# Copyright 2023 Attila Szollosi
# SPDX-License-Identifier: GPL-3.0-or-later
from pathlib import Path
from pmb.helpers import logging
import re
import os
from typing import Literal, overload

import pmb.build
import pmb.config
import pmb.parse
import pmb.helpers.pmaports
import pmb.parse.kconfigcheck
from pmb.helpers.exceptions import NonBugError
from pmb.types import PathString


def is_set(config: str, option: str) -> bool:
    """
    Check, whether a boolean or tristate option is enabled
    either as builtin or module.

    :param config: full kernel config as string
    :param option: name of the option to check, e.g. EXT4_FS
    :returns: True if the check passed, False otherwise
    """
    return re.search("^CONFIG_" + option + "=[ym]$", config, re.M) is not None


def is_set_str(config: str, option: str, string: str) -> bool:
    """
    Check, whether a config option contains a string as value.

    :param config: full kernel config as string
    :param option: name of the option to check, e.g. EXT4_FS
    :param string: the expected string
    :returns: True if the check passed, False otherwise
    """
    match = re.search("^CONFIG_" + option + '="(.*)"$', config, re.M)
    if match:
        return string == match.group(1)
    else:
        return False


def is_in_array(config: str, option: str, string: str) -> bool:
    """
    Check, whether a config option contains string as an array element

    :param config: full kernel config as string
    :param option: name of the option to check, e.g. EXT4_FS
    :param string: the string expected to be an element of the array
    :returns: True if the check passed, False otherwise
    """
    match = re.search("^CONFIG_" + option + '="(.*)"$', config, re.M)
    if match:
        values = match.group(1).split(",")
        return string in values
    else:
        return False


def check_option(
    component: str,
    details: bool,
    config: str,
    config_path: PathString,
    option: str,
    option_value: bool | str | list[str],
) -> bool:
    """
    Check, whether one kernel config option has a given value.

    :param component: name of the component to test (postmarketOS, waydroid, …)
    :param details: print all warnings if True, otherwise one per component
    :param config: full kernel config as string
    :param config_path: full path to kernel config file
    :param option: name of the option to check, e.g. EXT4_FS
    :param option_value: expected value, e.g. True, "str", ["str1", "str2"]
    :returns: True if the check passed, False otherwise
    """

    def warn_ret_false(should_str: str) -> bool:
        config_name = os.path.basename(config_path)
        if details:
            logging.warning(
                f"WARNING: {config_name}: CONFIG_{option} should {should_str} ({component})"
            )
        else:
            logging.warning(
                f"WARNING: {config_name} isn't configured properly"
                f" ({component}), run 'pmbootstrap kconfig check'"
                " for details!"
            )
        return False

    if isinstance(option_value, list):
        for string in option_value:
            if not is_in_array(config, option, string):
                return warn_ret_false(f'contain "{string}"')
    elif isinstance(option_value, str):
        if not is_set_str(config, option, option_value):
            return warn_ret_false(f'be set to "{option_value}"')
    elif option_value in [True, False]:
        if option_value != is_set(config, option):
            return warn_ret_false("be set" if option_value else "*not* be set")
    else:
        raise RuntimeError(
            "kconfig check code can only handle booleans,"
            f" strings and arrays. Given value {option_value}"
            " is not supported. If you need this, please patch"
            " pmbootstrap or open an issue."
        )
    return True


def check_config_options_set(
    config: str,
    config_path: PathString,
    config_arch: str,  # TODO: Replace with Arch type?
    options: dict[str, dict],
    component: str,
    pkgver: str,
    details: bool = False,
) -> bool:
    """
    Check, whether all the kernel config passes all rules of one component.

    Print a warning if any is missing.

    :param config: full kernel config as string
    :param config_path: full path to kernel config file
    :param config_arch: architecture name (alpine format, e.g. aarch64, x86_64)
    :param options: dictionary returned by pmb.parse.kconfigcheck.read_category().
    :param component: name of the component to test (postmarketOS, waydroid, …)
    :param pkgver: kernel version
    :param details: print all warnings if True, otherwise one per component
    :returns: True if the check passed, False otherwise
    """
    ret = True
    for rules, archs_options in options.items():
        # Skip options irrelevant for the current kernel's version
        # Example rules: ">=4.0 <5.0"
        skip = False
        for rule in rules.split(" "):
            if not pmb.parse.version.check_string(pkgver, rule):
                skip = True
                break
        if skip:
            continue

        for archs, arch_options in archs_options.items():
            if archs != "all":
                # Split and check if the device's architecture architecture has
                # special config options. If option does not contain the
                # architecture of the device kernel, then just skip the option.
                architectures = archs.split(" ")
                if config_arch not in architectures:
                    continue

            for option, option_value in arch_options.items():
                if not check_option(component, details, config, config_path, option, option_value):
                    ret = False
                    # Stop after one non-detailed error
                    if not details:
                        return False
    return ret


# TODO: This should probably use Arch and not str for config_arch
def check_config(
    config_path: PathString,
    config_arch: str,
    pkgver: str,
    categories: list[str],
    details: bool = False,
) -> bool:
    """
    Check, whether one kernel config passes the rules of multiple components.

    :param config_path: full path to kernel config file
    :param config_arch: architecture name (alpine format, e.g. aarch64, x86_64)
    :param pkgver: kernel version
    :param categories: what to check for, e.g. ["waydroid", "iwd"]
    :param details: print all warnings if True, otherwise one per component
    :returns: True if the check passed, False otherwise
    """
    logging.debug(f"Check kconfig: {config_path}")
    with open(config_path) as handle:
        config = handle.read()

    if "default" not in categories:
        categories += ["default"]

    # Get all rules
    rules: dict = {}
    for category in categories:
        rules |= pmb.parse.kconfigcheck.read_category(category)

    # Check the rules of each category
    ret = []
    for category in rules.keys():
        ret += [
            check_config_options_set(
                config, config_path, config_arch, rules[category], category, pkgver, details
            )
        ]

    return all(ret)


@overload
def check(
    pkgname: str,
    components_list: list[str] = ...,
    details: bool = ...,
    must_exist: Literal[False] = ...,
) -> bool | None: ...


@overload
def check(
    pkgname: str,
    components_list: list[str] = ...,
    details: bool = ...,
    must_exist: Literal[True] = ...,
) -> bool: ...


def check(
    pkgname: str, components_list: list[str] = [], details: bool = False, must_exist: bool = True
) -> bool | None:
    """
    Check for necessary kernel config options in a package.

    :param pkgname: the package to check for, optionally without "linux-"
    :param components_list: what to check for, e.g. ["waydroid", "iwd"]
    :param details: print all warnings if True, otherwise one generic warning
    :param must_exist: if False, just return if the package does not exist
    :returns: True when the check was successful, False otherwise
              None if the aport cannot be found (only if must_exist=False)
    """
    # Don't modify the original component_list (arguments are passed as
    # reference, a list is not immutable)
    components_list = components_list.copy()

    # Pkgname: allow omitting "linux-" prefix
    if pkgname.startswith("linux-"):
        flavor = pkgname.split("linux-")[1]
    else:
        flavor = pkgname

    # Read all kernel configs in the aport
    ret = True
    aport: Path
    try:
        aport = pmb.helpers.pmaports.find("linux-" + flavor)
    except RuntimeError as e:
        if must_exist:
            raise e
        return None
    apkbuild = pmb.parse.apkbuild(aport / "APKBUILD")
    pkgver = apkbuild["pkgver"]

    # Get categories from the APKBUILD
    categories = []
    for option in apkbuild["options"]:
        if not option.startswith("pmb:kconfigcheck-"):
            continue
        category = option.split("-", 1)[1]
        categories += [category]

    for config_path in aport.glob("config-*"):
        # The architecture of the config is in the name, so it just needs to be
        # extracted
        config_name = os.path.basename(config_path)
        config_name_split = config_name.split(".")

        if len(config_name_split) != 2:
            raise NonBugError(
                f"{config_name} is not a valid kernel config"
                "name. Ensure that the _config property in your "
                "kernel APKBUILD has a . before the "
                "architecture name, e.g. .aarch64 or .armv7, "
                "and that there is no excess punctuation "
                "elsewhere in the name."
            )

        config_arch = config_name_split[1]
        ret &= check_config(
            config_path,
            config_arch,
            pkgver,
            categories,
            details=details,
        )
    return ret


# TODO: Make this use the Arch type probably
def extract_arch(config_path: PathString) -> str:
    # Extract the architecture out of the config
    with open(config_path) as f:
        config = f.read()
    if is_set(config, "ARM"):
        return "armv7"
    elif is_set(config, "ARM64"):
        return "aarch64"
    elif is_set(config, "RISCV"):
        return "riscv64"
    elif is_set(config, "X86_32"):
        return "x86"
    elif is_set(config, "X86_64"):
        return "x86_64"

    # No match
    logging.info("WARNING: failed to extract arch from kernel config")
    return "unknown"


def extract_version(config_path: PathString) -> str:
    # Try to extract the version string out of the comment header
    with open(config_path) as f:
        # Read the first 3 lines of the file and get the third line only
        text = [next(f) for x in range(3)][2]
    ver_match = re.match(r"# Linux/\S+ (\S+) Kernel Configuration", text)
    if ver_match:
        return ver_match.group(1).replace("-", "_")

    # No match
    logging.info("WARNING: failed to extract version from kernel config")
    return "unknown"


def check_file(
    config_path: PathString, components_list: list[str] = [], details: bool = False
) -> bool:
    """
    Check for necessary kernel config options in a kconfig file.

    :param config_path: full path to kernel config file
    :param components_list: what to check for, e.g. ["waydroid", "iwd"]
    :param details: print all warnings if True, otherwise one generic warning
    :returns: True when the check was successful, False otherwise
    """
    arch = extract_arch(config_path)
    version = extract_version(config_path)
    logging.debug(f"Check kconfig: parsed arch={arch}, version={version} from file: {config_path}")
    return check_config(config_path, arch, version, components_list, details=details)