import logging
from fastapi import FastAPI, HTTPException
from fastapi.responses import HTMLResponse
from fastapi.middleware.cors import CORSMiddleware
from datasets import load_dataset, load_from_disk
import numpy as np
import os

app = FastAPI()

# ---------------------------------------------------------
# Logging
# ---------------------------------------------------------
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(message)s"
)
logger = logging.getLogger(__name__)

# ---------------------------------------------------------
# CORS
# ---------------------------------------------------------
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

# ---------------------------------------------------------
# Dataset caching configuration
# ---------------------------------------------------------
DATASET_NAME = "kurry/sp500_earnings_transcripts"
CACHE_PATH = "/data/hf_dataset"   # persistent bucket mount
dataset_cache = None


def load_hf_dataset():
    """
    Loads the HF dataset with persistent caching.
    - If /data/hf_dataset exists → load from disk (fast, offline)
    - Else → download once, save to disk, then load
    """
    global dataset_cache

    # Already loaded in memory
    if dataset_cache is not None:
        return dataset_cache

    # Load from persistent cache
    if os.path.exists(CACHE_PATH):
        logger.info(f"Loading dataset from cache at {CACHE_PATH}")
        dataset_cache = load_from_disk(CACHE_PATH)
        logger.info(f"Loaded {len(dataset_cache)} rows from cached dataset")
        return dataset_cache

    # Download once, then save
    logger.info(f"Downloading HF dataset: {DATASET_NAME}")
    ds = load_dataset(DATASET_NAME, split="train")

    logger.info(f"Saving dataset to cache at {CACHE_PATH}")
    ds.save_to_disk(CACHE_PATH)

    dataset_cache = ds
    logger.info(f"Dataset cached and loaded ({len(ds)} rows)")
    return ds


# ---------------------------------------------------------
# JSON-safe conversion
# ---------------------------------------------------------
def to_json_safe(obj):
    if isinstance(obj, (np.integer,)):
        return int(obj)
    if isinstance(obj, (np.floating,)):
        return float(obj)
    if isinstance(obj, (np.ndarray, list)):
        return [to_json_safe(x) for x in obj]
    if isinstance(obj, dict):
        return {k: to_json_safe(v) for k, v in obj.items()}
    return obj


# ---------------------------------------------------------
# Serve index.html
# ---------------------------------------------------------
@app.get("/", response_class=HTMLResponse)
def serve_index():
    if not os.path.exists("index.html"):
        return "<h1>index.html not found</h1>"
    with open("index.html", "r") as f:
        return f.read()


# ---------------------------------------------------------
# List all tickers
# ---------------------------------------------------------
@app.get("/tickers")
def get_tickers():
    ds = load_hf_dataset()
    tickers = sorted(set([t.upper() for t in ds["ticker"]]))
    return {"tickers": tickers}


# ---------------------------------------------------------
# Get transcript for a symbol
# ---------------------------------------------------------
@app.get("/transcript/{symbol}")
def get_transcript(symbol: str):
    ds = load_hf_dataset()
    symbol = symbol.upper()

    logger.info(f"Fetching transcript for: {symbol}")

    rows = [r for r in ds if r["ticker"].upper() == symbol]

    if not rows:
        raise HTTPException(status_code=404, detail=f"No transcript found for {symbol}")

    safe_rows = [to_json_safe(r) for r in rows]

    return {"symbol": symbol, "records": safe_rows}