//! Tests for TenantManager - Per-tenant isolation and resource quotas
//! Following strict TDD: These are FAILING tests written FIRST

use chrono::Utc;
use rtx_platform::{
    PlatformConfig, PlatformError,
    error::TenantError,
    tenant::{IsolationLevel, ResourceQuota, TenantConfig, TenantManager},
};
use std::collections::HashMap;
use uuid::Uuid;

/// Create test configuration
fn create_test_config() -> PlatformConfig {
    // Use the same config as region tests for consistency
    let mut regions = HashMap::new();
    regions.insert(
        "us-east-1".to_string(),
        rtx_platform::region::RegionConfig {
            id: "us-east-1".to_string(),
            name: "US East 1".to_string(),
            endpoint: "https://us-east-1.rustytorch.com".to_string(),
            capacity_limits: HashMap::from([
                ("gpu".to_string(), 1000),
                ("memory_gb".to_string(), 10000),
            ]),
            availability_zone_count: 3,
            latency_targets_ms: HashMap::new(),
        },
    );

    PlatformConfig {
        database_url: "postgresql://test:test@localhost/test".to_string(),
        redis_urls: vec!["redis://localhost:6379".to_string()],
        kafka_brokers: vec!["localhost:9092".to_string()],
        metrics_endpoint: "http://localhost:9090".to_string(),
        regions,
        sla_targets: rtx_platform::slo::SlaTargets {
            availability_percentage: 99.95,
            max_latency_p50_ms: 100,
            max_latency_p99_ms: 500,
            max_latency_p999_ms: 2000,
            max_error_rate_percentage: 0.1,
            error_budget_burn_rate_threshold: 2.0,
            downtime_budget_minutes_per_month: 43.8,
        },
    }
}

#[tokio::test]
async fn test_tenant_manager_creation_and_basic_operations() {
    let config = create_test_config();

    // This test WILL FAIL initially - TenantManager doesn't exist yet
    let mut manager = TenantManager::new(&config)
        .await
        .expect("Failed to create TenantManager");
    manager
        .start()
        .await
        .expect("Failed to start TenantManager");

    // Create a new tenant
    let tenant_id = Uuid::new_v4();
    let tenant_config = TenantConfig {
        id: tenant_id,
        name: "Test Tenant".to_string(),
        created_at: Utc::now(),
        isolation_level: IsolationLevel::Strict,
        resource_quotas: HashMap::from([
            (
                "gpu".to_string(),
                ResourceQuota {
                    limit: 100,
                    used: 0,
                    reserved: 0,
                    burst_limit: Some(150),
                },
            ),
            (
                "memory_gb".to_string(),
                ResourceQuota {
                    limit: 1000,
                    used: 0,
                    reserved: 0,
                    burst_limit: Some(1500),
                },
            ),
        ]),
        allowed_regions: vec!["us-east-1".to_string()],
        priority: 1,
    };

    manager
        .create_tenant(tenant_config)
        .await
        .expect("Failed to create tenant");

    // Verify tenant was created
    let retrieved_tenant = manager
        .get_tenant(tenant_id)
        .await
        .expect("Failed to get tenant");
    assert_eq!(retrieved_tenant.id, tenant_id);
    assert_eq!(retrieved_tenant.name, "Test Tenant");
    assert_eq!(retrieved_tenant.isolation_level, IsolationLevel::Strict);
}

#[tokio::test]
async fn test_resource_quota_enforcement() {
    let config = create_test_config();
    let mut manager = TenantManager::new(&config).await.unwrap();
    manager.start().await.unwrap();

    let tenant_id = Uuid::new_v4();
    let tenant_config = TenantConfig {
        id: tenant_id,
        name: "Quota Test Tenant".to_string(),
        created_at: Utc::now(),
        isolation_level: IsolationLevel::Standard,
        resource_quotas: HashMap::from([(
            "gpu".to_string(),
            ResourceQuota {
                limit: 50, // Small limit for testing
                used: 0,
                reserved: 0,
                burst_limit: Some(70),
            },
        )]),
        allowed_regions: vec!["us-east-1".to_string()],
        priority: 1,
    };

    manager.create_tenant(tenant_config).await.unwrap();

    // This test WILL FAIL - quota enforcement not implemented
    // Request within quota - should succeed
    let allocation_result = manager
        .allocate_resources(
            tenant_id,
            "us-east-1",
            HashMap::from([("gpu".to_string(), 30)]),
        )
        .await;
    assert!(allocation_result.is_ok());

    let allocation = allocation_result.unwrap();
    assert_eq!(allocation.allocated_resources.get("gpu"), Some(&30));

    // Check quota usage updated
    let updated_tenant = manager.get_tenant(tenant_id).await.unwrap();
    assert_eq!(updated_tenant.resource_quotas.get("gpu").unwrap().used, 30);

    // Request that would exceed quota - should fail
    let over_quota_result = manager
        .allocate_resources(
            tenant_id,
            "us-east-1",
            HashMap::from([("gpu".to_string(), 25)]), // 30 + 25 = 55 > 50 limit
        )
        .await;

    assert!(matches!(
        over_quota_result,
        Err(PlatformError::Tenant(TenantError::QuotaExceeded { .. }))
    ));
}

#[tokio::test]
async fn test_burst_quota_mechanism() {
    let config = create_test_config();
    let mut manager = TenantManager::new(&config).await.unwrap();
    manager.start().await.unwrap();

    let tenant_id = Uuid::new_v4();
    let tenant_config = TenantConfig {
        id: tenant_id,
        name: "Burst Test Tenant".to_string(),
        created_at: Utc::now(),
        isolation_level: IsolationLevel::Standard,
        resource_quotas: HashMap::from([(
            "gpu".to_string(),
            ResourceQuota {
                limit: 40,
                used: 35, // Already near limit
                reserved: 0,
                burst_limit: Some(60), // Allows bursting
            },
        )]),
        allowed_regions: vec!["us-east-1".to_string()],
        priority: 2, // Higher priority for burst
    };

    manager.create_tenant(tenant_config).await.unwrap();

    // This test WILL FAIL - burst quota mechanism not implemented
    // Request that exceeds normal quota but within burst - should succeed temporarily
    let burst_allocation = manager
        .allocate_resources_with_burst(
            tenant_id,
            "us-east-1",
            HashMap::from([("gpu".to_string(), 20)]), // 35 + 20 = 55, exceeds 40 but within 60
            std::time::Duration::from_secs(300),      // 5 minutes burst duration
        )
        .await;

    assert!(burst_allocation.is_ok());
    let allocation = burst_allocation.unwrap();
    assert!(allocation.is_burst_allocation);
    assert!(allocation.burst_expires_at.is_some());

    // Verify burst quota tracking
    let tenant = manager.get_tenant(tenant_id).await.unwrap();
    assert_eq!(tenant.resource_quotas.get("gpu").unwrap().used, 55);

    // Check burst expiration triggers cleanup
    manager
        .cleanup_expired_burst_allocations()
        .await
        .expect("Failed to cleanup burst");
}

#[tokio::test]
async fn test_tenant_isolation_enforcement() {
    let config = create_test_config();
    let mut manager = TenantManager::new(&config).await.unwrap();
    manager.start().await.unwrap();

    // Create two tenants with different isolation levels
    let tenant_a = Uuid::new_v4();
    let tenant_b = Uuid::new_v4();

    let strict_tenant = TenantConfig {
        id: tenant_a,
        name: "Strict Isolation Tenant".to_string(),
        created_at: Utc::now(),
        isolation_level: IsolationLevel::Strict, // No resource sharing
        resource_quotas: HashMap::from([(
            "gpu".to_string(),
            ResourceQuota {
                limit: 50,
                used: 0,
                reserved: 0,
                burst_limit: None,
            },
        )]),
        allowed_regions: vec!["us-east-1".to_string()],
        priority: 1,
    };

    let standard_tenant = TenantConfig {
        id: tenant_b,
        name: "Standard Isolation Tenant".to_string(),
        created_at: Utc::now(),
        isolation_level: IsolationLevel::Standard, // Allows some sharing
        resource_quotas: HashMap::from([(
            "gpu".to_string(),
            ResourceQuota {
                limit: 50,
                used: 0,
                reserved: 0,
                burst_limit: None,
            },
        )]),
        allowed_regions: vec!["us-east-1".to_string()],
        priority: 1,
    };

    manager.create_tenant(strict_tenant).await.unwrap();
    manager.create_tenant(standard_tenant).await.unwrap();

    // This test WILL FAIL - isolation enforcement not implemented
    // Allocate resources for strict tenant
    manager
        .allocate_resources(
            tenant_a,
            "us-east-1",
            HashMap::from([("gpu".to_string(), 25)]),
        )
        .await
        .unwrap();

    // Verify isolation - strict tenant resources should be completely isolated
    let isolation_check = manager.check_isolation_violations(tenant_a).await.unwrap();
    assert_eq!(isolation_check.violations.len(), 0);
    assert!(isolation_check.has_dedicated_resources);

    // Attempt to access strict tenant's resources from another tenant should fail
    let cross_access_result = manager
        .attempt_cross_tenant_access(tenant_b, tenant_a, "read_tensor_data")
        .await;

    assert!(matches!(
        cross_access_result,
        Err(PlatformError::Tenant(
            TenantError::IsolationViolation { .. }
        ))
    ));
}

#[tokio::test]
async fn test_tenant_authentication_and_authorization() {
    let config = create_test_config();
    let mut manager = TenantManager::new(&config).await.unwrap();
    manager.start().await.unwrap();

    let tenant_id = Uuid::new_v4();
    let tenant_config = TenantConfig {
        id: tenant_id,
        name: "Auth Test Tenant".to_string(),
        created_at: Utc::now(),
        isolation_level: IsolationLevel::Standard,
        resource_quotas: HashMap::new(),
        allowed_regions: vec!["us-east-1".to_string()],
        priority: 1,
    };

    manager.create_tenant(tenant_config).await.unwrap();

    // This test WILL FAIL - authentication not implemented
    // Generate API key for tenant
    let api_key = manager
        .generate_tenant_api_key(
            tenant_id,
            vec!["compute:execute".to_string(), "data:read".to_string()],
            Some(chrono::Utc::now() + chrono::Duration::hours(24)), // Expires in 24h
        )
        .await
        .expect("Failed to generate API key");

    // Verify authentication with valid key
    let auth_result = manager
        .authenticate_request(&api_key.key, "compute:execute")
        .await;
    assert!(auth_result.is_ok());

    let auth_context = auth_result.unwrap();
    assert_eq!(auth_context.tenant_id, tenant_id);
    assert!(
        auth_context
            .permissions
            .contains(&"compute:execute".to_string())
    );

    // Test authorization failure for insufficient permissions
    let unauth_result = manager
        .authenticate_request(&api_key.key, "admin:delete")
        .await;
    assert!(matches!(
        unauth_result,
        Err(PlatformError::Tenant(TenantError::AuthFailed { .. }))
    ));

    // Test expired key handling
    let expired_key = manager
        .generate_tenant_api_key(
            tenant_id,
            vec!["compute:execute".to_string()],
            Some(chrono::Utc::now() - chrono::Duration::hours(1)), // Already expired
        )
        .await
        .unwrap();

    let expired_auth_result = manager
        .authenticate_request(&expired_key.key, "compute:execute")
        .await;
    assert!(expired_auth_result.is_err());
}

#[tokio::test]
async fn test_resource_reservation_system() {
    let config = create_test_config();
    let mut manager = TenantManager::new(&config).await.unwrap();
    manager.start().await.unwrap();

    let tenant_id = Uuid::new_v4();
    let tenant_config = TenantConfig {
        id: tenant_id,
        name: "Reservation Test Tenant".to_string(),
        created_at: Utc::now(),
        isolation_level: IsolationLevel::Standard,
        resource_quotas: HashMap::from([(
            "gpu".to_string(),
            ResourceQuota {
                limit: 100,
                used: 0,
                reserved: 0,
                burst_limit: None,
            },
        )]),
        allowed_regions: vec!["us-east-1".to_string()],
        priority: 1,
    };

    manager.create_tenant(tenant_config).await.unwrap();

    // This test WILL FAIL - reservation system not implemented
    // Create a future reservation
    let reservation_time = chrono::Utc::now() + chrono::Duration::hours(2);
    let reservation = manager
        .create_resource_reservation(
            tenant_id,
            "us-east-1",
            HashMap::from([("gpu".to_string(), 50)]),
            reservation_time,
            chrono::Duration::hours(4), // 4-hour reservation
        )
        .await
        .expect("Failed to create reservation");

    assert!(reservation.reservation_id.is_some());
    assert_eq!(reservation.scheduled_start, reservation_time);

    // Check that quota shows reserved resources
    let tenant = manager.get_tenant(tenant_id).await.unwrap();
    assert_eq!(tenant.resource_quotas.get("gpu").unwrap().reserved, 50);

    // Try to reserve more than quota allows - should fail
    let over_reservation_result = manager
        .create_resource_reservation(
            tenant_id,
            "us-east-1",
            HashMap::from([("gpu".to_string(), 60)]), // 50 + 60 = 110 > 100 limit
            chrono::Utc::now() + chrono::Duration::hours(3),
            chrono::Duration::hours(2),
        )
        .await;

    assert!(matches!(
        over_reservation_result,
        Err(PlatformError::Tenant(TenantError::QuotaExceeded { .. }))
    ));

    // Test reservation activation
    manager
        .activate_reservation(reservation.reservation_id.unwrap())
        .await
        .expect("Failed to activate reservation");

    let updated_tenant = manager.get_tenant(tenant_id).await.unwrap();
    assert_eq!(updated_tenant.resource_quotas.get("gpu").unwrap().used, 50);
    assert_eq!(
        updated_tenant.resource_quotas.get("gpu").unwrap().reserved,
        0
    );
}

#[tokio::test]
async fn test_multi_region_tenant_coordination() {
    let config = create_test_config();
    let mut manager = TenantManager::new(&config).await.unwrap();
    manager.start().await.unwrap();

    let tenant_id = Uuid::new_v4();
    let tenant_config = TenantConfig {
        id: tenant_id,
        name: "Multi-Region Tenant".to_string(),
        created_at: Utc::now(),
        isolation_level: IsolationLevel::Standard,
        resource_quotas: HashMap::from([(
            "gpu".to_string(),
            ResourceQuota {
                limit: 200, // Global quota across regions
                used: 0,
                reserved: 0,
                burst_limit: None,
            },
        )]),
        allowed_regions: vec!["us-east-1".to_string(), "us-west-1".to_string()],
        priority: 1,
    };

    manager.create_tenant(tenant_config).await.unwrap();

    // This test WILL FAIL - multi-region coordination not implemented
    // Allocate resources in multiple regions simultaneously
    let (east_result, west_result) = tokio::join!(
        manager.allocate_resources(
            tenant_id,
            "us-east-1",
            HashMap::from([("gpu".to_string(), 80)]),
        ),
        manager.allocate_resources(
            tenant_id,
            "us-west-1",
            HashMap::from([("gpu".to_string(), 70)]),
        )
    );

    assert!(east_result.is_ok());
    assert!(west_result.is_ok());

    // Verify global quota tracking across regions
    let tenant = manager.get_tenant(tenant_id).await.unwrap();
    assert_eq!(tenant.resource_quotas.get("gpu").unwrap().used, 150); // 80 + 70

    // Attempt allocation that would exceed global quota
    let over_global_quota = manager
        .allocate_resources(
            tenant_id,
            "us-east-1",
            HashMap::from([("gpu".to_string(), 60)]), // 150 + 60 = 210 > 200
        )
        .await;

    assert!(matches!(
        over_global_quota,
        Err(PlatformError::Tenant(TenantError::QuotaExceeded { .. }))
    ));
}