export const noEmptyFunction = {
  meta: {
    type: "problem",
    docs: {
      description:
        "禁止空函数体，并提供项目约定的修复指引：生产代码使用 () => undefined，测试代码使用 () => {} + eslint-disable",
    },
    messages: {
      unexpectedProduction:
        "生产代码中空函数应使用 () => undefined 明确表意（如 noop/voidLog）。如果确需空实现且为接口契约，请添加注释说明原因。",
      unexpectedTest:
        "测试代码中空函数使用 () => {} 并在文件顶部添加 /* eslint-disable @typescript-eslint/no-empty-function */。",
    },
    schema: [],
  },

  create(context) {
    const sourceCode = context.sourceCode ?? context.getSourceCode();

    const allowedFunctionTypes = new Set([
      "ArrowFunctionExpression",
      "FunctionDeclaration",
      "FunctionExpression",
    ]);

    function isEmptyBody(body) {
      return (
        body.type === "BlockStatement" &&
        body.body.length === 0 &&
        sourceCode.getCommentsInside(body).length === 0
      );
    }

    function hasDecorator(node) {
      return Array.isArray(node.decorators) && node.decorators.length > 0;
    }

    function isPrivateOrProtectedConstructor(node) {
      if (node.parent?.type !== "MethodDefinition") return false;
      if (node.parent.kind !== "constructor") return false;
      const accessibility = node.parent.accessibility;
      return accessibility === "private" || accessibility === "protected";
    }

    function isOverrideMethod(node) {
      if (node.parent?.type !== "MethodDefinition") return false;
      return node.parent.override === true;
    }

    function check(node) {
      if (!allowedFunctionTypes.has(node.type)) return;
      if (!isEmptyBody(node.body)) return;
      if (hasDecorator(node)) return;
      if (isPrivateOrProtectedConstructor(node)) return;
      if (isOverrideMethod(node)) return;

      const isTest = /[\\/]tests?[\\/]/.test(context.filename ?? "") || context.filename?.includes("test");

      context.report({
        node,
        messageId: isTest ? "unexpectedTest" : "unexpectedProduction",
        data: { name: node.id?.name ?? node.key?.name ?? "function" },
      });
    }

    return {
      ArrowFunctionExpression: check,
      FunctionDeclaration: check,
      FunctionExpression: check,
    };
  },
};