// SiYuan - Refactor your thinking
// Copyright (c) 2020-present, b3log.org
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package util

import (
	"net"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"time"

	"github.com/88250/gulu"
	"github.com/88250/lute/ast"
	"github.com/gin-gonic/gin"
	"github.com/imroc/req/v3"
	"github.com/siyuan-note/httpclient"
	"github.com/siyuan-note/logging"
)

func ValidOptionalPort(port string) bool {
	if port == "" {
		return true
	}
	if port[0] != ':' {
		return false
	}
	for _, b := range port[1:] {
		if b < '0' || b > '9' {
			return false
		}
	}
	return true
}

func IsLocalHostname(hostname string) bool {
	if "localhost" == hostname || strings.HasSuffix(hostname, ".localhost") {
		return true
	}
	if ip := net.ParseIP(hostname); nil != ip {
		return ip.IsLoopback()
	}
	return false
}

func IsLocalHost(host string) bool {
	if hostname, _, err := net.SplitHostPort(strings.TrimSpace(host)); err != nil {
		return false
	} else {
		return IsLocalHostname(hostname)
	}
}

func IsLocalOrigin(origin string) bool {
	if url, err := url.Parse(origin); err == nil {
		return IsLocalHostname(url.Hostname())
	}
	return false
}

func IsOnline(checkURL string, skipTlsVerify bool, timeout int) bool {
	_, err := url.Parse(checkURL)
	if err != nil {
		logging.LogWarnf("invalid check URL [%s]", checkURL)
		return false
	}

	if "" == checkURL {
		return false
	}

	if isOnline(checkURL, skipTlsVerify, timeout) {
		return true
	}

	logging.LogWarnf("network is offline [checkURL=%s]", checkURL)
	return false
}

func IsPortOpen(port string) bool {
	timeout := time.Second
	conn, err := net.DialTimeout("tcp", net.JoinHostPort("127.0.0.1", port), timeout)
	if err != nil {
		return false
	}
	if nil != conn {
		conn.Close()
		return true
	}
	return false
}

func isOnline(checkURL string, skipTlsVerify bool, timeout int) (ret bool) {
	c := req.C().SetTimeout(time.Duration(timeout) * time.Millisecond)
	if skipTlsVerify {
		c.EnableInsecureSkipVerify()
	}
	c.SetUserAgent(UserAgent)

	for i := 0; i < 2; i++ {
		resp, err := c.R().Get(checkURL)

		if resp.GetHeader("Location") != "" {
			return true
		}

		switch err.(type) {
		case *url.Error:
			if err.(*url.Error).URL != checkURL {
				// DNS 重定向
				logging.LogWarnf("network is online [DNS redirect, checkURL=%s, retURL=%s]", checkURL, err.(*url.Error).URL)
				return true
			}
		}

		ret = err == nil
		if ret {
			break
		}

		time.Sleep(1 * time.Second)
		logging.LogWarnf("check url [%s] is online failed: %s", checkURL, err)
	}
	return
}

func GetRemoteAddr(req *http.Request) string {
	ret := req.Header.Get("X-forwarded-for")
	ret = strings.TrimSpace(ret)
	if "" == ret {
		ret = req.Header.Get("X-Real-IP")
	}
	ret = strings.TrimSpace(ret)
	if "" == ret {
		return req.RemoteAddr
	}
	return strings.Split(ret, ",")[0]
}

func JsonArg(c *gin.Context, result *gulu.Result) (arg map[string]interface{}, ok bool) {
	arg = map[string]interface{}{}
	if err := c.BindJSON(&arg); err != nil {
		result.Code = -1
		result.Msg = "parses request failed"
		return
	}

	ok = true
	return
}

func InvalidIDPattern(idArg string, result *gulu.Result) bool {
	if ast.IsNodeIDPattern(idArg) {
		return false
	}

	result.Code = -1
	result.Msg = "invalid ID argument"
	return true
}

func IsValidURL(str string) bool {
	_, err := url.Parse(str)
	return err == nil
}

func initHttpClient() {
	http.DefaultClient = httpclient.GetCloudFileClient2Min()
	http.DefaultTransport = httpclient.NewTransport(false)
}

func ParsePort(portString string) (uint16, error) {
	if port, err := strconv.ParseUint(portString, 10, 16); err != nil {
		logging.LogErrorf("parse port [%s] failed: %s", portString, err)
		return 0, err
	} else {
		return uint16(port), nil
	}
}
