#!/usr/bin/env bash
# ============================================================================
# SHARP-ER - generate the Strapi secrets an environment file needs
# ----------------------------------------------------------------------------
#   ./scripts/generate-secrets.sh                      print a block to paste
#   ./scripts/generate-secrets.sh --write .env         fill the empty keys in .env
#   ./scripts/generate-secrets.sh --write apps/cms/.env
#   ./scripts/generate-secrets.sh --write .env --force rotate values already set
#
# Safe by default: an existing, non-placeholder value is never overwritten
# unless --force is given, so re-running it after adding one key only fills the
# gap. With --force the previous file is kept as <file>.bak.
#
# Rotating APP_KEYS signs everyone out of the admin panel; rotating
# ENCRYPTION_KEY makes values already encrypted in the database unreadable.
# ============================================================================
set -euo pipefail

KEYS=(APP_KEYS API_TOKEN_SALT ADMIN_JWT_SECRET JWT_SECRET TRANSFER_TOKEN_SALT ENCRYPTION_KEY)
APP_KEYS_COUNT=4

TARGET=""
FORCE=0

if [ -t 1 ] && [ -z "${NO_COLOR:-}" ]; then
  C_OK=$'\033[32m'; C_WARN=$'\033[33m'; C_ERR=$'\033[31m'; C_DIM=$'\033[2m'; C_OFF=$'\033[0m'
else
  C_OK=""; C_WARN=""; C_ERR=""; C_DIM=""; C_OFF=""
fi
ok()   { printf '%s  ok  %s %s\n' "$C_OK" "$C_OFF" "$*"; }
info() { printf '%s ..   %s %s\n' "$C_DIM" "$C_OFF" "$*"; }
warn() { printf '%s warn %s %s\n' "$C_WARN" "$C_OFF" "$*" >&2; }
die()  { printf '%s fail %s %s\n' "$C_ERR" "$C_OFF" "$*" >&2; exit 1; }

usage() {
  cat <<'USAGE'
generate-secrets.sh - fresh random secrets for Strapi.

  ./scripts/generate-secrets.sh                        print a block to paste
  ./scripts/generate-secrets.sh --write .env           fill empty keys in place
  ./scripts/generate-secrets.sh --write .env --force   rotate values already set

Keys handled: APP_KEYS (4 comma-separated), API_TOKEN_SALT, ADMIN_JWT_SECRET,
JWT_SECRET, TRANSFER_TOKEN_SALT, ENCRYPTION_KEY.

If the target does not exist but a matching .env.example sits next to it, the
template is copied first, so this also bootstraps a new environment file.
Existing values are preserved unless --force is passed (previous file kept as
<file>.bak).
USAGE
  exit 0
}

while [ $# -gt 0 ]; do
  case "$1" in
    --write)   TARGET="${2:?--write needs a file path}"; shift 2 ;;
    --force)   FORCE=1; shift ;;
    -h|--help) usage ;;
    *) die "unknown option: $1 (try --help)" ;;
  esac
done

# --- Randomness -------------------------------------------------------------
# 32 bytes, base64. openssl is used when present; node and /dev/urandom are
# equally good fallbacks so the script works on a bare machine.
random_secret() {
  if command -v openssl >/dev/null 2>&1; then
    openssl rand -base64 32 | tr -d '\n'
  elif command -v node >/dev/null 2>&1; then
    node -e "process.stdout.write(require('node:crypto').randomBytes(32).toString('base64'))"
  elif [ -r /dev/urandom ]; then
    head -c 32 /dev/urandom | base64 | tr -d '\n'
  else
    die "no source of randomness found (need openssl, node, or /dev/urandom)."
  fi
}

value_for() {
  local key="$1" i out=""
  if [ "$key" = "APP_KEYS" ]; then
    for ((i = 0; i < APP_KEYS_COUNT; i++)); do
      out+="${out:+,}$(random_secret)"
    done
    printf '%s' "$out"
  else
    random_secret
  fi
}

# A value that still has to be replaced: empty, or one of the template's
# own placeholders.
is_placeholder() {
  local value="$1"
  value="${value%\"}"; value="${value#\"}"
  value="${value%\'}"; value="${value#\'}"
  [ -z "$value" ] && return 0
  case "$value" in
    replace-with*|changeme*|CHANGEME*|todo*|TODO*) return 0 ;;
    *) return 1 ;;
  esac
}

# --- Print mode -------------------------------------------------------------
if [ -z "$TARGET" ]; then
  printf '# Strapi secrets - generated %s. Paste into .env / apps/cms/.env.\n' "$(date -u '+%Y-%m-%dT%H:%M:%SZ')"
  for key in "${KEYS[@]}"; do
    printf '%s=%s\n' "$key" "$(value_for "$key")"
  done
  exit 0
fi

# --- Write mode -------------------------------------------------------------
if [ ! -f "$TARGET" ]; then
  template="$(dirname -- "$TARGET")/.env.example"
  [ -f "$template" ] || die "$TARGET does not exist and there is no $template to copy."
  cp -- "$template" "$TARGET"
  info "created $TARGET from $(basename -- "$(dirname -- "$template")")/.env.example"
fi

tmp="$(mktemp "${TARGET}.XXXXXX")"
# Secrets must never be world-readable, not even for a moment.
chmod 600 "$tmp"
trap 'rm -f -- "$tmp"' EXIT

declare -A seen=()
filled=(); kept=(); rotated=()

while IFS= read -r line || [ -n "$line" ]; do
  key="${line%%=*}"
  handled=0
  for candidate in "${KEYS[@]}"; do
    [ "$key" = "$candidate" ] || continue
    handled=1
    seen["$candidate"]=1
    current="${line#*=}"
    if [ "$FORCE" -eq 1 ]; then
      printf '%s=%s\n' "$candidate" "$(value_for "$candidate")" >> "$tmp"
      rotated+=("$candidate")
    elif is_placeholder "$current"; then
      printf '%s=%s\n' "$candidate" "$(value_for "$candidate")" >> "$tmp"
      filled+=("$candidate")
    else
      printf '%s\n' "$line" >> "$tmp"
      kept+=("$candidate")
    fi
    break
  done
  [ "$handled" -eq 1 ] || printf '%s\n' "$line" >> "$tmp"
done < "$TARGET"

missing=()
for key in "${KEYS[@]}"; do
  [ -n "${seen[$key]:-}" ] || missing+=("$key")
done

if [ "${#missing[@]}" -gt 0 ]; then
  {
    printf '\n# Strapi secrets - added by scripts/generate-secrets.sh on %s\n' "$(date -u '+%Y-%m-%d')"
    for key in "${missing[@]}"; do
      printf '%s=%s\n' "$key" "$(value_for "$key")"
    done
  } >> "$tmp"
  filled+=("${missing[@]}")
fi

if [ "$FORCE" -eq 1 ]; then
  cp -- "$TARGET" "${TARGET}.bak"
  chmod 600 "${TARGET}.bak"
  warn "previous values kept in ${TARGET}.bak - delete it once the new ones work."
fi

cat -- "$tmp" > "$TARGET"
chmod 600 "$TARGET"
rm -f -- "$tmp"
trap - EXIT

[ "${#filled[@]}"  -gt 0 ] && ok "generated: ${filled[*]}"
[ "${#rotated[@]}" -gt 0 ] && ok "rotated:   ${rotated[*]}"
[ "${#kept[@]}"    -gt 0 ] && info "left alone (already set): ${kept[*]}"
ok "$TARGET is ready (mode 600)"
exit 0