Self-Coded Integrations

# Generated skill: execute.py
# Skill: fetch_vendor_invoices_sap v1
# Generated by: agent/supply-chain-monitor
# Source: OpenAPI spec at https://api.sap.com/api/API_BUSINESS_PARTNER/resource
# Timestamp: 2026-03-08T14:22:00Z

import requests
from datetime import datetime
from zenera.auth import get_token
from zenera.logging import skill_logger

logger = skill_logger(__name__)

def execute(params: dict, context: dict) -> dict:
    """
    Retrieves vendor invoices from SAP S/4HANA.
    Handles pagination automatically. Normalizes currency.
    
    Args:
        params: {date_from, date_to, vendor_ids?, currency?}
        context: {run_id, agent_id, workflow_id}
    
    Returns:
        {invoices: [...], total_count: int, pagination_complete: bool}
    """
    token = get_token("sap-s4hana-prod")
    base_url = "https://myinstance.s4hana.cloud.sap"
    target_currency = params.get("currency", "USD")
    
    all_invoices = []
    skip = 0
    page_size = 100
    
    while True:
        query_params = {
            "$filter": (
                f"PostingDate ge datetime'{params['date_from']}T00:00:00' "
                f"and PostingDate le datetime'{params['date_to']}T23:59:59'"
            ),
            "$top": page_size,
            "$skip": skip,
            "$select": "InvoiceID,VendorID,VendorName,Amount,Currency,PostingDate,LineItems",
            "$expand": "LineItems"
        }
        
        if params.get("vendor_ids"):
            vendor_filter = " or ".join(
                f"VendorID eq '{vid}'" for vid in params["vendor_ids"]
            )
            query_params["$filter"] += f" and ({vendor_filter})"
        
        logger.info(f"Fetching page at skip={skip}", extra={"run_id": context["run_id"]})
        
        response = requests.get(
            f"{base_url}/sap/opu/odata/sap/API_BUSINESS_PARTNER/A_VendorInvoice",
            params=query_params,
            headers={
                "Authorization": f"Bearer {token}",
                "Accept": "application/json",
                "sap-language": "en"
            },
            timeout=30
        )
        response.raise_for_status()
        
        data = response.json()
        results = data.get("d", {}).get("results", [])
        
        for inv in results:
            normalized = {
                "invoice_id": inv["InvoiceID"],
                "vendor_id": inv["VendorID"],
                "vendor_name": inv["VendorName"],
                "amount": float(inv["Amount"]),
                "currency": target_currency,
                "date": inv["PostingDate"],
                "line_items": [
                    {
                        "description": li.get("Description", ""),
                        "amount": float(li.get("Amount", 0)),
                        "quantity": int(li.get("Quantity", 1))
                    }
                    for li in inv.get("LineItems", {}).get("results", [])
                ]
            }
            if inv["Currency"] != target_currency:
                normalized["amount"] = _convert_currency(
                    normalized["amount"], inv["Currency"], target_currency
                )
            all_invoices.append(normalized)
        
        if len(results) < page_size:
            break
        skip += page_size
        
        if skip > 1_000_000:
            logger.warning("Pagination safety limit reached", extra={"skip": skip})
            break
    
    return {
        "invoices": all_invoices,
        "total_count": len(all_invoices),
        "pagination_complete": True
    }


def _convert_currency(amount: float, from_currency: str, to_currency: str) -> float:
    """Simple currency conversion using SAP exchange rates."""
    token = get_token("sap-s4hana-prod")
    resp = requests.get(
        f"https://myinstance.s4hana.cloud.sap/sap/opu/odata/sap/API_EXCHANGERATE_SRV",
        params={
            "$filter": (
                f"FromCurrency eq '{from_currency}' "
                f"and ToCurrency eq '{to_currency}'"
            ),
            "$top": 1,
            "$orderby": "ValidFrom desc"
        },
        headers={"Authorization": f"Bearer {token}", "Accept": "application/json"},
        timeout=10
    )
    resp.raise_for_status()
    rate = float(resp.json()["d"]["results"][0]["ExchangeRate"])
    return round(amount * rate, 2)