package api

import (
	"context"
	"fmt"
	"next-terminal/server/common"
	"next-terminal/server/common/maps"
	"next-terminal/server/global/session"
	"next-terminal/server/log"
	"next-terminal/server/model"
	"next-terminal/server/repository"
	"next-terminal/server/utils"
	"os"
	"path"
	"strconv"
	"strings"
	"time"

	"github.com/labstack/echo/v4"
	"github.com/pkg/sftp"
)

type FileSystemApi struct{}

func (api FileSystemApi) recordFilesystemLog(ctx context.Context, sessionId, action, fileName string) {
	sess, err := repository.SessionRepository.FindById(ctx, sessionId)
	if err != nil {
		log.Error("Failed to find session for filesystem log", log.NamedError("err", err))
		return
	}

	filesystemLog := &model.FilesystemLog{
		ID:        utils.UUID(),
		AssetId:   sess.AssetId,
		SessionId: sessionId,
		UserId:    sess.Creator,
		Action:    action,
		FileName:  fileName,
		Created:   common.NowJsonTime(),
	}

	if err := repository.FilesystemLogRepository.Create(ctx, filesystemLog); err != nil {
		log.Error("Failed to create filesystem log", log.NamedError("err", err))
	}
}

func (api FileSystemApi) LsEndpoint(c echo.Context) error {
	sessionId := c.Param("id")
	dir := c.QueryParam("dir")
	hiddenFileVisible := c.QueryParam("hiddenFileVisible") == "true"

	log.Debug("FileSystem Ls: sessionId=" + sessionId + " dir=" + dir)

	sess := session.GlobalSessionManager.GetById(sessionId)
	if sess == nil || sess.NextTerminal == nil || sess.NextTerminal.SshClient == nil {
		return Fail(c, -1, "session not found or SSH connection closed")
	}

	sftpClient, err := sftp.NewClient(sess.NextTerminal.SshClient)
	if err != nil {
		log.Debug("FileSystem Ls: failed to create SFTP client: " + err.Error())
		return Fail(c, -1, "failed to create SFTP client: "+err.Error())
	}
	defer sftpClient.Close()

	files, err := sftpClient.ReadDir(dir)
	if err != nil {
		log.Debug("FileSystem Ls: failed to read directory: " + err.Error())
		return Fail(c, -1, "failed to read directory: "+err.Error())
	}

	var result []maps.Map
	for _, f := range files {
		name := f.Name()
		if !hiddenFileVisible && strings.HasPrefix(name, ".") {
			continue
		}
		result = append(result, maps.Map{
			"name":    name,
			"size":    f.Size(),
			"modTime": f.ModTime().UnixMilli(),
			"path":    path.Join(dir, name),
			"mode":    f.Mode().String(),
			"isDir":   f.IsDir(),
			"isLink":  f.Mode()&os.ModeSymlink != 0,
		})
	}

	return Success(c, result)
}

func (api FileSystemApi) MkdirEndpoint(c echo.Context) error {
	sessionId := c.Param("id")
	dir := c.QueryParam("dir")

	log.Debug("FileSystem Mkdir: sessionId=" + sessionId + " dir=" + dir)

	sess := session.GlobalSessionManager.GetById(sessionId)
	if sess == nil || sess.NextTerminal == nil || sess.NextTerminal.SshClient == nil {
		return Fail(c, -1, "session not found or SSH connection closed")
	}

	sftpClient, err := sftp.NewClient(sess.NextTerminal.SshClient)
	if err != nil {
		return Fail(c, -1, "failed to create SFTP client: "+err.Error())
	}
	defer sftpClient.Close()

	err = sftpClient.MkdirAll(dir)
	if err != nil {
		return Fail(c, -1, "failed to create directory: "+err.Error())
	}

	go api.recordFilesystemLog(context.TODO(), sessionId, "mkdir", dir)

	return Success(c, nil)
}

func (api FileSystemApi) TouchEndpoint(c echo.Context) error {
	sessionId := c.Param("id")
	filename := c.QueryParam("filename")

	log.Debug("FileSystem Touch: sessionId=" + sessionId + " filename=" + filename)

	sess := session.GlobalSessionManager.GetById(sessionId)
	if sess == nil || sess.NextTerminal == nil || sess.NextTerminal.SshClient == nil {
		return Fail(c, -1, "session not found or SSH connection closed")
	}

	sftpClient, err := sftp.NewClient(sess.NextTerminal.SshClient)
	if err != nil {
		return Fail(c, -1, "failed to create SFTP client: "+err.Error())
	}
	defer sftpClient.Close()

	f, err := sftpClient.Create(filename)
	if err != nil {
		return Fail(c, -1, "failed to create file: "+err.Error())
	}
	f.Close()

	go api.recordFilesystemLog(context.TODO(), sessionId, "touch", filename)

	return Success(c, nil)
}

func (api FileSystemApi) RmEndpoint(c echo.Context) error {
	sessionId := c.Param("id")
	filename := c.QueryParam("filename")

	log.Debug("FileSystem Rm: sessionId=" + sessionId + " filename=" + filename)

	sess := session.GlobalSessionManager.GetById(sessionId)
	if sess == nil || sess.NextTerminal == nil || sess.NextTerminal.SshClient == nil {
		return Fail(c, -1, "session not found or SSH connection closed")
	}

	sftpClient, err := sftp.NewClient(sess.NextTerminal.SshClient)
	if err != nil {
		return Fail(c, -1, "failed to create SFTP client: "+err.Error())
	}
	defer sftpClient.Close()

	f, err := sftpClient.Stat(filename)
	if err != nil {
		return Fail(c, -1, "file not found: "+err.Error())
	}

	if f.IsDir() {
		err = sftpClient.RemoveDirectory(filename)
		if err != nil {
			err = api.removeRecursive(sftpClient, filename)
			if err != nil {
				return Fail(c, -1, "failed to remove directory: "+err.Error())
			}
		}
	} else {
		err = sftpClient.Remove(filename)
		if err != nil {
			return Fail(c, -1, "failed to remove file: "+err.Error())
		}
	}

	go api.recordFilesystemLog(context.TODO(), sessionId, "rm", filename)

	return Success(c, nil)
}

func (api FileSystemApi) removeRecursive(sftpClient *sftp.Client, dirPath string) error {
	files, err := sftpClient.ReadDir(dirPath)
	if err != nil {
		return err
	}

	for _, f := range files {
		fullPath := path.Join(dirPath, f.Name())
		if f.IsDir() {
			err = api.removeRecursive(sftpClient, fullPath)
			if err != nil {
				return err
			}
		} else {
			err = sftpClient.Remove(fullPath)
			if err != nil {
				return err
			}
		}
	}

	return sftpClient.RemoveDirectory(dirPath)
}

func (api FileSystemApi) RenameEndpoint(c echo.Context) error {
	sessionId := c.Param("id")
	oldName := c.QueryParam("oldName")
	newName := c.QueryParam("newName")

	log.Debug("FileSystem Rename: sessionId=" + sessionId + " oldName=" + oldName + " newName=" + newName)

	sess := session.GlobalSessionManager.GetById(sessionId)
	if sess == nil || sess.NextTerminal == nil || sess.NextTerminal.SshClient == nil {
		return Fail(c, -1, "session not found or SSH connection closed")
	}

	sftpClient, err := sftp.NewClient(sess.NextTerminal.SshClient)
	if err != nil {
		return Fail(c, -1, "failed to create SFTP client: "+err.Error())
	}
	defer sftpClient.Close()

	err = sftpClient.Rename(oldName, newName)
	if err != nil {
		return Fail(c, -1, "failed to rename: "+err.Error())
	}

	go api.recordFilesystemLog(context.TODO(), sessionId, "rename", oldName+" -> "+newName)

	return Success(c, nil)
}

func (api FileSystemApi) EditEndpoint(c echo.Context) error {
	sessionId := c.Param("id")

	var req struct {
		Filename    string `json:"filename"`
		FileContent string `json:"fileContent"`
	}
	if err := c.Bind(&req); err != nil {
		return err
	}

	log.Debug("FileSystem Edit: sessionId=" + sessionId + " filename=" + req.Filename)

	sess := session.GlobalSessionManager.GetById(sessionId)
	if sess == nil || sess.NextTerminal == nil || sess.NextTerminal.SshClient == nil {
		return Fail(c, -1, "session not found or SSH connection closed")
	}

	sftpClient, err := sftp.NewClient(sess.NextTerminal.SshClient)
	if err != nil {
		return Fail(c, -1, "failed to create SFTP client: "+err.Error())
	}
	defer sftpClient.Close()

	f, err := sftpClient.OpenFile(req.Filename, os.O_WRONLY|os.O_TRUNC|os.O_CREATE)
	if err != nil {
		return Fail(c, -1, "failed to open file: "+err.Error())
	}
	defer f.Close()

	_, err = f.Write([]byte(req.FileContent))
	if err != nil {
		return Fail(c, -1, "failed to write file: "+err.Error())
	}

	go api.recordFilesystemLog(context.TODO(), sessionId, "edit", req.Filename)

	return Success(c, nil)
}

func (api FileSystemApi) ReadEndpoint(c echo.Context) error {
	sessionId := c.Param("id")
	filename := c.QueryParam("filename")

	log.Debug("FileSystem Read: sessionId=" + sessionId + " filename=" + filename)

	sess := session.GlobalSessionManager.GetById(sessionId)
	if sess == nil || sess.NextTerminal == nil || sess.NextTerminal.SshClient == nil {
		return Fail(c, -1, "session not found or SSH connection closed")
	}

	sftpClient, err := sftp.NewClient(sess.NextTerminal.SshClient)
	if err != nil {
		return Fail(c, -1, "failed to create SFTP client: "+err.Error())
	}
	defer sftpClient.Close()

	f, err := sftpClient.Open(filename)
	if err != nil {
		return Fail(c, -1, "failed to open file: "+err.Error())
	}
	defer f.Close()

	content, err := readFileContent(f, 10*1024*1024)
	if err != nil {
		return Fail(c, -1, "failed to read file: "+err.Error())
	}

	go api.recordFilesystemLog(context.TODO(), sessionId, "read", filename)

	return Success(c, maps.Map{
		"content": content,
		"path":    filename,
	})
}

func readFileContent(f *sftp.File, maxSize int64) (string, error) {
	stat, err := f.Stat()
	if err != nil {
		return "", err
	}

	if stat.Size() > maxSize {
		return "", fmt.Errorf("file too large (max %d bytes)", maxSize)
	}

	buf := make([]byte, stat.Size())
	_, err = f.Read(buf)
	if err != nil {
		return "", err
	}

	return string(buf), nil
}

func (api FileSystemApi) ChmodEndpoint(c echo.Context) error {
	sessionId := c.Param("id")
	filename := c.QueryParam("filename")
	modeStr := c.QueryParam("mode")

	log.Debug("FileSystem Chmod: sessionId=" + sessionId + " filename=" + filename + " mode=" + modeStr)

	sess := session.GlobalSessionManager.GetById(sessionId)
	if sess == nil || sess.NextTerminal == nil || sess.NextTerminal.SshClient == nil {
		return Fail(c, -1, "session not found or SSH connection closed")
	}

	mode, err := strconv.ParseUint(modeStr, 10, 32)
	if err != nil {
		return Fail(c, -1, "invalid mode: "+err.Error())
	}

	sftpClient, err := sftp.NewClient(sess.NextTerminal.SshClient)
	if err != nil {
		return Fail(c, -1, "failed to create SFTP client: "+err.Error())
	}
	defer sftpClient.Close()

	err = sftpClient.Chmod(filename, os.FileMode(mode))
	if err != nil {
		return Fail(c, -1, "failed to chmod: "+err.Error())
	}

	go api.recordFilesystemLog(context.TODO(), sessionId, "chmod", filename+" ("+modeStr+")")

	return Success(c, nil)
}

func (api FileSystemApi) UploadProgressEndpoint(c echo.Context) error {
	sessionId := c.Param("id")
	id := c.QueryParam("id")

	log.Debug("FileSystem UploadProgress: sessionId=" + sessionId + " id=" + id)

	return Success(c, maps.Map{
		"total":       0,
		"written":     0,
		"percent":     100,
		"speed":       0,
		"elapsedTime": 0,
		"isCompleted": true,
	})
}

func (api FileSystemApi) DownloadEndpoint(c echo.Context) error {
	sessionId := c.Param("id")
	filename := c.QueryParam("filename")

	log.Debug("FileSystem Download: sessionId=" + sessionId + " filename=" + filename)

	sess := session.GlobalSessionManager.GetById(sessionId)
	if sess == nil || sess.NextTerminal == nil || sess.NextTerminal.SshClient == nil {
		return Fail(c, -1, "session not found or SSH connection closed")
	}

	sftpClient, err := sftp.NewClient(sess.NextTerminal.SshClient)
	if err != nil {
		return Fail(c, -1, "failed to create SFTP client: "+err.Error())
	}
	defer sftpClient.Close()

	f, err := sftpClient.Open(filename)
	if err != nil {
		return Fail(c, -1, "failed to open file: "+err.Error())
	}
	defer f.Close()

	stat, err := f.Stat()
	if err != nil {
		return Fail(c, -1, "failed to stat file: "+err.Error())
	}

	go api.recordFilesystemLog(context.TODO(), sessionId, "download", filename)

	c.Response().Header().Set("Content-Disposition", "attachment; filename="+path.Base(filename))
	c.Response().Header().Set("Content-Type", "application/octet-stream")
	c.Response().Header().Set("Content-Length", strconv.FormatInt(stat.Size(), 10))

	return c.Stream(200, "application/octet-stream", f)
}

func (api FileSystemApi) UploadEndpoint(c echo.Context) error {
	sessionId := c.Param("id")
	destDir := c.QueryParam("dir")

	log.Debug("FileSystem Upload: sessionId=" + sessionId + " dir=" + destDir)

	sess := session.GlobalSessionManager.GetById(sessionId)
	if sess == nil || sess.NextTerminal == nil || sess.NextTerminal.SshClient == nil {
		return Fail(c, -1, "session not found or SSH connection closed")
	}

	file, err := c.FormFile("file")
	if err != nil {
		return Fail(c, -1, "failed to get upload file: "+err.Error())
	}

	src, err := file.Open()
	if err != nil {
		return Fail(c, -1, "failed to open upload file: "+err.Error())
	}
	defer src.Close()

	sftpClient, err := sftp.NewClient(sess.NextTerminal.SshClient)
	if err != nil {
		return Fail(c, -1, "failed to create SFTP client: "+err.Error())
	}
	defer sftpClient.Close()

	destPath := path.Join(destDir, file.Filename)
	dst, err := sftpClient.Create(destPath)
	if err != nil {
		return Fail(c, -1, "failed to create remote file: "+err.Error())
	}
	defer dst.Close()

	buf := make([]byte, 32*1024)
	for {
		n, err := src.Read(buf)
		if n > 0 {
			_, writeErr := dst.Write(buf[:n])
			if writeErr != nil {
				return Fail(c, -1, "failed to write remote file: "+writeErr.Error())
			}
		}
		if err != nil {
			break
		}
	}

	go api.recordFilesystemLog(context.TODO(), sessionId, "upload", destPath)

	return Success(c, maps.Map{
		"path":      destPath,
		"size":      file.Size,
		"timestamp": time.Now().UnixMilli(),
	})
}