app.py

from fastapi import FastAPI, HTTPException
from pydantic import BaseModel, Field, validator
from typing import Optional
import pandas as pd
import joblib

app = FastAPI()

# === Paths ===
TFIDF_PATH = "models/tfidf_vectorizer.pkl"
MODEL_PATH = "models/xgb_models.pkl"
ENCODER_PATH = "models/label_encoders.pkl"

# === Load artifacts ===
tfidf_vectorizer = joblib.load(TFIDF_PATH)
models = joblib.load(MODEL_PATH)
label_encoders = joblib.load(ENCODER_PATH)

# === Input Schema ===
class TransactionData(BaseModel):
    Transaction_Id: str
    Hit_Seq: int
    Hit_Id_List: str
    Origin: str
    Designation: str
    Keywords: str
    Name: str
    SWIFT_Tag: str
    Currency: str
    Entity: str
    Message: str
    City: str
    Country: str
    State: str
    Hit_Type: str
    Record_Matching_String: str
    WatchList_Match_String: str
    Payment_Sender_Name: Optional[str] = ""
    Payment_Reciever_Name: Optional[str] = ""
    Swift_Message_Type: str
    Text_Sanction_Data: str
    Matched_Sanctioned_Entity: str
    Is_Match: int
    Red_Flag_Reason: str
    Risk_Level: str
    Risk_Score: float
    Risk_Score_Description: str
    CDD_Level: str
    PEP_Status: str
    Value_Date: str
    Last_Review_Date: str
    Next_Review_Date: str
    Sanction_Description: str
    Checker_Notes: str
    Sanction_Context: str = Field(..., min_length=5)
    Maker_Action: str
    Customer_ID: int
    Customer_Type: str
    Industry: str
    Transaction_Date_Time: str
    Transaction_Type: str
    Transaction_Channel: str
    Originating_Bank: str
    Beneficiary_Bank: str
    Geographic_Origin: str
    Geographic_Destination: str
    Match_Score: float
    Match_Type: str
    Sanctions_List_Version: str
    Screening_Date_Time: str
    Risk_Category: str
    Risk_Drivers: str
    Alert_Status: str
    Investigation_Outcome: str
    Case_Owner_Analyst: str
    Escalation_Level: str
    Escalation_Date: str
    Regulatory_Reporting_Flags: bool
    Audit_Trail_Timestamp: str
    Source_Of_Funds: str
    Purpose_Of_Transaction: str
    Beneficial_Owner: str
    Sanctions_Exposure_History: bool

    @validator("Sanction_Context")
    def context_not_blank(cls, v):
        if not v.strip():
            raise ValueError("Sanction_Context must not be blank.")
        return v

class PredictionRequest(BaseModel):
    transaction_data: TransactionData

@app.get("/")
def root():
    return {"status": "healthy", "message": "XGBoost TF-IDF API is running"}

@app.post("/validate")
def validate_input(request: PredictionRequest):
    try:
        _ = request.transaction_data
        return {"status": "success", "message": "Input schema is valid."}
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))

@app.post("/predict")
def predict(request: PredictionRequest):
    try:
        input_data = pd.DataFrame([request.transaction_data.dict()])

        text_input = f"""
        Transaction ID: {input_data['Transaction_Id'].iloc[0]}
        Origin: {input_data['Origin'].iloc[0]}
        Designation: {input_data['Designation'].iloc[0]}
        Keywords: {input_data['Keywords'].iloc[0]}
        Name: {input_data['Name'].iloc[0]}
        SWIFT Tag: {input_data['SWIFT_Tag'].iloc[0]}
        Currency: {input_data['Currency'].iloc[0]}
        Entity: {input_data['Entity'].iloc[0]}
        Message: {input_data['Message'].iloc[0]}
        City: {input_data['City'].iloc[0]}
        Country: {input_data['Country'].iloc[0]}
        State: {input_data['State'].iloc[0]}
        Hit Type: {input_data['Hit_Type'].iloc[0]}
        Record Matching String: {input_data['Record_Matching_String'].iloc[0]}
        WatchList Match String: {input_data['WatchList_Match_String'].iloc[0]}
        Payment Sender: {input_data['Payment_Sender_Name'].iloc[0]}
        Payment Receiver: {input_data['Payment_Reciever_Name'].iloc[0]}
        Swift Message Type: {input_data['Swift_Message_Type'].iloc[0]}
        Text Sanction Data: {input_data['Text_Sanction_Data'].iloc[0]}
        Matched Sanctioned Entity: {input_data['Matched_Sanctioned_Entity'].iloc[0]}
        Red Flag Reason: {input_data['Red_Flag_Reason'].iloc[0]}
        Risk Level: {input_data['Risk_Level'].iloc[0]}
        Risk Score: {input_data['Risk_Score'].iloc[0]}
        CDD Level: {input_data['CDD_Level'].iloc[0]}
        PEP Status: {input_data['PEP_Status'].iloc[0]}
        Sanction Description: {input_data['Sanction_Description'].iloc[0]}
        Checker Notes: {input_data['Checker_Notes'].iloc[0]}
        Sanction Context: {input_data['Sanction_Context'].iloc[0]}
        Maker Action: {input_data['Maker_Action'].iloc[0]}
        Customer Type: {input_data['Customer_Type'].iloc[0]}
        Industry: {input_data['Industry'].iloc[0]}
        Transaction Type: {input_data['Transaction_Type'].iloc[0]}
        Transaction Channel: {input_data['Transaction_Channel'].iloc[0]}
        Geographic Origin: {input_data['Geographic_Origin'].iloc[0]}
        Geographic Destination: {input_data['Geographic_Destination'].iloc[0]}
        Risk Category: {input_data['Risk_Category'].iloc[0]}
        Risk Drivers: {input_data['Risk_Drivers'].iloc[0]}
        Alert Status: {input_data['Alert_Status'].iloc[0]}
        Investigation Outcome: {input_data['Investigation_Outcome'].iloc[0]}
        Source of Funds: {input_data['Source_Of_Funds'].iloc[0]}
        Purpose of Transaction: {input_data['Purpose_Of_Transaction'].iloc[0]}
        Beneficial Owner: {input_data['Beneficial_Owner'].iloc[0]}
        """

        X_tfidf = tfidf_vectorizer.transform([text_input])
        response = {}

        for label, model in models.items():
            proba = model.predict_proba(X_tfidf)[0]
            pred_idx = proba.argmax()
            decoded = label_encoders[label].inverse_transform([pred_idx])[0]

            response[label] = {
                "prediction": decoded,
                "probabilities": {
                    label_encoders[label].classes_[i]: float(p)
                    for i, p in enumerate(proba)
                }
            }

        return response

    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))