# services/tenant/app/api/tenants.py
"""
Tenant API endpoints
"""

from fastapi import APIRouter, Depends, HTTPException, status, Path
from sqlalchemy.ext.asyncio import AsyncSession
from typing import List, Dict, Any
import structlog
from uuid import UUID
from sqlalchemy import select, delete, func
from datetime import datetime
import uuid

from app.core.database import get_db
from app.services.messaging import publish_tenant_deleted_event
from app.schemas.tenants import (
    BakeryRegistration, TenantResponse, TenantAccessResponse, 
    TenantUpdate, TenantMemberResponse
)
from app.services.tenant_service import TenantService
from shared.auth.decorators import (
    get_current_user_dep,
    require_admin_role
)

logger = structlog.get_logger()
router = APIRouter()

@router.post("/tenants/register", response_model=TenantResponse)
async def register_bakery(
    bakery_data: BakeryRegistration,
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):
    
    try:
        result = await TenantService.create_bakery(bakery_data, current_user["user_id"], db)
        logger.info(f"Bakery registered: {bakery_data.name} by {current_user['email']}")
        return result
        
    except Exception as e:
        logger.error(f"Bakery registration failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Bakery registration failed"
        )

@router.get("/tenants/{tenant_id}/access/{user_id}", response_model=TenantAccessResponse)
async def verify_tenant_access(
    user_id: str, 
    tenant_id: UUID = Path(..., description="Tenant ID"),
    db: AsyncSession = Depends(get_db)
):
    """Verify if user has access to tenant - Called by Gateway"""
    # Check if this is a service request
    if user_id in ["training-service", "data-service", "forecasting-service"]:
        # Services have access to all tenants for their operations
        return TenantAccessResponse(
            has_access=True,
            role="service",
            permissions=["read", "write"]
        )
    
    try:
        access_info = await TenantService.verify_user_access(user_id, tenant_id, db)
        return access_info
        
    except Exception as e:
        logger.error(f"Access verification failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Access verification failed"
        )

@router.get("/tenants/users/{user_id}", response_model=List[TenantResponse])
async def get_user_tenants(
    user_id: str,
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):

    # Users can only see their own tenants
    if current_user["user_id"] != user_id:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Access denied"
        )
    
    try:
        tenants = await TenantService.get_user_tenants(user_id, db)
        return tenants
        
    except Exception as e:
        logger.error(f"Failed to get user tenants: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to retrieve tenants"
        )

@router.get("/tenants/{tenant_id}", response_model=TenantResponse)
async def get_tenant(
    tenant_id: UUID = Path(..., description="Tenant ID"),
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):

    # Verify user has access to tenant
    access = await TenantService.verify_user_access(current_user["user_id"], tenant_id, db)
    if not access.has_access:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Access denied to tenant"
        )
    
    tenant = await TenantService.get_tenant_by_id(tenant_id, db)
    if not tenant:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Tenant not found"
        )
    
    return tenant

@router.put("/tenants/{tenant_id}", response_model=TenantResponse)
async def update_tenant(
    update_data: TenantUpdate,
    tenant_id: UUID = Path(..., description="Tenant ID"),
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):

    try:
        result = await TenantService.update_tenant(tenant_id, update_data, current_user["user_id"], db)
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Tenant update failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Tenant update failed"
        )

@router.post("/tenants/{tenant_id}/members", response_model=TenantMemberResponse)
async def add_team_member(
    user_id: str,
    role: str,
    tenant_id: UUID = Path(..., description="Tenant ID"),
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
    db: AsyncSession = Depends(get_db)
):

    try:
        result = await TenantService.add_team_member(
            tenant_id, user_id, role, current_user["user_id"], db
        )
        return result
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Add team member failed: {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to add team member"
        )

@router.delete("/tenants/{tenant_id}")
async def delete_tenant_complete(
    tenant_id: str,
    current_user = Depends(get_current_user_dep),
    _admin_check = Depends(require_admin_role),
    db: AsyncSession = Depends(get_db)
):
    """
    Delete a tenant completely with all associated data.
    
    **WARNING: This operation is irreversible!**
    
    This endpoint:
    1. Validates tenant exists and user has permissions
    2. Deletes all tenant memberships
    3. Deletes tenant subscription data
    4. Deletes the tenant record
    5. Publishes deletion event
    
    Used by admin user deletion process when a tenant has no other admins.
    """
    
    try:
        tenant_uuid = uuid.UUID(tenant_id)
    except ValueError:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid tenant ID format"
        )
    
    try:
        from app.models.tenants import Tenant, TenantMember, Subscription
        
        # Step 1: Verify tenant exists
        tenant_query = select(Tenant).where(Tenant.id == tenant_uuid)
        tenant_result = await db.execute(tenant_query)
        tenant = tenant_result.scalar_one_or_none()
        
        if not tenant:
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail=f"Tenant {tenant_id} not found"
            )
        
        deletion_stats = {
            "tenant_id": tenant_id,
            "tenant_name": tenant.name,
            "deleted_at": datetime.utcnow().isoformat(),
            "memberships_deleted": 0,
            "subscriptions_deleted": 0,
            "errors": []
        }
        
        # Step 2: Delete all tenant memberships
        try:
            membership_count_query = select(func.count(TenantMember.id)).where(
                TenantMember.tenant_id == tenant_uuid
            )
            membership_count_result = await db.execute(membership_count_query)
            membership_count = membership_count_result.scalar()
            
            membership_delete_query = delete(TenantMember).where(
                TenantMember.tenant_id == tenant_uuid
            )
            await db.execute(membership_delete_query)
            deletion_stats["memberships_deleted"] = membership_count
            
            logger.info("Deleted tenant memberships", 
                       tenant_id=tenant_id, 
                       count=membership_count)
            
        except Exception as e:
            error_msg = f"Error deleting memberships: {str(e)}"
            deletion_stats["errors"].append(error_msg)
            logger.error(error_msg)
        
        # Step 3: Delete subscription data
        try:
            subscription_count_query = select(func.count(Subscription.id)).where(
                Subscription.tenant_id == tenant_uuid
            )
            subscription_count_result = await db.execute(subscription_count_query)
            subscription_count = subscription_count_result.scalar()
            
            subscription_delete_query = delete(Subscription).where(
                Subscription.tenant_id == tenant_uuid
            )
            await db.execute(subscription_delete_query)
            deletion_stats["subscriptions_deleted"] = subscription_count
            
            logger.info("Deleted tenant subscriptions", 
                       tenant_id=tenant_id, 
                       count=subscription_count)
            
        except Exception as e:
            error_msg = f"Error deleting subscriptions: {str(e)}"
            deletion_stats["errors"].append(error_msg)
            logger.error(error_msg)
        
        # Step 4: Delete the tenant record
        try:
            tenant_delete_query = delete(Tenant).where(Tenant.id == tenant_uuid)
            tenant_result = await db.execute(tenant_delete_query)
            
            if tenant_result.rowcount == 0:
                raise Exception("Tenant record was not deleted")
            
            await db.commit()
            
            logger.info("Tenant deleted successfully", 
                       tenant_id=tenant_id,
                       tenant_name=tenant.name)
            
        except Exception as e:
            await db.rollback()
            error_msg = f"Error deleting tenant record: {str(e)}"
            deletion_stats["errors"].append(error_msg)
            logger.error(error_msg)
            raise HTTPException(
                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
                detail=error_msg
            )
        
        # Step 5: Publish tenant deletion event
        try:
            await publish_tenant_deleted_event(tenant_id, deletion_stats)
        except Exception as e:
            logger.warning("Failed to publish tenant deletion event", error=str(e))
        
        return {
            "success": True,
            "message": f"Tenant {tenant_id} deleted successfully",
            "deletion_details": deletion_stats
        }
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error("Unexpected error deleting tenant", 
                    tenant_id=tenant_id, 
                    error=str(e))
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to delete tenant: {str(e)}"
        )

@router.get("/tenants/memberships/{user_id}")
async def get_user_tenants(
    user_id: str,
    current_user = Depends(get_current_user_dep),
    _admin_check = Depends(require_admin_role),
    db: AsyncSession = Depends(get_db)
):
    """Get all tenant memberships for a user (admin only)"""
    try:
        user_uuid = uuid.UUID(user_id)
    except ValueError:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid user ID format"
        )
    
    try:
        from app.models.tenants import TenantMember, Tenant
        
        # Get all memberships for the user
        membership_query = select(TenantMember, Tenant).join(
            Tenant, TenantMember.tenant_id == Tenant.id
        ).where(TenantMember.user_id == user_uuid)
        
        result = await db.execute(membership_query)
        memberships_data = result.all()
        
        memberships = []
        for membership, tenant in memberships_data:
            memberships.append({
                "user_id": str(membership.user_id),
                "tenant_id": str(membership.tenant_id),
                "tenant_name": tenant.name,
                "role": membership.role,
                "joined_at": membership.created_at.isoformat() if membership.created_at else None
            })
        
        return {
            "user_id": user_id,
            "total_tenants": len(memberships),
            "memberships": memberships
        }
        
    except Exception as e:
        logger.error("Failed to get user tenants", user_id=user_id, error=str(e))
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to get user tenants"
        )

@router.get("/tenants/{tenant_id}/check-other-admins/{user_id}")
async def check_tenant_has_other_admins(
    tenant_id: str,
    user_id: str,
    current_user = Depends(get_current_user_dep),
    _admin_check = Depends(require_admin_role),
    db: AsyncSession = Depends(get_db)
):
    """Check if tenant has other admin users besides the specified user"""
    try:
        tenant_uuid = uuid.UUID(tenant_id)
        user_uuid = uuid.UUID(user_id)
    except ValueError:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid UUID format"
        )
    
    try:
        from app.models.tenants import TenantMember
        
        # Count admin/owner members excluding the specified user
        admin_count_query = select(func.count(TenantMember.id)).where(
            TenantMember.tenant_id == tenant_uuid,
            TenantMember.role.in_(['admin', 'owner']),
            TenantMember.user_id != user_uuid
        )
        
        result = await db.execute(admin_count_query)
        admin_count = result.scalar()
        
        return {
            "tenant_id": tenant_id,
            "excluded_user_id": user_id,
            "has_other_admins": admin_count > 0,
            "other_admin_count": admin_count
        }
        
    except Exception as e:
        logger.error("Failed to check tenant admins", 
                    tenant_id=tenant_id, 
                    user_id=user_id, 
                    error=str(e))
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to check tenant admins"
        )

@router.post("/tenants/{tenant_id}/transfer-ownership")
async def transfer_tenant_ownership(
    tenant_id: str,
    transfer_data: dict,  # {"current_owner_id": str, "new_owner_id": str}
    current_user = Depends(get_current_user_dep),
    _admin_check = Depends(require_admin_role),
    db: AsyncSession = Depends(get_db)
):
    """Transfer tenant ownership from one user to another (admin only)"""
    try:
        tenant_uuid = uuid.UUID(tenant_id)
        current_owner_id = uuid.UUID(transfer_data.get("current_owner_id"))
        new_owner_id = uuid.UUID(transfer_data.get("new_owner_id"))
    except (ValueError, TypeError):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid UUID format in request data"
        )
    
    try:
        from app.models.tenants import TenantMember, Tenant
        
        # Verify tenant exists
        tenant_query = select(Tenant).where(Tenant.id == tenant_uuid)
        tenant_result = await db.execute(tenant_query)
        tenant = tenant_result.scalar_one_or_none()
        
        if not tenant:
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail=f"Tenant {tenant_id} not found"
            )
        
        # Get current owner membership
        current_owner_query = select(TenantMember).where(
            TenantMember.tenant_id == tenant_uuid,
            TenantMember.user_id == current_owner_id,
            TenantMember.role == 'owner'
        )
        current_owner_result = await db.execute(current_owner_query)
        current_owner_membership = current_owner_result.scalar_one_or_none()
        
        if not current_owner_membership:
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail="Current owner membership not found"
            )
        
        # Get new owner membership (should be admin)
        new_owner_query = select(TenantMember).where(
            TenantMember.tenant_id == tenant_uuid,
            TenantMember.user_id == new_owner_id
        )
        new_owner_result = await db.execute(new_owner_query)
        new_owner_membership = new_owner_result.scalar_one_or_none()
        
        if not new_owner_membership:
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail="New owner must be a member of the tenant"
            )
        
        if new_owner_membership.role not in ['admin', 'owner']:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="New owner must have admin or owner role"
            )
        
        # Perform the transfer
        current_owner_membership.role = 'admin'  # Demote current owner to admin
        new_owner_membership.role = 'owner'      # Promote new owner
        
        current_owner_membership.updated_at = datetime.utcnow()
        new_owner_membership.updated_at = datetime.utcnow()
        
        await db.commit()
        
        logger.info("Tenant ownership transferred", 
                   tenant_id=tenant_id,
                   from_user=str(current_owner_id),
                   to_user=str(new_owner_id))
        
        return {
            "success": True,
            "message": "Ownership transferred successfully",
            "tenant_id": tenant_id,
            "previous_owner": str(current_owner_id),
            "new_owner": str(new_owner_id),
            "transferred_at": datetime.utcnow().isoformat()
        }
        
    except HTTPException:
        raise
    except Exception as e:
        await db.rollback()
        logger.error("Failed to transfer tenant ownership", 
                    tenant_id=tenant_id, 
                    error=str(e))
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to transfer tenant ownership"
        )

@router.delete("/users/{user_id}/memberships")
async def delete_user_memberships(
    user_id: str,
    current_user = Depends(get_current_user_dep),
    _admin_check = Depends(require_admin_role),
    db: AsyncSession = Depends(get_db)
):
    """Delete all tenant memberships for a user (admin only)"""
    try:
        user_uuid = uuid.UUID(user_id)
    except ValueError:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid user ID format"
        )
    
    try:
        from app.models.tenants import TenantMember
        
        # Count memberships before deletion
        count_query = select(func.count(TenantMember.id)).where(
            TenantMember.user_id == user_uuid
        )
        count_result = await db.execute(count_query)
        membership_count = count_result.scalar()
        
        # Delete all memberships
        delete_query = delete(TenantMember).where(TenantMember.user_id == user_uuid)
        delete_result = await db.execute(delete_query)
        
        await db.commit()
        
        logger.info("Deleted user memberships", 
                   user_id=user_id,
                   memberships_deleted=delete_result.rowcount)
        
        return {
            "success": True,
            "user_id": user_id,
            "memberships_deleted": delete_result.rowcount,
            "expected_count": membership_count,
            "deleted_at": datetime.utcnow().isoformat()
        }
        
    except Exception as e:
        await db.rollback()
        logger.error("Failed to delete user memberships", user_id=user_id, error=str(e))
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to delete user memberships"
        )