import { mkdir, readFile, writeFile } from "node:fs/promises";
import { dirname, resolve } from "node:path";
import { fileURLToPath, pathToFileURL } from "node:url";

const repositoryRoot = resolve(dirname(fileURLToPath(import.meta.url)), "..");
const bankRequirements = {
  functions: ["contractVersion", "paused", "asset", "owner", "totalLiabilities", "balanceOf"],
  events: ["Deposited", "Withdrawn", "Paused", "Unpaused", "OwnershipTransferred", "Upgraded"],
};
const tokenRequirements = { functions: ["balanceOf"], events: [] };

export function extractAbi(artifact, contractName) {
  if (!artifact || typeof artifact !== "object" || !Array.isArray(artifact.abi)) {
    throw new Error(`${contractName} artifact must contain an ABI`);
  }
  const requirements = contractName === "BankV1" ? bankRequirements : contractName === "MockUSDC" ? tokenRequirements : null;
  if (!requirements) throw new Error(`unsupported contract artifact ${contractName}`);
  for (const [type, names] of Object.entries(requirements)) {
    for (const name of names) {
      if (!artifact.abi.some((entry) => entry && entry.type === type.slice(0, -1) && entry.name === name)) {
        throw new Error(`${contractName} ABI is missing required ${type.slice(0, -1)} ${name}`);
      }
    }
  }
  return artifact.abi;
}

export function renderContractsModule(bankV1Abi, mockUsdcAbi) {
  return `/* This file is generated by tools/sync-web-artifacts.mjs. Do not edit. */\n\nexport const bankV1Abi = ${JSON.stringify(bankV1Abi, null, 2)} as const;\n\nexport const mockUsdcAbi = ${JSON.stringify(mockUsdcAbi, null, 2)} as const;\n`;
}

export async function syncArtifacts({
  bankArtifactPath = resolve(repositoryRoot, "out/BankV1.sol/BankV1.json"),
  tokenArtifactPath = resolve(repositoryRoot, "out/MockUSDC.sol/MockUSDC.json"),
  outputPath = resolve(repositoryRoot, "web/src/generated/contracts.ts"),
  check = false,
} = {}) {
  const [bankArtifact, tokenArtifact] = await Promise.all([
    readArtifact(bankArtifactPath, "BankV1"),
    readArtifact(tokenArtifactPath, "MockUSDC"),
  ]);
  const contents = renderContractsModule(extractAbi(bankArtifact, "BankV1"), extractAbi(tokenArtifact, "MockUSDC"));
  if (check) {
    let existing;
    try { existing = await readFile(outputPath, "utf8"); } catch { throw new Error("generated contracts module is stale or missing"); }
    if (existing !== contents) throw new Error("generated contracts module is stale");
    return contents;
  }
  await mkdir(dirname(outputPath), { recursive: true });
  await writeFile(outputPath, contents);
  return contents;
}

async function readArtifact(path, contractName) {
  let contents;
  try { contents = await readFile(path, "utf8"); } catch { throw new Error(`${contractName} artifact is missing at ${path}`); }
  try { return JSON.parse(contents); } catch { throw new Error(`${contractName} artifact contains invalid JSON`); }
}

if (process.argv[1] && pathToFileURL(resolve(process.argv[1])).href === import.meta.url) {
  const check = process.argv.slice(2).every((argument) => argument === "--check") && process.argv.includes("--check");
  if (process.argv.slice(2).some((argument) => argument !== "--check")) {
    console.error("usage: sync-web-artifacts.mjs [--check]");
    process.exitCode = 1;
  } else {
    syncArtifacts({ check }).catch((error) => { console.error(error.message); process.exitCode = 1; });
  }
}