"""SCPI command parsing.

This module provides SCPI (Standard Commands for Programmable Instruments)
command parsing for instrument communication. It handles IEEE 488.2 common
commands (*IDN?, *RST, etc.) and instrument-specific commands.
"""

from dataclasses import dataclass


@dataclass
class SCPICommand:
    """Parsed SCPI command.

    Attributes:
        header: The command header (e.g., "TEMP:SETPOINT" or "*IDN").
        arguments: List of command arguments (e.g., ["85.0"]).
        is_query: True if the command ends with '?' (query command).
    """

    header: str
    arguments: list[str]
    is_query: bool

    @property
    def keyword(self) -> str:
        """Return the command keyword without '?'.

        For query commands like "TEMP:SETPOINT?", returns "TEMP:SETPOINT".
        For regular commands like "VOLT", returns "VOLT".
        """
        return self.header.rstrip("?")


class SCPIParser:
    """Parse SCPI command strings.

    Handles both IEEE 488.2 common commands (e.g., *IDN?, *RST) and
    instrument-specific commands (e.g., VOLT 3.3, TEMP:SETPOINT?).

    Examples:
        >>> parser = SCPIParser()
        >>> cmd = parser.parse("*IDN?")
        >>> cmd.header, cmd.is_query
        ('*IDN?', True)
        >>> cmd = parser.parse("VOLT 3.3")
        >>> cmd.header, cmd.arguments
        ('VOLT', ['3.3'])
    """

    def parse(self, command_string: str) -> SCPICommand:
        """Parse a SCPI command string.

        Args:
            command_string: The raw SCPI command string to parse.

        Returns:
            SCPICommand with parsed header, arguments, and query flag.

        Examples:
            "*IDN?" -> SCPICommand("*IDN?", [], True)
            "VOLT 3.3" -> SCPICommand("VOLT", ["3.3"], False)
            "TEMP:SETPOINT?" -> SCPICommand("TEMP:SETPOINT?", [], True)
            "CONF:VOLT:DC 10,0.001" -> SCPICommand("CONF:VOLT:DC", ["10", "0.001"], False)
        """
        command_string = command_string.strip()
        if not command_string:
            return SCPICommand(header="", arguments=[], is_query=False)

        # Split into header and arguments on first whitespace
        parts = command_string.split(None, 1)
        header = parts[0]
        arguments: list[str] = []

        if len(parts) > 1:
            # Parse comma-separated arguments
            arg_string = parts[1]
            arguments = [arg.strip() for arg in arg_string.split(",")]

        # Query is determined by whether the header ends with '?'
        is_query = header.endswith("?")

        return SCPICommand(
            header=header,
            arguments=arguments,
            is_query=is_query,
        )