refresh migrations, used with github.com/golang-migrate/migrate

refresh_migrations

#!/usr/bin/env bash
set -euo pipefail

DIR="migrations"

error() { echo -e "\033[31m[ERROR]\033[0m $*" >&2; exit 1; }
info()  { echo -e "\033[32m[INFO]\033[0m $*"; }
warn()  { echo -e "\033[33m[WARN]\033[0m $*"; }

command -v git >/dev/null 2>&1 || error "git is required but not installed."
command -v fzf >/dev/null 2>&1 || error "fzf is required but not installed."
command -v bat >/dev/null 2>&1 || PREVIEW_CMD="cat {}"
PREVIEW_CMD=${PREVIEW_CMD:-"bat --style=plain --color=always {} || cat {}"}

[ -d "$DIR" ] || error "Directory '$DIR' does not exist."
git rev-parse --is-inside-work-tree >/dev/null 2>&1 || error "Not inside a git repository."

ensure_clean_staging() {
  local staged non_migrations
  non_migrations=$(git diff --cached --name-only -- . ":(exclude)${DIR%/}/**" 2>/dev/null || true)
  if [ -z "${non_migrations}" ]; then
    staged=$(git diff --cached --name-only 2>/dev/null || true)
    if [ -n "${staged}" ]; then
      non_migrations=$(printf '%s\n' "$staged" | grep -v -E "^${DIR%/}/" || true)
    fi
  fi
  if [ -n "${non_migrations}" ]; then
    echo "Staged changes outside '$DIR':"
    printf '  - %s\n' "$non_migrations"
    error "You already have staged changes outside '$DIR'. Commit or unstage them first."
  fi
}

check_duplicate_numbers() {
  local conflicts
  conflicts=$(find "$DIR" -type f -name "*.sql" \
    | awk -F/ '{print $NF}' \
    | awk -v RS='' '
       function base(x){
         sub(/^[0-9]+_/,"",x)
         sub(/\.(up|down)\.sql$/,"",x)
         sub(/_down$/,"",x)
         sub(/_up$/,"",x)
         return x
       }
       {
         if (match($0,/^([0-9]+)_/,m)) {
           n=m[1]; b=base($0)
           if (!(b in seen[n])) {
             seen[n][b]=1
             counts[n]++
             basenames[n]=(basenames[n] ? basenames[n] "|" b : b)
           }
         }
       }
       END {
         for (n in counts) {
           if (counts[n] > 2) {
             print "HARD|" n "|" basenames[n]
           } else if (counts[n] == 2) {
             print "FUZZY|" n "|" basenames[n]
           }
         }
       }')

  if [ -n "$conflicts" ]; then
    echo
    while IFS= read -r line; do
      [ -z "$line" ] && continue
      kind=$(echo "$line" | cut -d'|' -f1)
      num=$(echo "$line" | cut -d'|' -f2)
      bases=$(echo "$line" | cut -d'|' -f3-)
      if [ "$kind" = "HARD" ]; then
        echo -e "\033[31m[ERROR]\033[0m Number $num used by multiple distinct basenames:"
        IFS='|' read -ra arr <<< "$bases"
        for b in "${arr[@]}"; do
          find "$DIR" -type f -name "${num}_${b}*.sql" -printf "    %P\n"
        done
        return 1
      elif [ "$kind" = "FUZZY" ]; then
        echo -e "\033[33m[WARN]\033[0m Number $num may contain a typo (two similar basenames):"
        IFS='|' read -ra arr <<< "$bases"
        for b in "${arr[@]}"; do
          find "$DIR" -type f -name "${num}_${b}*.sql" -printf "    %P\n"
        done
      fi
    done <<< "$conflicts"
  fi
  return 0
}

ensure_clean_staging
check_duplicate_numbers || error "Resolve duplicates before continuing."

if [ -n "$(git status --porcelain --untracked-files=no)" ]; then
  warn "You have unstaged changes."
  read -rp "Continue anyway? [y/N]: " ans
  [[ "$ans" =~ ^[Yy]$ ]] || exit 1
fi

SELECTED_UP_FILE=$(find "$DIR" -type f -name "*.up.sql" | sort -r | \
  fzf --prompt="Select a migration to refresh number: " \
      --preview="$PREVIEW_CMD")

[ -z "$SELECTED_UP_FILE" ] && { warn "No file selected."; exit 0; }

LAST_NUM=$(find "$DIR" -type f -name "*.up.sql" \
  | sed -E 's#.*/([0-9]+)_.*#\1#' \
  | sort -n \
  | tail -n1)

if [ -z "$LAST_NUM" ]; then
  NEXT_NUM="000001"
else
  NEXT_DEC=$((10#$LAST_NUM + 1))
  NEXT_NUM=$(printf "%06d" "$NEXT_DEC")
fi

BASENAME=$(basename "$SELECTED_UP_FILE" | sed -E 's/^[0-9]+_//;s/.up.sql$//')

UP_FILE="$SELECTED_UP_FILE"
NEW_UP_FILE="$DIR/${NEXT_NUM}_${BASENAME}.up.sql"

if [[ "${1:-}" == "--dry-run" ]]; then
  info "Dry-run mode:"
  echo "  Would rename: $UP_FILE -> $NEW_UP_FILE"
else
  git mv "$UP_FILE" "$NEW_UP_FILE"
  info "Renamed: $UP_FILE -> $NEW_UP_FILE"
fi

DOWN_FILE=$(find "$DIR" -type f -name "*_${BASENAME}.down.sql" | head -n1 || true)
if [ -n "$DOWN_FILE" ]; then
  NEW_DOWN_FILE="$DIR/${NEXT_NUM}_${BASENAME}.down.sql"
  if [[ "${1:-}" == "--dry-run" ]]; then
    echo "  Would rename: $DOWN_FILE -> $NEW_DOWN_FILE"
  else
    git mv "$DOWN_FILE" "$NEW_DOWN_FILE"
    info "Renamed: $DOWN_FILE -> $NEW_DOWN_FILE"
  fi
else
  warn "No corresponding .down.sql file found for base name: $BASENAME"
fi

if ! check_duplicate_numbers; then
  warn "Rolling back renames due to conflicting numbers."
  git reset --hard HEAD || {
    warn "git reset failed, stashing instead."
    git stash push -k -u -m "rollback from refresh_migration"
  }
  error "Aborted due to conflicting migration numbers."
fi

if [[ "${1:-}" == "--dry-run" ]]; then
  info "Dry-run complete. No changes made."
  exit 0
fi

git add "$DIR"
ensure_clean_staging

git status --short
read -rp "Create commit with only migration changes? [y/N]: " confirm
if [[ "$confirm" =~ ^[Yy]$ ]]; then
  git commit -m "migrations: bumped ${NEXT_NUM}_${BASENAME}"
  info "Commit created successfully!"
else
  warn "Changes staged but not committed. Run 'git commit' manually if needed."
fi