# Toolchain builder for the Serene programming language
#
# Copyright (c) 2019-2023 Sameer Rahmani <lxsameer@gnu.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 2.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
import os
import contextlib

import shutil
from pathlib import Path


class current_dir:
    def __init__(self, path):
        self.current = os.getcwd()
        self.target = path

    def __enter__(self):
        print(f"Entering dir: {self.target} from: {self.current}")
        os.chdir(self.target)
        return self

    def __exit__(self, exc_type, exc_value, exc_traceback):
        print(f"Exiting dir: {self.target}")
        os.chdir(self.current)


def get_version(pkg_name):
    env = os.environ.get(f"{pkg_name.upper()}_VERSION")

    if not env:
        raise ValueError(
            f"""Can't find the version for {pkg_name}!
        Did you forget to define the '{pkg_name.upper()}_VERSION' in the builder?"""
        )
    return env


def copy_tree(src, dst, preserve_symlinks=True, ignore=None):
    src = Path(src)
    dst = Path(dst)

    dst.mkdir(exist_ok=True, parents=True)

    for item in src.iterdir():
        skip_this = False
        if ignore:
            for pattern in ignore:
                if fnmatch(item.name, pattern):
                    skip_this = True
                    break
        if skip_this:
            continue
        if item.is_dir():
            copy_tree(
                item,
                dst / item.name,
                preserve_symlinks,
                ignore,
            )
        elif item.is_file() or item.is_symlink:
            try:
                shutil.copy2(
                    item, dst / item.name, follow_symlinks=not preserve_symlinks
                )
            except Exception as e:
                if not item.is_symlink:
                    raise e


def with_static_flags(cmake_vars={}):
    cmake_vars["CMAKE_C_FLAGS"] = f"-static {cmake_vars.get('CMAKE_C_FLAGS', '')}"
    cmake_vars["CMAKE_CXX_FLAGS"] = f"-static {cmake_vars.get('CMAKE_CXX_FLAGS', '')}"
    cmake_vars[
        "CMAKE_EXE_LINKER_FLAGS_INIT"
    ] = f"-static {cmake_vars.get('CMAKE_EXE_LINKER_FLAGS_INIT', '')}"
    return cmake_vars


def with_musl_toolchain(conanfile, tc, sysroot=None, envname="TARGET"):
    target = os.environ[envname]

    opts = {
        "CMAKE_SYSTEM_NAME": "Linux",
        "CMAKE_C_COMPILER": "clang",
        "CMAKE_CXX_COMPILER": "clang++",
        "CMAKE_ASM_COMPILER": "clang",
        "CMAKE_C_COMPILER_TARGET": target,
        # "CMAKE_C_FLAGS": f"--target={target}",
        "CMAKE_CXX_COMPILER_TARGET": target,
        # "CMAKE_CXX_FLAGS": f"--target={target}",
        "CMAKE_ASM_COMPILER_TARGET": target,
        # "CMAKE_ASM_FLAGS": f"--target={target}",
    }
    if sysroot:
        opts.update(
            {
                "CMAKE_SYSROOT": sysroot,
                "CMAKE_DEFAULT_SYSROOT": sysroot,
                "CMAKE_FIND_ROOT_PATH": sysroot,
                "CMAKE_FIND_ROOT_PATH_MODE_PROGRAM": "BOTH",
                "CMAKE_FIND_ROOT_PATH_MODE_LIBRARY": "ONLY",
                "CMAKE_FIND_ROOT_PATH_MODE_INCLUDE": "ONLY",
                "CMAKE_FIND_ROOT_PATH_MODE_PACKAGE": "ONLY",
            }
        )

    for k, v in opts.items():
        tc.variables[k] = v


def copy_template(conanfile, src, dest, varmap):
    result = Path(src).read_text()
    target_file = Path(dest)

    for k, v in varmap.items():
        print(f">> replacing @{k}@ with {str(v)}")
        result = result.replace(f"@{k}@", str(v))

    target_file.write_text(result)


def copy_dependency_tree(conanfile, dependencies_to_copy=[], dest=None):
    root = Path(conanfile.package_folder)
    if dest:
        root = Path(dest)

    for dependency in dependencies_to_copy:
        conanfile.output.info(f"Copy the tree of '{dependency}' to '{root}'")
        dep = Path(conanfile.dependencies[dependency].package_folder)

        for dir_path in ["include", "lib", "bin", "share"]:
            try:
                copy_tree(dep / dir_path, root / dir_path)
            except FileNotFoundError:
                conanfile.output.info(
                    f"Dir '{dep / dir_path}' does not exist, skipping"
                )


@contextlib.contextmanager
def chpath(path: Path) -> None:
    """
    Changes working directory and returns to previous on exit.
    """
    prev_cwd = Path.cwd()
    os.chdir(path)
    try:
        yield
    finally:
        os.chdir(prev_cwd)