#!/usr/bin/env python3
import os
import subprocess
import time
import datetime
import argparse
import sys
from pathlib import Path

about_tool = """
Build toolchains using Spack.

This function builds toolchains for toolchains at the appropriate directory for the current system architecture
and MPSD software stack version.
The toolchains are built using the bash script spack_setup.sh, and the results are logged.
"""
config_vars = {
    "cmd_log_file": "logs/install-software-environment.log",
    "build_log_file": f"build_toolchains_mpsd_spack_ver_{time.strftime('%Y%m%d-%H%M%S')}.log", # TODO: modify toolchains,mpsd_spack_ver when the variable is available
    "spack_environments_repo": "https://gitlab.gwdg.de/mpsd-cs/spack-environments.git",

}
shared_var ={
    "script_branch": subprocess.run(["git", "rev-parse", "--abbrev-ref", "HEAD"], stdout=subprocess.PIPE).stdout.decode().strip(),
    "script_commit_hash": subprocess.run(["git", "rev-parse", "--short", "HEAD"], stdout=subprocess.PIPE).stdout.decode().strip(),
    "spe_branch": None,
    "spe_commit_hash": None,
    "available_toolchains": None,
    "toolchain_base_dir": None,

}

# Helper class to change directory via context manager
class os_chdir:
    def __init__(self, new_dir):
        self.new_dir = new_dir
        self.saved_dir = os.getcwd()

    def __enter__(self):
        os.chdir(self.new_dir)

    def __exit__(self, exc_type, exc_val, exc_tb):
        os.chdir(self.saved_dir)

def setup_log_cmd(shared_var, msg=None):
    # Create log directory if it doesn't exist
    if not os.path.exists("logs"):
        os.makedirs("logs")
    # Write to the log file with the following format
    # --------------------------------------------------
    # 2023-02-29T23:32:01, install-software-environment.py --release dev-23a --install ALL
    # Software environment installer branch: script_branch (commit hash: script_commit_hash)
    # Spack environments branch: dev-23a (commit hash: spe_commit_hash)
    # MSGs
    with open(config_vars['cmd_log_file'], "a") as f:
        if msg:
            f.write(msg + "\n")
        else:
            f.write("-" * 50 + "\n")
            cmd_line = " ".join(sys.argv)
            f.write(f"{datetime.datetime.now().isoformat()}, {cmd_line}\n")
            f.write(
                f"Software environment installer branch: {shared_var['script_branch']} (commit hash: {shared_var['script_commit_hash']})\n"
            )
            f.write(
                f"Spack environments branch: {shared_var['spe_branch']} (commit hash: {shared_var['spe_commit_hash']})\n"
            )




def main():
    parser = argparse.ArgumentParser(description=about_tool)
    parser.add_argument(
        "--release", type=str, help="Specify the release version to install"
    )
    parser.add_argument(
        "--target-directory",
        type=str,
        help="Specify the target directory for installation (use DEFAULT to use /opt_mpsd/<MPSD_OS>/<MPSD_RELEASE>/<MPSD_MICROARCH)",
    )
    parser.add_argument(
        "--install",
        nargs="+",
        help="Specify toolchain(s) to install eg foss2021a-mpi (use ALL to install all available toolchains)",
    )
    parser.add_argument("--remove", type=str, help="Specify toolchain to remove")
    parser.add_argument(
        "--set-up",
        type=str,
        help="Start a new software environment version, must specify --from <release>",
    )
    parser.add_argument(
        "--from",
        dest="from_release",
        type=str,
        help="Specify the release version to start from",
    )
    parser.add_argument(
        "--force-reinstall",
        action="store_true",
        help="Delete and reinstall an existing toolchain directory",
    )
    parser.add_argument(
        "--skip-build-cache",
        action="store_true",
        help="Skip Spack build cache during installation",
    )
    parser.add_argument(
        "--skip-dir-check",
        action="store_true",
        help="Skip checking if the target directory already exists",
    )

    args = parser.parse_args()

    if args.release is None:
        parser.print_help()
        sys.exit(1)

    if args.remove:
        cmd = "remove"
    elif args.set_up:
        cmd = "start_new"
    else:
        if args.install:
            cmd = "install"
        else:
            cmd = "prepare_env"
    run = builder(
        release=args.release,
        cmd=cmd,
        toolchain_list=args.install,
        target_dir=args.target_directory,
        # force_reinstall=args.force_reinstall,
        skip_build_cache=args.skip_build_cache,
    )
    run.run()


if __name__ == "__main__":
    main()