const ynab = require("ynab");
const { argv } = require('yargs');
const fs = require('fs');
const { pat, cacheDir } = require('./config');
const ynabAPI = new ynab.API(pat);

const ensureDataDir = async function(path) {
    if (!fs.existsSync(path)) {
        await fs.promises.mkdir(path);
    }
}

const getCachedJsonOrHydrate = async function(fileName, hydrator) {
    const filePath = `${cacheDir}/${fileName}`

    if (fs.existsSync(filePath)) {
        return JSON.parse(await fs.promises.readFile(filePath));
    }

    const data = await hydrator();
    await ensureDataDir(cacheDir);
    await fs.promises.writeFile(filePath, JSON.stringify(data));
    return data;
}

const getBudgetId = async function(budgetName) {
    const budgets = await getCachedJsonOrHydrate("budgets.json", async () => {
        console.log("Grabbing budgets from YNAB");
        const budgetsResponse = await ynabAPI.budgets.getBudgets();
        return budgetsResponse.data.budgets;
    });
    
    const budgetId = budgets.filter(b => { return b.name === budgetName; })[0].id;
    return budgetId;
}

const getAccountId = async function(budgetId, accountName) {
    let accounts = await getCachedJsonOrHydrate("accounts.json", async () => {
        console.log("Grabbing accounts from YNAB");
        const accountsResponse = await ynabAPI.accounts.getAccounts(budgetId);
        return accountsResponse.data.accounts;
    });

    const accountId = accounts.filter(a => { return a.name === accountName; })[0].id;
    return accountId;
}

const getTransactions = async function(budgetId, accountId) {
    const date = new Date();
    const jsonFile = `${date.getFullYear()}-${date.getMonth()}-${date.getDate()}-transactions.json`;
    let transactions = await getCachedJsonOrHydrate(jsonFile, async () => {
        console.log("Grabbing transactions from YNAB");
        const transactionsResponse = await ynabAPI.transactions.getTransactionsByAccount(budgetId, accountId);
        return transactionsResponse.data.transactions;
    });

    return transactions;
}

const main = async function(budgetName, accountName) {
    console.log(`Looking for account '${accountName}' in budget named '${budgetName}'.`);

    const budgetId = await getBudgetId(budgetName);
    const accountId = await getAccountId(budgetId, accountName);
    const transactions = await getTransactions(budgetId, accountId);    

    console.log(transactions.length);
    console.log(transactions[transactions.length - 1]);
};

main(argv.budgetName, argv.accountName);