print_location.py

"""Print location in GraphQL source"""

from __future__ import annotations

import re
from typing import TYPE_CHECKING, Tuple, cast

from .location import SourceLocation, get_location

if TYPE_CHECKING:
    from .ast import Location
    from .source import Source

__all__ = ["print_location", "print_source_location"]


def print_location(location: Location) -> str:
    """Render a helpful description of the location in the GraphQL Source document."""
    return print_source_location(
        location.source, get_location(location.source, location.start)
    )


_re_newline = re.compile(r"\r\n|[\n\r]")


def print_source_location(source: Source, source_location: SourceLocation) -> str:
    """Render a helpful description of the location in the GraphQL Source document."""
    first_line_column_offset = source.location_offset.column - 1
    body = "".rjust(first_line_column_offset) + source.body

    line_index = source_location.line - 1
    line_offset = source.location_offset.line - 1
    line_num = source_location.line + line_offset

    column_offset = first_line_column_offset if source_location.line == 1 else 0
    column_num = source_location.column + column_offset
    location_str = f"{source.name}:{line_num}:{column_num}\n"

    lines = _re_newline.split(body)  # works a bit different from splitlines()
    location_line = lines[line_index]

    # Special case for minified documents
    if len(location_line) > 120:
        sub_line_index, sub_line_column_num = divmod(column_num, 80)
        sub_lines = [
            location_line[i : i + 80] for i in range(0, len(location_line), 80)
        ]

        return location_str + print_prefixed_lines(
            (f"{line_num} |", sub_lines[0]),
            *[("|", sub_line) for sub_line in sub_lines[1 : sub_line_index + 1]],
            ("|", "^".rjust(sub_line_column_num)),
            (
                "|",
                sub_lines[sub_line_index + 1]
                if sub_line_index < len(sub_lines) - 1
                else None,
            ),
        )

    return location_str + print_prefixed_lines(
        (f"{line_num - 1} |", lines[line_index - 1] if line_index > 0 else None),
        (f"{line_num} |", location_line),
        ("|", "^".rjust(column_num)),
        (
            f"{line_num + 1} |",
            lines[line_index + 1] if line_index < len(lines) - 1 else None,
        ),
    )


def print_prefixed_lines(*lines: tuple[str, str | None]) -> str:
    """Print lines specified like this: ("prefix", "string")"""
    existing_lines = [
        cast(Tuple[str, str], line) for line in lines if line[1] is not None
    ]
    pad_len = max(len(line[0]) for line in existing_lines)
    return "\n".join(
        prefix.rjust(pad_len) + (" " + line if line else "")
        for prefix, line in existing_lines
    )