#!/usr/bin/python3

# The MIT License (MIT)
#
# Copyright © 2024 pacman64
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the “Software”), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.


from base64 import b64encode
from mimetypes import guess_type
from sys import argv, exit, stderr, stdout


info = '''
datauri [options...] [filepaths/URIs...]

Turn each named input (file/URI) given into a data-URI line.

Data-URIs are base64-encoded text representations of arbitrary data, which
include their payload's MIME-type, and which are directly useable/shareable
in web-browsers as links, despite not looking like normal links/URIs.
'''

# no args or a leading help-option arg means show the help message and quit
if len(argv) == 1 or argv[1] in ('-h', '--h', '-help', '--help'):
    print(info.strip(), file=stderr)
    exit(0)


def seems_url(s: str) -> bool:
    protocols = ('https://', 'http://', 'file://', 'ftp://', 'data:')
    return any(s.startswith(p) for p in protocols)


def handle_input(w, src, path: str) -> None:
    mime = ''

    # get MIME-type from response headers, if input is an HTTP response
    if hasattr(inp, 'getheader'):
        mime = inp.getheader('content-type')

    # failing that, guess the MIME-type from the input's name/URI
    if not mime:
        (mime, _) = guess_type(path)

    if not mime:
        raise Exception(f'{path}: can\'t guess MIME-type')

    w.write(b'data:')
    w.write(bytes(mime, encoding='utf-8'))
    w.write(b';base64,')
    w.write(b64encode(src.read()))
    w.write(b'\n')


try:
    if '-' in argv:
        raise Exception('can\'t use standard input, only named sources')

    if any(seems_url(e) for e in argv):
        from urllib.request import urlopen

    for path in argv[1:]:
        if seems_url(path):
            with urlopen(path) as inp:
                handle_input(stdout.buffer, inp, path)
            continue

        with open(path, mode='rb') as inp:
            handle_input(stdout.buffer, inp, path)
except BrokenPipeError:
    # quit quietly, instead of showing a confusing error message
    stderr.close()
except KeyboardInterrupt:
    exit(2)
except Exception as e:
    print(f'\x1b[31m{e}\x1b[0m', file=stderr)
    exit(1)