const fs = require("fs");
const path = require("path");

async function createPlugin(ctx) {
  return {
    async execute(action) {
      if (action !== "getTxState") {
        throw new Error(`Unknown action: ${action}`);
      }
      return readTxState(ctx);
    },
    async getStatus() {
      return readTxState(ctx);
    },
    async health() {
      return { ok: true };
    }
  };
}

function readTxState(ctx) {
  const stateFilePath = resolvePath(String(ctx.getSetting("stateFilePath", ctx.env.TX_STATE_PATH || "./data/tx-state.json")));
  const fallback = {
    txActive: false,
    source: "tx-state-file",
    updatedAt: null,
    path: stateFilePath
  };
  if (!stateFilePath || !fs.existsSync(stateFilePath)) {
    return fallback;
  }
  try {
    const raw = fs.readFileSync(stateFilePath, "utf8");
    const parsed = JSON.parse(raw);
    return {
      txActive: Boolean(parsed && parsed.txActive),
      source: "tx-state-file",
      updatedAt: parsed && parsed.updatedAt ? parsed.updatedAt : null,
      path: stateFilePath,
      details: parsed && typeof parsed === "object" ? parsed : null
    };
  } catch {
    return fallback;
  }
}

function resolvePath(value) {
  const v = String(value || "").trim();
  if (!v) return "";
  if (path.isAbsolute(v)) return v;
  return path.resolve(process.cwd(), v);
}

module.exports = {
  createPlugin
};