package router

import (
	"addrss/pkg/auth"
	"addrss/pkg/config"
	"errors"
	"fmt"
	"net/http"
	"os"
	"path/filepath"
	"strings"
)

var routeMap = map[string][]Route{}

type router struct{}

func Serve(addr string) error {
	if len(routeMap) == 0 {
		return errors.New("no registered routes")
	}

	return http.ListenAndServe(addr, router{})
}

func (r router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	route, ok := getRoute(req)
	if !ok {
		// See if the request is for a file that exists in the content directory
		file := filepath.Join("content", req.URL.Path)
		if info, err := os.Stat(file); err == nil && !info.IsDir() {
			http.ServeFile(w, req, file)
			return
		}

		w.WriteHeader(http.StatusNotFound)
		return
	}

	ctx := Context{
		Request:  Request{req, map[string]any{}},
		Response: Response{w},
		Claims:   auth.AccessClaims{},
		route:    route,
	}

	defer func() {
		if rec := recover(); rec != nil {
			err := fmt.Errorf("recovered from panic: %v", rec)
			ctx.Response.InternalServerError(err)
		}
	}()

	originHeader := req.Header.Get("Origin")
	if originHeader != "" {
		o, err := config.Get("cors.origins")
		if err != nil {
			panic(err)
		}

		origins := o.([]any)
		for _, origin := range origins {
			if origin.(string) == originHeader {
				w.Header().Add("Access-Control-Allow-Origin", origin.(string))
			}
		}
	}

	if req.Method == http.MethodOptions {
		acrh := req.Header.Get("Access-Control-Request-Headers")
		acrm := req.Header.Get("Access-Control-Request-Method")
		if route.method != acrm {
			w.WriteHeader(http.StatusForbidden)
			return
		}

		// Congrats, you get whatever headers you want
		w.Header().Add("Access-Control-Allow-Headers", acrh)
		w.Header().Add("Access-Control-Allow-Methods", acrm)
		w.WriteHeader(http.StatusNoContent)

		return
	}

	if !route.anonymous {
		authSegments := strings.Split(req.Header.Get("Authorization"), " ")

		if len(authSegments) != 2 || authSegments[0] != "Bearer" {
			w.WriteHeader(http.StatusUnauthorized)
			return
		}

		if err := auth.ValidateJwtToken(authSegments[1], &ctx.Claims); err != nil {
			w.WriteHeader(http.StatusUnauthorized)
			return
		}
	}

	if route.scope != "" {
		if !strings.Contains(ctx.Claims.Scopes, route.scope) {
			w.WriteHeader(http.StatusForbidden)
			return
		}
	}

	route.handler(&ctx)
}

func AddGet(pattern string, handler func(*Context)) Route {
	return addRoute(http.MethodGet, pattern, handler)
}

func AddPost(pattern string, handler func(*Context)) Route {
	return addRoute(http.MethodPost, pattern, handler)
}

func AddPut(pattern string, handler func(*Context)) Route {
	return addRoute(http.MethodPut, pattern, handler)
}

func AddPatch(pattern string, handler func(*Context)) Route {
	return addRoute(http.MethodPatch, pattern, handler)
}

func AddDelete(pattern string, handler func(*Context)) Route {
	return addRoute(http.MethodDelete, pattern, handler)
}

func addRoute(method string, path string, handler func(*Context)) Route {
	route := Route{
		handler: handler,
		method:  method,
		path:    path,
	}

	if routeMap[method] == nil {
		routeMap[method] = []Route{}
	}

	routeMap[method] = append(routeMap[method], route)

	return route
}

func getRoute(req *http.Request) (Route, bool) {
	method := req.Method
	if method == http.MethodOptions {
		method = req.Header.Get("Access-Control-Request-Method")
	}

	req.URL.Path = strings.TrimSuffix(req.URL.Path, "/")

	for _, route := range routeMap[method] {
		//if strings.Contains(route.path, ":") {
		//	rte, ok := regexMatchRoute(route, req.URL.Path)
		//	if ok {
		//		return rte, true
		//	}
		//} else {
		if route.path == req.URL.Path {
			return route, true
		}
		//}
	}

	return Route{}, false
}

//func regexMatchRoute(route Route, path string) (Route, bool) {
//	regex := regexp.MustCompile(`:[a-zA-Z]+`)
//	matchPath := regex.ReplaceAllString(route.path, `([A-Za-z0-9\-_.]+)`)
//	matchPath += "$"
//	regex = regexp.MustCompile(matchPath)
//
//	// matchPath := route.path
//	if matches := regex.FindStringSubmatch(path); len(matches) > 0 {
//		if len(matches) > 1 {
//			route.params = map[string]any{}
//
//			values := strings.Split(path, "/")
//			for i, param := range strings.Split(route.path, "/") {
//				if strings.Contains(param, ":") {
//					route.params[param[1:]] = values[i]
//				}
//			}
//		}
//
//		return route, true
//	}
//
//	return route, false
//}