#!/bin/sh
set -eu

TARBALL_TEMPLATE='https://git.euandreh.xyz/@NAME@/snapshot/@NAME@-@VERSION@.tar.gz'

tarball_url() {
  NAME="$1"
  VERSION="$2"
  echo "$TARBALL_TEMPLATE" | \
    sed -e "s/@NAME@/$NAME/g" \
        -e "s/@VERSION@/$VERSION/g"
}

gen_guix() {
  GUIX_OUT="$(mktemp)"

  cat <<EOF >>"$GUIX_OUT"
(define-module (xyz euandreh packages)
  #:use-module (json)
  #:use-module ((ice-9 textual-ports) #:prefix textual-ports:)
  #:use-module ((guix licenses) #:prefix license:)
  #:use-module (gnu packages)
  #:use-module (guix transformations)
  #:use-module (guix gexp)
  #:use-module (guix packages)
  #:use-module (guix download)
  #:use-module (guix git-download)
  #:use-module (guix utils)
  #:use-module (guix store)
  #:use-module (guix build-system gnu))
EOF

  for p in $(jq -r '.packages[] | @base64' < paku.json); do
    NAME="$(echo "$p" | base64 --decode | jq -r '.name')"
    VERSION="$(echo "$p" | base64 --decode | jq -r '.version')"
  
    TARBALL="$(tarball_url "$NAME" "$VERSION")"
    SHA256="$(guix download "$TARBALL" | tail -n 1)"
  
    JSON_CHECK_INPUTS="$(echo "$p" | base64 --decode | jq -r '.check_inputs')"
    if [ "$JSON_CHECK_INPUTS" = 'null' ]; then
      CHECK_INPUTS=''
    else
      INPUTS=''
      for check_input in $(echo "$JSON_CHECK_INPUTS" | jq -r '.[]'); do
        if [ "$INPUTS" = '' ]; then
          INPUTS="(\"$check_input\" ,(specification->package \"$check_input\"))"
        else
          INPUTS="$INPUTS
        (\"$check_input\" ,(specification->package \"$check_input\"))"
        fi
      done

      CHECK_INPUTS="
    (inputs
      \`($INPUTS))"
    fi

    cat <<EOF >>"$GUIX_OUT"

(define-public $NAME
  (package
    (name "$NAME")
    (version "$VERSION")
    (source (origin
              (method url-fetch)
              (uri (string-append
                     "https://git.euandreh.xyz/$NAME/snapshot/$NAME-"
                     version
                     ".tar.gz"))
              (sha256
                (base32
                  "$SHA256"))))
    (build-system gnu-build-system)$CHECK_INPUTS
    (arguments \`(#:make-flags (list (string-append "CC=" ,(cc-for-target)))))
    (synopsis (file-append source "/description"))
    (description (file-append source "/long-description"))
    (home-page (string-append "https://" name ".euandreh.xyz"))
    (license license:agpl3+)))
EOF
  done
  
  printf '\n(list' >>"$GUIX_OUT"
  for name in $(jq -r '.packages[].name' < paku.json); do
    printf '\n  %s' "$name" >>"$GUIX_OUT"
  done
  printf ')\n' >>"$GUIX_OUT"

  mv "$GUIX_OUT" src/xyz/euandreh/packages.scm
}

gen_nix() {
  NIX_OUT="$(mktemp)"

  cat <<EOF >>"$NIX_OUT"
{ pkgs }:
self: super: {
  xyz-euandreh = {
EOF

  for p in $(jq -r '.packages[] | @base64' < paku.json); do
    NAME="$(echo "$p" | base64 --decode | jq -r '.name')"
    VERSION="$(echo "$p" | base64 --decode | jq -r '.version')"
    TARBALL="$(tarball_url "$NAME" "$VERSION")"
    SHA256="$(nix-prefetch-url --unpack "$TARBALL")"
    JSON_CHECK_INPUTS="$(echo "$p" | base64 --decode | jq -r '.check_inputs')"
    if [ "$JSON_CHECK_INPUTS" = 'null' ]; then
      CHECK_INPUTS=''
    else
      INPUTS='['
      for check_input in $(echo "$JSON_CHECK_INPUTS" | jq -r '.[]'); do
        INPUTS="$INPUTS $check_input"
      done
      INPUTS="$INPUTS ]"

      CHECK_INPUTS="
      checkInputs = with pkgs; $INPUTS;"
    fi

    cat <<EOF >>"$NIX_OUT"
    $NAME = pkgs.stdenv.mkDerivation rec {
      name = "$NAME";
      version = "$VERSION";

      src = fetchTarball {
        url =
          "https://git.euandreh.xyz/\${name}/snapshot/\${name}-\${version}.tar.gz";
        sha256 = "$SHA256";
      };

      makeFlags = [ "CC=cc" ];
$CHECK_INPUTS
      doCheck = true;

      meta = with pkgs.lib; {
        description = readFile "\${src}/description";
        longDescription = readFile "\${src}/long-description";
        homepage = "https://\${name}.euandreh.xyz";
        changelog = "https://\${name}.euandreh.xyz/CHANGELOG.html";
        downloadPage = "https://\${name}.euandreh.xyz/#releases";
        license = licenses.agpl3;
        platforms = platforms.unix;
      };
    };
EOF
  done

  cat <<EOF >>"$NIX_OUT"
  };
}
EOF

  mv "$NIX_OUT" default.nix
}

refresh_packages() {
	COUNT="$(jq -r '.packages[].name' < paku.json | wc -l)"
	INDEXES="$(seq 0 "$((COUNT - 1))")"
  for N in $INDEXES; do
		NAME="$(jq -r ".packages[$N].name" < paku.json)"
		cd "../$NAME/"
		NEW_VERSION="$(git rev-parse HEAD)"
		cd - >/dev/null
		jq -r ".packages[$N].version = \"$NEW_VERSION\"" paku.json | sponge paku.json
	done
}

while getopts 'gr' flag; do
	case "$flag" in
		g)
			gen_guix
			gen_nix
			;;
		r)
			refresh_packages
			;;
		*)
			printf 'Unrecognized flag "%s".\n' "$flag" >&2
			;;
	esac
done