#!/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 json import load, dump
from sys import argv, stderr, stdin, stdout


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


This script converts away from JSON into other formats, like TSV tables,
auto-detecting a sensible output format, if possible.
'''

if len(argv) == 2 and argv[1] in ('-h', '--h', '-help', '--help'):
    print(info.strip())
    exit(0)


def table_keys(data):
    if not isinstance(data, (list, tuple)):
        return tuple()
    if len(data) == 0:
        return tuple()

    keys = {}
    for row in data:
        if not isinstance(row, dict):
            return tuple()
        for k in row.keys():
            keys[k] = None
    return tuple(keys.keys())


def dejson(w, data):
    if isinstance(data, (bool, float, int, str)):
        print(data, file=w)
        return
    if isinstance(data, (list, tuple)):
        handle_array(w, data)
        return


def handle_array(w, data):
    keys = table_keys(data)
    if len(keys) > 0:
        handle_tsv(w, data)
        return

    for e in data:
        if isinstance(e, dict):
            dump(e, w)
        else:
            print(e, file=w)


def fix_cell(data):
    if isinstance(data, (list, tuple)):
        return ','.join(str(e) for e in data)
    return str(data) if not data is None else ''


def handle_tsv(w, data):
    check_tsv_cells(data[0].keys())
    print('\t'.join(data[0].keys()), file=w)
    for row in data:
        check_tsv_cells(row.values())
        print('\t'.join((fix_cell(e) for e in row.values())), file=w)


def tsv_type_error(e):
    raise ValueError(f'can\'t convert values of type {type(e)} into TSV')


def check_tsv_cells(values):
    for e in values:
        if e is None or isinstance(e, (bool, int, float)):
            continue

        if isinstance(e, str):
            if any(b in e for b in ('\t', '\n', '\r', '\v', '\f')):
                raise ValueError('string has TSV-incompatible symbol')
            continue

        if isinstance(e, (list, tuple)):
            for v in e:
                if not isinstance(v, (bool, int, float, str)):
                    tsv_type_error(v)
                if isinstance(v, str) and ',' in v:
                    m = 'can\'t join arrays with strings with commas in them'
                    raise ValueError(m)
            continue

        tsv_type_error(e)


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


try:
    if len(argv) < 2:
        dejson(stdout, load(stdin))
    elif len(argv) == 2:
        name = argv[1]
        if name == '-':
            dejson(stdout, load(stdin))
        elif seems_url(name):
            from urllib.request import urlopen
            with urlopen(name) as inp:
                dejson(stdout, load(inp))
        else:
            with open(name, encoding='utf-8') as inp:
                dejson(stdout, load(inp))
    else:
        raise ValueError('multiple inputs not allowed')
except BrokenPipeError:
    # quit quietly, instead of showing a confusing error message
    stderr.close()
    exit(0)
except KeyboardInterrupt:
    exit(2)
except Exception as e:
    print(f'\x1b[31m{e}\x1b[0m', file=stderr)
    exit(1)