add mcp (Model Context Protocol) support

pkg/core/ip_pattern.go

@@ -0,0 +1,177 @@
+package core
+
+import (
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/mayswind/ezbookkeeping/pkg/errs"
+)
+
+// IPPattern represents a pattern for matching IP addresses, either IPv4 or IPv6
+type IPPattern struct {
+	Pattern string
+	regex   *regexp.Regexp
+}
+
+// Match returns if the given IP address matches the pattern
+func (p *IPPattern) Match(ip string) bool {
+	if p.regex == nil {
+		return false
+	}
+
+	return p.regex.MatchString(ip)
+}
+
+// GobEncode returns the encoded data for this IP pattern
+func (p *IPPattern) GobEncode() ([]byte, error) {
+	return []byte(p.Pattern), nil
+}
+
+// GobDecode decodes the data into the IP pattern
+func (p *IPPattern) GobDecode(data []byte) error {
+	pattern := string(data)
+
+	if pattern == "" {
+		p.Pattern = ""
+		p.regex = nil
+		return nil
+	}
+
+	newPattern, err := ParseIPPattern(pattern)
+
+	if err != nil {
+		return err
+	}
+
+	p.Pattern = newPattern.Pattern
+	p.regex = newPattern.regex
+	return nil
+}
+
+// ParseIPPattern parses the given IP address pattern and returns an IPPattern object
+func ParseIPPattern(ipPattern string) (*IPPattern, error) {
+	if ipPattern == "" {
+		return nil, nil
+	}
+
+	hasDot := false
+	hasSemicolon := false
+
+	for i := 0; i < len(ipPattern); i++ {
+		ch := rune(ipPattern[i])
+
+		if ch == '.' { // may be IPv4
+			if hasSemicolon {
+				return nil, errs.ErrInvalidIpAddressPattern
+			}
+			hasDot = true
+		} else if ch == ':' { // may be IPv6
+			if hasDot {
+				return nil, errs.ErrInvalidIpAddressPattern
+			}
+			hasSemicolon = true
+		}
+	}
+
+	if hasDot {
+		return ParseIPv4Pattern(ipPattern)
+	} else if hasSemicolon {
+		return ParseIPv6Pattern(ipPattern)
+	} else {
+		return nil, errs.ErrInvalidIpAddressPattern
+	}
+}
+
+// ParseIPv4Pattern parses the given IPv4 address pattern and returns an IPPattern object
+func ParseIPv4Pattern(ipPattern string) (*IPPattern, error) {
+	items := strings.Split(ipPattern, ".")
+
+	if len(items) != 4 {
+		return nil, errs.ErrInvalidIpAddressPattern
+	}
+
+	regexBuilder := strings.Builder{}
+	regexBuilder.WriteRune('^')
+
+	for i := 0; i < len(items); i++ {
+		item := strings.TrimSpace(items[i])
+
+		if item == "*" {
+			regexBuilder.WriteString("[0-9]{1,3}")
+		} else if item == "" {
+			return nil, errs.ErrInvalidIpAddressPattern
+		} else {
+			num, err := strconv.Atoi(item)
+
+			if err != nil || num < 0 || num > 255 {
+				return nil, errs.ErrInvalidIpAddressPattern
+			}
+
+			regexBuilder.WriteString(item)
+		}
+
+		if i < len(items)-1 {
+			regexBuilder.WriteRune('\\')
+			regexBuilder.WriteRune('.')
+		}
+	}
+
+	regexBuilder.WriteRune('$')
+	regex, err := regexp.Compile(regexBuilder.String())
+
+	if err != nil {
+		return nil, errs.ErrInvalidIpAddressPattern
+	}
+
+	return &IPPattern{
+		Pattern: ipPattern,
+		regex:   regex,
+	}, nil
+}
+
+// ParseIPv6Pattern parses the given IPv6 address pattern and returns an IPPattern object
+func ParseIPv6Pattern(ipPattern string) (*IPPattern, error) {
+	items := strings.Split(ipPattern, ":")
+
+	if len(items) < 2 || len(items) > 8 {
+		return nil, errs.ErrInvalidIpAddressPattern
+	}
+
+	regexBuilder := strings.Builder{}
+	regexBuilder.WriteRune('^')
+
+	for i := 0; i < len(items); i++ {
+		item := strings.TrimSpace(items[i])
+
+		if item == "*" {
+			regexBuilder.WriteString("[0-9a-fA-F]{1,4}")
+		} else if i < len(items)-1 && item == "" {
+			// Do Nothing
+		} else {
+			num, err := strconv.ParseInt(item, 16, 32)
+
+			if err != nil || num < 0 || num > 0xFFFF {
+				return nil, errs.ErrInvalidIpAddressPattern
+			}
+
+			regexBuilder.WriteString(item)
+		}
+
+		if i < len(items)-1 {
+			regexBuilder.WriteRune(':')
+		}
+	}
+
+	regexBuilder.WriteRune('$')
+	regex, err := regexp.Compile(regexBuilder.String())
+
+	if err != nil {
+		return nil, errs.ErrInvalidIpAddressPattern
+	}
+
+	return &IPPattern{
+		Pattern: ipPattern,
+		regex:   regex,
+	}, nil
+}