export const enforceCatchType = {
  meta: {
    type: "problem",
    docs: {
      description:
        "强制 catch 子句使用 e: unknown，并用 instanceof Error 提取错误信息；空的 catch 块应添加注释说明原因",
    },
    messages: {
      missingTypeAnnotation:
        "catch 子句缺少类型注解。请使用 catch (e: unknown)，然后用 e instanceof Error ? e.message : String(e) 提取错误信息。",
      nonUnknownType:
        "catch 的类型注解应为 unknown，切勿使用 any。请改为 catch (e: unknown)，然后用 e instanceof Error ? e.message : String(e) 提取错误信息。",
      emptyCatchNoComment:
        "空的 catch 块应添加注释说明为什么忽略此异常。如果确有理由静默吞掉错误，请在该 catch body 内添加注释。",
    },
    schema: [],
  },

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

    function isUnknownType(typeAnnotation) {
      if (!typeAnnotation) return false;
      const type = typeAnnotation.typeAnnotation;
      if (type?.type === "TSTypeReference") {
        return type.typeName?.name === "unknown";
      }
      return false;
    }

    function hasCommentsInBody(body) {
      if (!body) return false;
      return sourceCode.getCommentsInside(body).length > 0;
    }

    function check(node) {
      const { param, body } = node;

      if (param) {
        const typeAnnotation = param.typeAnnotation;
        if (!typeAnnotation) {
          context.report({ node: param, messageId: "missingTypeAnnotation" });
        } else if (!isUnknownType(typeAnnotation)) {
          context.report({ node: typeAnnotation, messageId: "nonUnknownType" });
        }
      }

      if (
        body &&
        body.type === "BlockStatement" &&
        body.body.length === 0 &&
        !hasCommentsInBody(body)
      ) {
        context.report({ node: body, messageId: "emptyCatchNoComment" });
      }
    }

    return {
      CatchClause: check,
    };
  },
};