feat!(flake): convert to fs-defined configurations

Place all configurations in `machines/${manager}/${system}/${hostname}/...`:
    - `${manager}` - One of `nixos`, `nix-on-droid`, `nix-darwin` or `home-manager`
    - `${system}` - A system's architecture (can be many)
    - `${hostname}` - A system's hostname (can be many)

The flake now automatically generates the needed configurations based on the above structure.

It only generates configurations for valid directory structures:
    - It wouldn't generate a NixOS config if there isn't a `configuration.nix` file
    - ...

machines/nix-on-droid/aarch64-linux/cheetah/configuration.nix

@@ -0,0 +1,42 @@
+{ inputs, outputs, lib, config, pkgs, ... }:
+
+{
+  environment.packages = with pkgs; [];
+
+  # Backup etc files instead of failing to activate generation if a file already exists in /etc
+  environment.etcBackupExtension = ".bak";
+
+  # Remove motd
+  environment.motd = null;
+
+  # # Set $EDITOR
+  # environment.variables.EDITOR = "nvim";
+
+  user.shell = "${pkgs.zsh}/bin/zsh";
+
+  # Read the changelog before changing this value
+  system.stateVersion = "22.05";
+
+  nix.extraOptions = ''
+    experimental-features = nix-command flakes
+  '';
+
+  time.timeZone = "Europe/Sofia";
+
+  terminal.font =
+    let
+      firacode = pkgs.nerdfonts.override {
+        fonts = [ "FiraCode" ];
+      };
+      fontPath = "share/fonts/truetype/NerdFonts/Fira Code Regular Nerd Font Complete Mono.ttf";
+    in
+      "${firacode}/${fontPath}";
+
+  home-manager = {
+    config = ./home.nix;
+    backupFileExtension = "hm-bak";
+    # useGlobalPkgs = true;
+
+    extraSpecialArgs = { inherit inputs; };
+  };
+}

machines/nix-on-droid/aarch64-linux/cheetah/home.nix

@@ -0,0 +1,341 @@
+{ inputs, lib, config, pkgs, ... }:
+
+{
+  # Home Manager needs a bit of information about you and the
+  # paths it should manage.
+  home = {
+    username = "nix-on-droid";
+    # username = "reo101";
+    homeDirectory = "/data/data/com.termux.nix/files/home";
+    stateVersion = "22.05";
+  };
+
+  # Let Home Manager install and manage itself.
+  programs.home-manager.enable = true;
+
+  home.packages = with pkgs; [
+    # neovim
+    # clang
+    gcc
+
+    diffutils
+    findutils
+    utillinux
+    tzdata
+    hostname
+    man
+    ncurses
+    gnugrep
+    gnupg
+    gnused
+    gnutar
+    bzip2
+    gzip
+    xz
+    zip
+    unzip
+
+    direnv
+    nix-direnv
+
+    # Bling
+    onefetch
+    neofetch
+
+    # Utils
+    ripgrep
+
+    # Passwords
+    pass
+    passExtensions.pass-otp
+
+    # Dhall
+    dhall
+    dhall-lsp-server
+
+    # Zig
+    zigpkgs.master
+    inputs.zls-overlay.packages.aarch64-linux.default
+  ];
+
+  nixpkgs = {
+    overlays = [
+      inputs.neovim-nightly-overlay.overlay
+      inputs.zig-overlay.overlays.default
+      # inputs.zls-overlay.???
+    ];
+
+    config.allowUnfree = true;
+  };
+
+  programs.neovim = {
+    enable = true;
+    package = pkgs.neovim-nightly;
+    # defaultEditor = true;
+
+    viAlias = true;
+    vimAlias = true;
+    vimdiffAlias = true;
+
+    withPython3 = false;
+    withNodeJs = false;
+    withRuby = false;
+
+    # neovimRcContent = "";
+
+    extraPackages = with pkgs; [
+        tree-sitter
+        rnix-lsp
+        # sumneko-lua-language-server
+        # stylua
+        # texlab
+        # rust-analyzer
+    ];
+  };
+
+  programs.zsh = {
+    enable = true;
+    enableCompletion = true;
+    defaultKeymap = "viins";
+
+    shellAliases = {
+      # ll = "ls -l";
+      # update = "sudo nixos-rebuild switch";
+    };
+
+    history = {
+      size = 10000;
+      path = "${config.xdg.dataHome}/zsh/history";
+    };
+
+    initExtra = ''
+      eval "$(direnv hook zsh)"
+    '';
+
+    plugins = [
+      {
+        name = "zsh-nix-shell";
+        file = "nix-shell.plugin.zsh";
+        src = pkgs.fetchFromGitHub {
+          owner = "chisui";
+          repo = "zsh-nix-shell";
+          rev = "v0.5.0";
+          sha256 = "0za4aiwwrlawnia4f29msk822rj9bgcygw6a8a6iikiwzjjz0g91";
+        };
+      }
+    ];
+  };
+
+  programs.starship = {
+    enable = true;
+
+    settings = {
+      # Get editor completions based on the config schema
+      "$schema" = "https://starship.rs/config-schema.json";
+
+      # Use custom format
+      format = ''
+        [╭───────┨](bold green)[nix-on-droid](bright-white)[@](bold yellow)$hostname[┠───────>](bold green)$status$cmd_duration$git_branch$git_status$git_state$git_commit
+        [│](bold green)$time$jobs: $directory$package
+        [╰─](bold green)$character
+      '';
+
+      # ${custom.local}\
+      # ${custom.local_root}\
+      # ${custom.ssh}\
+      # ${custom.ssh_root}\
+
+      add_newline = true;
+
+      character = {
+        success_symbol = "[→](bold green)";
+        error_symbol = "[→](red)";
+      };
+
+      git_branch = {
+        symbol = "🌱 ";
+        truncation_length = 15;
+        truncation_symbol = "…"; # …
+      };
+
+      git_commit = {
+        commit_hash_length = 6;
+        tag_symbol = "🔖 ";
+      };
+
+      git_state = {
+        format = "[\($state( $progress_current of $progress_total)\)]($style) ";
+        cherry_pick = "[🍒 PICKING](bold red)";
+      };
+
+      git_status = {
+        # conflicted = "🏳";
+        # ahead = "🏎💨";
+        # behind = "😰";
+        # diverged = "😵";
+        # untracked = "🤷‍";
+        # stashed = "📦";
+        # modified = "📝";
+        # staged = '[++\($count\)](green)';
+        # renamed = "👅";
+        # deleted = "🗑";
+        format = "[\\[$all_status$ahead_behind\\]]($style) ";
+        conflicted = "=[\($count\)](green) ";
+        ahead = "⇡[\($count\)](green) ";
+        behind = "⇣[\($count\)](green) ";
+        diverged = "⇕[\($count\)](green) ";
+        untracked = "?[\($count\)](green) ";
+        stashed = "$[\($count\)](green) ";
+        modified = "![\($count\)](green) ";
+        staged = "+[\($count\)](green) ";
+        renamed = "»[\($count\)](green) ";
+        deleted = "✘[\($count\)](green) ";
+      };
+
+      status = {
+        style = "bg:blue fg:red";
+        symbol = "🔴";
+        format = "[\[$symbol $common_meaning$signal_name$maybe_int\]]($style) ";
+        map_symbol = true;
+        disabled = false;
+      };
+
+      time = {
+        disabled = false;
+        format = "🕙[$time]($style) ";
+        # format = '🕙[\[ $time \]]($style) ';
+        time_format = "%T";
+        utc_time_offset = "+3";
+        # time_range = "10:00:00-14:00:00";
+      };
+
+      cmd_duration = {
+        min_time = 2000; # miliseconds
+        # show_notifications = true;
+        min_time_to_notify = 45000; # miliseconds
+        format = "took [$duration](bold yellow) ";
+      };
+
+      hostname = {
+        ssh_only = false;
+        format = "[$hostname](bold fg:#CC59B0)";
+        disabled = false;
+      };
+
+      username = {
+        disabled = false;
+        style_user = "white bold";
+        style_root = "red bold";
+        format = "[$user]($style)[@](bold yellow)";
+        show_always = true;
+      };
+
+      directory = {
+        read_only = "🔒";
+        read_only_style = "bold white";
+        style = "fg:#A7F3E4";
+        truncate_to_repo = false;
+        truncation_length = 5;
+        truncation_symbol = "…/";
+        home_symbol = "🏡";
+        format = "[$read_only]($read_only_style)[$path]($style) ";
+      };
+
+      directory.substitutions = {
+        ".config" = " ";
+        "nvim" = "";
+        "emacs" = "𝓔";
+        "doom" = "𝓔";
+        "Projects" = "💻";
+        "FMI" = "🏫";
+        "Home" = "🏠";
+        "CPP" = "";
+        "Java" = "";
+        "Python" = "";
+      };
+
+      # Language Environments
+      package = {
+        style = "bold fg:#5E5E5E";
+      };
+
+      python = {
+        style = "bold fg:#5E5E5E";
+        symbol = "[](bold yellow) ";
+      };
+
+      nodejs = {
+        style = "bold fg:#5E5E5E";
+        symbol = "[⬢](bold green) ";
+      };
+
+      # Custom
+      jobs = {
+        format = "[ $symbol$number ]($style)";
+        style = "bg:#587744 fg:bright-white";
+        symbol = "⚙";
+      };
+
+      custom.local = {
+        shell = ["zsh" "-d" "-f"];
+        when = ''[[ -z "$SSH_CLIENT" ]] && [[ `whoami` != "root" ]]'';
+        format = "[$symbol$output]($style)[@](bold yellow)";
+        command = "whoami";
+        style = "fg:bright-white";
+        symbol = "";
+      };
+
+      custom.local_root = {
+        shell = ["zsh" "-d" "-f"];
+        when = ''[[ -z "$SSH_CLIENT" ]] && [[ `whoami` == "root" ]]'';
+        format = "[ $output ]($style)[@](bold yellow)";
+        command = "whoami";
+        style = "bg:red fg:bright-white";
+      };
+
+      custom.ssh = {
+        shell = ["zsh" "-d" "-f"];
+        when = ''[[ -n "$SSH_CLIENT" ]] && [[ `whoami` != "root" ]]'';
+        format = "[ $symbol$output ]($style)[@](bold yellow)";
+        command = "whoami";
+        style = "bg:blue fg:bright-white";
+        # style = "bg:#FD7208 fg:bright-white";
+        symbol = "⌁";
+      };
+
+      custom.ssh_root = {
+        shell = ["zsh" "-d" "-f"];
+        when = ''[[ -n "$SSH_CLIENT" ]] && [[ `whoami` == "root" ]]'';
+        format = "[ $symbol$output ]($style)[@](bold yellow)";
+        command = "whoami";
+        style = "bg:red fg:bright-white";
+        symbol = "⌁";
+      };
+    };
+  };
+
+  home.file = {
+    ".config/nvim" = {
+      recursive = true;
+      source = /data/data/com.termux.nix/files/home/.local/src/reovim;
+    };
+  };
+
+  programs.git = {
+    enable = true;
+    userName = "reo101";
+    # userName = "Pavel Atanasov";
+    userEmail = "pavel.atanasov2001@gmail.com";
+  };
+
+  services.gpg-agent = {
+    enable = true;
+    defaultCacheTtl = 1800;
+    enableSshSupport = true;
+  };
+
+  # Using nix-direnv
+  # services.lorri = {
+  #   enable = true;
+  # };
+}