#!/usr/bin/env nix-shell
#!nix-shell -p nix-prefetch-git luarocks-nix python3 python3Packages.GitPython nix -i python3

# format:
# $ nix run nixpkgs.python3Packages.black -c black update.py
# type-check:
# $ nix run nixpkgs.python3Packages.mypy -c mypy update.py
# linted:
# $ nix run nixpkgs.python3Packages.flake8 -c flake8 --ignore E501,E265,E402 update.py

import inspect
import os
import tempfile
import shutil
from dataclasses import dataclass
import subprocess
import csv
import logging
import textwrap
from multiprocessing.dummy import Pool

from typing import List, Tuple
from pathlib import Path

log = logging.getLogger()
log.addHandler(logging.StreamHandler())

ROOT = Path(os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe())))).parent.parent
from pluginupdate import Editor, update_plugins, PluginDesc, CleanEnvironment, LOG_LEVELS, Cache

PKG_LIST="maintainers/scripts/luarocks-packages.csv"
TMP_FILE="$(mktemp)"
GENERATED_NIXFILE="pkgs/development/lua-modules/generated-packages.nix"
LUAROCKS_CONFIG="$NIXPKGS_PATH/maintainers/scripts/luarocks-config.lua"

HEADER = """
/* {GENERATED_NIXFILE} is an auto-generated file -- DO NOT EDIT!
Regenerate it with:
nixpkgs$ ./maintainers/scripts/update-luarocks-packages

You can customize the generated packages in pkgs/development/lua-modules/overrides.nix
*/
""".format(GENERATED_NIXFILE=GENERATED_NIXFILE)

FOOTER="""
}
/* GENERATED - do not edit this file */
"""

@dataclass
class LuaPlugin:
    name: str
    version: str
    server: str
    luaversion: str
    maintainers: str

    @property
    def normalized_name(self) -> str:
        return self.name.replace(".", "-")

# rename Editor to LangUpdate/ EcosystemUpdater
class LuaEditor(Editor):
    def get_current_plugins(self):
        return []

    def load_plugin_spec(self, input_file) -> List[LuaPlugin]:
        luaPackages = []
        csvfilename=input_file
        log.info("Loading package descriptions from %s", csvfilename)

        with open(csvfilename, newline='') as csvfile:
            reader = csv.DictReader(csvfile,)
            for row in reader:
                # name,server,version,luaversion,maintainers
                plugin = LuaPlugin(**row)
                luaPackages.append(plugin)
        return luaPackages

    def generate_nix(
        self,
        results: List[Tuple[LuaPlugin, str]],
        outfilename: str
        ):

        with tempfile.NamedTemporaryFile("w+") as f:
            f.write(HEADER)
            header2 = textwrap.dedent(
            # header2 = inspect.cleandoc(
            """
                { self, stdenv, lib, fetchurl, fetchgit, ... } @ args:
                self: super:
                with self;
                {
            """)
            f.write(header2)
            for (plugin, nix_expr) in results:
                f.write(f"{plugin.normalized_name} = {nix_expr}")
            f.write(FOOTER)
            f.flush()

            # if everything went fine, move the generated file to its destination
            # using copy since move doesn't work across disks
            shutil.copy(f.name, outfilename)

        print(f"updated {outfilename}")

    @property
    def attr_path(self):
        return "luaPackages"

    def get_update(self, input_file: str, outfile: str, proc: int):
        _prefetch = generate_pkg_nix

        def update() -> dict:
            plugin_specs = self.load_plugin_spec(input_file)
            sorted_plugin_specs = sorted(plugin_specs, key=lambda v: v.name.lower())

            try:
                pool = Pool(processes=proc)
                results = pool.map(_prefetch, sorted_plugin_specs)
            finally:
                pass

            self.generate_nix(results, outfile)

            redirects = []
            return redirects

        return update

    def rewrite_input(self, input_file: str, *args, **kwargs):
        # vim plugin reads the file before update but that shouldn't be our case
        # not implemented yet
        # fieldnames = ['name', 'server', 'version', 'luaversion', 'maintainers']
        # input_file = "toto.csv"
        # with open(input_file, newline='') as csvfile:
        #     writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
        #     writer.writeheader()
        #     for row in reader:
        #         # name,server,version,luaversion,maintainers
        #         plugin = LuaPlugin(**row)
        #         luaPackages.append(plugin)
        pass

def generate_pkg_nix(plug: LuaPlugin):
    '''
    Generate nix expression for a luarocks package
    Our cache key associates "p.name-p.version" to its rockspec
    '''
    log.debug("Generating nix expression for %s", plug.name)
    cmd = [ "luarocks", "nix", plug.name]

    if plug.server:
        cmd.append(f"--only-server={plug.server}")

    if plug.maintainers:
        cmd.append(f"--maintainers={plug.maintainers}")

    if plug.version:
        cmd.append(plug.version)

    if plug.luaversion:
        with CleanEnvironment():
            local_pkgs = str(ROOT.resolve())
            cmd2 = ["nix-build", "--no-out-link", local_pkgs, "-A", f"{plug.luaversion}"]

            log.debug("running %s", ' '.join(cmd2))
            lua_drv_path=subprocess.check_output(cmd2, text=True).strip()
            cmd.append(f"--lua-dir={lua_drv_path}/bin")

    log.debug("running %s", cmd)
    output = subprocess.check_output(cmd, text=True)
    return (plug, output)

def main():

    editor = LuaEditor("lua", ROOT, '',
        default_in = ROOT.joinpath(PKG_LIST),
        default_out = ROOT.joinpath(GENERATED_NIXFILE)
        )

    parser = editor.create_parser()
    args = parser.parse_args()
    log.setLevel(LOG_LEVELS[args.debug])

    update_plugins(editor, args)


if __name__ == "__main__":

    main()