#!/usr/bin/env python3
"""
Pre-warm LLM cache for remaining uncached cities.

Processes combos concurrently (2 workers) to maximize throughput while
respecting Nominatim's 1 req/s rate limit via a thread-safe limiter.

Each worker randomly picks between OpenRouter DeepSeek and Ollama Cloud
DeepSeek as the primary provider (via _get_providers_randomized), splitting
the workload and reducing rate-limit pressure on either provider.

Usage:
    cd roamify && python scripts/prewarm_remaining.py
"""

import json
import os
import random
import sys
import threading
import time
from concurrent.futures import ThreadPoolExecutor, as_completed

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "src"))

from dotenv import load_dotenv
load_dotenv(dotenv_path=os.path.join(os.path.dirname(__file__), "..", ".env"), override=True)

from services.recommender import (
    get_recommendations_cached,
    _LLM_CACHE,
    _save_llm_cache,
    _save_image_cache,
    _save_geocode_cache,
)

CATEGORY_NAMES = ["Landmark", "Culture", "Nature", "Gems", "Photo", "Food", "Shopping"]

# 15 cities still uncached (updated as more get prewarmed)
UNCATEGORIZED_CITIES = [
    "Montreal", "Moscow", "Osaka", "Oslo", "Reykjavik",
    "Santiago", "Shanghai", "Stockholm", "Taipei", "Tel Aviv",
    "Toronto", "Vancouver", "Venice", "Warsaw", "Washington",
]

_COMBO_STATS = {"success": 0, "skipped": 0, "fail": 0, "total": 0}
_COMBO_LOCK = threading.Lock()


def process_combo(city: str, cat_name: str, combo_idx: int, total: int) -> None:
    """Process a single city/category combo and update stats."""
    categories = {name: (name == cat_name) for name in CATEGORY_NAMES}
    cat_hash = json.dumps(categories, sort_keys=True)

    if (city, cat_hash) in _LLM_CACHE:
        with _COMBO_LOCK:
            _COMBO_STATS["skipped"] += 1
        print(f"  [{combo_idx:>3}/{total}] ⏭️  {city} / {cat_name} — already cached", flush=True)
        return

    print(f"  [{combo_idx:>3}/{total}] 🔍 {city} / {cat_name}...", end=" ", flush=True)
    start = time.time()
    try:
        result = get_recommendations_cached(
            city=city,
            num_attractions=6,
            categories=categories,
            temperature=0,
        )
        elapsed = time.time() - start
        if result:
            items = len(result)
            with _COMBO_LOCK:
                _COMBO_STATS["success"] += 1
            print(f"✅ {items} items in {elapsed:.1f}s", flush=True)
        else:
            with _COMBO_LOCK:
                _COMBO_STATS["fail"] += 1
            print(f"❌ returned None in {elapsed:.1f}s", flush=True)
    except Exception as e:
        elapsed = time.time() - start
        with _COMBO_LOCK:
            _COMBO_STATS["fail"] += 1
        print(f"❌ error after {elapsed:.1f}s: {e}", flush=True)


def prewarm():
    """Run all combos concurrently with 2 workers."""
    total_combos = len(UNCATEGORIZED_CITIES) * len(CATEGORY_NAMES)
    _COMBO_STATS["total"] = total_combos

    llm_before = len(_LLM_CACHE)

    print(f"Pre-warming caches: {len(UNCATEGORIZED_CITIES)} cities × {len(CATEGORY_NAMES)} categories = {total_combos} combos")
    print(f"  Workers: 2 (concurrent) — each uses random DeepSeek provider")
    print(f"  Existing LLM cache entries: {llm_before}")
    print()

    # Build all combos, shuffle for load distribution across workers
    all_combos = []
    idx = 0
    for city in UNCATEGORIZED_CITIES:
        for cat_name in CATEGORY_NAMES:
            idx += 1
            all_combos.append((city, cat_name, idx))

    random.shuffle(all_combos)
    # Re-assign sequential indices after shuffle (for display only)
    for i, (city, cat_name, _) in enumerate(all_combos):
        all_combos[i] = (city, cat_name, i + 1)

    with ThreadPoolExecutor(max_workers=2) as pool:
        futures = [
            pool.submit(process_combo, city, cat_name, idx, total_combos)
            for city, cat_name, idx in all_combos
        ]
        # Process results as they complete
        for future in as_completed(futures):
            try:
                future.result()
            except Exception:
                pass  # Errors are already logged in process_combo

    # Summary
    llm_new = len(_LLM_CACHE) - llm_before

    print()
    print("═" * 55)
    print("Pre-warm complete!")
    print(f"  Combos: {_COMBO_STATS['success']} succeeded, {_COMBO_STATS['skipped']} skipped, {_COMBO_STATS['fail']} failed")
    print(f"  New LLM cache entries: {llm_new} (total: {len(_LLM_CACHE)})")

    _save_llm_cache()
    _save_image_cache()
    _save_geocode_cache()
    print()
    print("All caches saved to disk ✅")


if __name__ == "__main__":
    prewarm()