import os
import json
import redis
import requests
from fastapi import FastAPI # This import is not strictly needed in this file if it's just a module
from fastapi.responses import JSONResponse # This import is not strictly needed in this file if it's just a module
import logging

logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')

# 🌐 Configuration from Environment Variables
# These variables MUST be set in your environment (e.g., .env file, shell exports, deployment configs)
REDIS_URL = os.environ.get("UPSTASH_REDIS_URL", "redis://localhost:6379")
WHATSAPP_API_URL = os.environ.get("WHATSAPP_API_URL", "https://api.gupshup.io/wa/api/v1/msg") 
WHATSAPP_TOKEN = os.environ.get("WHATSAPP_TOKEN")
WHATSAPP_TO_NUMBER = os.environ.get("WHATSAPP_TO_NUMBER", "353899495777")  # e.g., "91xxxxxxxxxx"
GUPSHUP_SOURCE_NUMBER = os.environ.get("GUPSHUP_SOURCE_NUMBER")  # e.g., your WABA number
GUPSHUP_APP_NAME = os.environ.get("GUPSHUP_APP_NAME")  # e.g., your Gupshup app name

# ✅ Redis connection
try:
    redis_client = redis.Redis.from_url(REDIS_URL, decode_responses=True)
    redis_client.ping() # Test connection
    logging.info("Redis client connected successfully.")
except Exception as e:
    logging.error(f"❌ Failed to connect to Redis: {e}")
    raise

# 🧾 Fetch and format headlines
def fetch_cached_headlines() -> str:
    try:
        raw = redis_client.get("detailed_news_feed_cache") 
        if not raw:
            logging.warning("⚠️ No detailed news headlines found in cache.")
            return "⚠️ No daily headlines found in cache."
        data = json.loads(raw)
    except Exception as e:
        logging.error(f"❌ Error reading from Redis: {e}")
        return f"❌ Error reading from Redis: {e}"

    message_parts = ["🗞️ *Your Daily Digest* 🟡\n"]
    
    sorted_topics = sorted(data.keys())

    for topic_key in sorted_topics:
        stories = data[topic_key]
        title = topic_key.replace("_", " ").title() 
        message_parts.append(f"\n🏷️ *{title}*") # Added newline before topic title
        
        sorted_story_ids = sorted(stories.keys(), key=int) 

        for ref_id in sorted_story_ids:
            item = stories[ref_id]
            summary = item.get("title", "") 
            description = item.get("description", "") 
            
            message_parts.append(f"{ref_id}. {summary}\n_Why this matters_: {description}")
        # No extra empty line needed here if we add newline to topic title

    return "\n".join(message_parts)

# 📤 Send via Gupshup WhatsApp API
def send_to_whatsapp(message_text: str) -> dict: # Function expects the full message text
    # Validate critical environment variables for sending a message
    if not WHATSAPP_TOKEN or \
       not WHATSAPP_TO_NUMBER or \
       not GUPSHUP_SOURCE_NUMBER or \
       not GUPSHUP_APP_NAME:
        error_msg = "❌ Missing one or more critical WhatsApp API environment variables (WHATSAPP_TOKEN, WHATSAPP_TO_NUMBER, GUPSHUP_SOURCE_NUMBER, GUPSHUP_APP_NAME)."
        logging.error(error_msg)
        return {"status": "failed", "error": error_msg, "code": 500}

    headers = {
        "Content-Type": "application/x-www-form-urlencoded",
        "apikey": WHATSAPP_TOKEN, # API key in 'apikey' header
        "Cache-Control": "no-cache" # Add Cache-Control header
    }

    whatsapp_message_content = {
        "type": "text",
        "text": message_text # This is the full formatted text
    }
    
    payload = {
        "channel": "whatsapp",
        "source": GUPSHUP_SOURCE_NUMBER,
        "destination": WHATSAPP_TO_NUMBER,
        "src.name": GUPSHUP_APP_NAME,
        "message": json.dumps(whatsapp_message_content) # 'message' parameter with JSON string for text type
    }

    try:
        logging.info(f"Attempting to send standard text WhatsApp message to {WHATSAPP_TO_NUMBER} via Gupshup. API URL: {WHATSAPP_API_URL}")
        response = requests.post(
            WHATSAPP_API_URL, 
            headers=headers,
            data=payload, 
        )
        response.raise_for_status() # Raise HTTPError for bad responses (4xx or 5xx)

        return {"status": "success", "details": response.json()}
    except requests.exceptions.RequestException as e:
        logging.error(f"❌ Failed to send WhatsApp message: {e}")
        return {"status": "failed", "error": str(e), "code": e.response.status_code if e.response else 500}
    except Exception as e:
        logging.error(f"❌ An unexpected error occurred during WhatsApp send: {e}")
        return {"status": "failed", "error": str(e), "code": 500}

# Removed the FastAPI app instance and endpoint from here,
# as it will be defined in routes/api/wa_headlines.py
# and then included in app.py.

# Removed the if __name__ == "__main__": block from here,
# as it will be in routes/api/wa_headlines.py for local testing.