Command Line utility to convert Yahoo Finance CSV export into markdown table for ChatGPT

yMunch.swift

import SwiftCSV
import Foundation

extension Double {
	/// Rounds the double to decimal places value
	func rounded(toPlaces places:Int) -> Double {
		let divisor = pow(10.0, Double(places))
		return (self * divisor).rounded() / divisor
	}
}


guard CommandLine.arguments.count >= 2 else {
	print("Usage: yMunch path/to/input_file.csv")
	exit(1)
}

let fileManager = FileManager.default
let currentDirectory = fileManager.currentDirectoryPath
let inputFile = CommandLine.arguments[1]
let fileURL = URL(fileURLWithPath: inputFile.hasPrefix("/") ? inputFile : "\(currentDirectory)/\(inputFile)")

var transactionsBySymbol = [String: (quantity: Double, purchasePrice: Double, currentPrice: Double)]()

do {
	let csv = try CSV<Named>(url: fileURL) // I needed to add the <Named> and change the param to url:
	let rows = csv.rows
	for row in rows {
		let symbol = row["Symbol"]!
		let quantity = Double(row["Quantity"]!)!
		let purchasePrice = Double(row["Purchase Price"]!)!
		let currentPrice = Double(row["Current Price"]!)!
		
		if transactionsBySymbol[symbol] == nil {
			transactionsBySymbol[symbol] = (quantity: 0, purchasePrice: 0, currentPrice: 0)
		}
		
		var transaction = transactionsBySymbol[symbol]!
		transaction.quantity += quantity
		transaction.purchasePrice = (transaction.purchasePrice * (transaction.quantity - quantity) + quantity * purchasePrice) / transaction.quantity
		transaction.currentPrice = currentPrice
		transactionsBySymbol[symbol] = transaction
	}
} catch {
	print("Error reading input file: \(error)")
}

let transactions = transactionsBySymbol.map { (symbol, transaction) in
	let averagePurchasePrice = transaction.purchasePrice
	let totalQuantity = transaction.quantity
	let currentPrice = transaction.currentPrice
	let totalMarketValue = totalQuantity * currentPrice
	let profitLoss = totalQuantity * (currentPrice - averagePurchasePrice)
	return (symbol: symbol, totalQuantity: totalQuantity, averagePurchasePrice: averagePurchasePrice, currentPrice: currentPrice, totalMarketValue: totalMarketValue, profitLoss: profitLoss)
}

let sortedTransactions = transactions.sorted { $0.profitLoss < $1.profitLoss }

print("| Symbol | Quantity | Average Price | Current Price | Current Market Value | Unrealized Performance |")
print("| --- | --- | --- | --- | --- | --- |")
for transaction in sortedTransactions {
	let symbol = transaction.symbol
	let averagePurchasePrice = transaction.averagePurchasePrice.rounded(toPlaces: 2)
	let totalQuantity = Int(transaction.totalQuantity)
	let currentPrice = transaction.currentPrice.rounded(toPlaces: 2)
	let totalMarketValue = transaction.totalMarketValue.rounded(toPlaces: 2)
	let profitLoss = transaction.profitLoss.rounded(toPlaces: 2)
	print("| \(symbol) | \(totalQuantity) | \(averagePurchasePrice) | \(currentPrice) | \(totalMarketValue) | \(profitLoss) |")
}