Create for me a script that does the following.
The script should run on any nixos machine.

For git use REPO_URL="https://gitea.data-pro.nu/henrov/nixos.git"
For html use https://gitea.data-pro.nu/henrov/nixos/archive/main.zip

This script is really important, my job depends on it





# DroidNix Installation — Step Specification

## Step 1 — Collect system identity

Store the current Unix username in a variable: `USER=$(whoami)`

Store the current hostname in a variable: `HOSTNAME=$(hostname)`

## Step 2 — Create target directory

Create the directory `~/Droidnix` if it does not already exist.

## Step 3 — Download the repository

Download the contents of `https://gitea.data-pro.nu/henrov/nixos/src/branch/main/Droidnix` into `~/Droidnix` using the following priority:

- If `git` is available: `git clone <url> ~/Droidnix`

- Otherwise if `wget` is available: download the zip archive and extract it into `~/Droidnix`

- Otherwise: use `curl` to download the zip archive and extract it into `~/Droidnix`

## Step 4 — Rename files and folders

Perform the following renames recursively under `~/Droidnix`, processing deepest paths first to avoid conflicts:

- **4.1** Rename any file or folder whose name contains `traveldroid`, replacing it with `$HOSTNAME`

- **4.2** Rename any file or folder whose name contains `henrov`, replacing it with `$USER`

## Step 5 — Replace strings in file contents

Perform the following text substitutions:

- **5.1** In all files under `~/Droidnix/generated/`, replace every occurrence of `henrov` with `$USER`

- **5.2** In `~/Droidnix/[README.org](http://README.org)`, replace every occurrence of `henrov` with `$USER`, but **only within blocks** that begin with the string `** =` and end with a line matching `#+END_SRC`. Leave all text outside these blocks unchanged.

- **5.3** In all files under `~/Droidnix/` (recursively, excluding binary files), replace every occurrence of `~/Repos/nixos/Droidnix` with `~/Droidnix`

- **5.4.** In all files under `~/Droidnix`, replace every occurrence of `traveldroid` with `$HOSTNAME`

- **5.6** In `~/Droidnix/[README.org](http://README.org)`, replace every occurrence of `traveldroid` with `$HOSTNAME`, but **only within blocks** that begin with a line matching `** =` and end with a line matching `#+END_SRC`

## Step 6 — Generate hardware configuration

Create the directory `~/Droidnix/generated/hosts/$HOSTNAME/` if it does not already exist.

Run the following command and write its output to `~/Droidnix/generated/hosts/$HOSTNAME/hardware-configuration.nix`:

```bash

sudo nixos-generate-config --show-hardware-config

```

## Step 7 — Update [README.org](http://README.org) with generated hardware configuration

In `~/Droidnix/[README.org](http://README.org)`, locate the block that begins with exactly this line:

```

#+BEGIN_SRC nix :tangle generated/hosts/$HOSTNAME/hardware-configuration.nix :noweb yes :mkdirp yes :eval never

```

and ends with the next line containing exactly `#+END_SRC`.

Replace everything between (but not including) those two boundary lines with the full contents of `~/Droidnix/generated/hosts/$HOSTNAME/hardware-configuration.nix`.

## Step 8 — Build and activate the NixOS configuration

Change directory to `~/Droidnix` and run:

```bash

sudo nixos-rebuild switch --flake .#$HOSTNAME

```

## Step 9 — Inform the user

Print the following message:

```

Installation complete. Please reboot your system.

After rebooting, any changes to your NixOS configuration must be made in

~/Droidnix/[README.org](http://README.org). Before rebuilding, first tangle the org file using:

  emacs --batch --no-init-file ~/Droidnix/[README.org](http://README.org) \

    --eval "(require 'org)" \

    --eval "(require 'ob-tangle)" \

    --eval "(find-file \"[README.org](http://README.org)\")" \

    --eval "(with-temp-message \"\" (org-babel-tangle))" \

    --eval "(with-temp-message \"\" (org-html-export-to-html))"

Then rebuild with:

  cd ~/Droidnix && sudo nixos-rebuild switch --flake .#$(hostname)

```