body_analyzer.py

import requests
import os
import re

HF_API_KEY = os.getenv("HF_API_KEY")
HF_HEADERS = {"Authorization": f"Bearer {HF_API_KEY}"} if HF_API_KEY else {}

MODELS = {
    "ai_detector": "roberta-base-openai-detector",
    "sentiment": "finiteautomata/bertweet-base-sentiment-analysis",
    "spam": "mrm8488/bert-tiny-finetuned-sms-spam-detection",
}

SUSPICIOUS_PATTERNS = [
    r"verify your account",
    r"urgent action",
    r"click here",
    r"reset (your )?password",
    r"confirm (your )?identity",
    r"bank account",
    r"invoice",
    r"payment (required|overdue|failed|method expired)",
    r"unauthorized login",
    r"compromised",
    r"final reminder",
    r"account (suspended|deactivated|locked)",
    r"update your (information|details|billing)",
    r"legal action",
    r"free trial",
    r"limited time offer",
    r"click below",
    r"winner",
    r"congratulations",
    r"urgent response",
    r"claim your prize",
    r"act now",
    r"unsubscribe",
    r"lottery",
    r"risk-free",
]

def query_hf(model, text):
    if not HF_API_KEY:
        return None
    try:
        res = requests.post(
            f"https://api-inference.huggingface.co/models/{model}",
            headers=HF_HEADERS,
            json={"inputs": text[:1000]},
            timeout=15,
        )
        return res.json()
    except Exception:
        return None

def parse_hf_result(result):
    # Common shapes: [{"label": "...", "score": ...}] or {"labels":[...], "scores":[...]}
    if not result:
        return None, None
    if isinstance(result, list) and result and isinstance(result[0], dict):
        if "label" in result[0] and "score" in result[0]:
            return result[0]["label"], result[0]["score"]
    if isinstance(result, dict):
        labels = result.get("labels") or []
        scores = result.get("scores") or []
        if labels and scores:
            return labels[0], scores[0]
    return None, None

def analyze_body(text):
    findings = []
    score = 0
    body_lower = (text or "").lower()
    highlighted_body = text or ""

    # 1) Suspicious phrases
    for pattern in SUSPICIOUS_PATTERNS:
        matches = re.findall(pattern, body_lower)
        for match in matches:
            display = match if isinstance(match, str) else (match[0] if match else "")
            if not display:
                continue
            findings.append(f'Suspicious phrase detected: "{display}"')
            score += 15  # tuned down to reduce instant Malicious
            highlighted_body = re.sub(
                re.escape(display),
                f"<mark>{display}</mark>",
                highlighted_body,
                flags=re.IGNORECASE,
            )

    # 2) URLs
    urls = re.findall(r'https?://[^\s]+', body_lower)
    for url in urls:
        findings.append(f"Suspicious URL detected: {url}")
        score += 10
        highlighted_body = re.sub(re.escape(url), f"<mark>{url}</mark>", highlighted_body, flags=re.IGNORECASE)

    # 3) AI text detector
    label, confidence = parse_hf_result(query_hf(MODELS["ai_detector"], text or ""))
    if label:
        findings.append(f"Body: AI Detector → {label} (confidence {confidence:.2f})")

    # 4) Sentiment
    label, confidence = parse_hf_result(query_hf(MODELS["sentiment"], text or ""))
    if label:
        findings.append(f"Body: Sentiment → {label} (confidence {confidence:.2f})")
        if label.lower() == "negative":
            score += 10

    # 5) Spam detector
    label, confidence = parse_hf_result(query_hf(MODELS["spam"], text or ""))
    if label:
        findings.append(f"Body: Spam Detector → {label} (confidence {confidence:.2f})")
        if label.lower() == "spam":
            score += 25

    # 6) Verdict
    if score >= 50:
        verdict = "Malicious / Spam"
    elif score >= 20:
        verdict = "Suspicious"
    else:
        verdict = "Safe"
        findings.append("No suspicious content detected in body.")

    return findings, score, highlighted_body, verdict