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

const schemaPath = path.resolve(process.cwd(), "db-schema.json");
const outPath = path.resolve(process.cwd(), "src", "types", "db-client.d.ts");

if (!fs.existsSync(schemaPath)) {
  console.error("db-schema.json not found");
  process.exit(1);
}

const schema = JSON.parse(fs.readFileSync(schemaPath, "utf8"));
const tables = schema.tables || {};

function fieldTypeToTs(t) {
  switch (t) {
    case "number":
      return "number";
    case "string":
      return "string";
    case "boolean":
      return "boolean";
    default:
      return "any";
  }
}

let out = `// GENERATED FILE — edit db-schema.json and run npm run generate:db-types\n\n`;
out += `type DBAction<TRequest = any, TResponse = any> = (payload?: TRequest) => Promise<TResponse>;\n\n`;

out += `// Generated tables\n`;
out += `interface DBTables {\n`;
for (const [table, def] of Object.entries(tables)) {
  out += `  ${table}: {\n`;
  out += `    create: DBAction<{ data: Partial<{`;
  const fields = def.fields || {};
  const fPairs = Object.entries(fields).map(
    ([n, t]) => `${n}: ${fieldTypeToTs(t)}`
  );
  out += fPairs.join("; ");
  out += `}> }, any>;\n`;
  out += `    update: DBAction<{ where: any; data: any }, any>;\n`;
  out += `    delete: DBAction<{ where: any }, any>;\n`;
  out += `    findFirst: DBAction<{ where?: any; include?: any; select?: any }, any>;\n`;
  out += `    findMany: DBAction<any, any[]>;\n`;
  out += `  };\n`;
}
out += `}\n\n`;

out += `type DBClient = {\n  [K in keyof DBTables]: DBTables[K];\n} & { [table: string]: { [action: string]: DBAction<any, any> } };\n\n`;

out += `declare module "@/lib/dbClient" {\n  const db: DBClient;\n  export default db;\n}\n`;

fs.mkdirSync(path.dirname(outPath), { recursive: true });
fs.writeFileSync(outPath, out, "utf8");
console.log("Wrote", outPath);