#!/bin/sh
set -eu

TARBALL_TEMPLATE='https://euandreh.xyz/@NAME@.git/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 ((guix licenses) #:prefix license:)
  #:use-module (guix gexp)
  #:use-module (guix packages)
  #:use-module (guix download)
  #:use-module (guix build-system gnu))
EOF

	for p in $(jq -r '.packages[] | @base64' < paku.json); do
		NAME="$(echo "$p" | base64 --decode | jq -r '.name')"
		SUFFIX="$(echo "$p" | base64 --decode | jq -r '.suffix')"
		VERSION="$(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 $NAME$SUFFIX
  (package
    (name "$NAME$SUFFIX")
    (version "$VERSION")
    (source (origin
              (method url-fetch)
              (uri (string-append
                    "https://euandreh.xyz/$NAME.git/snapshot/$NAME-"
                    version
                    ".tar.gz"))
              (sha256
               (base32
                "$SHA256"))))
    (build-system gnu-build-system)$CHECK_INPUTS
    (arguments \`(#:make-flags
                 (list (string-append "PREFIX=" %output))
                 #:phases
                 (modify-phases %standard-phases
                   (delete 'configure))))
    (synopsis (file-append source "/description"))
    (description (file-append source "/long-description"))
    (home-page "https://euandreh.xyz/$NAME/")
    (license license:agpl3+)))
EOF
	done
	
	printf '\n(list' >>"$GUIX_OUT"
	for p in $(jq -r '.packages[] | @base64' < paku.json); do
		NAME="$(echo "$p" | base64 --decode | jq -r '.name')"
		SUFFIX="$(echo "$p" | base64 --decode | jq -r '.suffix')"

		printf '\n %s%s' "$NAME" "$SUFFIX" >>"$GUIX_OUT"
	done
	printf ')\n' >>"$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 "$p" | base64 --decode | jq -r '.name')"
		SUFFIX="$(echo "$p" | base64 --decode | jq -r '.suffix')"
		VERSION="$(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"
    $NAME$SUFFIX = pkgs.stdenv.mkDerivation rec {
      name = "$NAME";
      version = "$VERSION";

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

      makeFlags = [ "PREFIX=\$(out)" ];
$CHECK_INPUTS
      doCheck = true;

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

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

	mv "$NIX_OUT" default.nix
}

pascalize() {
	awk '{printf "%s", toupper(substr($1,1,1)) substr($1,2)}'
}

gen_homebrew() {
	for p in $(jq -r '.packages[] | @base64' < paku.json); do
		HOMEBREW_OUT="$(mktemp)"
		NAME="$(echo "$p" | base64 --decode | jq -r '.name')"
		NAME_UC="$(echo "$NAME" | pascalize)"
		SUFFIX="$(echo "$p" | base64 --decode | jq -r '.suffix')"
		SUFFIX_UC="$(echo "$SUFFIX" | cut -c2- | pascalize)"
		VERSION="$(echo "$p" | base64 --decode | jq -r '.version')"
		TYPE="$(echo "$p" | base64 --decode | jq -r '.type')"
		TARBALL_URL="$(tarball_url "$NAME" "$VERSION")"
		TARBALL="$(mktemp)"
		wget -O "$TARBALL" "$TARBALL_URL"
		SHA256="$(sha256sum "$TARBALL" | cut -d\  -f 1)"
		DESCRIPTION="$(tar xvf "$TARBALL" -O "$NAME-$VERSION/description")"
		JSON_CHECK_INPUTS="$(echo "$p" | base64 --decode | jq -r '.check_inputs')"
		if [ "$JSON_CHECK_INPUTS" = 'null' ]; then
			CHECK_INPUTS=''
		else
			CHECK_INPUTS=''
			for check_input in $(echo "$JSON_CHECK_INPUTS" | jq -r '.[]'); do
				CHECK_INPUTS="$CHECK_INPUTS
  depends_on '$check_input' => :build"
			done
			CHECK_INPUTS="$CHECK_INPUTS
"
		fi

		TEST_SECTION=''
		if [ "$TYPE" = 'bin' ]; then
			TEST_SECTION="

  test do
    system \"#{bin}/$NAME\", '-V'
  end"
		fi

		cat <<EOF >>"$HOMEBREW_OUT"
class ${NAME_UC}$SUFFIX_UC < Formula
  desc '$DESCRIPTION'
  homepage 'https://euandreh.xyz/$NAME/'
  url '$TARBALL_URL'
  sha256 '$SHA256'
  license 'AGPL-3.0-or-later'
$CHECK_INPUTS
  def install
    system 'make'
    system 'make', 'check'
    system 'make', 'install', "PREFIX=#{prefix}"
  end$TEST_SECTION
end
EOF
		mv "$HOMEBREW_OUT" "Formula/$NAME$SUFFIX.rb"
	done
}

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[$N].name" < paku.json)"
		SUFFIX="$(jq -r ".packages[$N].suffix" < paku.json)"
		cd "../$NAME/"
		if [ "$SUFFIX" = '-latest' ]; then
			NEW_VERSION="$(git rev-parse HEAD)"
		else
			NEW_VERSION="$(git describe --tags --abbrev=0 | cut -c2-)"
		fi
		DESCRIPTION="$(cat description)"
		cd - >/dev/null
		jq -r ".packages[$N].version = \"$NEW_VERSION\"" paku.json | sponge paku.json
		jq -r ".packages[$N].description = \"$DESCRIPTION\"" paku.json | sponge paku.json
	done
}

report_index() {
	HTML_OUT='public/paku.html'
	cat <<EOF > "$HTML_OUT"
<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="UTF-8" />
		<meta name="viewport" content="width=device-width, initial-scale=" />
		<link rel="icon" type="image/svg+html" href="favicon.svg" />
		<title>Package index</title>

		<style>
			ul {
				list-style: none;
			}
			li {
				margin-top: 30px;
			}
		</style>
	</head>
	<body>
		<h1>
			Package index
		</h1>
		<ul>
EOF

	for p in $(jq -r '.packages[] | @base64' < paku.json); do
		NAME="$(echo "$p" | base64 --decode | jq -r '.name')"
		DESCRIPTION="$(echo "$p" | base64 --decode | jq -r '.description')"
		SUFFIX="$(echo "$p" | base64 --decode | jq -r '.suffix')"
		if [ -z "$SUFFIX" ]; then
			VERSION="$(echo "$p" | base64 --decode | jq -r '.version')"
			ID='released'
		else
			VERSION='latest'
			ID='latest'
		fi

		cat <<EOF >> "$HTML_OUT"
			<li id="$NAME-$ID">
				<details>
					<summary><a href="#$NAME-$ID">$NAME</a> ($VERSION) - $DESCRIPTION</summary>
					<p>
						<a href="https://euandreh.xyz/$NAME/">Homepage</a>.
					</p>

					<section>
						<h2>Guix</h2>
						<p>
							After following the
							<a href="#guix-instructions">Guix instructions</a> to include this
							channel, now you can create an environment that includes this
							package:
						</p>
						<pre><code>$ guix environment --ad-hoc $NAME$SUFFIX</code></pre>
						<p>
							Alternatively, you can install it imperatively:
						</p>
						<pre><code>$ guix install $NAME$SUFFIX</code></pre>
					</section>
					<section>
						<h2>Nix</h2>
						<p>
							After following the
							<a href="#nix-instructions">Nix instructions</a> to include this
							repository as an overlay, now you can create a new Nix shell that
							includes this package:
						</p>
						<pre><code>$ nix-shell -p $NAME$SUFFIX</code></pre>
						<p>
							Alternatively, you can install it imperatively:
						</p>
						<pre><code>$ nix-env -i $NAME$SUFFIX</code></pre>
					</section>
				</details>
			</li>
EOF
	done

	cat <<EOF >> "$HTML_OUT"
		</ul>
		<article id="guix-instructions">
			<h2>Guix instructions</h2>
			<p>
				Add this channel to your <code>~/.config/guix/channels.scm</code>:
			</p>
			<pre><code>(cons*
 (channel
  (name 'xyz-euandreh)
  (url "git://euandreh.xyz/package-repository")
  (branch "main")
  (introduction
   (make-channel-introduction
    "d749e053e6db365069cb9b2ef47a78b06f9e7361"
    (openpgp-fingerprint
     "5BDA E9B8 B2F6 C6BC BB0D  6CE5 81F9 0EC3 CD35 6060"))))
 %default-channels)</code></pre>
		</article>

		<article id="nix-instructions">
			<h2>Nix instructions</h2>
			<p>
				Add the overlay to your <code>/etc/nixox/configuration.nix</code>:
			</p>
			<pre></code>nixpkgs = {
  overlays = [
    (import (fetchTarball {
      url = "https://euandreh.xyz/package-repository.git/snapshot/package-repository-main.tar.gz";
    }) { inherit pkgs; })
  ];
};</code></pre>
		</article>
	</body>
</html>
EOF
}

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