#!/usr/bin/env bash
# Usage: ./scripts/fetch-year.sh YEAR [--reverse]
# Fetches sequentially; prints JSON responses to stdout and errors to stderr.
set -euo pipefail

reverse=false
year=
for arg in "$@"; do
  case "$arg" in
    --reverse) reverse=true ;;
    *)
      if [[ -n $year ]]; then
        echo "Usage: $0 YEAR [--reverse]" >&2
        exit 1
      fi
      year=$arg
      ;;
  esac
done
if [[ -z $year ]]; then
  echo "Usage: $0 YEAR [--reverse]" >&2
  exit 1
fi
if [[ ! $year =~ ^[0-9]{4}$ || $year == 0000 ]]; then
  echo "YEAR must be a four-digit year from 0001 to 9999." >&2
  exit 1
fi

year_number=$((10#$year))
days_in_month=(31 28 31 30 31 30 31 31 30 31 30 31)
if (( year_number % 400 == 0 || (year_number % 4 == 0 && year_number % 100 != 0) )); then
  days_in_month[1]=29
fi

# Reuse a reachable service, or keep a port-forward alive while fetching.
service_ready() {
  curl --fail --silent --output /dev/null --connect-timeout 1 --max-time 2 \
    'http://localhost:4101/api/health'
}

forward_pid=
cleanup() {
  if [[ -n $forward_pid ]]; then
    kill "$forward_pid" 2>/dev/null || true
    wait "$forward_pid" 2>/dev/null || true
  fi
}
trap cleanup EXIT
trap 'exit 130' INT
trap 'exit 143' TERM

if ! service_ready; then
  if ! command -v kubectl >/dev/null 2>&1; then
    echo "Service unavailable on localhost:4101 and kubectl is not installed." >&2
    exit 1
  fi
  echo "Starting kubectl port-forward for sejs/btcdata..." >&2
  kubectl -n sejs port-forward svc/btcdata 4101:4101 >&2 &
  forward_pid=$!

  ready=false
  for (( attempt = 0; attempt < 30; attempt++ )); do
    if ! kill -0 "$forward_pid" 2>/dev/null; then
      echo "Port-forward exited before the service became ready." >&2
      exit 1
    fi
    if service_ready; then
      ready=true
      break
    fi
    sleep 1
  done
  if [[ $ready != true ]]; then
    echo "Timed out waiting for the service on localhost:4101." >&2
    exit 1
  fi
fi

# Generate dates without relying on platform-specific date command options.
status=0
for (( month_index = 0; month_index < 12; month_index++ )); do
  month=$((month_index + 1))
  if [[ $reverse == true ]]; then
    month=$((12 - month_index))
  fi
  days=${days_in_month[month - 1]}
  for (( day_index = 0; day_index < days; day_index++ )); do
    day=$((day_index + 1))
    if [[ $reverse == true ]]; then
      day=$((days - day_index))
    fi
    printf -v date '%s-%02d-%02d' "$year" "$month" "$day"
    if ! curl --fail --silent --show-error -X GET \
      "http://localhost:4101/api/price/day/$date" \
      -H "accept: application/json" --write-out '\n'; then
      echo "Failed to fetch $date" >&2
      status=1
    fi
  done
done
exit "$status"