Implement continuation tokens

internal/continuation_token/continuation_token.go

@@ -0,0 +1,145 @@
+package continuationtoken
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/pikami/cosmium/internal/logger"
+)
+
+type ContinuationTokenExternal struct {
+	Token string `json:"token"`
+	Range struct {
+		Min string `json:"min"`
+		Max string `json:"max"`
+	} `json:"range"`
+}
+
+type ContinuationToken struct {
+	Token struct {
+		ResourceId   string // RID
+		PageIndex    int    // RT
+		TotalResults int    // TRC
+		ISV          int    // ISV
+		IEO          int    // IEO
+		QCF          int    // QCF
+		LR           int    // LR
+	}
+	Range struct {
+		Min string
+		Max string
+	}
+}
+
+func Generate(resourceid string, pageIndex int, totalResults int) ContinuationToken {
+	ct := ContinuationToken{}
+	ct.Token.ResourceId = resourceid
+	ct.Token.PageIndex = pageIndex
+	ct.Token.TotalResults = totalResults
+	ct.Token.ISV = 2
+	ct.Token.IEO = 65567
+	ct.Token.QCF = 8
+	ct.Token.LR = 1
+	ct.Range.Min = ""
+	ct.Range.Max = "FF"
+
+	return ct
+}
+
+func GenerateDefault(resourceid string) ContinuationToken {
+	return Generate(resourceid, 0, 0)
+}
+
+func (ct *ContinuationToken) ToString() string {
+	token := fmt.Sprintf(
+		"-RID:~%s#RT:%d#TRC:%d#ISV:%d#IEO:%d#QCF:%d#LR:%d",
+		ct.Token.ResourceId,
+		ct.Token.PageIndex,
+		ct.Token.TotalResults,
+		ct.Token.ISV,
+		ct.Token.IEO,
+		ct.Token.QCF,
+		ct.Token.LR,
+	)
+
+	ect := ContinuationTokenExternal{}
+	ect.Token = token
+	ect.Range.Min = ct.Range.Min
+	ect.Range.Max = ct.Range.Max
+
+	json, err := json.Marshal(ect)
+	if err != nil {
+		logger.Error(err, "failed to marshal continuation token")
+		return ""
+	}
+
+	return string(json)
+}
+
+func FromString(token string) ContinuationToken {
+	ect := ContinuationTokenExternal{}
+	err := json.Unmarshal([]byte(token), &ect)
+	if err != nil {
+		logger.Error(err, "failed to unmarshal continuation token")
+		return ContinuationToken{}
+	}
+
+	ct, err := parseContinuationToken(ect.Token, ect.Range.Min, ect.Range.Max)
+	if err != nil {
+		logger.Error(err, "failed to parse continuation token")
+		return ContinuationToken{}
+	}
+
+	return *ct
+}
+
+func parseContinuationToken(token string, minRange string, maxRange string) (*ContinuationToken, error) {
+	const prefix = "-RID:~"
+	if !strings.HasPrefix(token, prefix) {
+		return nil, fmt.Errorf("invalid token prefix")
+	}
+
+	parts := strings.Split(token[len(prefix):], "#")
+	if len(parts) != 7 {
+		return nil, fmt.Errorf("invalid token format: expected 7 fields, got %d", len(parts))
+	}
+
+	ct := &ContinuationToken{}
+
+	ct.Token.ResourceId = parts[0]
+
+	parseIntField := func(part, key string) (int, error) {
+		if !strings.HasPrefix(part, key+":") {
+			return 0, fmt.Errorf("expected %s field", key)
+		}
+		return strconv.Atoi(strings.TrimPrefix(part, key+":"))
+	}
+
+	var err error
+
+	if ct.Token.PageIndex, err = parseIntField(parts[1], "RT"); err != nil {
+		return nil, err
+	}
+	if ct.Token.TotalResults, err = parseIntField(parts[2], "TRC"); err != nil {
+		return nil, err
+	}
+	if ct.Token.ISV, err = parseIntField(parts[3], "ISV"); err != nil {
+		return nil, err
+	}
+	if ct.Token.IEO, err = parseIntField(parts[4], "IEO"); err != nil {
+		return nil, err
+	}
+	if ct.Token.QCF, err = parseIntField(parts[5], "QCF"); err != nil {
+		return nil, err
+	}
+	if ct.Token.LR, err = parseIntField(parts[6], "LR"); err != nil {
+		return nil, err
+	}
+
+	ct.Range.Min = minRange
+	ct.Range.Max = maxRange
+
+	return ct, nil
+}

internal/continuation_token/continuation_token_test.go

@@ -0,0 +1,35 @@
+package continuationtoken
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Generate(t *testing.T) {
+	token := Generate("test-resource-id", 1, 100)
+
+	assert.Equal(t, "test-resource-id", token.Token.ResourceId)
+	assert.Equal(t, 1, token.Token.PageIndex)
+	assert.Equal(t, 100, token.Token.TotalResults)
+}
+
+func Test_FromString(t *testing.T) {
+	token := FromString("{\"token\":\"-RID:~test-resource-id#RT:1#TRC:100#ISV:2#IEO:65567#QCF:8#LR:1\",\"range\":{\"min\":\"\",\"max\":\"FF\"}}")
+
+	assert.Equal(t, "test-resource-id", token.Token.ResourceId)
+	assert.Equal(t, 1, token.Token.PageIndex)
+	assert.Equal(t, 100, token.Token.TotalResults)
+}
+
+func Test_ToString(t *testing.T) {
+	token := Generate("test-resource-id", 1, 100)
+	assert.Equal(t, "{\"token\":\"-RID:~test-resource-id#RT:1#TRC:100#ISV:2#IEO:65567#QCF:8#LR:1\",\"range\":{\"min\":\"\",\"max\":\"FF\"}}", token.ToString())
+}
+
+func Test_GenerateDefault(t *testing.T) {
+	token := GenerateDefault("test-resource-id")
+	assert.Equal(t, "test-resource-id", token.Token.ResourceId)
+	assert.Equal(t, 0, token.Token.PageIndex)
+	assert.Equal(t, 0, token.Token.TotalResults)
+}