sentiment.py

"""
Multi-layered NLP sentiment scoring engine.

Produces 12 sentiment dimensions per text, aggregated into composite scores per model.
Designed for time-series analysis of LLM perception across social/developer platforms.

Architecture:
  Layer 1 — Lexicon-based (VADER + TextBlob): fast, interpretable, baseline
  Layer 2 — Transformer-based (FinBERT / distilbert-sst2): nuanced financial + general sentiment
  Layer 3 — Domain-specific aspect extraction: LLM performance dimensions
  Layer 4 — Engagement-weighted scoring: likes/upvotes amplify signal strength
  Layer 5 — Time-series indicators: momentum, volatility, z-scores
"""

import re
import math
import logging
from dataclasses import dataclass, field, asdict
from datetime import datetime, timezone

from vaderSentiment.vaderSentiment import SentimentIntensityAnalyzer
from textblob import TextBlob

logger = logging.getLogger(__name__)

# ── Layer 1: Lexicon Scorers ──────────────────────────────────────────────────

_vader = SentimentIntensityAnalyzer()

def vader_scores(text: str) -> dict:
    """VADER: optimised for social media (handles emojis, slang, caps, punctuation)."""
    vs = _vader.polarity_scores(text)
    return {
        "vader_compound": vs["compound"],    # -1 to +1 overall
        "vader_pos":      vs["pos"],         # 0-1 proportion positive
        "vader_neg":      vs["neg"],         # 0-1 proportion negative
        "vader_neu":      vs["neu"],         # 0-1 proportion neutral
    }

def textblob_scores(text: str) -> dict:
    """TextBlob: pattern-based, captures polarity + subjectivity."""
    blob = TextBlob(text)
    return {
        "tb_polarity":     blob.sentiment.polarity,      # -1 to +1
        "tb_subjectivity": blob.sentiment.subjectivity,   # 0 (objective) to 1 (subjective)
    }

# ── Layer 2: Transformer Scorers ─────────────────────────────────────────────

_finbert = None
_distilbert = None

def _get_finbert():
    global _finbert
    if _finbert is None:
        from transformers import pipeline
        _finbert = pipeline("sentiment-analysis", model="ProsusAI/finbert",
                            truncation=True, max_length=512)
        logger.info("[sentiment] FinBERT loaded")
    return _finbert

def _get_distilbert():
    global _distilbert
    if _distilbert is None:
        from transformers import pipeline
        _distilbert = pipeline("sentiment-analysis",
                               model="distilbert/distilbert-base-uncased-finetuned-sst-2-english",
                               truncation=True, max_length=512)
        logger.info("[sentiment] DistilBERT-SST2 loaded")
    return _distilbert

def finbert_scores(text: str) -> dict:
    """FinBERT: financial sentiment (positive / negative / neutral)."""
    try:
        result = _get_finbert()(text[:512])[0]
        label = result["label"].lower()  # positive, negative, neutral
        score = result["score"]
        # Convert to -1 to +1 scale
        if label == "positive":
            finbert_val = score
        elif label == "negative":
            finbert_val = -score
        else:
            finbert_val = 0.0
        return {"finbert_sentiment": finbert_val, "finbert_confidence": score}
    except Exception as e:
        logger.debug("finbert error: %s", e)
        return {"finbert_sentiment": 0.0, "finbert_confidence": 0.0}

def distilbert_scores(text: str) -> dict:
    """DistilBERT SST-2: general positive/negative sentiment."""
    try:
        result = _get_distilbert()(text[:512])[0]
        label = result["label"]  # POSITIVE or NEGATIVE
        score = result["score"]
        val = score if label == "POSITIVE" else -score
        return {"distilbert_sentiment": val, "distilbert_confidence": score}
    except Exception as e:
        logger.debug("distilbert error: %s", e)
        return {"distilbert_sentiment": 0.0, "distilbert_confidence": 0.0}


# ── Layer 3: Domain-Specific Aspect Extraction ────────────────────────────────
#
# Instead of general "positive/negative", detect LLM-specific dimensions:
#   - Performance perception (speed, quality, accuracy)
#   - Reliability perception (downtime, errors, hallucinations)
#   - Cost perception (expensive, cheap, value)
#   - Innovation perception (breakthrough, impressive, game-changer)
#   - Adoption signal (using, switched to, migrated, building with)
#   - Complaint signal (broken, worse, degraded, disappointed)

ASPECT_LEXICONS = {
    "performance": {
        "positive": ["fast", "quick", "impressive", "excellent", "powerful", "capable",
                     "accurate", "smart", "intelligent", "brilliant", "amazing",
                     "best", "superior", "outperforms", "crushes", "dominates",
                     "state-of-the-art", "sota", "benchmark", "top", "leading"],
        "negative": ["slow", "dumb", "stupid", "terrible", "awful", "poor",
                     "inaccurate", "wrong", "garbage", "useless", "mediocre",
                     "worse", "inferior", "disappointing", "underwhelming"],
    },
    "reliability": {
        "positive": ["reliable", "stable", "consistent", "dependable", "solid",
                     "robust", "uptime", "available", "works well"],
        "negative": ["hallucinate", "hallucination", "unreliable", "inconsistent",
                     "broken", "crash", "error", "bug", "fail", "down", "outage",
                     "degraded", "throttled", "timeout", "429", "500", "rate limit"],
    },
    "cost": {
        "positive": ["cheap", "affordable", "value", "cost-effective", "free",
                     "fair price", "reasonable", "bargain", "open source", "open-source"],
        "negative": ["expensive", "overpriced", "costly", "ripoff", "pricey",
                     "not worth", "waste of money", "too much", "$$$"],
    },
    "innovation": {
        "positive": ["breakthrough", "revolutionary", "game-changer", "innovative",
                     "novel", "impressive", "exciting", "next-gen", "frontier",
                     "leap", "paradigm", "unprecedented"],
        "negative": ["incremental", "nothing new", "overhyped", "hype", "marketing",
                     "same old", "rehash", "disappointed"],
    },
    "adoption": {
        "positive": ["using", "switched to", "migrated", "building with", "deployed",
                     "adopted", "integrated", "love using", "recommend", "try it",
                     "my go-to", "daily driver", "production"],
        "negative": ["stopped using", "switched away", "abandoned", "dropped",
                     "going back to", "unsubscribed", "cancelled"],
    },
}

def aspect_scores(text: str) -> dict:
    """Score text along domain-specific LLM perception dimensions."""
    text_lower = text.lower()
    scores = {}

    for aspect, lexicon in ASPECT_LEXICONS.items():
        pos_count = sum(1 for w in lexicon["positive"] if w in text_lower)
        neg_count = sum(1 for w in lexicon["negative"] if w in text_lower)
        total     = pos_count + neg_count

        if total == 0:
            scores[f"aspect_{aspect}"] = 0.0
            scores[f"aspect_{aspect}_intensity"] = 0.0
        else:
            # Score: -1 (all negative mentions) to +1 (all positive)
            scores[f"aspect_{aspect}"] = (pos_count - neg_count) / total
            # Intensity: how much does this text discuss this aspect? (0 = not at all)
            scores[f"aspect_{aspect}_intensity"] = min(total / 5.0, 1.0)

    return scores


# ── Layer 4: Engagement-Weighted Scoring ──────────────────────────────────────

def engagement_weight(likes: int = 0, reposts: int = 0, replies: int = 0,
                      score: int = 0, views: int = 0) -> float:
    """
    Compute an engagement multiplier that amplifies high-signal posts.
    Uses log-scale to prevent viral posts from dominating.
    Returns a weight in [0.1, 5.0] range.
    """
    raw = (likes or 0) + (reposts or 0) * 2 + (replies or 0) * 0.5 + (score or 0) + (views or 0) * 0.01
    if raw <= 0:
        return 0.1
    # log-scale: 1 engagement → 0.1, 10 → ~1.1, 100 → ~2.1, 1000 → ~3.1
    return min(0.1 + math.log10(max(raw, 1)), 5.0)


# ── Composite Scorer ──────────────────────────────────────────────────────────

@dataclass
class SentimentResult:
    """All sentiment dimensions for a single text."""
    # Layer 1: Lexicon
    vader_compound: float = 0.0
    vader_pos: float = 0.0
    vader_neg: float = 0.0
    vader_neu: float = 0.0
    tb_polarity: float = 0.0
    tb_subjectivity: float = 0.0

    # Layer 2: Transformer
    finbert_sentiment: float = 0.0
    finbert_confidence: float = 0.0
    distilbert_sentiment: float = 0.0
    distilbert_confidence: float = 0.0

    # Layer 3: Aspects
    aspect_performance: float = 0.0
    aspect_performance_intensity: float = 0.0
    aspect_reliability: float = 0.0
    aspect_reliability_intensity: float = 0.0
    aspect_cost: float = 0.0
    aspect_cost_intensity: float = 0.0
    aspect_innovation: float = 0.0
    aspect_innovation_intensity: float = 0.0
    aspect_adoption: float = 0.0
    aspect_adoption_intensity: float = 0.0

    # Layer 4: Engagement
    engagement_weight: float = 0.1

    # Composites
    composite_sentiment: float = 0.0     # weighted average of all sentiment layers
    composite_quality: float = 0.0       # performance + reliability aspects
    composite_buzz: float = 0.0          # innovation + adoption + engagement

    def to_dict(self) -> dict:
        return asdict(self)


def score_text(text: str, likes: int = 0, reposts: int = 0, replies: int = 0,
               score: int = 0, views: int = 0,
               use_transformers: bool = True) -> SentimentResult:
    """
    Score a single text across all sentiment dimensions.

    Args:
        text: the post/title text
        likes/reposts/replies/score/views: engagement metrics from the platform
        use_transformers: if False, skip FinBERT + DistilBERT (faster, CPU-only)

    Returns:
        SentimentResult with all 20+ dimensions populated
    """
    if not text or not text.strip():
        return SentimentResult()

    # Clean text
    text = re.sub(r'https?://\S+', '', text)  # remove URLs
    text = re.sub(r'@\w+', '', text)          # remove @mentions
    text = text.strip()
    if len(text) < 5:
        return SentimentResult()

    # Layer 1
    v = vader_scores(text)
    t = textblob_scores(text)

    # Layer 2
    f = {"finbert_sentiment": 0.0, "finbert_confidence": 0.0}
    d = {"distilbert_sentiment": 0.0, "distilbert_confidence": 0.0}
    if use_transformers:
        f = finbert_scores(text)
        d = distilbert_scores(text)

    # Layer 3
    a = aspect_scores(text)

    # Layer 4
    ew = engagement_weight(likes, reposts, replies, score, views)

    # ── Composites ────────────────────────────────────────────────────────

    # Composite sentiment: weighted blend of all sentiment signals
    # VADER is best for social media, FinBERT for financial framing, DistilBERT for general
    composite_sentiment = (
        v["vader_compound"] * 0.30 +
        t["tb_polarity"] * 0.10 +
        f["finbert_sentiment"] * 0.35 +
        d["distilbert_sentiment"] * 0.25
    )

    # Composite quality perception: performance + reliability aspects
    perf = a.get("aspect_performance", 0) * a.get("aspect_performance_intensity", 0)
    reli = a.get("aspect_reliability", 0) * a.get("aspect_reliability_intensity", 0)
    composite_quality = (perf + reli) / 2

    # Composite buzz: innovation + adoption + engagement amplification
    inno = a.get("aspect_innovation", 0) * a.get("aspect_innovation_intensity", 0)
    adop = a.get("aspect_adoption", 0) * a.get("aspect_adoption_intensity", 0)
    composite_buzz = (inno + adop) / 2 * ew

    return SentimentResult(
        **v, **t, **f, **d, **a,
        engagement_weight=ew,
        composite_sentiment=composite_sentiment,
        composite_quality=composite_quality,
        composite_buzz=composite_buzz,
    )