/**
* CSV Parser for New York Medicaid Formulary
*
* Parses standard CSV format from eMedNY
* Source: https://docs.emedny.org/ReimbursableDrugs/MedReimbDrugsFormulary.csv
*/
const axios = require('axios');
/**
* Download and parse New York Medicaid formulary CSV
* @param {string} url - CSV download URL
* @returns {Promise<Array>} Normalized formulary data
*/
async function downloadAndParseCSV(url) {
console.log('[CSV Parser] Downloading NY Medicaid formulary...');
const response = await axios.get(url, {
responseType: 'text',
timeout: 60000, // 60 seconds
maxContentLength: 10 * 1024 * 1024 // 10 MB max
});
console.log('[CSV Parser] Download complete, parsing CSV...');
// Split into lines
const lines = response.data.split('\n').filter(line => line.trim());
if (lines.length < 2) {
throw new Error('CSV file appears to be empty or malformed');
}
// Parse header
const headerLine = lines[0];
const headers = parseCSVLine(headerLine);
console.log(`[CSV Parser] Found ${headers.length} columns`);
// Column indices (based on NY Medicaid CSV structure)
const COL_TYPE = 0; // TYPE (BND, GEN)
const COL_NDC = 1; // NDC
const COL_MRA_COST = 2; // MRA COST
const COL_ALT_COST = 3; // ALTERNATE COST
const COL_DESCRIPTION = 4; // DESCRIPTION
const COL_PA = 5; // PA (Prior Authorization code)
const COL_LABELER = 6; // LABELER (manufacturer)
const COL_BASIS_MRA = 7; // BASIS OF MRA (ML, EA)
const COL_OTC = 8; // OTC IND
const COL_GENERIC = 9; // GENERIC NAME
const COL_RX_TYPE = 10; // RX TYPE
const COL_EFFECTIVE = 11; // EFFECTIVE DATE
const COL_MAX_QTY = 12; // MAXIMUM QUANTITIES
const COL_PREFERRED = 13; // PREFERRED DRUG CODE
const COL_AGE_RANGE = 14; // AGE RANGE
const COL_REFILLS = 15; // REFILLS ALLOWED
// Parse data rows
const dataRows = lines.slice(1);
const normalized = [];
for (let i = 0; i < dataRows.length; i++) {
const line = dataRows[i];
const values = parseCSVLine(line);
if (values.length < 16) {
console.warn(`[CSV Parser] Skipping malformed row ${i + 2}: insufficient columns`);
continue;
}
// Extract NDC and generic name
const ndc = (values[COL_NDC] || '').trim();
const genericName = (values[COL_GENERIC] || '').trim();
// Skip rows without NDC or generic name
if (!ndc || !genericName) {
continue;
}
// Parse pricing
const mraCost = parseFloat(values[COL_MRA_COST]) || null;
const altCost = parseFloat(values[COL_ALT_COST]) || null;
// Parse PA code
const paCode = (values[COL_PA] || '').trim();
const requiresPA = paCode !== '0' && paCode !== '';
// Parse preferred status
const preferredCode = (values[COL_PREFERRED] || '').trim();
const isPreferred = preferredCode === 'Y';
// Parse quantity limits
const maxQuantity = parseFloat(values[COL_MAX_QTY]) || null;
// Parse type (Brand vs Generic)
const type = (values[COL_TYPE] || '').trim();
normalized.push({
// Core fields
ndc: ndc,
label_name: (values[COL_DESCRIPTION] || '').trim(),
generic_name: genericName,
manufacturer: (values[COL_LABELER] || '').trim(),
// Drug type
drug_type: type, // BND (Brand) or GEN (Generic)
is_brand: type === 'BND',
is_generic: type === 'GEN',
// Pricing (MRA = Maximum Reimbursable Amount)
mra_cost: mraCost,
mra_per_unit: mraCost, // Alias for consistency
alternate_cost: altCost,
pricing_unit: (values[COL_BASIS_MRA] || '').trim(), // ML, EA
// Access restrictions
prior_authorization: requiresPA,
pa_code: paCode, // G, 0, or other codes
preferred_drug: isPreferred,
preferred_code: preferredCode, // Y, X, or blank
// Clinical information
otc_indicator: (values[COL_OTC] || '').trim(),
rx_type: (values[COL_RX_TYPE] || '').trim(),
age_range: (values[COL_AGE_RANGE] || '').trim(),
// Quantity management
maximum_quantity: maxQuantity,
refills_allowed: parseInt(values[COL_REFILLS]) || null,
// Administrative
effective_date: (values[COL_EFFECTIVE] || '').trim()
});
}
console.log(`[CSV Parser] Parsed ${normalized.length} valid formulary records`);
return normalized;
}
/**
* Parse a CSV line handling quoted fields with commas
* @param {string} line - CSV line
* @returns {Array<string>} Parsed values
*/
function parseCSVLine(line) {
const values = [];
let current = '';
let inQuotes = false;
for (let i = 0; i < line.length; i++) {
const char = line[i];
if (char === '"') {
inQuotes = !inQuotes;
} else if (char === ',' && !inQuotes) {
values.push(current.trim());
current = '';
} else {
current += char;
}
}
// Push last value
values.push(current.trim());
return values;
}
module.exports = {
downloadAndParseCSV
};
