import hashlib
import argparse
import sys
import os

FLATID = "io.github.zen_browser.zen"

def get_sha256sum(filename):  
  """Calculate the SHA256 checksum of a file."""
  sha256 = hashlib.sha256()
  try:
    with open(filename, "rb") as f:
      for byte_block in iter(lambda: f.read(4096), b""):
        sha256.update(byte_block)
  except FileNotFoundError:
    print(f"File {filename} not found.")
    sys.exit(1)
  return sha256.hexdigest()

def build_template(template, linux_sha256, flatpak_sha256, version):
  """Build the template with the provided hashes and version."""
  print(f"Building template with version {version}")
  print(f"\tLinux archive sha256: {linux_sha256}")
  print(f"\tFlatpak archive sha256: {flatpak_sha256}")
  return template.format(
    linux_sha256=linux_sha256,
    flatpak_sha256=flatpak_sha256,
    version=version
  )

def get_template(template_root):
  """Get the template content from the specified root directory."""
  file = os.path.join(template_root, f"{FLATID}.yml.template")
  print(f"Reading template {file}")
  try:
    with open(file, "r") as f:
      return f.read()
  except FileNotFoundError:
    print(f"Template {file} not found.")
    sys.exit(1)

def main():
  """Main function to parse arguments and process files."""
  parser = argparse.ArgumentParser(description='Prepare flatpak release')
  parser.add_argument('--version', help='Version of the release', required=True)
  parser.add_argument('--linux-archive', help='Linux archive', required=True)
  parser.add_argument('--flatpak-archive', help='Flatpak archive', required=True)
  parser.add_argument('--output', help='Output file', default=f"{FLATID}.yml")
  parser.add_argument('--template-root', help='Template root', default="flatpak")
  args = parser.parse_args()

  linux_sha256 = get_sha256sum(args.linux_archive)
  flatpak_sha256 = get_sha256sum(args.flatpak_archive)
  template = build_template(get_template(args.template_root), linux_sha256, flatpak_sha256, args.version)

  print(f"Writing output to {args.output}")
  with open(args.output, "w") as f:
    f.write(template)

if __name__ == "__main__":
  main()