import os, json, time, threading, logging
from datetime import datetime
from typing import List, Tuple

try:
    import boto3
    from botocore.exceptions import ClientError, NoCredentialsError
except Exception:
    boto3 = None
    ClientError = NoCredentialsError = Exception

LOG_FILE = os.getenv("CONVO_LOG_FILE", "conversation_history.jsonl")
UPLOAD_ENABLED = os.getenv("SPACES_UPLOAD_CONVO", "true").lower() == "true"

SPACES_KEY = os.getenv("SPACES_KEY")
SPACES_SECRET = os.getenv("SPACES_SECRET")
SPACES_BUCKET = os.getenv("SPACES_BUCKET")
SPACES_REGION = os.getenv("SPACES_REGION", "ams3")

_lock = threading.Lock()

def load_history(max_lines: int = 500) -> List[Tuple[str,str]]:
    if not os.path.exists(LOG_FILE):
        return []
    pairs: List[Tuple[str,str]] = []
    try:
        with open(LOG_FILE, "r", encoding="utf-8") as f:
            for line in f.readlines()[-max_lines:]:
                try:
                    obj = json.loads(line)
                    if obj.get("role") == "exchange":
                        pairs.append((obj.get("user",""), obj.get("assistant","")))
                except json.JSONDecodeError:
                    continue
    except Exception as e:
        logging.error(f"Failed to load history: {e}")
    return pairs

def _write_line(obj: dict):
    with open(LOG_FILE, "a", encoding="utf-8") as f:
        f.write(json.dumps(obj, ensure_ascii=False) + "\n")

def _upload_file():
    if not (UPLOAD_ENABLED and boto3 and SPACES_KEY and SPACES_SECRET and SPACES_BUCKET):
        return
    try:
        session = boto3.session.Session()
        client = session.client(
            's3',
            region_name=SPACES_REGION,
            endpoint_url=f"https://{SPACES_REGION}.digitaloceanspaces.com",
            aws_access_key_id=SPACES_KEY,
            aws_secret_access_key=SPACES_SECRET,
        )
        object_name = os.getenv("SPACES_CONVO_OBJECT", f"chat-logs/{os.path.basename(LOG_FILE)}")
        client.upload_file(LOG_FILE, SPACES_BUCKET, object_name)
    except (ClientError, NoCredentialsError) as e:
        logging.error(f"Spaces upload failed: {e}")
    except Exception as e:
        logging.error(f"Unexpected upload error: {e}")

def log_exchange(user_msg: str, assistant_msg: str, meta: dict = None):
    ts = time.time()
    record = {
        "role": "exchange",
        "timestamp": datetime.utcfromtimestamp(ts).isoformat() + "Z",
        "user": user_msg,
        "assistant": assistant_msg,
        "meta": meta or {}
    }
    with _lock:
        _write_line(record)
    # Upload in background thread to avoid blocking UI
    threading.Thread(target=_upload_file, daemon=True).start()