#!/usr/bin/env bash
# Preflight: RPC reachability and eth_chainId for XDC Zero second pair (parent ↔ Chain 138).
# Optional: ETHEREUM_MAINNET_RPC (or other vars) for quick public mainnet access checks.
#
# Usage:
#   bash scripts/verify/xdc-zero-chain138-preflight.sh
#   XDC mainnet (default in .env.master.example): XDC_PARENTNET_URL=https://rpc.xinfin.network
#   Apothem: XDC_PARENTNET_URL=https://rpc.apothem.network bash scripts/verify/xdc-zero-chain138-preflight.sh
#
# Loads repo dotenv via scripts/lib/load-project-env.sh when sourced from repo root.

# Avoid nounset while sourcing dotenv (some .env lines reference optional vars).
set -eo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
# shellcheck source=/dev/null
source "${PROJECT_ROOT}/scripts/lib/load-project-env.sh"

_rpc_chain_id() {
  local url="$1"
  local name="$2"
  if [[ -z "$url" || "$url" == "devnet" || "$url" == "testnet" ]]; then
    echo "SKIP $name: empty or alias URL ($url) — resolve to HTTPS RPC for this check."
    return 0
  fi
  local out
  if ! out="$(curl -sS --connect-timeout 8 --max-time 20 -X POST "$url" \
    -H 'Content-Type: application/json' \
    -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}' 2>/dev/null)"; then
    echo "FAIL $name: no HTTP response from $url"
    return 1
  fi
  local hex
  hex="$(printf '%s' "$out" | sed -n 's/.*"result":"\([^"]*\)".*/\1/p')"
  if [[ -z "$hex" ]]; then
    echo "FAIL $name: bad JSON or error from $url — $out"
    return 1
  fi
  echo "OK   $name ($url) eth_chainId=$hex"
}

echo "=== XDC Zero Chain 138 pair — RPC preflight ==="

fail=0
PARENT="${XDC_PARENTNET_URL:-${PARENTNET_URL:-}}"
PEER="${XDC_ZERO_PEER_RPC_URL:-${RPC_URL_138:-${CHAIN138_RPC_URL:-${CHAIN138_RPC:-}}}}"

if [[ -n "$PARENT" ]]; then
  _rpc_chain_id "$PARENT" "XDC_PARENTNET / PARENTNET" || fail=1
else
  echo "WARN XDC_PARENTNET_URL and PARENTNET_URL unset — set one for parent checks."
fi

if [[ -n "$PEER" ]]; then
  _rpc_chain_id "$PEER" "Chain138 RPC_URL_138" || fail=1
else
  echo "WARN RPC_URL_138 (or CHAIN138_RPC_URL) unset — set for Chain 138 checks."
fi

if [[ -n "${ETHEREUM_MAINNET_RPC:-}" ]]; then
  _rpc_chain_id "$ETHEREUM_MAINNET_RPC" "ETHEREUM_MAINNET_RPC (optional)" || fail=1
fi

if [[ -n "${BSC_RPC_URL:-}" ]]; then
  _rpc_chain_id "$BSC_RPC_URL" "BSC_RPC_URL (optional)" || fail=1
fi

if [[ "$fail" -ne 0 ]]; then
  echo "=== Preflight finished with failures ==="
  exit 1
fi
echo "=== Preflight finished ==="
echo "Next: deploy Endpoint/CSC per docs/03-deployment/CHAIN138_XDC_ZERO_BRIDGE_RUNBOOK.md"