"""Quick end-to-end test of the Task A agent on real data.

Picks a user from the training set, picks one of their held-out test
reviews (which is real ground truth we know), generates a predicted
rating + review for that item, and prints both side by side.

Usage:
    python -m scripts.test_task_a
    python -m scripts.test_task_a --user <user_id>
    python -m scripts.test_task_a --naija
    python -m scripts.test_task_a --user <user_id> --naija
"""
from __future__ import annotations

import argparse
import logging

import pandas as pd

from core.config import settings
from core.persona import PersonaEngine
from task_a_user_modeling.agent import ImpersonationAgent, ItemInput

logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s")


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--user", type=str, default=None,
                    help="Specific user_id; else picks a cross-domain user with the most reviews")
    ap.add_argument("--naija", action="store_true",
                    help="Apply Nigerian English style transfer to the generated review")
    args = ap.parse_args()

    reviews_path = settings.processed_dir / "reviews.parquet"
    items_path = settings.processed_dir / "items.parquet"
    if not reviews_path.exists() or not items_path.exists():
        raise SystemExit("Run `python data/prepare_data.py` first.")

    reviews = pd.read_parquet(reviews_path)
    items = pd.read_parquet(items_path)
    train = reviews[reviews["split"] == "train"]
    test = reviews[reviews["split"] == "test"]

    # Pick a user
    if args.user:
        user_id = args.user
    else:
        cross_users = (train.groupby("user_id")
                            .agg(n=("rating", "size"), d=("domain", "nunique"))
                            .reset_index())
        cross_users = cross_users[cross_users["d"] >= 2]
        # Prefer users who also have test reviews
        users_with_test = set(test["user_id"])
        cross_users = cross_users[cross_users["user_id"].isin(users_with_test)]
        if cross_users.empty:
            raise SystemExit("No cross-domain user has test reviews. Try --user <id>")
        user_id = cross_users.nlargest(1, "n").iloc[0]["user_id"]
        print(f"Auto-selected cross-domain user: {user_id}\n")

    # Pick a test review for this user
    user_test = test[test["user_id"] == user_id]
    if user_test.empty:
        raise SystemExit(f"User {user_id} has no test reviews — try a different user.")
    test_review = user_test.iloc[0]
    target_item_id = test_review["parent_asin"]

    # Look up item metadata
    item_meta = items[items["parent_asin"] == target_item_id]
    if item_meta.empty:
        print(f"WARN: no item metadata for {target_item_id}; using review title only")
        item = ItemInput(
            parent_asin=target_item_id,
            title=str(test_review.get("title", "")),
            description="",
            categories="",
            domain=test_review["domain"],
        )
    else:
        meta = item_meta.iloc[0]
        item = ItemInput(
            parent_asin=target_item_id,
            title=str(meta.get("title", "")),
            description=str(meta.get("description", ""))[:1500],
            categories=str(meta.get("categories", "")),
            domain=test_review["domain"],
            average_rating=float(meta["average_rating"]) if pd.notna(meta.get("average_rating")) else None,
        )

    # Build persona (with LLM enrichment)
    print(f"Building persona for {user_id}...")
    engine = PersonaEngine()
    persona = engine.from_dataframe(user_id, train)
    persona = engine.enrich(persona)

    # Run the agent
    print(f"\nGenerating review for item: {item.title[:80]}...\n")
    agent = ImpersonationAgent()
    result = agent.run(persona, item, naija_mode=args.naija)

    # Print side-by-side comparison with ground truth
    print("=" * 70)
    print("PERSONA SUMMARY")
    print("=" * 70)
    print(f"User: {user_id}")
    print(f"Avg rating: {persona.avg_rating:.2f}  |  Tone: {persona.tone}")
    print(f"Voice: {persona.voice_one_liner}")

    print("\n" + "=" * 70)
    print("TARGET ITEM")
    print("=" * 70)
    print(f"Domain: {item.domain}")
    print(f"Title: {item.title}")
    if item.description:
        print(f"Description: {item.description[:300]}...")

    print("\n" + "=" * 70)
    print(f"AI-GENERATED PREDICTION  {'(Naija mode)' if args.naija else ''}")
    print("=" * 70)
    print(f"Rating:    {result.rating}★")
    print(f"Reasoning: {result.reasoning}")
    print(f"\nReview:\n{result.review}")

    print("\n" + "=" * 70)
    print("GROUND TRUTH (what the user actually wrote)")
    print("=" * 70)
    print(f"Rating:    {test_review['rating']}★")
    print(f"\nReview:\n{test_review['text']}")

    print("\n" + "=" * 70)
    print("DELTA")
    print("=" * 70)
    rating_delta = abs(result.rating - float(test_review["rating"]))
    print(f"Rating absolute error: {rating_delta:.1f} stars")
    print(f"Generated review length: {len(result.review.split())} words")
    print(f"Ground truth length:    {len(str(test_review['text']).split())} words")


if __name__ == "__main__":
    main()