#!/usr/bin/env sh
# DEP-03: postgres and sqlite migration sets must have matching numbered pairs.
set -eu

ROOT="$(CDPATH= cd -- "$(dirname "$0")/.." && pwd)"
PG="$ROOT/migrations/postgres"
SQL="$ROOT/migrations/sqlite"

list_nums() {
  dir="$1"
  ls "$dir" 2>/dev/null | sed -n 's/^\([0-9]\{6\}\)_.*\.up\.sql$/\1/p' | sort -u
}

migration_only_in() {
  # Prints numbers present in $1 but not in $2 (space-separated lists).
  haystack="$2 "
  for n in $1; do
    case "$haystack" in
      *" $n "*) ;;
      *) echo "$n" ;;
    esac
  done
}

pg_nums="$(list_nums "$PG")"
sql_nums="$(list_nums "$SQL")"

if [ "$pg_nums" != "$sql_nums" ]; then
  echo "check-migrations-pair: postgres and sqlite migration numbers differ" >&2
  only_pg="$(migration_only_in "$pg_nums" "$sql_nums")"
  only_sql="$(migration_only_in "$sql_nums" "$pg_nums")"
  if [ -n "$only_pg" ]; then
    echo "postgres only:" >&2
    for n in $only_pg; do
      echo "  $n" >&2
    done
  fi
  if [ -n "$only_sql" ]; then
    echo "sqlite only:" >&2
    for n in $only_sql; do
      echo "  $n" >&2
    done
  fi
  exit 1
fi

for n in $pg_nums; do
  pg_up=""
  sql_up=""
  for f in "$PG"/${n}_*.up.sql; do
    if [ -f "$f" ]; then
      pg_up="$f"
      break
    fi
  done
  for f in "$SQL"/${n}_*.up.sql; do
    if [ -f "$f" ]; then
      sql_up="$f"
      break
    fi
  done
  if [ -z "$pg_up" ] || [ -z "$sql_up" ]; then
    echo "check-migrations-pair: missing .up.sql for $n" >&2
    exit 1
  fi
  pg_base="$(basename "$pg_up" .up.sql)"
  sql_base="$(basename "$sql_up" .up.sql)"
  if [ "$pg_base" != "$sql_base" ]; then
    echo "check-migrations-pair: name mismatch for $n: $pg_base vs $sql_base" >&2
    exit 1
  fi
done

echo "check-migrations-pair: ok ($PG and $SQL)"