/**
 * Step 3 — Coin module: network layer (explorer/RPC wrapper)
 * Target: ledger-live libs/coin-modules/coin-ethereum (or coin-defi_oracle_meta) src/network/
 *
 * Wraps Chain 138 RPC and Blockscout for sync, history, fees. Use in bridge.
 */

const RPC_URL = "https://rpc-http-pub.d-bis.org";
const EXPLORER_API = "https://explorer.d-bis.org/api";

export async function getLastBlock(): Promise<number> {
  const res = await fetch(RPC_URL, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ jsonrpc: "2.0", id: 1, method: "eth_blockNumber", params: [] }),
  });
  const data = await res.json();
  return parseInt(data.result, 16);
}

export async function getBalance(address: string): Promise<string> {
  const res = await fetch(RPC_URL, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      jsonrpc: "2.0",
      id: 1,
      method: "eth_getBalance",
      params: [address, "latest"],
    }),
  });
  const data = await res.json();
  return data.result ?? "0x0";
}

export async function getTransactionCount(address: string): Promise<number> {
  const res = await fetch(RPC_URL, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      jsonrpc: "2.0",
      id: 1,
      method: "eth_getTransactionCount",
      params: [address, "latest"],
    }),
  });
  const data = await res.json();
  return parseInt(data.result ?? "0x0", 16);
}

/**
 * Explorer: get transactions for address.
 * Blockscout REST v2: GET /api/v2/addresses/{address_hash}/transactions
 * Response: { items: Tx[], next_page_params?: { block_number, index, items_count } }
 */
const EXPLORER_API_V2 = "https://explorer.d-bis.org/api/v2";

export async function getAddressTransactions(
  address: string,
  params?: { block_number?: number; index?: number; items_count?: number }
): Promise<{ items: unknown[]; next_page_params?: { block_number: number; index: number; items_count: number } }> {
  let url = `${EXPLORER_API_V2}/addresses/${encodeURIComponent(address)}/transactions`;
  if (params?.block_number != null && params?.index != null && params?.items_count != null) {
    url += `?block_number=${params.block_number}&index=${params.index}&items_count=${params.items_count}`;
  }
  const res = await fetch(url);
  if (!res.ok) return { items: [] };
  const data = await res.json();
  return {
    items: data.items ?? [],
    next_page_params: data.next_page_params,
  };
}

export { RPC_URL, EXPLORER_API, EXPLORER_API_V2 };