#!/usr/bin/python3

# The MIT License (MIT)
#
# Copyright © 2020-2025 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 json import load, dump
from sys import argv, exit, stderr, stdin, stdout


info = '''
jk [filepath/URI...]

Json Keys loads JSON data and finds all its keys non-recursively. Its output
is always JSON Lines (JSONL).

When the top-level value is an object, the result is a JSON line with the all
top-level keys. Top-level arrays are checked non-recursively for objects, and
all unique arrays of keys are emitted as JSON Lines, without repeating.
'''

# handle standard help cmd-line options, quitting right away in that case
if len(argv) > 1 and argv[1] in ('-h', '--h', '-help', '--help'):
    print(info.strip())
    exit(0)


def output_line(w, data) -> None:
    dump(data, w, indent=None, allow_nan=False, separators=(',', ': '))
    w.write('\n')


def json_keys(w, src, sort_keys) -> None:
    data = load(src)

    if isinstance(data, dict):
        keys = sorted(data.keys()) if sort_keys else data.keys()
        output_line(w, keys)
        return

    if not isinstance(data, (list, tuple)):
        return

    got = set()

    for e in data:
        if not isinstance(e, dict):
            continue

        keys = tuple(e.keys())
        if sort_keys:
            keys = sorted(keys)

        if keys in got:
            continue

        output_line(w, keys)
        got.add(keys)


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


args = argv[1:]
sort_keys = False
sort_opts = ('-s', '--s', '-sort', '--sort', '-sorted', '--sorted')
if len(args) > 0 and args[0] in sort_opts:
    sort_keys = True
    args = args[1:]

try:
    if len(args) < 1:
        json_keys(stdout, stdin.buffer, sort_keys)
    elif len(args) == 1:
        name = args[0]
        if name == '-':
            json_keys(stdout, stdin.buffer, sort_keys)
        elif seems_url(name):
            from urllib.request import urlopen
            with urlopen(name) as inp:
                json_keys(stdout, inp, sort_keys)
        else:
            with open(name, mode='rb') as inp:
                json_keys(stdout, inp, sort_keys)
    else:
        raise ValueError('multiple inputs not allowed')
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)