#!/usr/bin/env nix-shell
#!nix-shell update-luarocks-shell.nix -i bash

# You'll likely want to use
# ``
# nixpkgs $ maintainers/scripts/update-luarocks-packages pkgs/development/lua-modules/generated-packages.nix
# ``
# to update all libraries in that folder.
# to debug, redirect stderr to stdout with 2>&1

# stop the script upon C-C
set -eu -o pipefail

CSV_FILE="maintainers/scripts/luarocks-packages.csv"
TMP_FILE="$(mktemp)"
# Set in the update-luarocks-shell.nix
NIXPKGS_PATH="$LUAROCKS_NIXPKGS_PATH"
export LUAROCKS_CONFIG="$NIXPKGS_PATH/maintainers/scripts/luarocks-config.lua"

# 10 is a pretty arbitrary number of simultaneous jobs, but it is generally
# impolite to hit a webserver with *too* many simultaneous connections :)
PARALLEL_JOBS=1

exit_trap() {
    local lc="$BASH_COMMAND" rc=$?
    test $rc -eq 0 || echo -e "*** error $rc: $lc.\nGenerated temporary file in $TMP_FILE" >&2
}

print_help() {
    echo "Usage: $0 <GENERATED_FILE>"
    echo "(most likely pkgs/development/lua-modules/generated-packages.nix)"
    echo ""
    echo " -c <CSV_FILE> to set the list of luarocks package to generate"
    exit 1
}

if [ $# -lt 1 ]; then
    print_help
    exit 1
fi

trap exit_trap EXIT

while getopts ":hc:" opt; do
    case $opt in
    h)
        print_help
        ;;
    c)
        echo "Loading package list from $OPTARG !" >&2
        CSV_FILE="$OPTARG"
        ;;
    \?)
        echo "Invalid option: -$OPTARG" >&2
        ;;
    esac
    shift $((OPTIND - 1))
done

GENERATED_NIXFILE="$1"

HEADER="
/* ${GENERATED_NIXFILE} is an auto-generated file -- DO NOT EDIT!
Regenerate it with:
nixpkgs$ ${0} ${GENERATED_NIXFILE}

These packages are manually refined in lua-overrides.nix
*/
{ self, stdenv, lib, fetchurl, fetchgit, pkgs, ... } @ args:
self: super:
with self;
{
"

FOOTER="
}
/* GENERATED */
"

function convert_pkg() {
    nix_pkg_name="$1"
    lua_pkg_name="$2"
    server="$3"
    pkg_version="$4"
    lua_version="$5"
    maintainers="$6"

    if [ "${nix_pkg_name:0:1}" == "#" ]; then
        echo "Skipping comment ${*}" >&2
        return
    fi

    # Normalize package name
    nix_pkg_name_normalized=$(sed 's/\./-/' <(echo "$nix_pkg_name"))

    if [ -z "$lua_pkg_name" ]; then
        echo "Using nix_name as lua_pkg_name for '$nix_pkg_name'" >&2
        lua_pkg_name="$nix_pkg_name"
    fi

    echo "Building expression for $lua_pkg_name (version $pkg_version) from server [$server]" >&2
    luarocks_args=(nix)
    if [[ -n $server ]]; then
        luarocks_args+=("--only-server=$server")
    fi
    if [[ -n $maintainers ]]; then
        luarocks_args+=("--maintainers=$maintainers")
    fi
    if [[ -n $lua_version ]]; then
        lua_drv_path=$(nix-build --no-out-link "$NIXPKGS_PATH" -A "$lua_version")
        luarocks_args+=("--lua-dir=$lua_drv_path/bin")
    fi
    luarocks_args+=("$lua_pkg_name")
    if [[ -n $pkg_version ]]; then
        luarocks_args+=("$pkg_version")
    fi
    echo "Running 'luarocks ${luarocks_args[*]}'" >&2
    if drv="$nix_pkg_name_normalized = $(luarocks "${luarocks_args[@]}")"; then
        echo "$drv"
    else
        echo "Failed to convert $nix_pkg_name" >&2
        return 1
    fi
}

# params needed when called via callPackage
echo "$HEADER" | tee "$TMP_FILE"

# Ensure parallel can run our bash function
export -f convert_pkg
export SHELL=bash
# Read each line in the csv file and run convert_pkg for each, in parallel
parallel --group --keep-order --halt now,fail=1 --jobs "$PARALLEL_JOBS" --colsep ',' convert_pkg {} <"$CSV_FILE" | tee -a "$TMP_FILE"

# close the set
echo "$FOOTER" | tee -a "$TMP_FILE"

cp "$TMP_FILE" "$GENERATED_NIXFILE"

# vim: set ts=4 sw=4 ft=sh: