import subprocess
import re
import logging
import os

'''
Initializes TMSU in a given directory.
Does nothing, if it is already initialized.

Parameters:
base: Directory to initialize.
'''
def tmsu_init(base):
    logger = logging.getLogger(__name__)
    if not os.path.exists(os.path.join(base, ".tmsu")):
        logger.info("TMSU database does not exist, creating ...")
        proc = subprocess.Popen(["tmsu", "init"], cwd=base)
        proc.wait()
        logger.debug("TMSU returncode: {}".format(proc.returncode))
        if proc.returncode != 0:
            logger.error("Could not initialize TMSU database.")
            return False
    return True

'''
Reads the tags for the specified file.

Parameters:
base: Base directory for the database.
file: File to get the tags for.
'''
def tmsu_tags(base, file):
    logger = logging.getLogger(__name__)
    logger.debug("Getting existing tags for file {}".format(file))
    tags = set()
    proc = subprocess.Popen(["tmsu", "tags", os.path.relpath(file, base)], cwd=base, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    proc.wait()
    logger.debug("TMSU returncode: {}".format(proc.returncode))
    if proc.returncode == 0:
        ret = proc.stdout.read().decode()
        logger.debug("Raw TMSU tags: {}".format(ret))
        tags.update(re.split("\s", ret.split(":")[1])[1:-1])
    else:
        logger.error("Could not get tags for file {}".format(file))
    return tags

'''
Sets tags for the specified file.

Parameters:
base: Base directory for the database.
file: File to set the tags for.
tags: Tags to set.
untag: If True, it will remove all existing tags first. If False, it will just append new tags.
'''
def tmsu_tag(base, file, tags, untag=True):
    logger = logging.getLogger(__name__)
    if untag:
        logger.debug("Untagging file")
        proc = subprocess.Popen(["tmsu", "untag", "--all", os.path.relpath(file, base)], cwd=base, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        proc.wait()
        if proc.returncode != 0:
            logger.error("Could not untag file {}".format(file))
    if tags:
        logger.debug("Writing tags {}".format(tags))
        proc = subprocess.Popen(["tmsu", "tag", os.path.relpath(file, base)] + list(tags), cwd=base, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        proc.wait()
        if proc.returncode != 0:
            logger.error("Could not write tags to file {}".format(file))
    else:
        logger.info("Tags are empty, ignoring")