import json
import logging
from fastapi import FastAPI, HTTPException
from fastapi.responses import HTMLResponse
from fastapi.middleware.cors import CORSMiddleware
import pandas as pd
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 (optional but useful for frontend)
# ---------------------------------------------------------
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

# ---------------------------------------------------------
# Lazy-loaded dataset
# ---------------------------------------------------------
DATASET_PATH = "transcripts.csv"   # change if needed
df_cache = None

def load_dataset():
    global df_cache
    if df_cache is None:
        logger.info("Loading dataset...")
        if not os.path.exists(DATASET_PATH):
            raise FileNotFoundError(f"Dataset not found: {DATASET_PATH}")
        df_cache = pd.read_csv(DATASET_PATH)
        logger.info(f"Dataset loaded with {len(df_cache)} rows.")
    return df_cache

# ---------------------------------------------------------
# JSON-safe conversion
# ---------------------------------------------------------
def to_json_safe(obj):
    if isinstance(obj, (np.integer, np.int64)):
        return int(obj)
    if isinstance(obj, (np.floating, np.float64)):
        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 at "/"
# ---------------------------------------------------------
@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():
    df = load_dataset()
    tickers = sorted(df["symbol"].unique().tolist())
    return {"tickers": tickers}

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

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

    subset = df[df["symbol"] == symbol]

    if subset.empty:
        raise HTTPException(status_code=404, detail=f"No transcript found for {symbol}")

    # Convert each row to JSON-safe dict
    records = subset.to_dict(orient="records")
    safe_records = [to_json_safe(r) for r in records]

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