/**
 * SolaceScan Explorer (Blockscout v2) client for Chain 138.
 *
 * Base URL: https://api.explorer.d-bis.org (CORS *)
 * Fallback: https://explorer.d-bis.org/api/v2 (same data, different host)
 *
 * We hit the `api.*` subdomain by default because it returns clean JSON
 * without the Next.js HTML wrapper.
 */

import { httpJson } from './http';
import { endpoints } from '../config/endpoints';

const api = (path: string) => `${endpoints.explorer.apiBaseUrl}/api/v2${path}`;

export interface ExplorerStats {
  total_blocks: number;
  total_transactions: number;
  total_addresses: number;
  latest_block: number;
  average_block_time: number;
  gas_prices: { average: number; fast?: number; slow?: number };
  network_utilization_percentage: number;
  transactions_today: number;
}

export async function getExplorerStats(): Promise<ExplorerStats> {
  const raw = await httpJson<ExplorerStats>(api('/stats'));
  // Blockscout returns `average_block_time` in milliseconds; normalize to seconds
  // so callers can display `${value.toFixed(1)}s` directly. Chain-138 block time
  // is ~4s, so a raw value > 60 is a reliable signal that it is still in ms.
  const average_block_time =
    typeof raw.average_block_time === 'number' && raw.average_block_time > 60
      ? raw.average_block_time / 1000
      : raw.average_block_time;
  return { ...raw, average_block_time };
}

export interface ExplorerBlock {
  height: number;
  hash: string;
  timestamp: string;
  tx_count: number;
  gas_used: string;
  gas_limit: string;
  size: number;
  miner: { hash: string };
}

export async function getLatestBlocks(): Promise<ExplorerBlock[]> {
  return httpJson<ExplorerBlock[]>(api('/main-page/blocks'));
}

export interface ExplorerTx {
  hash: string;
  block_number: number;
  timestamp: string;
  from: { hash: string };
  to: { hash: string } | null;
  value: string; // wei
  gas_used: string;
  gas_price: string;
  status: 'ok' | 'error' | null;
  method: string | null;
  fee: { value: string };
}

interface PagedTxResponse { items: ExplorerTx[]; next_page_params?: unknown }

export async function getLatestTransactions(limit = 20): Promise<ExplorerTx[]> {
  const data = await httpJson<PagedTxResponse>(api('/transactions'));
  return (data.items ?? []).slice(0, limit);
}

export async function getAddressTransactions(address: string, limit = 20): Promise<ExplorerTx[]> {
  const data = await httpJson<PagedTxResponse>(api(`/addresses/${address}/transactions`));
  return (data.items ?? []).slice(0, limit);
}

export function explorerTxUrl(hash: string): string {
  return `${endpoints.explorer.baseUrl}/tx/${hash}`;
}

export function explorerAddressUrl(address: string): string {
  return `${endpoints.explorer.baseUrl}/address/${address}`;
}

export function explorerBlockUrl(height: number): string {
  return `${endpoints.explorer.baseUrl}/block/${height}`;
}