Updated readme

README.md

@@ -1,3 +1,78 @@
-# InstructionsDownloader
+# Instruction Downloader Script
 
-Script to download LEGO instructions
+This Python script is designed to download LEGO building instructions for a given set ID from the Rebrickable website. It will search for all available instruction links related to a set, and based on the presence of a "V29" (or "V 29") tag in the alt text, it will download specific versions of the instructions.
+
+## Features
+
+- **Download Specific Versions**: Automatically handles downloading of instructions based on the `V29` version.
+- **Handle Complex Alt Text**: The script handles alt text that includes variations like `V29`, including `x/y` patterns and ignores invalid patterns.
+- **Fallback for Missing or Invalid V29 Versions**: If no valid V29 instruction links are found, the script will download all available instructions.
+- **Customizable Download Filenames**: Instructions are saved with filenames based on the set ID and the instruction variant.
+- **User-Agent Spoofing**: The script mimics a browser request to avoid being blocked as a bot.
+
+## Requirements
+
+- Python 3.x
+- `requests` library
+- `beautifulsoup4` library
+
+You can install the required dependencies by running:
+
+```bash
+python3 -m pip install requests beautifulsoup4
+```
+
+## Usage
+
+### Running the Script
+
+To use this script, you need to provide the LEGO set ID as an argument. The set ID is typically in the format `####-1` (e.g., `10313-1`).
+
+### Example Command
+
+```bash
+python3 dl.py 10313-1
+```
+
+This will download the LEGO building instructions for the set `10313-1` (Wildflower Bouquet). 
+
+### How It Works
+
+1. The script will visit the Rebrickable page for the provided set ID.
+2. It will search for all available instruction links containing "LEGO Building Instructions" in the `alt` text.
+3. If links with "V29" are found, the script will download them in order, naming them as `{set_id}+1.pdf`, `{set_id}+2.pdf`, etc.
+4. If the `x/y` values in the `alt` text are invalid (i.e., `x` or `y` greater than 10), those links will be ignored.
+5. If no valid `V29` links are found, the script will fall back to downloading all available instruction links, with filenames based on the alt text.
+
+## Script Output
+
+The script will print status messages during the execution, including:
+
+- URLs of the files being downloaded.
+- The filenames that the instructions will be saved as.
+- Any errors encountered while downloading.
+
+## Example Output
+
+```bash
+Downloading: https://rebrickable.com/instructions/10313-1/123456/download/?expire=1737409263 -> 10313+1.pdf
+Saved: 10313+1.pdf
+Downloading: https://rebrickable.com/instructions/10313-1/789012/download/?expire=1737409263 -> 10313+2.pdf
+Saved: 10313+2.pdf
+```
+
+If no valid `V29` links are found, the script will print out the available instruction links.
+
+## Error Handling
+
+- If the page cannot be loaded (e.g., invalid set ID), the script will print an error message and stop.
+- If an instruction download fails, the script will print an error message with the HTTP status code.
+
+## Customization
+
+- **User-Agent**: The script uses a browser-like User-Agent string to avoid being detected as a bot. You can customize the `headers` variable if needed.
+- **Download Filename Format**: The filenames for the downloaded instructions are automatically generated. You can modify the `download_instructions` function to change the naming convention.
+
+## License
+
+This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.