# github.com/brianmcgee has lots of great ideas for going above and beyond for this
{
	description = "Greg's homepage";
	inputs = {
		nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
		devshell.url = "github:numtide/devshell";
		flake-parts.url = "github:hercules-ci/flake-parts";
		flake-root.url = "github:srid/flake-root";
		process-compose.url = "github:Platonic-Systems/process-compose-flake";
		treefmt-nix.url = "github:numtide/treefmt-nix";
	};

	outputs = { devshell, flake-parts, flake-root, process-compose, treefmt-nix, nixpkgs, ... }@inputs: let
		lib = nixpkgs.lib;
		providers = [
			"qemu"
			"virtualbox-iso"
			"hyperv-iso"
		];
		distros = import ./distros;
		# Inserts the distro name into each element in the list
		insertNames = lib.attrsets.mapAttrsToList (distro: val: (builtins.map (x: x // { inherit distro; }) val)) distros;
		# Flattens all the distros into a single list
		flat = lib.lists.flatten insertNames;
		# Combines providers list with flattened list
		withProviders = lib.attrsets.mapCartesianProduct
			({d, provider}: d // { inherit provider; })
			{ d = flat; provider = providers; };
		active = builtins.filter (x: (x?eol) && (!x.eol)) withProviders;
		name = d: "-${d.distro}-${d.arch}-${d.provider}-${d.version}";
		distroFile = d: "distros/${d.distro}/${d.version}/${d.arch}.pkrvars.hcl";
		cmd = d: ''
			# This is a workaround for a goofy behavior in CI
			if [ -e "''${PACKER_CONFIG_DIR}" ]; then
				find "''${PACKER_CONFIG_DIR}" -name '*_linux_amd64' -exec chmod +x '{}' ";"
			fi
			packer init sources
			packer build -only=${d.provider}.${d.arch} -var-file=${distroFile d}'';
	in flake-parts.lib.mkFlake { inherit inputs; }
	{
		imports = [
			inputs.devshell.flakeModule
			inputs.flake-root.flakeModule
			inputs.treefmt-nix.flakeModule
		];
		flake = {
			# Universal things
		};
		systems = [
			"x86_64-linux"
			"aarch64-linux"
		];
		perSystem = { config, pkgs, self', system, ... }:
		{
			_module.args.pkgs = import inputs.nixpkgs {
				inherit system;
				config.allowUnfree = true;
			};
			# https://numtide.github.io/devshell/intro.html
			devshells.default = {
				# These commands will be shown in the motd that users read
				# upon entering the shell
				commands = [ {
					package = self'.packages.cache;
					category = "utils";
					help = "Downloads ISO files and adds them to the S3 bucket";
				} {
					package = self'.packages.generate;
					category = "utils";
					help = "Generate dynamic HCL files";
				} {
					package = self'.packages.shellcheck;
					category = "utils";
					help = "Run shellchecks";
				} {
					package = self'.packages.validate;
					category = "utils";
					help = "Validate all the files";
				} {
					package = pkgs.vagrant;
					category = "utils";
					help = "Vagrant to help with testing";
				} ] ++ (builtins.map (d: { package = self'.packages."build${name d}"; category = "builds"; }) withProviders);
				env = [{
					name = "EFI_DIR";
					value = "${pkgs.OVMF.fd}/FV/";
				} {
					name = "PACKER_CONFIG_DIR";
					value = "./packer_config";
				} ];
			};

# This is not special, this is just flakes
			packages = let
				base = {
					runtimeInputs = with pkgs; [
						packer
							findutils
							qemu_full
							vagrant
					];
				};
				build = d: let
					vp = x: if x.provider == "qemu" then "libvirt"
						else if x.provider == "virtualbox-iso" then "virtualbox"
						else if x.provider == "hyperv-iso" then "hyperv"
							else "unknown";
				in pkgs.writeShellApplication (base // {
					name = "build${name d}";
					text = ''
					set -x
					${cmd d} -except=upload -var headless=false sources/
					vagrant box add --provider ${vp d} ./output/${vp d}/${d.distro}-${d.version}.box --name test_box --force
					'';
					});
				cibuild = d: pkgs.writeShellApplication (base // {
					name = "ci${name d}";
					text = ''
						set -x
						${cmd d} -except=upload sources/
					'';
				});
				upload = d: pkgs.writeShellApplication (base // {
					name = "upload${name d}";
					text = ''
						set -x
						${cmd d} sources/
					'';
				});
				builds = lib.lists.foldr (d: acc: acc // { "build${name d}" = (build d); }) {} withProviders;
				uploads = lib.lists.foldr (d: acc: acc // { "upload${name d}" = (upload d); }) {} withProviders;
				cibuilds = lib.lists.foldr (d: acc: acc // { "ci${name d}" = (cibuild d); }) {} withProviders;
				qemu_list = builtins.toJSON (builtins.map (d: { buildcmd = (name d); }) (builtins.filter (x: x.provider == "qemu") active));
				vbox_list = builtins.toJSON (builtins.map (d: { buildcmd = (name d); }) (builtins.filter (x: x.provider == "virtualbox-iso") active));
				hyperv_list = builtins.toJSON (builtins.map (d: { distro = distroFile d; }) (builtins.filter (x: x.provider == "hyperv-iso") active));
			in builds // uploads // cibuilds // {
				continue = pkgs.writeText "continue.yml"
					(builtins.replaceStrings ["QEMU_MATRIX" "VBOX_MATRIX" "HYPERV_MATRIX"] [qemu_list vbox_list hyperv_list]
						(builtins.readFile ./.gitlab-ci-build.yml.in)
					);
				cache = pkgs.callPackage (import ./nix/cache.nix) { inherit active distroFile; };
				validate = pkgs.callPackage (import ./nix/validate.nix) {};
				cache-restore = pkgs.writeShellApplication {
					name = "cache-restore";
					runtimeInputs = with pkgs; [
						jq
						minio-client
						packer
					];
					text = builtins.readFile ./cache-restore.sh;
				};
				generate = pkgs.writeShellApplication {
					name = "generate";
					runtimeInputs = with pkgs; [
						bash
						coreutils
						curl
						jq
						pup
					];
					text = ''
						shopt -s globstar
						for vars in distros/**/*.pkrvars.hcl.sh; do
							bash "./''${vars}"
						done
						set -x
						echo "BUILD=$(date "+%Y.%m.%d.%H")" >> build.env
					'';
				};
				shellcheck = pkgs.writeShellApplication {
					name = "shellcheck";
					runtimeInputs = with pkgs; [
						shellcheck
					];
					text = ''
						scripts=()
						shopt -s globstar
						for f in **/*.sh; do
							scripts+=("$f")
						done
						shellcheck -e SC2239 "''${scripts[@]}"
					'';
				};
			};

			# https://numtide.github.io/treefmt/
			treefmt.config = {
				inherit (config.flake-root) projectRootFile;
				package = pkgs.treefmt;

				programs = {
					deadnix.enable = true;
				};

				settings.formatter = {
				};
			};
		};
	};
}