# Project rules for agents (read first)

This repository is building `beelloo`, a cli tool to build an invoice from a markdown file.

## General description of the project

Beelloo provides a way to generate simple invoices from a markdown file with a defined structure. The markdown is converted to an HTML file styled in CSS. The CSS rules make the generated file fit to be printed on A4 documents.

## Usage
- The invoices are emitted for French buyers. No need to care for translation and foreign law for now.
- The design must match the one of the current LaTeX template (provided in the sample `.tex` invoice and `.input` folder)

- The tool is to be used like this:
  - Optionally, calling `beelloo new document.md` generates a new "scaffold" document the user can fill in with the right information
  - The user writes the information in the structured markdown file.
      - `beelloo build document.md` validates the document and either:
      - return an error if something is missing or wrongly structured
      - generate an HTML file
      - `beelloo serve document.md` renders the document and serves it on an HTTP endpoint for live preview
  - The user visits the endpoint and "prints" the document from their web browser into a PDF.

## Document format
Generated invoices have the following sections:
A header with:
    - Seller identity and address (Name, address) 
    - Buyer identity address (Name, address, SIRET if needed)
    - Invoice ID
    - Invoice object (ex: Facture pour prestation de service)
A main body with:
    - List of "Billable" tasks with:
      - Designation
      - Unit price
      - quantity
      - Amount
    - Total Without VAT
    - A mention regarding VAT: "TVA non applicable, art 293 B du CGI"
A footer with:
    - The mention: "Paiement souhaité par virement bancaire"
    - Name of the bank account holder
    - IBAN
    
## Choice of technology
- Plain HTML/CSS for the generated document
- The cli tool must be using Go
- Markdown to HTML conversion should use the `blackfriday` library unless something else is required

## Core Constraints
- Support: Linux and FreeBSD (shouldn't be a problem with Go cross-compilation)
- UX: Comprehensive verb and command line parameters
- Testing: develop via **TDD** (tests drive design; behavior changes require tests)
- Unit and functional tests: fast, hermetic, run via `go test ./...`
- Use golden files when needed

## What to do when unsure
- Ask for clarification before adding major dependencies or widening scope.