# SPDX-FileCopyrightText: 2022-present deepset GmbH <info@deepset.ai>
#
# SPDX-License-Identifier: Apache-2.0

"""
Pre-commit hook that runs ruff format on Python code blocks in Markdown/MDX files.

Uses the ruff configuration from pyproject.toml automatically.
"""

import argparse
import logging
import os
import re
import subprocess
import sys
import tempfile

logger = logging.getLogger(__name__)
logger.setLevel(logging.INFO)
handler = logging.StreamHandler(sys.stderr)
handler.setFormatter(logging.Formatter("%(message)s"))
logger.addHandler(handler)

# ANSI color codes (disabled when stderr is not a terminal)
_USE_COLOR = hasattr(sys.stderr, "isatty") and sys.stderr.isatty()

PYTHON_FENCE_RE = re.compile(
    r"(?P<before>^```python\s*\n)"
    r"(?P<code>.*?)"
    r"(?P<after>^```\s*$)",
    re.MULTILINE | re.DOTALL,
)


def _color(code: str, text: str) -> str:
    """Colorize the text"""
    if _USE_COLOR:
        return f"\033[{code}m{text}\033[0m"
    return text


def _find_tool(name: str) -> str:
    """Find a tool installed in the same virtualenv as the running Python."""
    return os.path.join(os.path.dirname(sys.executable), name)


def _ruff(code: str, *, line_length: int) -> str:
    return subprocess.run(
        [
            _find_tool("ruff"),
            "format",
            f"--line-length={line_length}",
            "--config",
            "format.skip-magic-trailing-comma = false",
            "--stdin-filename",
            "block.py",
            "-",
        ],
        input=code,
        capture_output=True,
        text=True,
        check=True,
    ).stdout


def _add_trailing_commas(code: str) -> str:
    """Add trailing commas to multi-line expressions using add-trailing-comma."""
    with tempfile.NamedTemporaryFile(mode="w", suffix=".py", delete=False) as f:
        f.write(code)
        tmpfile = f.name
    try:
        subprocess.run([_find_tool("add-trailing-comma"), tmpfile], capture_output=True, check=False)
        with open(tmpfile) as f:
            return f.read()
    finally:
        os.unlink(tmpfile)


def _format_code_block(match: re.Match, *, line_length: int, path: str) -> str:
    """Format a single code block"""
    code = match.group("code")
    try:
        # 1. ruff format (may create new multi-line expressions)
        # 2. add trailing commas to all multi-line expressions
        # 3. ruff format again (respects trailing commas, ensures stable output)
        formatted = _ruff(_add_trailing_commas(_ruff(code, line_length=line_length)), line_length=line_length)
    except subprocess.CalledProcessError as exc:
        snippet = code.strip().splitlines()
        preview = "\n".join(snippet[:5])
        if len(snippet) > 5:
            preview += f"\n... ({len(snippet) - 5} more lines)"
        logger.warning(
            "%s %s\n%s\n%s %s",
            _color("33", "WARNING:"),
            _color("1", path),
            _color("2", preview),
            _color("31", "ruff stderr:"),
            exc.stderr.strip(),
        )
        return match.group(0)
    return match.group("before") + formatted + match.group("after")


def main() -> int:
    """Main entrypoint"""
    parser = argparse.ArgumentParser()
    parser.add_argument("--line-length", type=int, default=120)
    parser.add_argument("files", nargs="*")
    args = parser.parse_args()

    ret = 0
    for path in args.files:
        with open(path) as f:
            original = f.read()
        new = PYTHON_FENCE_RE.sub(
            lambda m, path=path: _format_code_block(m, line_length=args.line_length, path=path), original
        )
        if new != original:
            with open(path, "w") as f:
                f.write(new)
            logger.debug("%s %s", _color("32", "Rewriting:"), _color("1", path))
            ret = 1
    return ret


if __name__ == "__main__":
    raise SystemExit(main())