import { ActualImpl } from "@/actual.ts"
import { cronJobDaily } from "@/cron.ts"
import {
  BANK_ACCOUNT_IDS,
  TRANSACTION_RELATIVE_FROM_DATE,
  TRANSACTION_RELATIVE_TO_DATE,
} from "@/config.ts"
import logger from "@common/logger.ts"
import type { UUID } from "node:crypto"
import { CronJob } from "cron"
import dayjs from "dayjs"
import type { Actual, Bank, Interval } from "@common/types.ts"
import { Sparebank1Impl } from "@sb1impl/sparebank1.ts"

// TODO move tsx to devDependency. Requires ts support for Node with support for @ alias
// TODO verbatimSyntax in tsconfig, conflicts with jest
// TODO store last fetched date in db, and refetch from that date, if app has been offline for some time
// TODO do not fetch if saturday or sunday

async function main(): Promise<void> {
  logger.info("Starting application")
  const bank = new Sparebank1Impl()

  if (process.env.ONCE) {
    return await runOnce(bank)
  }
  await ActualImpl.testConnection()
  await runCronJob(bank)
}

export async function moveTransactions(
  actual: Actual,
  bank: Bank,
): Promise<void> {
  const actualTransactions = await bank.fetchTransactions(
    relativeInterval(),
    ...BANK_ACCOUNT_IDS,
  )
  logger.info(`Fetched ${actualTransactions.length} transactions`)

  const transactionsByAccount = Object.groupBy(
    actualTransactions,
    (transaction) => transaction.account,
  )

  const responses = await Promise.all(
    Object.entries(transactionsByAccount).map(([accountId, transactions]) =>
      actual.importTransactions(accountId as UUID, transactions || []),
    ),
  )

  logger.debug(
    responses.map((response) => ({
      added: response.added,
      updated: response.updated,
    })),
    "Finished importing transactions",
  )
}

function relativeInterval(): Interval {
  const today = dayjs()
  return {
    fromDate: today.subtract(TRANSACTION_RELATIVE_FROM_DATE, "days"),
    toDate: today.subtract(TRANSACTION_RELATIVE_TO_DATE, "days"),
  }
}

async function runOnce(bank: Bank) {
  const actual = await ActualImpl.init()

  registerInterrupt(bank)

  try {
    return await moveTransactions(actual, bank)
  } finally {
    await actual.shutdown()
    await shutdown(bank)
  }
}

async function runCronJob(bank: Bank): Promise<void> {
  logger.info("Waiting for CronJob to start")

  const cronJob = cronJobDaily(async () => {
    let actual: Actual | undefined
    try {
      actual = await ActualImpl.init()
      await moveTransactions(actual, bank)
    } catch (exception) {
      logger.error(exception, "Caught exception at CronJob, shutting down!")
      await shutdown(bank, cronJob)
    } finally {
      await actual?.shutdown()
    }
  })
  registerInterrupt(bank, cronJob)
}

let isShuttingDown = false

function registerInterrupt(
  bank: Bank,
  cronJob: CronJob | undefined = undefined,
): void {
  process.on("SIGINT", async () => {
    if (isShuttingDown) return
    isShuttingDown = true
    logger.info("Caught interrupt signal")
    await shutdown(bank, cronJob)
  })
}

async function shutdown(
  bank: Bank,
  cronJob: CronJob | undefined = undefined,
): Promise<void> {
  logger.info("Shutting down, Bye!")
  await bank.shutdown()
  cronJob?.stop()
}

void main()