# logbus/publisher.py

import logging
import os

logger = logging.getLogger("logbus")

logger.setLevel(logging.WARNING)

# ============================================================
# FILE LOGGER — log.txt in BOOKSCRAPER_OUTPUT_DIR
# ============================================================
try:
    root = os.getenv("BOOKSCRAPER_OUTPUT_DIR", "output")
    os.makedirs(root, exist_ok=True)

    file_path = os.path.join(root, "log.txt")

    file_handler = logging.FileHandler(file_path, mode="a", encoding="utf-8")
    file_formatter = logging.Formatter("%(message)s")  # exact zoals input
    file_handler.setFormatter(file_formatter)

    logger.addHandler(file_handler)

except Exception:
    # Logging naar file mag nooit de app laten crashen
    pass


def log(message: str):
    """
    Dumb logger:
    - skip lege messages
    - stuur message 1:1 door
    - geen prefixes
    - geen mutaties
    """

    if not message or not message.strip():
        return

    # console
    logger.warning(message)

    # UI-echo
    try:
        from scraper.ui_log import push_ui

        push_ui(message)
    except Exception:
        pass


# ============================================================
# Delta-based log retrieval using Redis indexes
# ============================================================


def get_ui_logs_delta(last_index: int):
    """
    Returns (new_lines, total_count)
    Only returns log lines AFTER last_index.

    Example:
        last_index = 10 → returns logs with Redis indexes 11..end
    """
    # Determine total lines in buffer
    total = r.llen(UI_LOG_KEY)

    if total == 0:
        return [], 0

    # First load OR index invalid → send entire buffer
    if last_index < 0 or last_index >= total:
        logs = r.lrange(UI_LOG_KEY, 0, -1)
        return logs, total

    # Only new lines:
    new_lines = r.lrange(UI_LOG_KEY, last_index + 1, -1)
    return new_lines, total