cmake-language-server/src/cmake_language_server/server.py

import logging
import re
from pathlib import Path
from typing import Any, Callable, List, Optional, Tuple

from pygls.features import (
    COMPLETION,
    FORMATTING,
    HOVER,
    INITIALIZE,
    INITIALIZED,
    TEXT_DOCUMENT_DID_SAVE,
)
from pygls.server import LanguageServer
from pygls.types import (
    CompletionItem,
    CompletionItemKind,
    CompletionList,
    CompletionParams,
    CompletionTriggerKind,
    DocumentFormattingParams,
    Hover,
    InitializeParams,
    MarkupContent,
    MarkupKind,
    Position,
    Range,
    TextDocumentPositionParams,
    TextEdit,
)

from .api import API
from .formatter import Formatter
from .parser import ListParser

logger = logging.getLogger(__name__)


class CMakeLanguageServer(LanguageServer):  # type: ignore
    _parser: ListParser
    _api: Optional[API]

    def __init__(self, *args: Any) -> None:
        super().__init__(*args)

        self._parser = ListParser()
        self._api = None

        @self.feature(INITIALIZE)
        def initialize(params: InitializeParams) -> None:
            opts = params.initializationOptions

            cmake = getattr(opts, "cmakeExecutable", "cmake")
            builddir = getattr(opts, "buildDirectory", "")
            logging.info(f"cmakeExecutable={cmake}, buildDirectory={builddir}")

            self._api = API(cmake, Path(builddir))
            self._api.parse_doc()

        trigger_characters = ["{", "("]

        @self.feature(COMPLETION, trigger_characters=trigger_characters)
        def completions(params: CompletionParams) -> CompletionList:
            assert self._api is not None

            if (
                hasattr(params, "context")
                and params.context.triggerKind == CompletionTriggerKind.TriggerCharacter
            ):
                token = ""
                trigger = params.context.triggerCharacter
            else:
                line = self._cursor_line(params.textDocument.uri, params.position)
                idx = params.position.character - 1
                if 0 <= idx < len(line) and line[idx] in trigger_characters:
                    token = ""
                    trigger = line[idx]
                else:
                    word = self._cursor_word(
                        params.textDocument.uri, params.position, False
                    )
                    token = "" if word is None else word[0]
                    trigger = None

            items: List[CompletionItem] = []

            if trigger is None:
                commands = self._api.search_command(token)
                items.extend(
                    CompletionItem(
                        x,
                        CompletionItemKind.Function,
                        documentation=self._api.get_command_doc(x),
                        insert_text=x,
                    )
                    for x in commands
                )

            if trigger is None or trigger == "{":
                variables = self._api.search_variable(token)
                items.extend(
                    CompletionItem(
                        x,
                        CompletionItemKind.Variable,
                        documentation=self._api.get_variable_doc(x),
                        insert_text=x,
                    )
                    for x in variables
                )

            if trigger is None:
                targets = self._api.search_target(token)
                items.extend(
                    CompletionItem(x, CompletionItemKind.Class, insert_text=x)
                    for x in targets
                )

            if trigger == "(":
                func = self._cursor_function(params.textDocument.uri, params.position)
                if func is not None:
                    func = func.lower()
                    if func == "include":
                        modules = self._api.search_module(token, False)
                        items.extend(
                            CompletionItem(
                                x,
                                CompletionItemKind.Module,
                                documentation=self._api.get_module_doc(x, False),
                                insert_text=x,
                            )
                            for x in modules
                        )
                    elif func == "find_package":
                        modules = self._api.search_module(token, True)
                        items.extend(
                            CompletionItem(
                                x,
                                CompletionItemKind.Module,
                                documentation=self._api.get_module_doc(x, True),
                                insert_text=x,
                            )
                            for x in modules
                        )

            return CompletionList(False, items)

        @self.feature(FORMATTING)
        def formatting(params: DocumentFormattingParams) -> Optional[List[TextEdit]]:
            doc = self.workspace.get_document(params.textDocument.uri)
            content = doc.source
            tokens, remain = self._parser.parse(content)
            if remain:
                self.show_message("CMake parser failed")
                return None

            formatted = Formatter().format(tokens)
            lines = content.count("\n")
            return [TextEdit(Range(Position(0, 0), Position(lines + 1, 0)), formatted)]

        @self.feature(HOVER)
        def hover(params: TextDocumentPositionParams) -> Optional[Hover]:
            assert self._api is not None
            api = self._api

            word = self._cursor_word(params.textDocument.uri, params.position, True)
            if not word:
                return None

            candidates: List[Callable[[str], Optional[str]]] = [
                lambda x: api.get_command_doc(x.lower()),
                lambda x: api.get_variable_doc(x),
                lambda x: api.get_module_doc(x, False),
                lambda x: api.get_module_doc(x, True),
            ]
            for c in candidates:
                doc = c(word[0])
                if doc is None:
                    continue
                return Hover(MarkupContent(MarkupKind.Markdown, doc), word[1])
            return None

        @self.thread()
        @self.feature(TEXT_DOCUMENT_DID_SAVE, includeText=False)
        @self.feature(INITIALIZED)
        def run_cmake(*args: Any) -> None:
            assert self._api is not None

            if self._api.query():
                self._api.read_reply()

    def _cursor_function(self, uri: str, position: Position) -> Optional[str]:
        doc = self.workspace.get_document(uri)
        lines = doc.source.split("\n")[: position.line + 1]
        lines[-1] = lines[-1][: position.character - 1].strip()
        words = re.split(r"[\s\n()]+", "\n".join(lines))
        return words[-1] if words else None

    def _cursor_line(self, uri: str, position: Position) -> str:
        doc = self.workspace.get_document(uri)
        content = doc.source
        line = content.split("\n")[position.line]
        return str(line)

    def _cursor_word(
        self, uri: str, position: Position, include_all: bool = True
    ) -> Optional[Tuple[str, Range]]:
        line = self._cursor_line(uri, position)
        cursor = position.character
        for m in re.finditer(r"\w+", line):
            end = m.end() if include_all else cursor
            if m.start() <= cursor <= m.end():
                word = (
                    line[m.start() : end],
                    Range(
                        Position(position.line, m.start()), Position(position.line, end)
                    ),
                )
                return word
        return None


def main() -> None:
    from argparse import ArgumentParser

    from . import __version__

    parser = ArgumentParser(description="CMake Language Server")
    parser.add_argument(
        "--version", action="version", version=f"%(prog)s {__version__}"
    )
    parser.parse_args()

    logging.basicConfig(level=logging.INFO)
    logging.getLogger("pygls").setLevel(logging.WARNING)
    CMakeLanguageServer().start_io()