package middleware

import (
	ctxpkg "github.com/noahlann/nnet/pkg/context"
)

// Middleware 中间件接口
type Middleware func(ctx ctxpkg.Context, next Handler) error

// Handler 处理器
type Handler func(ctx ctxpkg.Context) error

// Chain 中间件链
type Chain struct {
	middlewares []Middleware
}

// NewChain 创建中间件链
func NewChain(middlewares ...Middleware) *Chain {
	return &Chain{
		middlewares: middlewares,
	}
}

// Then 执行中间件链
func (c *Chain) Then(handler Handler) Handler {
	for i := len(c.middlewares) - 1; i >= 0; i-- {
		handler = c.wrapHandler(c.middlewares[i], handler)
	}
	return handler
}

// wrapHandler 包装处理器
func (c *Chain) wrapHandler(middleware Middleware, handler Handler) Handler {
	return func(ctx ctxpkg.Context) error {
		return middleware(ctx, handler)
	}
}