#!/usr/bin/env bash
# Merge Chain 138 XDC-Zero fragments into an existing endpointconfig.json (upstream XDC-Zero layout).
# Requires jq. Backs up the target file unless --dry-run or explicit stdout.
#
# Usage:
#   bash scripts/xdc-zero/merge-endpointconfig-chain138.sh path/to/endpointconfig.json
#   bash scripts/xdc-zero/merge-endpointconfig-chain138.sh path/to/endpointconfig.json path/to/out.json
#   bash scripts/xdc-zero/merge-endpointconfig-chain138.sh path/to/endpointconfig.json --dry-run
#   bash scripts/xdc-zero/merge-endpointconfig-chain138.sh --dry-run path/to/endpointconfig.json
# Or set XDC_ZERO_ENDPOINT_DIR to an XDC-Zero/endpoint clone path (uses .../endpointconfig.json).
#
# Sources: config/xdc-zero/endpointconfig.fragment.chain138.example.json,
#          config/xdc-zero/xdcparentnet-register-chain138.fragment.json

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
FRAG="$PROJECT_ROOT/config/xdc-zero/endpointconfig.fragment.chain138.example.json"
REG_FRAG="$PROJECT_ROOT/config/xdc-zero/xdcparentnet-register-chain138.fragment.json"

DRY_RUN=false
BASE=""
OUT=""
POSITIONAL=()
for a in "$@"; do
  if [[ "$a" == "--dry-run" ]]; then
    DRY_RUN=true
  else
    POSITIONAL+=("$a")
  fi
done

if [[ ${#POSITIONAL[@]} -ge 1 ]]; then
  BASE="${POSITIONAL[0]}"
fi
if [[ ${#POSITIONAL[@]} -ge 2 ]]; then
  OUT="${POSITIONAL[1]}"
fi

if [[ -z "$BASE" && -n "${XDC_ZERO_ENDPOINT_DIR:-}" ]]; then
  BASE="${XDC_ZERO_ENDPOINT_DIR%/}/endpointconfig.json"
fi

if [[ -z "$BASE" || ! -f "$BASE" ]]; then
  echo "Usage: $0 <endpointconfig.json> [out.json] [--dry-run]" >&2
  echo "  Or: XDC_ZERO_ENDPOINT_DIR=/path/to/XDC-Zero/endpoint $0 [--dry-run]" >&2
  exit 1
fi
if [[ ! -f "$FRAG" || ! -f "$REG_FRAG" ]]; then
  echo "ERROR: missing fragment under config/xdc-zero/" >&2
  exit 1
fi
command -v jq >/dev/null 2>&1 || { echo "ERROR: jq required" >&2; exit 1; }

_step1="$(jq --slurpfile f "$FRAG" '.chain138 = $f[0].chain138' "$BASE")"
MERGED="$(printf '%s\n' "$_step1" | jq --slurpfile r "$REG_FRAG" '
  (if .xdcparentnet == null then . + {xdcparentnet: {registers: []}} else . end)
  | .xdcparentnet.registers += $r[0]
')"

_c138_count="$(printf '%s' "$MERGED" | jq '[.xdcparentnet.registers[]? | select(.chainId == 138)] | length')"
if [[ "${_c138_count:-0}" -gt 1 ]]; then
  echo "WARN: xdcparentnet.registers has ${_c138_count} entries with chainId 138 — review manually." >&2
fi

if $DRY_RUN; then
  printf '%s\n' "$MERGED"
  exit 0
fi

if [[ -n "$OUT" ]]; then
  printf '%s\n' "$MERGED" >"$OUT"
  echo "Wrote $OUT"
  exit 0
fi

cp -a "$BASE" "${BASE}.bak.$(date +%Y%m%d%H%M%S)"
printf '%s\n' "$MERGED" >"$BASE"
echo "Merged into $BASE (backup beside file)."