#!/usr/bin/env python3

"""Parses pacstall packages into JSON."""

import sys
from json import dumps
from pathlib import Path
from shutil import rmtree
from subprocess import PIPE, Popen, run


def extract_var(line: str, var: str) -> str:
    """
    Strips off ``var=`` and quotes from a line and returns the variable.

    Parameters
    ----------
    line (str): The pacscript line.
    var (str): The variable to extract.

    Returns
    -------
    Extracted variable.
    """

    return line.replace(var, "").strip('"')


def query_data(pacscript_reader_process: "Popen[bytes]", query_command: str) -> str:
    """
    Queries data off of the pacscript reading subprocess.

    Parameters
    ----------
    pacscript_reader_process (Popen[bytes]): The pacscript reading subprocess.
    query_command (str): The command to execute in the ``pacscript_reader_process``.

    Returns
    -------
    The output of ``query_command`` in the subprocess.
    """

    if pacscript_reader_process.stdin is None:
        sys.exit("FATAL ERROR: Can't send commands to the pacscript reader!")
    if pacscript_reader_process.stdout is None:
        sys.exit("FATAL ERROR: Can't read output from the pacscript reader!")

    pacscript_reader_process.stdin.write(f"{query_command}\n".encode())
    pacscript_reader_process.stdin.flush()
    return pacscript_reader_process.stdout.readline().decode("utf-8").strip()


def main() -> None:
    """Main function."""

    CLONED_PACKAGES_DIR = Path("/tmp/pacparse")
    JSON = Path("pacstall.json")
    PACKAGE_LIST = CLONED_PACKAGES_DIR / "packagelist"

    if CLONED_PACKAGES_DIR.exists():
        rmtree(CLONED_PACKAGES_DIR)

    REPOSITORY_URL = "https://github.com/pacstall/pacstall-programs"
    # Clone the repo
    run(
        [
            "git",
            "clone",
            "--depth",
            "1",
            f"{REPOSITORY_URL}.git",
            CLONED_PACKAGES_DIR,
        ],
        check=True,
    )

    # Changed changed_pacscripts = all packages if none are specified
    # Otherwise changed_pacscripts = specified packages + all git packages
    changed_pacscripts = all_pacscripts = PACKAGE_LIST.read_text().splitlines()
    try:
        if sys.argv[1] in ["-p", "--packages"]:
            # Get the pacscript files supplied
            changed_pacscripts = [
                changed_package.split("/")[-1].replace(".pacscript", "")
                for changed_package in sys.argv[2:]
                if changed_package.endswith(".pacscript")
            ]

            for pacscript in all_pacscripts:
                if "-git" in pacscript:
                    changed_pacscripts.append(pacscript)

    except IndexError:
        pass

    print(f"\nComputing: {changed_pacscripts}\n")

    NAME = "name="
    VERSION = "version="
    URL = "url="
    DESCRIPTION = "description="
    DEPENDS = "depends="
    BUILD_DEPENDS = "build_depends="
    MAINTAINER = "maintainer="

    repology_data = {}
    for package in changed_pacscripts:
        print(f"Current Package: {package}")

        pacscript_data = {}
        pacscript_file = CLONED_PACKAGES_DIR / f"packages/{package}/{package}.pacscript"

        pacscript_reader = Popen(["/bin/bash"], stdin=PIPE, stdout=PIPE)

        if pacscript_reader.stdin is None:
            sys.exit("FATAL ERROR: Can't send commands to the pacscript reader!")

        pacscript_reader.stdin.write(f"source {pacscript_file}\n".encode())
        pacscript_reader.stdin.flush()

        try:
            pacscript_lines = pacscript_file.read_text().splitlines()
        except FileNotFoundError:
            print(f"Warning: '{pacscript_file}' not found")
            continue

        name = ""
        for line in pacscript_lines:
            if line.startswith(NAME):
                name = extract_var(line, NAME)

            elif line.startswith(VERSION):
                if any(
                    char in (version := extract_var(line, VERSION))
                    for char in ["$", "\\"]
                ):
                    version = query_data(pacscript_reader, "echo ${version}")
                pacscript_data["version"] = version

            elif line.startswith(URL):
                if any(char in (url := extract_var(line, URL)) for char in ["$", "\\"]):
                    url = query_data(pacscript_reader, "echo ${url}")
                pacscript_data["url"] = url

            elif line.startswith(DESCRIPTION):
                if any(
                    char in (description := extract_var(line, DESCRIPTION))
                    for char in ["$", "\\"]
                ):
                    description = query_data(pacscript_reader, "echo ${description}")
                pacscript_data["summary"] = description

            elif line.startswith(DEPENDS):
                if any(
                    char in (depends := extract_var(line, DEPENDS))
                    for char in ["$", "\\"]
                ):
                    depends = query_data(pacscript_reader, "echo ${depends}")
                try:
                    pacscript_data["dependencies"] += f" {depends}"
                except KeyError:
                    pacscript_data["dependencies"] = depends

            elif line.startswith(BUILD_DEPENDS):
                if any(
                    char in (build_depends := extract_var(line, BUILD_DEPENDS))
                    for char in ["$", "\\"]
                ):
                    build_depends = query_data(
                        pacscript_reader, "echo ${build_depends}"
                    )
                build_depends = query_data(pacscript_reader, "echo ${build_depends}")
                try:
                    pacscript_data["dependencies"] += f" {build_depends}"
                except KeyError:
                    pacscript_data["dependencies"] = build_depends

            elif line.startswith(MAINTAINER):
                if any(
                    char in (maintainer := extract_var(line, MAINTAINER))
                    for char in ["$", "\\"]
                ):
                    maintainer = query_data(pacscript_reader, "echo ${maintainer}")
                pacscript_data["maintainer"] = maintainer

        pacscript_data[
            "recipe"
        ] = f"{REPOSITORY_URL}/blob/master/packages/{name}/{name}.pacscript"
        repology_data[name] = pacscript_data

        pacscript_reader.stdin.close()
        pacscript_reader.wait()

    with open(JSON, "w") as file:
        print(f"Writing file: {JSON}")
        file.write(dumps(repology_data, indent="\t"))


if __name__ == "__main__":
    main()