#!/usr/bin/env nix-shell
#!nix-shell update-luarocks-shell.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, Optional
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 # type: ignore
from pluginupdate import Editor, update_plugins, FetchConfig, CleanEnvironment

PKG_LIST="maintainers/scripts/luarocks-packages.csv"
TMP_FILE="$(mktemp)"
GENERATED_NIXFILE="pkgs/development/lua-modules/generated-packages.nix"
LUAROCKS_CONFIG="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
    '''Name of the plugin, as seen on luarocks.org'''
    src: str
    '''address to the git repository'''
    ref: Optional[str]
    '''git reference (branch name/tag)'''
    version: Optional[str]
    '''Set it to pin a package '''
    server: Optional[str]
    '''luarocks.org registers packages under different manifests.
    Its value can be 'http://luarocks.org/dev'
    '''
    luaversion: Optional[str]
    '''Attribue of the lua interpreter if a package is available only for a specific lua version'''
    maintainers: Optional[str]
    ''' Optional string listing maintainers separated by spaces'''

    @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, callPackage, ... } @ args:
                final: prev:
                {
            """)
            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, config: FetchConfig):
        _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=config.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)
    custom_env = os.environ.copy()
    custom_env['LUAROCKS_CONFIG'] = LUAROCKS_CONFIG

    # we add --dev else luarocks wont find all the "scm" (=dev) versions of the
    # packages
	# , "--dev"
    cmd = [ "luarocks", "nix" ]

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

    # if plug.server == "src":
    if plug.src != "":
        if plug.src is None:
            msg = "src must be set when 'version' is set to \"src\" for package %s" % plug.name
            log.error(msg)
            raise RuntimeError(msg)
        log.debug("Updating from source %s", plug.src)
        cmd.append(plug.src)
    # update the plugin from luarocks
    else:
        cmd.append(plug.name)
        if plug.version and plug.version != "src":

            cmd.append(plug.version)

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

    if plug.luaversion:
        cmd.append(f"--lua-version={plug.luaversion}")

    log.debug("running %s", ' '.join(cmd))

    output = subprocess.check_output(cmd, env=custom_env, text=True)
    output = "callPackage(" + output.strip() + ") {};\n\n"
    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()

    update_plugins(editor, args)


if __name__ == "__main__":

    main()

#  vim: set ft=python noet fdm=manual fenc=utf-8 ff=unix sts=0 sw=4 ts=4 :