$(eval HOSTNAME=$(shell hostname))
HOMEMANAGER_CONFIG := $(PWD)/machines/$(HOSTNAME)/$(USER).nix
CONFIG_DIR := $(if $(XDG_CONFIG_HOME), $(XDG_CONFIG_HOME), $(HOME)/.config)
HOMEMANAGER_CONFIG_DIR := $(CONFIG_DIR)/home-manager

.PHONY: default all clean nixos home home-init /etc/nixos/config nvim

default:
	command -v nix > /dev/null || exit 1
	if [ -e /etc/nixos/ ]; then make nixos; else make home; fi

all: default nvim
	bat cache --build

clean:
	[ -e /etc/nixos ] && sudo rm /etc/nixos/config || rm -rf $(HOMEMANAGER_CONFIG_DIR)

nixos: /etc/nixos/config
	grep -i ./config/machines/$$(hostname) /etc/nixos/configuration.nix && sudo nixos-rebuild switch

home: $(HOMEMANAGER_CONFIG_DIR)/home.nix $(CONFIG_DIR)/nixpkgs/config.nix $(HOME)/.nix-defexpr/channels/home-manager
	nix-shell -p home-manager --run "home-manager switch"

home-init: $(HOMEMANAGER_CONFIG_DIR)/home.nix $(CONFIG_DIR)/nixpkgs/config.nix $(HOME)/.nix-defexpr/channels/home-manager
	nix-shell '<home-manager>' -A install

/etc/nixos/config:
	sudo rsync -avz --exclude-from=.rsyncignore --filter=':- .gitignore' --delete-during --delete-excluded ./ $@

nvim: $(CONFIG_DIR)/nvim

$(HOMEMANAGER_CONFIG):
	touch $@

$(HOMEMANAGER_CONFIG_DIR)/home.nix: $(HOMEMANAGER_CONFIG) $(HOMEMANAGER_CONFIG_DIR) /nix
	-ln -s $(HOMEMANAGER_CONFIG) $@

$(CONFIG_DIR)/nixpkgs/config.nix:
	echo '{ allowUnfree = true; }' > $@

$(HOME)/.nix-defexpr/channels/home-manager:
	nix-channel --add https://github.com/nix-community/home-manager/archive/master.tar.gz home-manager
	nix-channel --update

$(CONFIG_DIR)/nvim: $(CONFIG_DIR)
	-nix-shell -p git --run "git clone https://git.xenia.me.uk/xenia/nvim.git $@"
	-nix-shell -p git --run "git -C $@ pull --ff-only"

$(CONFIG_DIR) $(HOMEMANAGER_CONFIG_DIR):
	mkdir -p $@