Struct TaxLineGenerator 

pub struct TaxLineGenerator { /* private fields */ }

Generates tax lines for documents (AP invoices, AR invoices, JEs).

This is a decorator generator that takes a set of pre-generated TaxCodes and produces TaxLine records for source documents.

Tax Determination Logic

1. Exempt check — if the product category is in config.exempt_categories, no tax lines are emitted.
2. Jurisdiction determination — for VendorInvoice (input tax) the seller country is the taxing jurisdiction; for CustomerInvoice (output tax) the buyer country is used (destination-based); for JournalEntry the seller country is used.
3. EU reverse charge — when both countries are in the EU and differ, reverse-charge rules apply: the buyer self-assesses at their own rate.
4. Deductibility — vendor invoices are deductible (input VAT is recoverable), customer invoices and journal entries are not.

Examples

use datasynth_generators::tax::TaxLineGenerator;
use datasynth_generators::tax::TaxLineGeneratorConfig;
use datasynth_generators::tax::TaxCodeGenerator;

let mut code_gen = TaxCodeGenerator::new(42);
let (_jurisdictions, codes) = code_gen.generate();

let mut gen = TaxLineGenerator::new(TaxLineGeneratorConfig::default(), codes, 42);

Implementations

impl TaxLineGenerator

pub fn new( config: TaxLineGeneratorConfig, tax_codes: Vec<TaxCode>, seed: u64, ) -> Self

Creates a new tax line generator.

tax_codes are indexed by their jurisdiction_id for O(1) lookup.

pub fn generate_for_document( &mut self, doc_type: TaxableDocumentType, doc_id: &str, seller_country: &str, buyer_country: &str, taxable_amount: Decimal, date: NaiveDate, product_category: Option<&str>, ) -> Vec<TaxLine>

Generates tax lines for a single document.

Determines the applicable tax code based on:

• seller_country / buyer_country to select jurisdiction
• Cross-border EU B2B transactions trigger reverse charge
• product_category may trigger an exemption
• doc_type determines input (AP) vs output (AR) tax treatment

pub fn generate_batch( &mut self, doc_type: TaxableDocumentType, documents: &[(String, String, String, Decimal, NaiveDate, Option<String>)], ) -> Vec<TaxLine>

Batch-generates tax lines for multiple documents.

Each tuple element: (doc_id, seller_country, buyer_country, amount, date, optional category).