"""Common regular expressions."""

import re

DISCORD_INVITE = re.compile(
    r"(https?:\/\/)?(www\.)?"                    # Optional http(s) and www.
    r"(\B|discord(app)?)"                        # Optional discord(app)
    r"([.,]|dot)"                                # Various characters to cover dots
    r"("
        r"(gg|me)"                               # TLDs that embed within discord
        r"|com(\/|slash|\\)invite"               # Only match com/invite
    r")"
    r"(/|slash|\\+)"                              # / or 'slash' or 1+ of \
    r"(?P<invite>\S+)",                          # the invite code itself
    flags=re.IGNORECASE
)
"""
Regex for Discord server invites.

.. warning::
    This regex pattern will capture until a whitespace, if you are to use the 'invite' capture group in
    any HTTP requests or similar. Please ensure you sanitise the output using something
    such as :func:`urllib.parse.quote`.

:meta hide-value:
"""

FORMATTED_CODE_REGEX = re.compile(
    r"(?P<delim>(?P<block>```)|``?)"        # code delimiter: 1-3 backticks; (?P=block) only matches if it's a block
    r"(?(block)(?:(?P<lang>[a-z]+)\n)?)"    # if we're in a block, match optional language (only letters plus newline)
    r"(?:[ \t]*\n)*"                        # any blank (empty or tabs/spaces only) lines before the code
    r"(?P<code>.*?)"                        # extract all code inside the markup
    r"\s*"                                  # any more whitespace before the end of the code markup
    r"(?P=delim)",                          # match the exact same delimiter from the start again
    flags=re.DOTALL | re.IGNORECASE         # "." also matches newlines, case insensitive
)
"""
Regex for formatted code, using Discord's code blocks.

:meta hide-value:
"""

RAW_CODE_REGEX = re.compile(
    r"^(?:[ \t]*\n)*"                       # any blank (empty or tabs/spaces only) lines before the code
    r"(?P<code>.*?)"                        # extract all the rest as code
    r"\s*$",                                # any trailing whitespace until the end of the string
    flags=re.DOTALL                         # "." also matches newlines
)
"""
Regex for raw code, *not* using Discord's code blocks.

:meta hide-value:
"""