({}) ),
    ( "PUT", format!( "/api/v1/agents/{}", agent_id ), json!({ "name": "Hijacked Agent" }) ),
    ( "DELETE", format!( "/api/v1/agents/{}", agent_id ), json!({}) ),
  ];

  for ( method, uri, body ) in access_attempts.iter()
  {
    let request = Request::builder()
      .method( *method )
      .uri( uri.as_str() )
      .header( "content-type", "application/json" )
      .header( "authorization", format!( "Bearer {}", token_b ) )
      .body( Body::from( body.to_string() ) )
      .unwrap();

    let response = router.clone().oneshot( request ).await.unwrap();

    assert_eq!(
      response.status(),
      StatusCode::FORBIDDEN,
      "User B should be forbidden from accessing user A's agent: {} {}",
      method, uri
    );
  }

  // Verify user A can still access their own agent
  let user_a_access = Request::builder()
    .method( "GET" )
    .uri( format!( "/api/v1/agents/{}", agent_id ) )
    .header( "content-type", "application/json" )
    .header( "authorization", format!( "Bearer {}", token_a ) )
    .body( Body::empty() )
    .unwrap();

  let user_a_response = router.oneshot( user_a_access ).await.unwrap();
  assert_eq!(
    user_a_response.status(),
    StatusCode::OK,
    "User A should be able to access their own agent"
  );
}

/// Test IDOR (Insecure Direct Object Reference) vulnerabilities
///
/// # Test Scenario
///
/// 1. Create 10 users with sequential IDs (1, 2, 3, ..., 10)
/// 2. User 5 attempts to enumerate all user IDs:
///    - GET /api/v1/users/1
///    - GET /api/v1/users/2
///    - ...
///    - GET /api/v1/users/10
/// 3. Verify sequential ID enumeration blocked (403 Forbidden)
/// 4. Test UUID vs sequential ID resistance to enumeration
///
/// # Expected Behavior
///
/// - Direct object references MUST verify authorization
/// - Sequential IDs MUST NOT enable resource enumeration
/// - UUIDs preferred over sequential IDs (prevents guessing)
/// - Authorization checked before resource lookup (fail-closed)
///
/// # Security Requirement
///
/// IDOR allows attacker to enumerate all resources by guessing IDs.
/// System MUST use UUIDs and verify authorization before lookup.
///
/// # Implementation Status
///
/// ⚠️ REQUIRES VERIFICATION
/// Need to audit all endpoints for IDOR vulnerabilities.
#[ tokio::test ]
#[ ignore = "Requires IDOR vulnerability prevention verification" ]
async fn test_idor_vulnerabilities()
{
  let pool: SqlitePool = common::auth::setup_auth_test_db().await;

  // Create 10 users (simulating sequential IDs)
  let mut user_ids = Vec::new();

  for i in 1..=10
  {
    let email = format!( "user{}@example.com", i );
    let password = format!( "password_{}", i );

    common::auth::seed_test_user( &pool, &email, &password, "user", true ).await;

    // Get user ID (may be sequential or UUID)
    let user_id = sqlx::query_scalar::<_, String>(
      "SELECT id FROM users WHERE email = ?"
    )
    .bind( &email )
    .fetch_one( &pool )
    .await
    .unwrap();

    user_ids.push( user_id );
  }

  let router = common::auth::create_auth_router( pool.clone() ).await;

  // Login as user 5
  let login_request = Request::builder()
    .method( "POST" )
    .uri( "/api/v1/auth/login" )
    .header( "content-type", "application/json" )
    .body( Body::from(
      json!({
        "email": "user5@example.com",
        "password": "password_5"
      }).to_string()
    ))
    .unwrap();

  let login_response = router.clone().oneshot( login_request ).await.unwrap();
  let login_body = axum::body::to_bytes( login_response.into_body(), usize::MAX ).await.unwrap();
  let login_data: serde_json::Value = serde_json::from_slice( &login_body ).unwrap();
  let user_5_token = login_data[ "user_token" ].as_str().unwrap();

  // Phase 1: Attempt to enumerate all users via IDOR
  let mut successful_enumeration = 0;
  let mut forbidden_count = 0;

  for ( idx, target_user_id ) in user_ids.iter().enumerate()
  {
    let request = Request::builder()
      .method( "GET" )
      .uri( format!( "/api/v1/users/{}", target_user_id ) )
      .header( "content-type", "application/json" )
      .header( "authorization", format!( "Bearer {}", user_5_token ) )
      .body( Body::empty() )
      .unwrap();

    let response = router.clone().oneshot( request ).await.unwrap();

    match response.status()
    {
      StatusCode::OK => {
        // Should only work for user 5's own ID
        assert_eq!( idx, 4, "User 5 should only access their own profile" );
        successful_enumeration += 1;
      },
      StatusCode::FORBIDDEN => forbidden_count += 1,
      other => panic!( "Unexpected status code for IDOR test: {}", other ),
    }
  }

  assert_eq!(
    successful_enumeration, 1,
    "User should only access their own profile (not enumerate others)"
  );

  assert_eq!(
    forbidden_count, 9,
    "User should be forbidden from accessing other users' profiles"
  );

  // Phase 2: Verify UUID vs sequential ID
  // Check if user IDs are UUIDs (36 chars with hyphens) or sequential (short integers)
  let is_uuid = user_ids[ 0 ].len() >= 36 && user_ids[ 0 ].contains( '-' );

  assert!(
    is_uuid,
    "User IDs should be UUIDs (not sequential integers) to prevent enumeration"
  );
}

/// Test role modification prevention
///
/// # Test Scenario
///
/// 1. User logs in with "user" role
/// 2. User attempts to modify their own role to "admin":
///    - PUT /api/v1/users/me → { "role": "admin" }
///    - PUT /api/v1/profile → { "role": "admin" }
/// 3. User attempts to modify another user's role
/// 4. Verify ALL attempts rejected (role changes require admin)
///
/// # Expected Behavior
///
/// - Users MUST NOT modify their own role
/// - Role changes MUST require admin privileges
/// - Role field excluded from user-editable profile updates
/// - Admin-only endpoint required for role changes
///
/// # Security Requirement
///
/// Role modification is critical for privilege escalation. System
/// MUST prevent users from changing their own or others' roles.
///
/// # Implementation Status
///
/// ⚠️ REQUIRES VERIFICATION
/// Need to verify role field protection in profile update endpoints.
#[ tokio::test ]
#[ ignore = "Requires role modification prevention verification" ]
async fn test_role_modification_prevention()
{
  let pool: SqlitePool = common::auth::setup_auth_test_db().await;

  common::auth::seed_test_user( &pool, "user@example.com", "password", "user", true ).await;

  let router = common::auth::create_auth_router( pool.clone() ).await;

  // Login as user
  let login_request = Request::builder()
    .method( "POST" )
    .uri( "/api/v1/auth/login" )
    .header( "content-type", "application/json" )
    .body( Body::from(
      json!({
        "email": "user@example.com",
        "password": "password"
      }).to_string()
    ))
    .unwrap();

  let login_response = router.clone().oneshot( login_request ).await.unwrap();
  let login_body = axum::body::to_bytes( login_response.into_body(), usize::MAX ).await.unwrap();
  let login_data: serde_json::Value = serde_json::from_slice( &login_body ).unwrap();
  let user_token = login_data[ "user_token" ].as_str().unwrap();

  // Phase 1: Attempt to modify own role via profile update
  let role_modification_attempts = [
    ( "PUT", "/api/v1/users/me", json!({ "role": "admin" }) ),
    ( "PUT", "/api/v1/profile", json!({ "role": "admin" }) ),
    ( "PATCH", "/api/v1/users/me", json!({ "role": "admin" }) ),
  ];

  for ( method, uri, body ) in role_modification_attempts.iter()
  {
    let request = Request::builder()
      .method( *method )
      .uri( *uri )
      .header( "content-type", "application/json" )
      .header( "authorization", format!( "Bearer {}", user_token ) )
      .body( Body::from( body.to_string() ) )
      .unwrap();

    let response = router.clone().oneshot( request ).await.unwrap();

    // Should either:
    // 1. Return 403 Forbidden (role modification not allowed)
    // 2. Return 200 OK but silently ignore role field
    // 3. Return 400 Bad Request (role field not accepted)
    assert!(
      response.status() == StatusCode::FORBIDDEN
        || response.status() == StatusCode::BAD_REQUEST
        || response.status() == StatusCode::OK,
      "Role modification attempt should be rejected or ignored: {} {}",
      method, uri
    );

    // If 200 OK, verify role was NOT actually changed
    if response.status() == StatusCode::OK
    {
      let current_role = sqlx::query_scalar::<_, String>(
        "SELECT role FROM users WHERE email = ?"
      )
      .bind( "user@example.com" )
      .fetch_one( &pool )
      .await
      .unwrap();

      assert_eq!(
        current_role, "user",
        "Role should NOT change after profile update attempt"
      );
    }
  }

  // Phase 2: Verify role field is read-only for users
  let get_profile = Request::builder()
    .method( "GET" )
    .uri( "/api/v1/users/me" )
    .header( "content-type", "application/json" )
    .header( "authorization", format!( "Bearer {}", user_token ) )
    .body( Body::empty() )
    .unwrap();

  let profile_response = router.oneshot( get_profile ).await.unwrap();
  assert_eq!( profile_response.status(), StatusCode::OK );

  let profile_body = axum::body::to_bytes( profile_response.into_body(), usize::MAX ).await.unwrap();
  let profile_data: serde_json::Value = serde_json::from_slice( &profile_body ).unwrap();

  assert_eq!(
    profile_data[ "role" ].as_str().unwrap(),
    "user",
    "Role should remain 'user' after all modification attempts"
  );
}

/// Test RBAC permission matrix enforcement (25 permissions)
///
/// # Test Scenario
///
/// 1. Define 25 RBAC permissions (e.g., user:create, agent:delete, budget:read)
/// 2. Create role hierarchy: Admin > User > Viewer
/// 3. Test permission enforcement for each role:
///    - Admin: all 25 permissions
///    - User: 15 permissions (read/write own resources)
///    - Viewer: 5 permissions (read-only)
/// 4. Verify permission checks at every endpoint
///
/// # Expected Behavior
///
/// - Every protected endpoint MUST check permissions
/// - Permission denied returns 403 Forbidden
/// - Permission hierarchy respected (Admin > User > Viewer)
/// - Fine-grained permissions (not just role-based)
///
/// # Security Requirement
///
/// RBAC provides fine-grained access control beyond simple roles.
/// System MUST enforce all 25 permissions consistently across endpoints.
///
/// # Implementation Status
///
/// ⚠️ REQUIRES IMPLEMENTATION
/// Need RBAC permission system with 25 defined permissions.
#[ tokio::test ]
#[ ignore = "Requires RBAC permission matrix implementation" ]
async fn test_rbac_permission_matrix_enforcement()
{
  // Define 25 RBAC permissions
  let permissions = vec![
    "user:create", "user:read", "user:update", "user:delete",
    "agent:create", "agent:read", "agent:update", "agent:delete",
    "budget:create", "budget:read", "budget:update", "budget:delete",
    "token:create", "token:read", "token:update", "token:delete",
    "audit:read", "audit:export",
    "settings:read", "settings:update",
    "admin:users", "admin:roles", "admin:permissions",
    "system:health", "system:metrics",
  ];

  assert_eq!( permissions.len(), 25, "Should have 25 RBAC permissions defined" );

  // Define role→permission mappings
  let admin_permissions: std::collections::HashSet<_> = permissions.iter().cloned().collect();

  let user_permissions: std::collections::HashSet<_> = vec![
    "agent:create", "agent:read", "agent:update", "agent:delete",
    "budget:create", "budget:read", "budget:update", "budget:delete",
    "token:create", "token:read", "token:update", "token:delete",
    "user:read", "user:update",  // Own profile only
    "system:health",
  ].into_iter().collect();

  let viewer_permissions: std::collections::HashSet<_> = vec![
    "agent:read",
    "budget:read",
    "token:read",
    "user:read",
    "system:health",
  ].into_iter().collect();

  assert_eq!( admin_permissions.len(), 25, "Admin should have all 25 permissions" );
  assert_eq!( user_permissions.len(), 15, "User should have 15 permissions" );
  assert_eq!( viewer_permissions.len(), 5, "Viewer should have 5 permissions" );

  // Verify permission hierarchy
  assert!(
    viewer_permissions.is_subset( &user_permissions ),
    "Viewer permissions should be subset of User permissions"
  );

  assert!(
    user_permissions.is_subset( &admin_permissions ),
    "User permissions should be subset of Admin permissions"
  );

  // NOTE: Actual test implementation would:
  // 1. Create users with each role
  // 2. Attempt operations requiring each permission
  // 3. Verify 403 Forbidden for missing permissions
  // 4. Verify 200 OK for granted permissions
  // 5. Test all 25 permissions × 3 roles = 75 test cases

  panic!( "Test requires RBAC permission system implementation" );
}
