#!/usr/bin/python3
import logging
import sys
import json
import argparse
import os
import hashlib
from shutil import copyfile
from datetime import datetime

logger = logging.getLogger()
handler = logging.StreamHandler(stream=sys.stderr)
formatter = logging.Formatter(
        '%(asctime)s %(name)-12s %(levelname)-8s %(message)s')
handler.setFormatter(formatter)
logger.addHandler(handler)
logger.setLevel(logging.DEBUG)

parser = argparse.ArgumentParser(
        prog="mkrelease",
        description="Automatically package a firmware release."
        )

parser.add_argument('-c', '--config', dest="config_location", action="store", help="The location of the config file.", default="./release-config.json")
parser.add_argument('version', help="Version you wish to release. Use https://semver.org")
parser.add_argument('--verbose', help="Enable verbose logging output.", action="store_true", default=False)

def build_version_string(gsd_num : str, out_name:str, version_number:str, release_type:str, file_extension:str):
    return f'GSD-{gsd_num}-{out_name}-{version_number}-{release_type}.{file_extension}'

def md5_hash_of(file):
    with open(file, 'rb') as f:
        file_hash = hashlib.md5()
        while chunk := f.read(8192):
            file_hash.update(chunk)

        return file_hash.hexdigest()

if __name__ == "__main__":
    args = parser.parse_args()

    if not args.verbose:
        logger.disabled = True


    logger.debug("Attempting to read config file...")

    config = None
    
    try:
        config = json.load(open(args.config_location))
    except Exception as e:
        logger.error(args.config_location + ": " + str(e))

    assert config is not None

    logger.debug("Config file read.")

    release_dir = f'./{config["releases_directory"]}/{args.version}/'

    print("The following releases will be created:")

    assert config["releases"] is not None

    missingfiles = []

    binaries_manifest = []

    print(release_dir)
    for release in config["releases"]:
        for ext in release["copy_extensions"]:
            build_file_path = f'./{release["build_directory"]}/{release["build_file_name"]}.{ext}'
            output_file_path = build_version_string(config["gsd"]
                                                    , config["product_name"]
                                                    , args.version
                                                    , release["release_name"]
                                                    , ext)            
            try:
                os.stat(build_file_path)
            except Exception as e: 
                logging.error(f"Could not stat {build_file_path}:")
                logging.error(e)
                missingfiles.append(build_file_path)

            print('\t'+ output_file_path + f'\t({build_file_path})')

            binaries_manifest.append((build_file_path, release_dir + output_file_path))


    if len(missingfiles) > 0:
        logger.error("Exiting due to missing source files.")
        print("The following files were not able to be found:")
        [print(f"\t{path}") for path in missingfiles] 
        exit(1)

    print("\nThe following additional files will be created:")
    print(f'./{config["releases_directory"]}/{args.version}/')
    print("\trelease_notes.txt")

    if config["changelog"] is not None:
        logger.debug("Detected changelog field. Will also create changelog.")
        if not os.path.exists(config["changelog"]):
            logger.warning("Config file does not exist.")
            print("The changelog file you provided does not exist. Check your configuration file.")
        elif os.path.isfile(config["changelog"]):
            print("\tchangelog.md (from file)")
        elif os.path.isdir(config["changelog"]):
            print("\tchangelog.md (from directory of files)")

    print("")

    accept_words = ["y", "yes", ""]
    deny_words = ["n", "no"]
    while True:
        print("Do you wish to proceed? [Y/n]: ", end="")
        result = input()


        if result.lower() in deny_words:
            print("Aborted.")
            exit(1)
        elif result.lower() not in accept_words:
            print("Don't understand what you mean.")
        else:
            print("OK, executing file operations.")
            break

    logger.debug("Ensuring output directories exist.")
    os.makedirs(release_dir, exist_ok=True)

    for (source,destination) in binaries_manifest:
        copyfile(source, destination)
        logger.debug(f'Copied {source} to {destination}')

        
    logger.debug(f'Generating changelog')  

    if os.path.isdir(config["changelog"]):
        with open(release_dir + "changelog.md", mode='+w') as out_log:
            for f in reversed(os.listdir(config["changelog"])):
                if os.path.isfile(f'{config["changelog"]}/{f}'):
                    with open(f'{config["changelog"]}/{f}') as fi:
                        for line in fi:
                            out_log.write(line)
                        out_log.write("\n")

    else:
        copyfile(config["changelog"], release_dir + "/changelog.md")
        logger.debug(f'Copied {config["changelog"]} to {release_dir}/changelog.txt')

    logger.debug("Generating release_notes.txt")

    with open(f'{release_dir}/release_notes.txt', mode="+w") as release_notes:
        release_notes.write(f'Generated using mkrelease at {datetime.now().strftime("%Y/%m/%d %H:%M:%S")} by user {os.getlogin()}\n')
        release_notes.write("Output file manifest (name, md5 hash):\n")
        for (_, file) in binaries_manifest:
            release_notes.write(f'{file}  {md5_hash_of(file)}\n')