from pathlib import Path
import datetime

from tibi_hardlinks.backup_parser import read_backup_properties
from tibi_hardlinks.exceptions import ConfigurationException

HEIRACHY = (
    "sys_ro.product.model",
    "sys_ro.serialno",
    "app_label",
    "app_version_name",
    "backup_time",
)


def create_backup_directory_name(backup_info, time_format="%Y-%m-%d_%H-%M-%S"):
    utc_timestamp = backup_info["backup_time"]
    backup_datetime = datetime.datetime.utcfromtimestamp(utc_timestamp)

    try:
        new_time = backup_datetime.strftime(time_format)
        assert backup_datetime == datetime.datetime.strptime(new_time, time_format)
        backup_info["backup_time"] = new_time
    except (ValueError, AssertionError):
        raise ConfigurationException("customization", "time_format", time_format)
    backup_directory_name = Path("")
    for part in HEIRACHY:
        data = backup_info[part]
        if len(data) == 0:
            data = "DEFAULT"
        backup_directory_name /= data

    return backup_directory_name


def find_backup_data(property_file: Path, backup_info):
    # find the path of the *.apk, *.properties, and *.tar(.gz) corresponding to property_file
    backup_root = property_file.parent
    try:
        apk_hash = backup_info["app_apk_md5"]
        apk_file = filter(
            lambda apk_file: apk_hash in apk_file.name, backup_root.glob("*.apk*")
        )
    except KeyError:
        apk_file = None
    related_files = list(backup_root.glob(property_file.stem + "*"))
    if len(related_files) > 2:
        raise Exception
    tar_file = None
    for filename in related_files:
        if ".tar" in filename.name:
            tar_file = filename

    property_file = property_file
    return {"property_file": property_file, "apk_file": apk_file, "tar_file": tar_file}


class Backup:
    def __init__(self, property_file: Path):
        self.property_file = property_file
        self.backup_info = read_backup_properties(property_file)
        self.related_files = find_backup_data(self.property_file, self.backup_info)

    def hardlink_to(self, dest):
        for filepath in self.related_files.values():
            if filepath:
                filepath.link_to(dest)