1 files changed, 141 insertions, 0 deletions
diff --git a/pkg/auth/sip2/spec.go b/pkg/auth/sip2/spec.go
new file mode 100644
index 0000000..9c4ac48
--- /dev/null
+++ b/pkg/auth/sip2/spec.go
@@ -0,0 +1,141 @@
+package sip2
+
+import (
+	"log"
+	"strconv"
+	"strings"
+)
+
+type FixedFieldSpec struct {
+	length int
+	label  string
+}
+
+type FixedField struct {
+	spec  FixedFieldSpec
+	value string
+}
+
+type VariableFieldSpec struct {
+	id    string
+	label string
+}
+
+type VariableField struct {
+	spec  VariableFieldSpec
+	value string
+}
+
+type MessageSpec struct {
+	id     int
+	label  string
+	fields []FixedFieldSpec
+}
+
+type Message struct {
+	fields       []VariableField
+	fixed_fields []FixedField
+	msg_txt      string
+}
+
+type Parser struct {
+	getMessageSpecByCode   func(int) MessageSpec
+	getVariableFieldByCode func(string) VariableFieldSpec
+	getFixedFieldValue     func(*Message, string) (string, bool)
+	getFieldValue          func(*Message, string) (string, bool)
+	parseMessage           func(string) *Message
+}
+
+const (
+	YES                  string = "Y"
+	TRUE                 string = "1"
+	Ok                   string = "ok"
+	Language             string = "language"
+	PatronStatus         string = "patron status"
+	Date                 string = "transaction date"
+	PatronIdentifier     string = "patron identifier"
+	PatronPassword       string = "patron password"
+	PersonalName         string = "personal name"
+	ScreenMessage        string = "screen message"
+	InstitutionId        string = "institution id"
+	ValidPatron          string = "valid patron"
+	ValidPatronPassword  string = "valid patron password"
+	LoginResponse        string = "Login Response"
+	PatronStatusResponse string = "Patron Status Response"
+)
+
+func getParser() *Parser {
+
+	LanguageSpec := FixedFieldSpec{3, Language}
+	PatronStatusSpec := FixedFieldSpec{14, PatronStatus}
+	DateSpec := FixedFieldSpec{18, Date}
+	OkSpec := FixedFieldSpec{1, Ok}
+
+	msgByCodeMap := map[int]MessageSpec{
+		94: MessageSpec{94, LoginResponse, []FixedFieldSpec{OkSpec}},
+		24: MessageSpec{24, PatronStatusResponse, []FixedFieldSpec{PatronStatusSpec, LanguageSpec, DateSpec}},
+	}
+
+	variableFieldByCodeMap := map[string]VariableFieldSpec{
+		"AA": VariableFieldSpec{"AA", PatronIdentifier},
+		"AD": VariableFieldSpec{"AD", PatronPassword},
+		"AE": VariableFieldSpec{"AE", PersonalName},
+		"AF": VariableFieldSpec{"AF", ScreenMessage},
+		"AO": VariableFieldSpec{"AO", InstitutionId},
+		"BL": VariableFieldSpec{"BL", ValidPatron},
+		"CQ": VariableFieldSpec{"CQ", ValidPatronPassword},
+	}
+
+	parser := new(Parser)
+	parser.getMessageSpecByCode = func(code int) MessageSpec {
+		return msgByCodeMap[code]
+	}
+	parser.getVariableFieldByCode = func(code string) VariableFieldSpec {
+		return variableFieldByCodeMap[code]
+	}
+	parser.getFixedFieldValue = func(msg *Message, field string) (string, bool) {
+		for _, v := range msg.fixed_fields {
+			if v.spec.label == field {
+				return v.value, true
+			}
+		}
+		return "", false
+	}
+	parser.getFieldValue = func(msg *Message, field string) (string, bool) {
+		for _, v := range msg.fields {
+			if v.spec.label == field {
+				return v.value, true
+			}
+		}
+		return "", false
+	}
+
+	parser.parseMessage = func(msg string) *Message {
+		txt := msg[:len(msg)-len(terminator)]
+		code, err := strconv.Atoi(txt[:2])
+		if nil != err {
+			log.Println("Error parsing integer: %s", txt[:2])
+		}
+		spec := parser.getMessageSpecByCode(code)
+		txt = txt[2:]
+
+		message := new(Message)
+		for _, sp := range spec.fields {
+			value := txt[:sp.length]
+			txt = txt[sp.length:]
+			message.fixed_fields = append(message.fixed_fields, FixedField{sp, value})
+		}
+		if len(txt) == 0 {
+			return message
+		}
+		for _, part := range strings.Split(txt, "|") {
+			if len(part) > 0 {
+				part_spec := parser.getVariableFieldByCode(part[:2])
+				value := part[2:]
+				message.fields = append(message.fields, VariableField{part_spec, value})
+			}
+		}
+		return message
+	}
+	return parser
+}