# This is a configuration entry-point called "Flake".
# Here you define your inputs (dependencies) and outputs (hosts).
{
	# Those are external dependencies.
	inputs = {
		# Core system.
		# Homepage: https://github.com/NixOS/nixpkgs
		# Manual:   https://nixos.org/manual/nixos/stable
		# Search:   https://search.nixos.org/packages and https://search.nixos.org/options
		nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";

		# This thing manages user's /home directroies. Because NixOS only manages system itself.
		# Homepage: https://github.com/nix-community/home-manager
		# Manual:   https://nix-community.github.io/home-manager
		# Search:   https://home-manager-options.extranix.com
		home-manager = {
			url = "github:nix-community/home-manager";

			# This means that home-manager and our Flake both depend on the same nixpkgs version.
			inputs.nixpkgs.follows = "nixpkgs";
		};

		# This allows automatic styling based on active Wallpaper.
		# Homepage: https://github.com/danth/stylix
		# Manual:   https://danth.github.io/stylix
		stylix.url  = "github:danth/stylix";

		# I use this for a single container called jobber.
		# You likely won't need this one, so just skip it for now.
		poetry2nixJobber.url = "github:nix-community/poetry2nix/304f8235fb0729fd48567af34fcd1b58d18f9b95";
		nixpkgsJobber.url    = "github:nixos/nixpkgs/051f920625ab5aabe37c920346e3e69d7d34400e";

		# Nix on Android (inside Termux). It has no NixOS modules, but still allows the use of Nixpkgs arm packages with Home-Manager configurations.
		# Homepage: https://github.com/nix-community/nix-on-droid
		# Manual:   https://github.com/nix-community/nix-on-droid/blob/master/README.md
		nix-on-droid = {
			url = "github:t184256/nix-on-droid/release-23.05";
			inputs.nixpkgs.follows      = "nixpkgs";
			inputs.home-manager.follows = "home-manager";
		};

		# Those are Nvim plugins. I do not use package managers like Packer or Lazy, instead I use Nix to download them and later configure in [Neovim module](module/common/Nvim.nix).
		nvimAlign = {
			url   = "github:echasnovski/mini.align";
			flake = false;
		};
		nvimAutoclose = {
			url   = "github:m4xshen/autoclose.nvim";
			flake = false;
		};
		nvimBufferline = {
			url   = "github:akinsho/bufferline.nvim";
			flake = false;
		};
		nvimCloseBuffers = {
			url   = "github:kazhala/close-buffers.nvim";
			flake = false;
		};
		nvimColorizer = {
			url   = "github:brenoprata10/nvim-highlight-colors";
			flake = false;
		};
		nvimDevicons = {
			url   = "github:nvim-tree/nvim-web-devicons";
			flake = false;
		};
		nvimGitsigns = {
			url   = "github:lewis6991/gitsigns.nvim";
			flake = false;
		};
		nvimGruvboxMaterial = {
			url   = "github:sainnhe/gruvbox-material";
			flake = false;
		};
		nvimIndentoMatic = {
			url   = "github:Darazaki/indent-o-matic";
			flake = false;
		};
		nvimLspconfig = {
			url   = "github:neovim/nvim-lspconfig";
			flake = false;
		};
		nvimOllama = {
			url   = "github:nomnivore/ollama.nvim";
			flake = false;
		};
		nvimPlenary = {
			url   = "github:nvim-lua/plenary.nvim";
			flake = false;
		};
		nvimSingleComment = {
			url   = "github:LucasTavaresA/singlecomment.nvim";
			flake = false;
		};
		nvimTelescope = {
			url   = "github:nvim-telescope/telescope.nvim";
			flake = false;
		};
		nvimTodo = {
			url   = "github:folke/todo-comments.nvim";
			flake = false;
		};
		nvimTokyonight = {
			url   = "github:folke/tokyonight.nvim";
			flake = false;
		};
		nvimTree = {
			url   = "github:nvim-tree/nvim-tree.lua";
			flake = false;
		};
		nvimTreesitter = {
			url   = "github:nvim-treesitter/nvim-treesitter";
			flake = false;
		};
		nvimTrouble = {
			url   = "github:folke/trouble.nvim";
			flake = false;
		};
		nvimWhichKey = {
			url   = "github:folke/which-key.nvim";
			flake = false;
		};
	};

	# Those are outputs (hosts, configurations) that can be produced by this whole config.
	# Here you see a set of inputs we defined above, like nixpkgs, home-manager and so on.
	# `...` at the end of a set means "ignore other arguments provided to this function".
	# @inputs means aliasing all the inputs to the `inputs` name, so we can pass them all at once later.
	outputs = { self, nixpkgs, nix-on-droid, home-manager, stylix, poetry2nixJobber, nixpkgsJobber, ... } @inputs: {
		# Constant values.
		const = {
			droidStateVersion = "22.11";
			stateVersion      = "24.05";
			timeZone = "Europe/Moscow";
			url = "https://git.voronind.com/voronind/nixos.git";
		};

		# Common modules used across all the hosts.
		nixosModules.common = let
			# This function allows me to get the list of all the files from the directories I need.
			# It differs from the util.ls function because it also filters out all the directories.
			lsFiles = path: map (f: "${path}/${f}") (
				builtins.filter (i: builtins.readFileType "${path}/${i}" == "regular") (
					builtins.attrNames (builtins.readDir path)
				)
			);
		in {
			# Here I import everything from those directories.
			imports = (lsFiles ./module/common) ++ (lsFiles ./overlay) ++ [ ./user/Root.nix ];
		};

		# Function to create a host. It does basic setup, like adding common modules.
		mkHost = { system, hostname, modules } @args: nixpkgs.lib.nixosSystem {
			# `Inherit` is just an alias for `system = system;`, which means that
			# keep the `system` argument as a property in a resulting set.
			inherit system;

			# List of modules to use by defualt for all the hosts.
			modules = [
				# There I put host-specific configurations.
				./host/${hostname}

				# Make a device hostname match the one from this config.
				{ networking.hostName = hostname; }

				# Specify current release version.
				{ system.stateVersion = self.const.stateVersion; }

				# Add common modules.
				inputs.self.nixosModules.common

				# Add Home Manager module.
				home-manager.nixosModules.home-manager

				# Add Stylix module.
				stylix.nixosModules.stylix
			]
			# Also add host-specific modules from mkHost args.
			++ modules;

			# SpecialArgs allows you to pass objects down to other NixOS modules.
			specialArgs = let
				pkgs   = nixpkgs.legacyPackages.${system}.pkgs;
				lib    = nixpkgs.lib;
				config = self.nixosConfigurations.${hostname}.config;

				pkgsJobber = nixpkgsJobber.legacyPackages.${system}.pkgs;
			in {
				const     = self.const; # Constant values.
				flake     = self;       # This Flake itself.
				inputs    = inputs;     # Our dependencies.
				key       = import ./part/Key.nix       {}; # Keyboard keys config.
				secret    = import ./part/Secret.nix    {}; # Secrets (public keys).
				setting   = import ./part/Setting.nix   {}; # My own global settings.
				style     = import ./part/Style.nix     { inherit config;   }; # Style abstraction.
				util      = import ./part/Util.nix      { inherit pkgs lib; }; # Util functions.
				wallpaper = import ./part/Wallpaper.nix { inherit pkgs;     }; # Wallpaper.

				# Stuff for Jobber container, skip this part.
				inherit poetry2nixJobber pkgsJobber;
			};
		};

		# Bellow is the list of all the hosts I currently use.
		# They call the `mkHost` function that I defined above
		# with their specific parameters.
		# You might be interested in `live` and `nixOnDroidConfiguration`
		# for Live ISO and Android configurations respectively.
		nixosConfigurations.basic = self.mkHost {
			hostname = "basic";        # Hostname to use.
			system   = "x86_64-linux"; # System architecture.

			# Host-specific modules.
			modules = [
				# Force LTS kernel.
				({ pkgs, ... }: { boot.kernelPackages = nixpkgs.lib.mkForce pkgs.linuxPackages; })
			];
		};

		nixosConfigurations.dasha = self.mkHost {
			hostname = "dasha";
			system   = "x86_64-linux";
			modules = [
				./module/AmdGpu.nix
				./module/CapsToggle.nix
				./module/Gnome.nix
				./module/IntelCpu.nix
				./module/PowersaveIntel.nix
				./module/Print.nix
				./module/RemoteBuild.nix
				./module/StrongSwan.nix
				./module/Tablet.nix
				./user/Dasha.nix
			];
		};

		nixosConfigurations.desktop = self.mkHost {
			hostname = "desktop";
			system   = "x86_64-linux";
			modules = [
				./module/AmdCompute.nix
				./module/AmdCpu.nix
				./module/AmdGpu.nix
				# ./module/Ollama.nix # ISSUE: Currently broken.
				./module/PowersaveAmd.nix
				./module/Print.nix
				./module/RemoteBuild.nix
				./module/Sway.nix
				./module/VirtManager.nix
				./user/Voronind.nix
			];
		};

		nixosConfigurations.fsight = self.mkHost {
			hostname = "fsight";
			system   = "x86_64-linux";
			modules = [
				./module/Docker.nix
			];
		};

		nixosConfigurations.home = self.mkHost {
			hostname = "home";
			system   = "x86_64-linux";
			modules = [
				./module/AmdCpu.nix
				./module/AmdGpu.nix
				./module/Ftpd.nix
				./module/RemoteBuilder.nix
				./module/Sway.nix
				./user/Voronind.nix
			];
		};

		nixosConfigurations.laptop = self.mkHost {
			hostname = "laptop";
			system   = "x86_64-linux";
			modules = [
				./module/AmdCpu.nix
				./module/AmdGpu.nix
				./module/CapsToggle.nix
				./module/Gnome.nix
				./module/PowersaveAmd.nix
				./module/Print.nix
				./module/RemoteBuild.nix
				./module/StrongSwan.nix
				./module/Tablet.nix
				./user/Dasha.nix
				./user/Voronind.nix
			];
		};

		# Live ISO configuration.
		nixosConfigurations.live = self.mkHost {
			hostname = "live";
			system   = "x86_64-linux";
			modules = [
				# Those are basic modules for Live ISO image.
				# You can discover other possible base images here:
				# https://github.com/NixOS/nixpkgs/tree/master/nixos/modules/installer/cd-dvd
				"${nixpkgs}/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix"
				"${nixpkgs}/nixos/modules/installer/cd-dvd/channel.nix"

				# This is required for Live ISO in my case because I use NetworkManager,
				# but base Live images require this.
				{ networking.wireless.enable = nixpkgs.lib.mkForce false; }

				# Override my settings to allow SSH logins using root password.
				{ services.openssh.settings.PasswordAuthentication = nixpkgs.lib.mkForce true; }
				{ services.openssh.settings.PermitRootLogin        = nixpkgs.lib.mkForce "yes"; }

				# Disable auto-updates as they are not possible for Live ISO.
				{ systemd.services.autoupdate.enable = nixpkgs.lib.mkForce false; }

				# Base Live images also require the LTS kernel.
				({ pkgs, ... }: { boot.kernelPackages = nixpkgs.lib.mkForce pkgs.linuxPackages; })
			];
		};

		nixosConfigurations.work = self.mkHost {
			hostname = "work";
			system   = "x86_64-linux";
			modules = [
				./module/IntelCpu.nix
				./module/PowerlimitThinkpad.nix
				./module/PowersaveIntel.nix
				./module/Print.nix
				./module/RemoteBuild.nix
				./module/Sway.nix
				./user/Voronind.nix
			];
		};

		# Android.
		nixOnDroidConfigurations.default = nix-on-droid.lib.nixOnDroidConfiguration {
			modules = [
				# Android release version.
				{ system.stateVersion = inputs.self.const.droidStateVersion; }

				# I put all my Android configuration there.
				./module/android
			];

			# SpecialArgs allows you to pass objects down to other configuration.
			extraSpecialArgs = let
				# We want arm64 packages for Android.
				pkgs = nixpkgs.legacyPackages."aarch64-linux".pkgs;
				lib  = nixpkgs.lib;
			in {
				const   = self.const; # Constant values.
				flake   = self;       # This Flake itself.
				inputs  = inputs;     # Our dependencies.
				key     = import ./part/Key.nix     {}; # Keyboard keys config.
				secret  = import ./part/Secret.nix  {}; # Secrets (public keys).
				setting = import ./part/Setting.nix {}; # My own global settings.
				style   = import ./part/Style.nix   { config = import ./part/style/Gruvbox.nix {}; }; # Style abstraction. Stylix is not available for Android so I provide static Gruvbox style.
				util    = import ./part/Util.nix    { inherit pkgs lib; }; # Util functions.
			};
		};
	};
}
# That's it!