#!/usr/bin/env python3

from pathlib import Path
from datetime import datetime

import subprocess

from settings import *
from logger import Logger


logger = Logger()


def trigger_export(courseid, categoryid):
    output_name = f"course_{courseid}_{categoryid}_{int(datetime.now().timestamp())}.mbz"
    result = subprocess.run([MOOSH_PATH, "-p", MOODLE_PATH, "course-backup",
                             "-p", OUTPUT_PATH, "-f", output_name, "--template", courseid],
                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    for message in result.stdout.decode().splitlines():
        logger.debug(message)
    for error in result.stderr.decode().splitlines():
        logger.error(error)
    return output_name


def trigger_categories_export():
    OUTPUT_PATH = Path(OUTPUT_PATH)

    output_name = f"categories_{int(datetime.now().timestamp())}.xml"
    result = subprocess.run([MOOSH_PATH, "-p", MOODLE_PATH, "category-export", "0"],
                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)

    try:
        with open(OUTPUT_PATH / output_name, "wb") as xmlfile:
            xmlfile.write(result.stdout)
    except IOError as e:
        logger.error(
            f"Could not write categories to {OUTPUT_PATH / output_name}: {e}")

    for error in result.stderr.decode().splitlines():
        logger.error(error)


def main():
    global SIGNAL_PATH, OUTPUT_PATH
    logger.info("Moodle Export Worker starting")
    SIGNAL_PATH = Path(SIGNAL_PATH)
    OUTPUT_PATH = Path(OUTPUT_PATH)

    if SIGNAL_PATH.exists():
        if not SIGNAL_PATH.is_dir():
            logger.fatal(
                f"Cannot create signalling directory {SIGNAL_PATH} because a file with that name exists.")
            exit(1)
    else:
        try:
            SIGNAL_PATH.mkdir()
        except Exception as e:
            logger.fatal(
                f"Cannot create signalling directory {SIGNAL_PATH}: {e}")
            exit(1)

    for f in SIGNAL_PATH.glob("*-*.mew"):
        logger.debug(f"Found file {f.name} - start processing")
        try:
            pre = datetime.now()
            output_name = trigger_export(*f.name.split(".")[0].split("-"))
            dur = datetime.now() - pre
            size = Path(OUTPUT_PATH / output_name).stat().st_size
            f.unlink()
            logger.debug(
                f"Created file {output_name} ({size} bytes) in {dur.seconds} seconds")
        except Exception as e:
            logger.error(
                f"Export of course {f.name.split('.')[0].split('-')[0]} failed: {e}")

    if (SIGNAL_PATH / "categories.mew").exists():
        logger.debug(f"Found file categories.mew - processing categories")
        try:
            pre = datetime.now()
            output_name = trigger_categories_export()
            dur = datetime.now() - pre
            size = Path(OUTPUT_PATH / output_name).stat().st_size
            f.unlink()
            logger.debug(
                f"Created file {output_name} ({size} bytes) in {dur.seconds} seconds")
        except Exception as e:
            logger.error(
                f"Export of categories failed: {e}")

    logger.info("Moodle Export Worker done")


if __name__ == "__main__":
    main()