package device

import (
	"bufio"
	"fmt"
	"network-topology-discovery/pkg/models"
	"regexp"
	"strings"
)

// HuaweiParser 华为设备解析器
type HuaweiParser struct {
	BaseParser
}

// GetCommands 获取华为设备命令列表
func (p *HuaweiParser) GetCommands() []string {
	return []string{
		"display version",
		"display interface",
		"display interface brief",
		"display lldp neighbor",
	}
}

// Parse 解析华为设备输出
func (p *HuaweiParser) Parse(device *models.Device, outputs []string) error {
	if len(outputs) < 4 {
		return fmt.Errorf("insufficient command outputs")
	}

	p.parseVersion(device, outputs[0])
	device.Interfaces = p.parseInterfaces(outputs[1], outputs[2])
	device.Neighbors = p.parseNeighbors(outputs[3])

	return nil
}

func (p *HuaweiParser) parseVersion(device *models.Device, output string) {
	// 提取主机名
	hostnameRegex := regexp.MustCompile(`<(\S+)>`)
	if matches := hostnameRegex.FindStringSubmatch(output); len(matches) > 1 {
		device.Hostname = matches[1]
	}

	// 提取版本信息
	if strings.Contains(output, "VRP") {
		lines := strings.Split(output, "\n")
		for _, line := range lines {
			if strings.Contains(line, "VRP") {
				device.OSVersion = strings.TrimSpace(line)
				break
			}
		}
	}

	// 提取运行时间
	uptimeRegex := regexp.MustCompile(`uptime is\s+(\d+\s+\S+)`)
	if matches := uptimeRegex.FindStringSubmatch(output); len(matches) > 1 {
		device.Uptime = matches[1]
	}
}

func (p *HuaweiParser) parseInterfaces(interfaceOutput, briefOutput string) []models.Interface {
	var interfaces []models.Interface
	briefMap := p.parseInterfaceBrief(briefOutput)

	scanner := bufio.NewScanner(strings.NewReader(interfaceOutput))
	var currentInterface *models.Interface

	for scanner.Scan() {
		line := scanner.Text()

		// 匹配接口名称
		if nameRegex := regexp.MustCompile(`^(\S+)\s+current state\s+(UP|DOWN)`); nameRegex.MatchString(line) {
			if currentInterface != nil {
				interfaces = append(interfaces, *currentInterface)
			}
			matches := nameRegex.FindStringSubmatch(line)
			currentInterface = &models.Interface{
				Name:   matches[1],
				Status: strings.ToLower(matches[2]),
			}

			if brief, ok := briefMap[currentInterface.Name]; ok {
				currentInterface.IP = brief.IP
				if currentInterface.Speed == "" {
					currentInterface.Speed = brief.Speed
				}
				if currentInterface.Duplex == "" {
					currentInterface.Duplex = brief.Duplex
				}
				if currentInterface.VLAN == "" {
					currentInterface.VLAN = brief.VLAN
				}
			}
		}

		if currentInterface != nil {
			// 描述
			if descRegex := regexp.MustCompile(`Description:\s+(.+)`); descRegex.MatchString(line) {
				currentInterface.Description = descRegex.FindStringSubmatch(line)[1]
			}

			// MAC地址
			if macRegex := regexp.MustCompile(`Hardware address is\s+(\S+)`); macRegex.MatchString(line) {
				currentInterface.MAC = macRegex.FindStringSubmatch(line)[1]
			}

			// IP地址
			if ipRegex := regexp.MustCompile(`Internet Address is\s+(\d+\.\d+\.\d+\.\d+),\s+Subnet mask is\s+(\d+\.\d+\.\d+\.\d+)`); ipRegex.MatchString(line) {
				matches := ipRegex.FindStringSubmatch(line)
				currentInterface.IP = matches[1]
				currentInterface.Mask = matches[2]
			}

			// 带宽格式1: Speed : 1000Mbps
			if speedRegex := regexp.MustCompile(`Speed\s*:\s*(\d+)\s*(Kbps|Mbps|Gbps)`); speedRegex.MatchString(line) {
				matches := speedRegex.FindStringSubmatch(line)
				currentInterface.Speed = matches[1] + matches[2]
			}
			// 带宽格式2: BW 1000000 Kbit
			if speedRegex2 := regexp.MustCompile(`BW\s+(\d+)\s+(Kbit|Mbit|Gbit)`); speedRegex2.MatchString(line) && currentInterface.Speed == "" {
				matches := speedRegex2.FindStringSubmatch(line)
				currentInterface.Speed = matches[1] + " " + matches[2]
			}

			// VLAN信息: Port link-type
			if linkTypeRegex := regexp.MustCompile(`Port link-type\s*:\s*(\S+)`); linkTypeRegex.MatchString(line) {
				currentInterface.VLAN = linkTypeRegex.FindStringSubmatch(line)[1]
			}
			if untaggedRegex := regexp.MustCompile(`Untagged VLAN ID\s*:\s*(\S+)`); untaggedRegex.MatchString(line) {
				untagged := untaggedRegex.FindStringSubmatch(line)[1]
				if untagged != "none" && untagged != "--" {
					if currentInterface.VLAN != "" {
						currentInterface.VLAN = currentInterface.VLAN + " " + untagged
					} else {
						currentInterface.VLAN = untagged
					}
				}
			}
			if taggedRegex := regexp.MustCompile(`Tagged VLAN ID\s*:\s*(\S+)`); taggedRegex.MatchString(line) {
				tagged := taggedRegex.FindStringSubmatch(line)[1]
				if tagged != "none" && tagged != "--" {
					if currentInterface.VLAN != "" {
						currentInterface.VLAN = currentInterface.VLAN + " (T:" + tagged + ")"
					} else {
						currentInterface.VLAN = "T:" + tagged
					}
				}
			}
		}
	}

	if currentInterface != nil {
		interfaces = append(interfaces, *currentInterface)
	}

	return interfaces
}

func (p *HuaweiParser) parseInterfaceBrief(output string) map[string]models.Interface {
	interfaces := make(map[string]models.Interface)
	lines := strings.Split(output, "\n")

	mode := 0 // 0=未开始, 1=route mode, 2=bridge mode
	for _, line := range lines {
		trimmed := strings.TrimSpace(line)
		if trimmed == "" || strings.HasPrefix(trimmed, "---") {
			continue
		}

		if strings.Contains(trimmed, "route mode") {
			mode = 1
			continue
		}
		if strings.Contains(trimmed, "bridge mode") {
			mode = 2
			continue
		}

		fields := strings.Fields(trimmed)
		if len(fields) > 0 && (fields[0] == "Interface" || fields[0] == "interface") {
			continue
		}

		// Route mode: Interface Link Protocol Primary IP Description
		if mode == 1 && len(fields) >= 3 {
			fullName := expandH3CInterfaceName(fields[0])
			ip := ""
			if len(fields) >= 4 && fields[3] != "--" {
				ip = fields[3]
			}
			iface := models.Interface{
				Name:   fullName,
				Status: strings.ToLower(fields[1]),
				IP:     ip,
			}
			interfaces[fullName] = iface
		}

		// Bridge mode: Interface Link Speed Duplex Type PVID Description
		if mode == 2 && len(fields) >= 5 {
			fullName := expandH3CInterfaceName(fields[0])

			speed := fields[2]
			duplex := fields[3]
			switch duplex {
			case "A":
				duplex = "auto"
			case "F(a)", "F":
				duplex = "full"
			case "H":
				duplex = "half"
			}

			vlan := ""
			if len(fields) >= 5 {
				switch fields[4] {
				case "A":
					vlan = "Access"
				case "T":
					vlan = "Trunk"
				case "H":
					vlan = "Hybrid"
				}
			}
			if len(fields) >= 6 {
				vlan = vlan + " " + fields[5]
			}

			iface := models.Interface{
				Name:   fullName,
				Status: strings.ToLower(fields[1]),
				Speed:  speed,
				Duplex: duplex,
				VLAN:   strings.TrimSpace(vlan),
			}
			if existing, ok := interfaces[fullName]; ok {
				if existing.IP != "" {
					iface.IP = existing.IP
				}
			}
			interfaces[fullName] = iface
		}
	}

	return interfaces
}

func (p *HuaweiParser) parseNeighbors(output string) []models.Neighbor {
	var neighbors []models.Neighbor
	scanner := bufio.NewScanner(strings.NewReader(output))

	var currentNeighbor *models.Neighbor

	for scanner.Scan() {
		line := scanner.Text()

		// 跳过标题行
		if strings.Contains(line, "Local Interface") || strings.Contains(line, "-----") {
			continue
		}

		fields := strings.Fields(line)
		if len(fields) >= 5 {
			currentNeighbor = &models.Neighbor{
				LocalInterface:  fields[0],
				RemoteDevice:    fields[2],
				RemoteInterface: fields[4],
				Protocol:        "LLDP",
			}
			neighbors = append(neighbors, *currentNeighbor)
		}
	}

	return neighbors
}