package pmpanel

import (
	"bufio"
	"encoding/json"
	"fmt"
	"log"
	"os"
	"reflect"
	"regexp"
	"strconv"
	"time"

	"github.com/Aiko-Project/Aiko/api"
	"github.com/go-resty/resty/v2"
)

// APIClient create a api client to the panel.
type APIClient struct {
	client        *resty.Client
	APIHost       string
	NodeID        int
	Key           string
	NodeType      string
	EnableVless   bool
	EnableXTLS    bool
	SpeedLimit    float64
	DeviceLimit   int
	LocalRuleList []api.DetectRule
}

// New creat a api instance
func New(apiConfig *api.Config) *APIClient {

	client := resty.New()
	client.SetRetryCount(3)
	if apiConfig.Timeout > 0 {
		client.SetTimeout(time.Duration(apiConfig.Timeout) * time.Second)
	} else {
		client.SetTimeout(5 * time.Second)
	}
	client.OnError(func(req *resty.Request, err error) {
		if v, ok := err.(*resty.ResponseError); ok {
			// v.Response contains the last response from the server
			// v.Err contains the original error
			log.Print(v.Err)
		}
	})
	client.SetBaseURL(apiConfig.APIHost)
	// Create Key for each requests
	client.SetHeaders(map[string]string{
		"key": apiConfig.Key,
	})
	// Read local rule list
	localRuleList := readLocalRuleList(apiConfig.RuleListPath)
	apiClient := &APIClient{
		client:        client,
		NodeID:        apiConfig.NodeID,
		Key:           apiConfig.Key,
		APIHost:       apiConfig.APIHost,
		NodeType:      apiConfig.NodeType,
		EnableVless:   apiConfig.EnableVless,
		EnableXTLS:    apiConfig.EnableXTLS,
		SpeedLimit:    apiConfig.SpeedLimit,
		DeviceLimit:   apiConfig.DeviceLimit,
		LocalRuleList: localRuleList,
	}
	return apiClient
}

// readLocalRuleList reads the local rule list file
func readLocalRuleList(path string) (LocalRuleList []api.DetectRule) {

	LocalRuleList = make([]api.DetectRule, 0)
	if path != "" {
		// open the file
		file, err := os.Open(path)

		//handle errors while opening
		if err != nil {
			log.Printf("Error when opening file: %s", err)
			return LocalRuleList
		}

		fileScanner := bufio.NewScanner(file)

		// read line by line
		for fileScanner.Scan() {
			LocalRuleList = append(LocalRuleList, api.DetectRule{
				ID:      -1,
				Pattern: regexp.MustCompile(fileScanner.Text()),
			})
		}
		// handle first encountered error while reading
		if err := fileScanner.Err(); err != nil {
			log.Fatalf("Error while reading file: %s", err)
			return make([]api.DetectRule, 0)
		}

		file.Close()
	}

	return LocalRuleList
}

// Describe return a description of the client
func (c *APIClient) Describe() api.ClientInfo {
	return api.ClientInfo{APIHost: c.APIHost, NodeID: c.NodeID, Key: c.Key, NodeType: c.NodeType}
}

// Debug set the client debug for client
func (c *APIClient) Debug() {
	c.client.SetDebug(true)
}

func (c *APIClient) assembleURL(path string) string {
	return c.APIHost + path
}

func (c *APIClient) parseResponse(res *resty.Response, path string, err error) (*Response, error) {
	if err != nil {
		return nil, fmt.Errorf("request %s failed: %s", c.assembleURL(path), err)
	}

	if res.StatusCode() > 400 {
		body := res.Body()
		return nil, fmt.Errorf("request %s failed: %s, %s", c.assembleURL(path), string(body), err)
	}
	response := res.Result().(*Response)

	if response.Ret != 200 {
		res, _ := json.Marshal(&response)
		return nil, fmt.Errorf("Ret %s invalid", string(res))
	}
	return response, nil
}

// GetNodeInfo will pull NodeInfo Config from sspanel
func (c *APIClient) GetNodeInfo() (nodeInfo *api.NodeInfo, err error) {
	path := fmt.Sprintf("/api/node")
	var nodeType = ""
	switch c.NodeType {
	case "Shadowsocks":
		nodeType = "ss"
	case "V2ray":
		nodeType = "v2ray"
	case "Trojan":
		nodeType = "trojan"
	default:
		return nil, fmt.Errorf("NodeType Error: %s", c.NodeType)
	}
	// body := fmt.Sprintf(`{"type":"%s", "nodeId":%d}`, nodeType, c.NodeID)
	res, err := c.client.R().
		SetQueryParams(map[string]string{
			"type":   nodeType,
			"nodeId": strconv.Itoa(c.NodeID),
		}).
		SetResult(&Response{}).
		ForceContentType("application/json").
		Get(path)

	response, err := c.parseResponse(res, path, err)
	if err != nil {
		return nil, err
	}

	nodeInfoResponse := new(NodeInfoResponse)

	if err := json.Unmarshal(response.Data, nodeInfoResponse); err != nil {
		return nil, fmt.Errorf("Unmarshal %s failed: %s", reflect.TypeOf(nodeInfoResponse), err)
	}
	switch c.NodeType {
	case "V2ray":
		nodeInfo, err = c.ParseV2rayNodeResponse(nodeInfoResponse)
	case "Trojan":
		nodeInfo, err = c.ParseTrojanNodeResponse(nodeInfoResponse)
	case "Shadowsocks":
		nodeInfo, err = c.ParseSSNodeResponse(nodeInfoResponse)
	default:
		return nil, fmt.Errorf("Unsupported Node type: %s", c.NodeType)
	}

	if err != nil {
		res, _ := json.Marshal(nodeInfoResponse)
		return nil, fmt.Errorf("Parse node info failed: %s, \nError: %s", string(res), err)
	}

	return nodeInfo, nil
}

// GetUserList will pull user form sspanel
func (c *APIClient) GetUserList() (UserList *[]api.UserInfo, err error) {
	path := "/api/users"
	var nodeType = ""
	switch c.NodeType {
	case "Shadowsocks":
		nodeType = "ss"
	case "V2ray":
		nodeType = "v2ray"
	case "Trojan":
		nodeType = "trojan"
	default:
		return nil, fmt.Errorf("NodeType Error: %s", c.NodeType)
	}
	res, err := c.client.R().
		SetQueryParams(map[string]string{
			"type":   nodeType,
			"nodeId": strconv.Itoa(c.NodeID),
			"all":    "true",
		}).
		SetResult(&Response{}).
		ForceContentType("application/json").
		Get(path)

	response, err := c.parseResponse(res, path, err)
	if err != nil {
		return nil, err
	}

	var userListResponse *[]UserResponse
	if err := json.Unmarshal(response.Data, &userListResponse); err != nil {
		return nil, fmt.Errorf("Unmarshal %s failed: %s", reflect.TypeOf(userListResponse), err)
	}
	userList, err := c.ParseUserListResponse(userListResponse)
	if err != nil {
		res, _ := json.Marshal(userListResponse)
		return nil, fmt.Errorf("Parse user list failed: %s", string(res))
	}
	return userList, nil
}

// ReportNodeStatus reports the node status to the sspanel
func (c *APIClient) ReportNodeStatus(nodeStatus *api.NodeStatus) (err error) {
	return nil
}

//ReportNodeOnlineUsers reports online user ip
func (c *APIClient) ReportNodeOnlineUsers(onlineUserList *[]api.OnlineUser) error {
	var nodeType = ""
	switch c.NodeType {
	case "Shadowsocks":
		nodeType = "ss"
	case "V2ray":
		nodeType = "v2ray"
	case "Trojan":
		nodeType = "trojan"
	default:
		return fmt.Errorf("NodeType Error: %s", c.NodeType)
	}
	data := make([]OnlineUser, len(*onlineUserList))
	for i, user := range *onlineUserList {
		data[i] = OnlineUser{UID: user.UID, IP: user.IP}
	}
	postData := &PostData{Type: nodeType, NodeId: c.NodeID, Onlines: data}
	path := "/api/online"

	res, err := c.client.R().
		SetHeader("Content-Type", "application/json").
		SetBody(postData).
		SetResult(&Response{}).
		ForceContentType("application/json").
		Post(path)
	_, err = c.parseResponse(res, path, err)
	if err != nil {
		return err
	}

	return nil
}

// ReportUserTraffic reports the user traffic
func (c *APIClient) ReportUserTraffic(userTraffic *[]api.UserTraffic) error {
	var nodeType = ""
	switch c.NodeType {
	case "Shadowsocks":
		nodeType = "ss"
	case "V2ray":
		nodeType = "v2ray"
	case "Trojan":
		nodeType = "trojan"
	default:
		return fmt.Errorf("NodeType Error: %s", c.NodeType)
	}
	data := make([]UserTraffic, len(*userTraffic))
	for i, traffic := range *userTraffic {
		data[i] = UserTraffic{
			UID:      traffic.UID,
			Upload:   traffic.Upload,
			Download: traffic.Download,
		}
	}
	postData := &PostData{Type: nodeType, NodeId: c.NodeID, Users: data}
	path := "/api/traffic"

	res, err := c.client.R().
		SetHeader("Content-Type", "application/json").
		SetBody(postData).
		SetResult(&Response{}).
		ForceContentType("application/json").
		Post(path)
	_, err = c.parseResponse(res, path, err)
	if err != nil {
		return err
	}

	return nil
}

// GetNodeRule will pull the audit rule form pmpanel
func (c *APIClient) GetNodeRule() (*[]api.DetectRule, *[]string, error) {
	ruleList := c.LocalRuleList
	path := "/api/rules"
	var nodeType = ""
	switch c.NodeType {
	case "Shadowsocks":
		nodeType = "ss"
	case "V2ray":
		nodeType = "v2ray"
	case "Trojan":
		nodeType = "trojan"
	default:
		return nil, nil, fmt.Errorf("NodeType Error: %s", c.NodeType)
	}
	res, err := c.client.R().
		SetQueryParams(map[string]string{
			"type":   nodeType,
			"nodeId": strconv.Itoa(c.NodeID),
		}).
		SetResult(&Response{}).
		ForceContentType("application/json").
		Get(path)

	response, err := c.parseResponse(res, path, err)
	if err != nil {
		return nil, nil, err
	}

	ruleListResponse := new([]RuleItem)

	if err := json.Unmarshal(response.Data, ruleListResponse); err != nil {
		return nil, nil, fmt.Errorf("Unmarshal %s failed: %s", reflect.TypeOf(ruleListResponse), err)
	}

	for _, r := range *ruleListResponse {
		ruleList = append(ruleList, api.DetectRule{
			ID:      r.ID,
			Pattern: regexp.MustCompile(r.Content),
		})
	}
	return &ruleList, nil, nil
}

// ReportIllegal reports the user illegal behaviors
func (c *APIClient) ReportIllegal(detectResultList *[]api.DetectResult) error {
	return nil
}

// ParseV2rayNodeResponse parse the response for the given nodeinfor format
func (c *APIClient) ParseV2rayNodeResponse(nodeInfoResponse *NodeInfoResponse) (*api.NodeInfo, error) {
	var enableTLS bool
	var path, host, TLStype, transportProtocol, serviceName string
	var speedlimit uint64 = 0

	port := nodeInfoResponse.Port
	alterID := nodeInfoResponse.AlterId
	transportProtocol = nodeInfoResponse.Network
	switch transportProtocol {
	case "ws":
		host = nodeInfoResponse.Host
		path = nodeInfoResponse.Path
	case "grpc":
		serviceName = nodeInfoResponse.Sni
	case "tcp":
		// TODO
	}
	// Compatible with more node types config
	switch nodeInfoResponse.Security {
	case "tls", "xtls":
		if c.EnableXTLS {
			TLStype = "xtls"
		} else {
			TLStype = "tls"
		}
		enableTLS = true
	default:
		enableTLS = false
	}
	if c.SpeedLimit > 0 {
		speedlimit = uint64((c.SpeedLimit * 1000000) / 8)
	} else {
		speedlimit = uint64((nodeInfoResponse.SpeedLimit * 1000000) / 8)
	}
	// Create GeneralNodeInfo
	nodeinfo := &api.NodeInfo{
		NodeType:          c.NodeType,
		NodeID:            c.NodeID,
		Port:              port,
		SpeedLimit:        speedlimit,
		AlterID:           alterID,
		TransportProtocol: transportProtocol,
		EnableTLS:         enableTLS,
		TLSType:           TLStype,
		Path:              path,
		Host:              host,
		EnableVless:       c.EnableVless,
		ServiceName:       serviceName,
	}

	return nodeinfo, nil
}

// ParseSSNodeResponse parse the response for the given nodeinfor format
func (c *APIClient) ParseSSNodeResponse(nodeInfoResponse *NodeInfoResponse) (*api.NodeInfo, error) {
	var port int = 0
	var speedlimit uint64 = 0

	port = nodeInfoResponse.Port

	if c.SpeedLimit > 0 {
		speedlimit = uint64((c.SpeedLimit * 1000000) / 8)
	} else {
		speedlimit = uint64((nodeInfoResponse.SpeedLimit * 1000000) / 8)
	}
	// Create GeneralNodeInfo
	nodeinfo := &api.NodeInfo{
		NodeType:          c.NodeType,
		NodeID:            c.NodeID,
		Port:              port,
		SpeedLimit:        speedlimit,
		TransportProtocol: "tcp",
		CypherMethod:      nodeInfoResponse.Method,
	}

	return nodeinfo, nil
}

// ParseTrojanNodeResponse parse the response for the given nodeinfor format
func (c *APIClient) ParseTrojanNodeResponse(nodeInfoResponse *NodeInfoResponse) (*api.NodeInfo, error) {
	// 域名或IP;port=连接端口#偏移端口|host=xx
	// gz.aaa.com;port=443#12345|host=hk.aaa.com
	var TLSType, host string
	var transportProtocol = "tcp"
	var speedlimit uint64 = 0
	if c.EnableXTLS {
		TLSType = "xtls"
	} else {
		TLSType = "tls"
	}
	host = nodeInfoResponse.Host
	port := nodeInfoResponse.Port

	if c.SpeedLimit > 0 {
		speedlimit = uint64((c.SpeedLimit * 1000000) / 8)
	} else {
		speedlimit = uint64((nodeInfoResponse.SpeedLimit * 1000000) / 8)
	}
	if nodeInfoResponse.Grpc {
		transportProtocol = "grpc"
	}
	// Create GeneralNodeInfo
	nodeinfo := &api.NodeInfo{
		NodeType:          c.NodeType,
		NodeID:            c.NodeID,
		Port:              port,
		SpeedLimit:        speedlimit,
		TransportProtocol: transportProtocol,
		EnableTLS:         true,
		TLSType:           TLSType,
		Host:              host,
		ServiceName:       nodeInfoResponse.Sni,
	}

	return nodeinfo, nil
}

// ParseUserListResponse parse the response for the given nodeinfo format
func (c *APIClient) ParseUserListResponse(userInfoResponse *[]UserResponse) (*[]api.UserInfo, error) {
	var deviceLimit int = 0
	var speedlimit uint64 = 0
	userList := make([]api.UserInfo, len(*userInfoResponse))
	for i, user := range *userInfoResponse {
		if c.DeviceLimit > 0 {
			deviceLimit = c.DeviceLimit
		} else {
			deviceLimit = user.DeviceLimit
		}
		if c.SpeedLimit > 0 {
			speedlimit = uint64((c.SpeedLimit * 1000000) / 8)
		} else {
			speedlimit = uint64((user.SpeedLimit * 1000000) / 8)
		}
		userList[i] = api.UserInfo{
			UID:         user.ID,
			Passwd:      user.Passwd,
			UUID:        user.Passwd,
			SpeedLimit:  speedlimit,
			DeviceLimit: deviceLimit,
		}
	}

	return &userList, nil
}
