gow.go

package gow

import (
	"fmt"
	"github.com/gkzy/gow/lib/logy"
	"github.com/gkzy/gow/render"
	"html/template"
	"net"
	"net/http"
	"os"
	"path"
	"sync"
)

const (
	defaultMultipartMemory = 32 << 20 // 32 MB
	defaultMode            = "dev"
	DevMode                = "dev"
	TestMode			   = "test"
	ProdMode               = "prod"
	defaultViews           = "views"
	defaultStatic          = "static"
	defaultHttpAddr        = "127.0.0.1:8080"
)

var (
	default404Body = []byte("404 page not found")
	default405Body = []byte("405 method not allowed")
)

var defaultAppEngine bool

// HandlerFunc defines the handler used by gin middleware as return value.
type HandlerFunc func(*Context)

// HandlersChain defines a HandlerFunc array.
type HandlersChain []HandlerFunc

// Last returns the last handler in the chain. ie. the last handler is the main one.
func (c HandlersChain) Last() HandlerFunc {
	if length := len(c); length > 0 {
		return c[length-1]
	}
	return nil
}

// RouteInfo represents a request route's specification which contains method and path and its handler.
type RouteInfo struct {
	Method      string
	Path        string
	Handler     string
	HandlerFunc HandlerFunc
}

// RoutesInfo defines a RouteInfo array.
type RoutesInfo []RouteInfo

// Engine is the framework's instance, it contains the muxer, middleware and configuration settings.
// Create an instance of Engine, by using New() or Default()
type Engine struct {
	AppName  string
	RunMode  string
	httpAddr string

	//views and static
	AutoRender bool
	HTMLRender render.HTMLRender
	delims     render.Delims
	FuncMap    template.FuncMap
	Render     render.Render
	viewsPath  string
	staticPath string
	sessionOn  bool

	RouterGroup
	RedirectTrailingSlash  bool
	RedirectFixedPath      bool
	HandleMethodNotAllowed bool
	ForwardedByClientIP    bool
	AppEngine              bool
	UseRawPath             bool
	UnescapePathValues     bool
	MaxMultipartMemory     int64
	RemoveExtraSlash       bool

	secureJSONPrefix string
	allNoRoute       HandlersChain
	allNoMethod      HandlersChain
	noRoute          HandlersChain
	noMethod         HandlersChain
	pool             sync.Pool
	trees            methodTrees
	maxParams        uint16
}

var _ IRouter = &Engine{}

// New returns a new blank Engine instance without any middleware attached.
// By default the configuration is:
// - RedirectTrailingSlash:  true
// - RedirectFixedPath:      false
// - HandleMethodNotAllowed: false
// - ForwardedByClientIP:    true
// - UseRawPath:             false
// - UnescapePathValues:     true
func New() *Engine {
	engine := &Engine{
		RouterGroup: RouterGroup{
			Handlers: nil,
			basePath: "/",
			root:     true,
		},
		AppName:                "gow",
		RunMode:                defaultMode,
		AutoRender:             false,
		FuncMap:                template.FuncMap{},
		RedirectTrailingSlash:  true,
		RedirectFixedPath:      false,
		HandleMethodNotAllowed: false,
		ForwardedByClientIP:    true,
		AppEngine:              defaultAppEngine,
		UseRawPath:             false,
		RemoveExtraSlash:       false,
		UnescapePathValues:     true,
		MaxMultipartMemory:     defaultMultipartMemory,
		trees:                  make(methodTrees, 0, 9),
		delims:                 render.Delims{Left: "{{", Right: "}}"},
		secureJSONPrefix:       "while(1);",
		viewsPath:              defaultViews,
		Render:                 nil,
		staticPath:             defaultStatic,
		httpAddr:               defaultHttpAddr,
	}
	engine.RouterGroup.engine = engine
	engine.pool.New = func() interface{} {
		return engine.allocateContext()
	}
	return engine
}

// Default returns an Engine instance with the Logger and Recovery middleware already attached.
func Default() *Engine {
	engine := New()
	engine.Use(Logger(), Recovery())
	return engine
}

// SetAppConfig 统一的配置入口
//	读取conf下的配置文件
func (engine *Engine) SetAppConfig(app *AppConfig) {
	if app != nil {
		engine.AppName = app.AppName
		engine.RunMode = app.RunMode
		engine.viewsPath = app.Views
		engine.delims = render.Delims{Left: app.TemplateLeft, Right: app.TemplateRight}
		engine.AutoRender = app.AutoRender
		engine.httpAddr = app.HTTPAddr
		engine.sessionOn = app.SessionOn
		// session on
		if engine.sessionOn {
			InitSession()
			engine.Use(Session())
		}
	}
}

func (engine *Engine) allocateContext() *Context {
	v := make(Params, 0, engine.maxParams)
	return &Context{engine: engine, params: &v}
}

// SetDelims sets template left and right delims and returns a Engine instance.
func (engine *Engine) SetDelims(left, right string) *Engine {
	engine.delims = render.Delims{Left: left, Right: right}
	return engine
}

// AddFuncMap add fn func to template func map
func (engine *Engine) AddFuncMap(key string, fn interface{}) {
	engine.FuncMap[key] = fn
}

// SetView set views path
// 模板目录为 views 时，可不用设置此值
func (engine *Engine) SetView(path ...string) {
	dir := defaultViews
	if len(path) > 0 {
		dir = path[0]
	}
	engine.viewsPath = dir
}

// SetSessionOn SetSessionOn
func (engine *Engine) SetSessionOn(on bool) {
	engine.sessionOn = on
	//是否打开session
	if engine.sessionOn {
		InitSession()
		engine.Use(Session())
	}
}

// RoutesMap get all router map
func (engine *Engine) RouterMap() (routes RoutesInfo) {
	for _, tree := range engine.trees {
		routes = iterate("", tree.method, routes, tree.root)
	}
	return routes
}

// SecureJsonPrefix sets the secureJSONPrefix used in Context.SecureJSON.
func (engine *Engine) SecureJsonPrefix(prefix string) *Engine {
	engine.secureJSONPrefix = prefix
	return engine
}

// SetFuncMap sets the FuncMap used for template.FuncMap.
func (engine *Engine) SetFuncMap(funcMap template.FuncMap) {
	engine.FuncMap = funcMap
}

// NoRoute adds handlers for NoRoute. It return a 404 code by default.
func (engine *Engine) NoRoute(handlers ...HandlerFunc) {
	engine.noRoute = handlers
	engine.rebuild404Handlers()
}

// NoMethod sets the handlers called when... TODO.
func (engine *Engine) NoMethod(handlers ...HandlerFunc) {
	engine.noMethod = handlers
	engine.rebuild405Handlers()
}

// Use attaches a global middleware to the router. ie. the middleware attached though Use() will be
// included in the handlers chain for every single request. Even 404, 405, static files...
// For example, this is the right place for a logger or error management middleware.
func (engine *Engine) Use(middleware ...HandlerFunc) IRoutes {
	engine.RouterGroup.Use(middleware...)
	engine.rebuild404Handlers()
	engine.rebuild405Handlers()
	return engine
}

func (engine *Engine) rebuild404Handlers() {
	engine.allNoRoute = engine.combineHandlers(engine.noRoute)
}

func (engine *Engine) rebuild405Handlers() {
	engine.allNoMethod = engine.combineHandlers(engine.noMethod)
}

func (engine *Engine) addRoute(method, path string, handlers HandlersChain) {
	assert1(path[0] == '/', "path must begin with '/'")
	assert1(method != "", "HTTP method can not be empty")
	assert1(len(handlers) > 0, "there must be at least one handler")

	//debugPrintRoute
	//debugPrintRoute(method, path, handlers)

	root := engine.trees.get(method)
	if root == nil {
		root = new(node)
		root.fullPath = "/"
		engine.trees = append(engine.trees, methodTree{method: method, root: root})
	}
	root.addRoute(path, handlers)

	// Update maxParams
	if paramsCount := countParams(path); paramsCount > engine.maxParams {
		engine.maxParams = paramsCount
	}
}

// Routes returns a slice of registered routes, including some useful information, such as:
// the http method, path and the handler name.
func (engine *Engine) Routes() (routes RoutesInfo) {
	for _, tree := range engine.trees {
		routes = iterate("", tree.method, routes, tree.root)
	}
	return routes
}

func iterate(path, method string, routes RoutesInfo, root *node) RoutesInfo {
	path += root.path
	if len(root.handlers) > 0 {
		handlerFunc := root.handlers.Last()
		routes = append(routes, RouteInfo{
			Method:      method,
			Path:        path,
			Handler:     nameOfFunction(handlerFunc),
			HandlerFunc: handlerFunc,
		})
	}
	for _, child := range root.children {
		routes = iterate(path, method, routes, child)
	}
	return routes
}

// Run attaches the router to a http.Server and starts listening and serving HTTP requests.
// It is a shortcut for http.ListenAndServe(addr, router)
// Note: this method will block the calling goroutine indefinitely unless an error happens.
func (engine *Engine) Run(args ...interface{}) (err error) {
	defer func() { logy.Error(err) }()

	if engine.AutoRender {
		engine.Render = render.HTMLRender{}.NewHTMLRender(engine.viewsPath, engine.FuncMap, engine.delims, engine.AutoRender, engine.RunMode)
	}

	if engine.RunMode == DevMode {
		fmt.Println(logo)
	}

	address := engine.getAddress(args...)
	logy.Infof("[%s] [%s] Listening and serving HTTP on http://%s\n", engine.AppName, engine.RunMode, address)
	err = http.ListenAndServe(address, engine)
	return
}

// RunTLS attaches the router to a http.Server and starts listening and serving HTTPS (secure) requests.
// It is a shortcut for http.ListenAndServeTLS(addr, certFile, keyFile, router)
// Note: this method will block the calling goroutine indefinitely unless an error happens.
func (engine *Engine) RunTLS(certFile, keyFile string, args ...interface{}) (err error) {
	defer func() { logy.Error(err) }()

	if engine.AutoRender {
		engine.Render = render.HTMLRender{}.NewHTMLRender(engine.viewsPath, engine.FuncMap, engine.delims, engine.AutoRender, engine.RunMode)
	}

	if engine.RunMode == DevMode {
		fmt.Println(logo)
	}

	address := engine.getAddress(args...)
	logy.Infof("[%s] [%s] Listening and serving HTTPS on https://%s\n", engine.AppName, engine.RunMode, address)
	err = http.ListenAndServeTLS(address, certFile, keyFile, engine)
	return
}

// RunUnix attaches the router to a http.Server and starts listening and serving HTTP requests
// through the specified unix socket (ie. a file).
// Note: this method will block the calling goroutine indefinitely unless an error happens.
func (engine *Engine) RunUnix(file string) (err error) {
	debugPrint("Listening and serving HTTP on unix:/%s", file)
	defer func() { debugPrintError(err) }()

	listener, err := net.Listen("unix", file)
	if err != nil {
		return
	}
	defer listener.Close()
	defer os.Remove(file)

	err = http.Serve(listener, engine)
	return
}

// RunFd attaches the router to a http.Server and starts listening and serving HTTP requests
// through the specified file descriptor.
// Note: this method will block the calling goroutine indefinitely unless an error happens.
func (engine *Engine) RunFd(fd int) (err error) {
	debugPrint("Listening and serving HTTP on fd@%d", fd)
	defer func() { debugPrintError(err) }()

	f := os.NewFile(uintptr(fd), fmt.Sprintf("fd@%d", fd))
	listener, err := net.FileListener(f)
	if err != nil {
		return
	}
	defer listener.Close()
	err = engine.RunListener(listener)
	return
}

// RunListener attaches the router to a http.Server and starts listening and serving HTTP requests
// through the specified net.Listener
func (engine *Engine) RunListener(listener net.Listener) (err error) {
	debugPrint("Listening and serving HTTP on listener what's bind with address@%s", listener.Addr())
	defer func() { debugPrintError(err) }()
	err = http.Serve(listener, engine)
	return
}

// ServeHTTP conforms to the http.Handler interface.
func (engine *Engine) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	c := engine.pool.Get().(*Context)
	c.writermem.reset(w)
	c.Request = req
	c.reset()

	engine.handleHTTPRequest(c)

	engine.pool.Put(c)
}

// HandleContext re-enter a context that has been rewritten.
// This can be done by setting c.Request.URL.Path to your new target.
// Disclaimer: You can loop yourself to death with this, use wisely.
func (engine *Engine) HandleContext(c *Context) {
	oldIndexValue := c.index
	c.reset()
	engine.handleHTTPRequest(c)

	c.index = oldIndexValue
}

func (engine *Engine) handleHTTPRequest(c *Context) {
	httpMethod := c.Request.Method
	rPath := c.Request.URL.Path
	unescape := false
	if engine.UseRawPath && len(c.Request.URL.RawPath) > 0 {
		rPath = c.Request.URL.RawPath
		unescape = engine.UnescapePathValues
	}

	if engine.RemoveExtraSlash {
		rPath = cleanPath(rPath)
	}

	// Find root of the tree for the given HTTP method
	t := engine.trees
	for i, tl := 0, len(t); i < tl; i++ {
		if t[i].method != httpMethod {
			continue
		}
		root := t[i].root

		// use like mux router
		// sam 2020.10.16
		//value := root.getValue(rPath, c.params, unescape)
		value := root.getMuxValue(rPath, c.params, unescape)
		if value.params != nil {
			c.Params = *value.params
		}
		if value.handlers != nil {
			c.handlers = value.handlers
			c.fullPath = value.fullPath
			c.Next()
			c.writermem.WriteHeaderNow()
			return
		}
		if httpMethod != "CONNECT" && rPath != "/" {
			if value.tsr && engine.RedirectTrailingSlash {
				redirectTrailingSlash(c)
				return
			}
			if engine.RedirectFixedPath && redirectFixedPath(c, root, engine.RedirectFixedPath) {
				return
			}
		}
		break
	}

	if engine.HandleMethodNotAllowed {
		for _, tree := range engine.trees {
			if tree.method == httpMethod {
				continue
			}
			if value := tree.root.getValue(rPath, nil, unescape); value.handlers != nil {
				c.handlers = engine.allNoMethod
				serveError(c, http.StatusMethodNotAllowed, default405Body)
				return
			}
		}
	}
	c.handlers = engine.allNoRoute
	serveError(c, http.StatusNotFound, default404Body)
}

var mimePlain = []string{ContentPlain}

func serveError(c *Context, code int, defaultMessage []byte) {
	c.writermem.status = code
	c.Next()
	if c.writermem.Written() {
		return
	}
	if c.writermem.Status() == code {
		c.writermem.Header()["Content-Type"] = mimePlain
		_, err := c.Writer.Write(defaultMessage)
		if err != nil {
			debugPrint("cannot write message to writer during serve error: %v", err)
		}
		return
	}
	c.writermem.WriteHeaderNow()
}

func redirectTrailingSlash(c *Context) {
	req := c.Request
	p := req.URL.Path
	if prefix := path.Clean(c.Request.Header.Get("X-Forwarded-Prefix")); prefix != "." {
		p = prefix + "/" + req.URL.Path
	}
	req.URL.Path = p + "/"
	if length := len(p); length > 1 && p[length-1] == '/' {
		req.URL.Path = p[:length-1]
	}
	redirectRequest(c)
}

func redirectFixedPath(c *Context, root *node, trailingSlash bool) bool {
	req := c.Request
	rPath := req.URL.Path

	if fixedPath, ok := root.findCaseInsensitivePath(cleanPath(rPath), trailingSlash); ok {
		req.URL.Path = BytesToString(fixedPath)
		redirectRequest(c)
		return true
	}
	return false
}

func redirectRequest(c *Context) {
	req := c.Request
	rPath := req.URL.Path
	rURL := req.URL.String()

	code := http.StatusMovedPermanently // Permanent redirect, request with GET method
	if req.Method != http.MethodGet {
		code = http.StatusTemporaryRedirect
	}
	debugPrint("redirecting request %d: %s --> %s", code, rPath, rURL)
	http.Redirect(c.Writer, req, rURL, code)
	c.writermem.WriteHeaderNow()
}