"""SVDManager — combines SVD parsing, register decoding, and hardware reads.

This is the primary interface for SVD-based register inspection. It ties
the SVD parser, bitfield decoder, and the Memory subsystem together so
callers can do things like:

    decoded = await svd.read_register("GPIOA", "ODR")
    print(decoded)
"""

from __future__ import annotations

import asyncio
import logging
from pathlib import Path
from typing import TYPE_CHECKING

from openocd.svd.decoder import decode_register
from openocd.svd.parser import SVDParserWrapper
from openocd.types import DecodedRegister

if TYPE_CHECKING:
    from openocd.connection.base import Connection
    from openocd.memory import Memory

log = logging.getLogger(__name__)


class SVDManager:
    """High-level SVD register access: parse, read, decode."""

    def __init__(self, conn: Connection, memory: Memory) -> None:
        self._conn = conn
        self._memory = memory
        self._parser = SVDParserWrapper()

    @property
    def loaded(self) -> bool:
        """Whether an SVD file has been loaded."""
        return self._parser.loaded

    async def load(self, svd_path: Path) -> None:
        """Parse an SVD file and make its peripherals available.

        This is a synchronous file parse wrapped in the async interface
        for consistency with the rest of the API.

        Args:
            svd_path: Path to the .svd XML file.

        Raises:
            SVDError: If the file is missing or unparseable.
        """
        await asyncio.to_thread(self._parser.load, svd_path)

    def list_peripherals(self) -> list[str]:
        """Return sorted peripheral names from the loaded SVD.

        Raises:
            SVDError: If no SVD is loaded.
        """
        return self._parser.list_peripherals()

    def list_registers(self, peripheral: str) -> list[str]:
        """Return sorted register names for a peripheral.

        Args:
            peripheral: Peripheral name (e.g. "GPIOA").

        Raises:
            SVDError: If no SVD is loaded or peripheral not found.
        """
        return self._parser.list_registers(peripheral)

    async def read_register(self, peripheral: str, register: str) -> DecodedRegister:
        """Read a register from hardware and decode it using SVD metadata.

        This is the primary method: it computes the register's memory-mapped
        address from the SVD, reads 32 bits from the target, and returns
        a fully decoded result with named bitfields.

        Args:
            peripheral: Peripheral name (e.g. "GPIOA").
            register: Register name (e.g. "ODR").

        Returns:
            DecodedRegister with address, raw value, and decoded fields.

        Raises:
            SVDError: If peripheral/register not found.
            TargetError: If the memory read fails.
        """
        periph_obj = self._parser.get_peripheral(peripheral)
        reg_obj = self._parser.get_register(peripheral, register)
        address = periph_obj.base_address + reg_obj.address_offset

        values = await self._memory.read_u32(address)
        raw = values[0]
        return decode_register(periph_obj, reg_obj, raw)

    async def read_peripheral(self, peripheral: str) -> dict[str, DecodedRegister]:
        """Read and decode every register in a peripheral.

        Args:
            peripheral: Peripheral name.

        Returns:
            Dict mapping register name to its DecodedRegister.

        Raises:
            SVDError: If peripheral not found.
            TargetError: If any memory read fails.
        """
        periph_obj = self._parser.get_peripheral(peripheral)
        registers = periph_obj.registers or []
        result: dict[str, DecodedRegister] = {}

        for reg_obj in registers:
            address = periph_obj.base_address + reg_obj.address_offset
            try:
                values = await self._memory.read_u32(address)
                raw = values[0]
                result[reg_obj.name] = decode_register(periph_obj, reg_obj, raw)
            except Exception as exc:
                log.warning(
                    "Failed to read %s.%s @ 0x%08X: %s",
                    peripheral,
                    reg_obj.name,
                    address,
                    exc,
                )
                # Skip unreadable registers (write-only, reserved, etc.)

        return result

    def decode(self, peripheral: str, register: str, value: int) -> DecodedRegister:
        """Decode a raw value without reading hardware.

        Useful when you already have the register value (from a log,
        a previous read, or a known reset value).

        Args:
            peripheral: Peripheral name.
            register: Register name.
            value: Raw 32-bit register value.

        Returns:
            DecodedRegister with the decoded bitfields.
        """
        periph_obj = self._parser.get_peripheral(peripheral)
        reg_obj = self._parser.get_register(peripheral, register)
        return decode_register(periph_obj, reg_obj, value)


class SyncSVDManager:
    """Synchronous wrapper around SVDManager."""

    def __init__(self, manager: SVDManager, loop: asyncio.AbstractEventLoop) -> None:
        self._manager = manager
        self._loop = loop

    @property
    def loaded(self) -> bool:
        return self._manager.loaded

    def load(self, svd_path: Path) -> None:
        self._loop.run_until_complete(self._manager.load(svd_path))

    def list_peripherals(self) -> list[str]:
        return self._manager.list_peripherals()

    def list_registers(self, peripheral: str) -> list[str]:
        return self._manager.list_registers(peripheral)

    def read_register(self, peripheral: str, register: str) -> DecodedRegister:
        return self._loop.run_until_complete(
            self._manager.read_register(peripheral, register)
        )

    def read_peripheral(self, peripheral: str) -> dict[str, DecodedRegister]:
        return self._loop.run_until_complete(
            self._manager.read_peripheral(peripheral)
        )

    def decode(self, peripheral: str, register: str, value: int) -> DecodedRegister:
        return self._manager.decode(peripheral, register, value)