config.py

# config.py
#
# This module holds config related functions. This includes the EntryInfo data
# class too.

from collections import namedtuple
from dataclasses import dataclass

from utils import to_form_url

@dataclass
class EntryInfo:
    required: bool
    prompt: bool
    type: str
    key: str
    title: str
    value: str

    # See README's Config section for more info
    TYPES = {
        "words": ["w", "word", "text"],
        "choice": ["m", "mc", "multiple choice"],
        "checkboxes": ["c", "checkbox"],
        "date": ["d"],
        "time": ["t"],
        "extra": ["x", "xD", "extra data"],
    }

    @classmethod
    def from_string(cls, string):
        """
        Return info on a config file line.

        Parse a string of the format `[*] [!] type - key ; title = value`.
        Return a dataclass (simple object) with the config info.

        A string "*!type-key;title=value" would give `EntryInfo(required=True,
        prompt=True, type="type", key="key", title="title", value="value")`.

        Examples of config lines:
            w-1000;Question=Default
            ! time - 1001 ; Time = current
            *multiple choice - 1001 ; Class =
            checkbox-1002; Languages = Python, Java, C++
            *! extra-emailAddress; Email Address =
        """
        string = string.strip()

        if not string:
            raise ValueError("Empty entry")
        required = (string[0] == "*")
        string = string.removeprefix("*").strip()

        if not string:
            raise ValueError("Missing type")
        prompt = (string[0] == "!")
        string = string.removeprefix("!").strip()

        type, split, string = map(str.strip, string.partition("-"))
        for name, aliases in cls.TYPES.items():
            if type == name:
                break
            elif type in aliases:
                type = name
                break
        else:
            raise ValueError(f"Type not valid: {type}")
        if not split:
            raise ValueError("Missing type-key split '-'")

        key, split, string = map(str.strip, string.partition(";"))
        if not key:
            raise ValueError("Missing key")
        if not split:
            raise ValueError("Missing key-title split ';'")

        title, split, value = map(str.strip, string.partition("="))
        if not title:
            title = key  # Title defaults to the key if absent.
        if not split:
            raise ValueError("Missing title-value split '='")

        return cls(required, prompt, type, key, title, value)

    def __str__(self):
        return (
            f"{'*'*self.required}{'!'*self.prompt}{self.type}"
            f"-{self.key};{self.title}={self.value}"
        )

ConfigInfo = namedtuple("ConfigInfo", "url entries")
def open_config(file):
    """
    Open config file and return the URL and entries.
    """
    if isinstance(file, str):
        file = open(file)
    with file:
        url = to_form_url(file.readline())
        entries = []
        for line in file:
            line = line.strip()
            if not line:
                continue
            if line.startswith("#"):
                continue
            entries.append(EntryInfo.from_string(line))
    return ConfigInfo(url, entries)

# - Tests

def test_entry_from_string():
    # TODO: Add tests for ValueError (maybe use pytest)
    a = EntryInfo(True, True, "words", "key", "title", "value")
    assert EntryInfo.from_string(" *!words-key;title=value ") == a
    assert EntryInfo.from_string(" * ! words - key ; title = value ") == a

    b = EntryInfo(False, False, "words", "key", "key", "")
    assert EntryInfo.from_string("words-key;=") == b
    assert EntryInfo.from_string("w-key;=") == b
    assert EntryInfo.from_string("word-key;=") == b
    assert EntryInfo.from_string("text-key;=") == b

def test_entry_str():
    entry = EntryInfo(True, True, "words", "key", "title", "value")
    assert EntryInfo.from_string(str(entry)) == entry

    line = "*!words-key;title=value"
    assert str(entry) == line
    assert str(EntryInfo.from_string(line)) == line