import os
import json
import httpx
import logging
from azure.identity import ManagedIdentityCredential, AzureCliCredential, ChainedTokenCredential
import requests

# Obtain the token using Managed Identity
def get_managed_identity_token():
    credential = ChainedTokenCredential(
        ManagedIdentityCredential(),
        AzureCliCredential()
    )
    token = credential.get_token("https://management.azure.com/.default").token
    return token

def get_function_key():
    subscription_id = os.getenv('AZURE_SUBSCRIPTION_ID')
    resource_group = os.getenv('AZURE_RESOURCE_GROUP_NAME')
    function_app_name = os.getenv('AZURE_ORCHESTRATOR_FUNC_NAME')
    token = get_managed_identity_token()
    logging.info("[orchestrator_client] Obtaining function key.")
    
    # URL to get all function keys, including the default one
    requestUrl = f"https://management.azure.com/subscriptions/{subscription_id}/resourceGroups/{resource_group}/providers/Microsoft.Web/sites/{function_app_name}/functions/orchestrator_streaming/listKeys?api-version=2022-03-01"
    
    requestHeaders = {
        "Authorization": f"Bearer {token}",
        "Content-Type": "application/json"
    }
    
    response = requests.post(requestUrl, headers=requestHeaders)
    
    # Check for HTTP errors
    if response.status_code >= 400:
        logging.error(f"[orchestrator_client] Failed to obtain function key. HTTP status code: {response.status_code}. Error details: {response.text}")
        function_key = None
    else:    
        try:
            response_json = response.json()
            function_key = response_json['default']
        except KeyError as e:
            function_key = None
            logging.error(f"[orchestrator_client] Error when getting function key. Details: {str(e)}.")
    
    return function_key

async def call_orchestrator_stream(conversation_id: str, question: str, auth_info: dict):

    url = os.getenv("ORCHESTRATOR_STREAM_ENDPOINT")
    if not url:
        raise Exception("ORCHESTRATOR_STREAM_ENDPOINT not set in environment variables")

    if 'localhost' in url:
        function_key = "dont_need_function_key"
    else:
        function_key = get_function_key()
        if not function_key:
            raise Exception(f"Error getting function key. Conversation ID: {conversation_id if conversation_id else 'N/A'}")

    headers = {
            'Content-Type': 'application/json',
            'x-functions-key': function_key  
        }

    payload = {
        "conversation_id": conversation_id,
        "question": question,
        "client_principal_id": auth_info.get('client_principal_id', 'no-auth'),
        "client_principal_name": auth_info.get('client_principal_name', 'anonymous'),
        "client_group_names": auth_info.get('client_group_names', []),
        "access_token": auth_info.get('access_token')
    }

    async with httpx.AsyncClient(timeout=None) as client:
        async with client.stream("POST", url, json=payload, headers=headers) as response:
            if response.status_code >= 400:
                raise Exception(f"Error calling orchestrator. HTTP status code: {response.status_code}. Details: {response.reason_phrase}")
            async for chunk in response.aiter_text():
                if not chunk:
                    continue
                yield chunk
                # logging.info("[orchestrator_client] Yielding text chunk: %s", chunk)