balance

#!/bin/bash
set -euo pipefail

source ${BASH_SOURCE%/*}/.helpers.sh

usage() {
	cat<<-EOF
	$0 <address> [<address>, ...]
	
	Check the current balance of accounts in the ledger and the balance if all
	pending transactions.
	
	  --help -h	Print this help message.
	EOF
}

readonly balance_filter='.[$acc] // 0'

readonly debit_filter='
  map(select(.from == "\($acc)"))
  | map(.amount)
  | add
  // 0'

readonly credit_filter='
  map(select(.to == "\($acc)"))
  | map(.amount)
  | add
  // 0'

main() {
  accounts=()

  while [ $# -gt 0 ]; do
    case "$1" in
      --help|-h) usage ; exit 0 ; ;;
      -*) echo "unknown flag $1 (-h for help)" >&2 ; exit 1 ; ;;
      *) accounts+=("$1"); shift ;;
    esac
  done

  table ${accounts[@]}| column -t -s'	'
}

table() {
  echo "Account	Balance	Pending Balance"
  for acc in $@; do
    ledger_balance=$(jq -er --arg acc "$acc" "$balance_filter" "$ledger")

    # Create pending if it doesn't exist.
    [ -s "$pending" ] || touch "$pending"

    debit=$(jq -er --slurp --arg acc "$acc" "$debit_filter" "$pending")
    credit=$(jq -er --slurp --arg acc "$acc" "$credit_filter" "$pending")

    total=$((ledger_balance - debit + credit))

    echo  "$acc:	$ledger_balance	$total"
  done
}

main "$@"