// SiYuan - Build Your Eternal Digital Garden
// 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 (
	"fmt"
	"math/rand"
	"os"
	"path/filepath"
	"reflect"
	"runtime"
	"runtime/debug"
	"strings"
	"sync"
	"time"

	"github.com/88250/gulu"
	"github.com/denisbrodbeck/machineid"
	"github.com/siyuan-note/httpclient"
	"github.com/siyuan-note/logging"
)

const DatabaseVer = "20220501" // 修改表结构的话需要修改这里

const (
	ExitCodeReadOnlyDatabase      = 20 // 数据库文件被锁
	ExitCodeUnavailablePort       = 21 // 端口不可用
	ExitCodeCreateConfDirErr      = 22 // 创建配置目录失败
	ExitCodeBlockTreeErr          = 23 // 无法读写 blocktree.msgpack 文件
	ExitCodeWorkspaceLocked       = 24 // 工作空间已被锁定
	ExitCodeCreateWorkspaceDirErr = 25 // 创建工作空间失败
	ExitCodeFileSysInconsistent   = 26 // 文件系统不一致
	ExitCodeOk                    = 0  // 正常退出
	ExitCodeFatal                 = 1  // 致命错误
)

// IsExiting 是否正在退出程序。
var IsExiting = false

// MobileOSVer 移动端操作系统版本。
var MobileOSVer string

func logBootInfo() {
	plat, platVer := GetOSPlatform()
	osInfo := plat
	if "" != platVer {
		osInfo += " " + platVer
	}
	logging.LogInfof("kernel is booting:\n"+
		"    * ver [%s]\n"+
		"    * arch [%s]\n"+
		"    * os [%s]\n"+
		"    * pid [%d]\n"+
		"    * runtime mode [%s]\n"+
		"    * working directory [%s]\n"+
		"    * read only [%v]\n"+
		"    * container [%s]\n"+
		"    * database [ver=%s]\n"+
		"    * workspace directory [%s]",
		Ver, runtime.GOARCH, osInfo, os.Getpid(), Mode, WorkingDir, ReadOnly, Container, DatabaseVer, WorkspaceDir)
}

func IsMutexLocked(m *sync.Mutex) bool {
	state := reflect.ValueOf(m).Elem().FieldByName("state")
	return state.Int()&1 == 1
}

func RandomSleep(minMills, maxMills int) {
	r := gulu.Rand.Int(minMills, maxMills)
	time.Sleep(time.Duration(r) * time.Millisecond)
}

func GetDeviceID() string {
	if ContainerStd == Container {
		machineID, err := machineid.ID()
		if nil != err {
			return gulu.Rand.String(12)
		}
		return machineID
	}
	return gulu.Rand.String(12)
}

func SetNetworkProxy(proxyURL string) {
	if err := os.Setenv("HTTPS_PROXY", proxyURL); nil != err {
		logging.LogErrorf("set env [HTTPS_PROXY] failed: %s", err)
	}
	if err := os.Setenv("HTTP_PROXY", proxyURL); nil != err {
		logging.LogErrorf("set env [HTTP_PROXY] failed: %s", err)
	}

	if "" != proxyURL {
		logging.LogInfof("use network proxy [%s]", proxyURL)
	} else {
		logging.LogInfof("use network proxy [system]")
	}

	httpclient.CloseIdleConnections()
}

const (
	// FrontendQueueInterval 为前端请求队列轮询间隔。
	FrontendQueueInterval = 512 * time.Millisecond

	// SQLFlushInterval 为数据库事务队列写入间隔。
	SQLFlushInterval = 3000 * time.Millisecond
)

var (
	Langs           = map[string]map[int]string{}
	TimeLangs       = map[string]map[string]interface{}{}
	TaskActionLangs = map[string]map[string]interface{}{}
)

var (
	thirdPartySyncCheckTicker = time.NewTicker(time.Minute * 30)
	firstThirdPartySyncCheck  = true
)

func CheckFileSysStatus() {
	if ContainerStd != Container {
		return
	}

	if firstThirdPartySyncCheck {
		firstThirdPartySyncCheck = false
		time.Sleep(time.Second * 10)
	}

	reportFileSysFatalError := func(err error) {
		stack := debug.Stack()
		logging.LogErrorf("check file system status failed: %s, %s", err, stack)
		os.Exit(ExitCodeFileSysInconsistent)
	}

	const fileSysStatusCheckFile = ".siyuan/filesys_status_check"

	for {
		workspaceDirLower := strings.ToLower(WorkspaceDir)
		if strings.Contains(workspaceDirLower, "onedrive") || strings.Contains(workspaceDirLower, "dropbox") ||
			strings.Contains(workspaceDirLower, "google drive") || strings.Contains(workspaceDirLower, "pcloud") {
			reportFileSysFatalError(fmt.Errorf("workspace dir [%s] is in third party sync dir", WorkspaceDir))
			continue
		}

		dir := filepath.Join(DataDir, fileSysStatusCheckFile)
		if err := os.RemoveAll(dir); nil != err {
			reportFileSysFatalError(err)
			continue
		}

		if err := os.MkdirAll(dir, 0755); nil != err {
			reportFileSysFatalError(err)
			continue
		}

		for i := 0; i < 32; i++ {
			tmp := filepath.Join(dir, "check_"+gulu.Rand.String(7))
			data := make([]byte, 1024*4)
			_, err := rand.Read(data)
			if nil != err {
				reportFileSysFatalError(err)
				break
			}

			if err = os.WriteFile(tmp, data, 0644); nil != err {
				reportFileSysFatalError(err)
				break
			}

			time.Sleep(time.Second)

			for j := 0; j < 32; j++ {
				f, err := os.Open(tmp)
				if nil != err {
					reportFileSysFatalError(err)
					break
				}

				if err = f.Close(); nil != err {
					reportFileSysFatalError(err)
					break
				}

				time.Sleep(200 * time.Millisecond)

				if err = os.Rename(tmp, tmp+"_1"); nil != err {
					reportFileSysFatalError(err)
					break
				}

				time.Sleep(200 * time.Millisecond)
				if err = os.Rename(tmp+"_1", tmp); nil != err {
					reportFileSysFatalError(err)
					break
				}

				entries, err := os.ReadDir(dir)
				if nil != err {
					reportFileSysFatalError(err)
					break
				}

				count := 0
				for _, entry := range entries {
					if !entry.IsDir() && strings.Contains(entry.Name(), "check_") {
						count++
					}
				}
				if 1 < count {
					reportFileSysFatalError(fmt.Errorf("dir [%s] has more than 1 file", dir))
					break
				}
			}

			if err = os.RemoveAll(tmp); nil != err {
				reportFileSysFatalError(err)
				break
			}

			<-thirdPartySyncCheckTicker.C
		}
	}
}