import argparse
import hashlib
import json
import os
import re
import sys
import tarfile
from datetime import datetime
from pathlib import Path


import requests


class GetBaktaDatabaseInfo:
    """
    Extract bakta database information to make a json file for data_manager
    """

    def __init__(
        self,
        data_table_name="bakta_database",
        db_version="latest",
        tarball_name="db.tar.gz",
        test_mode=False,
    ):
        self.bakta_table_list = None
        self.db_url = None
        self.db_name = "bakta-db"
        self.db_type = ""
        self.data_table_entry = None
        self.data_table_name = data_table_name
        self.tar_name = tarball_name
        self.db_version = db_version
        self.DB_VERSIONS_URL = "https://raw.githubusercontent.com/oschwengers/bakta/master/db-versions.json"
        self.DB_TEST_URL = "https://zenodo.org/record/8021032/files/db-versions.json"
        self.test_mode = test_mode

    def get_database_type(self):
        self.light_db = bool(re.search(pattern="light", string=self.db_version))
        self.db_version = self.db_version.split(sep="_")[0]
        if self.light_db:
            self.db_type = "light"
            self.tar_name = "db-light.tar.gz"
            self.md5 = self.fetch_db_versions()["md5-light"]
        else:
            self.md5 = self.fetch_db_versions()["md5"]

    def get_data_table_format(self):
        """
        Skeleton of a data_table format
        return: a data table formated for json output
        """
        self.data_table_entry = {"data_tables": {self.data_table_name: {}}}
        return self.data_table_entry

    def fetch_db_versions(self):
        """
        List bakta database info related to the db_version selected
        """

        if self.test_mode:
            self.DB_VERSIONS_URL = self.DB_TEST_URL
        try:
            with requests.get(self.DB_VERSIONS_URL) as resp:
                versions = json.loads(resp.content)
        except IOError as e:
            print(e, file=sys.stderr)
            raise e

        if self.db_version == "latest":
            db_date_list = []
            for db_dic in versions:
                db_date_list.append(
                    datetime.strptime(db_dic["date"], "%Y-%m-%d").date()
                )
            filtered_version = max(versions, key=lambda x: x["date"])
        else:
            filtered_version = None
            for item in versions:
                if "{0}.{1}".format(item["major"], item["minor"]) == self.db_version:
                    filtered_version = item
                    break
        if filtered_version is None:
            print("No matching version detected in the list")
        else:
            self.db_url = f"https://zenodo.org/record/{filtered_version['record']}/files/{self.tar_name}"
            return filtered_version

    def get_data_manager(self, bakta_database_info):
        self.bakta_table_list = self.get_data_table_format()
        bakta_name = (
            f"V{bakta_database_info['major']}."
            f"{bakta_database_info['minor']}{self.db_type}_"
            f"{bakta_database_info['date']}"
        )
        tool_version = str(
            f"{bakta_database_info['software-min']['major']}."
            f"{bakta_database_info['software-min']['minor']}"
        )
        data_info = dict(
            value=bakta_name,
            dbkey=bakta_database_info["record"],
            bakta_version=tool_version,
            path=self.db_name,
        )
        self.bakta_table_list["data_tables"][self.data_table_name] = [data_info]
        return self.bakta_table_list


class InstallBaktaDatabase(GetBaktaDatabaseInfo):
    """
    Download the bakta database,
    check md5 sum,
    untar the download db and update for the amrfinderplus database
    """

    def __init__(
        self,
        db_dir=Path.cwd(),
        db_name="bakta-db",
        db_version="latest",
        test_mode=False
    ):
        super().__init__()
        self.md5 = None
        self.db_version = db_version
        self.db_dir = db_dir
        self.db_name = db_name
        self.tarball_path = ""
        self.test_mode = test_mode
        self.get_database_type()

    def download(self):
        #self.db_name = f"{self.db_name}_{self.db_version}{self.db_type}"
        bakta_path = Path(self.db_dir).joinpath(self.tar_name)
        try:
            with bakta_path.open("wb") as fh_out, requests.get(
                    self.db_url, stream=True) as resp:
                total_length = resp.headers.get("content-length")
                if total_length is None:  # no content length header
                    for data in resp.iter_content(chunk_size=1024 * 1024):
                        fh_out.write(data)
                else:
                    for data in resp.iter_content(chunk_size=1024 * 1024):
                        fh_out.write(data)
            print(f"Download bakta database {self.db_version}")
            self.tarball_path = bakta_path
        except IOError:
            print(
                f"ERROR: Could not download file from Zenodo!"
                f" url={self.db_url}, to={self.tarball_path}"
            )

    def untar(self):
        db_path = Path(self.db_dir).joinpath(self.db_name)
        try:
            with self.tarball_path.open("rb") as fh_in, tarfile.open(
                fileobj=fh_in, mode="r:gz"
            ) as tar_file:
                tar_file.extractall(path=db_path)
                print(f"Untar the database in {db_path}")
#                return db_path
        except OSError:
            sys.exit(f"ERROR: Could not extract {self.tar_name} " f"to {db_path}")

    def calc_md5_sum(self, buffer_size=1048576):
        tarball_path = Path(self.db_dir).joinpath(self.tar_name)
        md5 = hashlib.md5()
        with tarball_path.open("rb") as fh:
            data = fh.read(buffer_size)
            while data:
                md5.update(data)
                data = fh.read(buffer_size)
        if md5.hexdigest() == self.md5:
            print("\t...md5 control database OK")
        else:
            print(
                f"Error: corrupt database file! "
                f"calculated md5 = {md5.hexdigest()}"
                f" different from {self.md5} "
            )


def parse_arguments():
    # parse options and arguments
    arg_parser = argparse.ArgumentParser()
    arg_parser.add_argument("data_manager_json")
    arg_parser.add_argument(
        "-d",
        "--database_version",
        help="Select the database version "
        "(major and minor eg. 4.0),"
        "default is the latest version",
        default="latest",
        required=True,
    )
    arg_parser.add_argument(
        "-t",
        "--test",
        action="store_true",
        help="option to test the script with an empty database",
    )
    return arg_parser.parse_args()


def main():
    all_args = parse_arguments()
    with open(all_args.data_manager_json) as fh:
        params = json.load(fh)
    target_dir = params["output_data"][0]["extra_files_path"]
    os.makedirs(target_dir)
    # init the class to download bakta db
    bakta_upload = InstallBaktaDatabase(
        test_mode=all_args.test, db_version=all_args.database_version
    )
    bakta_db = bakta_upload.fetch_db_versions()
    # update the path for galaxy
    bakta_upload.db_dir = target_dir
    # download the database
    bakta_upload.download()
    # check md5 sum
    bakta_upload.calc_md5_sum()
    # untar db
    bakta_upload.untar()
    # make the data_manager metadata
    bakta_data_manager = bakta_upload.get_data_manager(bakta_database_info=bakta_db)
    with open(all_args.data_manager_json, "w") as fh:
        json.dump(bakta_data_manager, fh, sort_keys=True)


if __name__ == "__main__":
    main()