Files

526 lines
15 KiB
Go

package helpers
import (
"context"
"encoding/json"
"errors"
"fmt"
"strconv"
"strings"
"time"
"github.com/spf13/cobra"
)
const (
defaultPagedCommandPageLimit = 50
maxPagedCommandPageLimit = 500
defaultPagedCommandDelayMS = 200
)
type PagedCursorKind int
const (
PagedCursorString PagedCursorKind = iota
PagedCursorInt64
)
type PagedAggregationMode int
const (
PagedAggregationArray PagedAggregationMode = iota
PagedAggregationConversationMessages
)
type PagedMCPCommandConfig struct {
ServerID string
ToolName string
ItemPath string
CursorPath string
HasMorePath string
CursorArg string
CursorKind PagedCursorKind
AggregationMode PagedAggregationMode
BuildArgs func(*cobra.Command) (map[string]any, error)
Fallback func(map[string]any) error
ProjectResult func(map[string]any) map[string]any
}
type pagedCommandOptions struct {
pageAll bool
pageLimit int
maxItems int
delayMS int
}
func AddPagedMCPFlags(cmd *cobra.Command) {
cmd.Flags().Bool("page-all", false, "自动按 nextCursor 拉取所有分页;未设置时保持单页调用")
cmd.Flags().Int("page-limit", defaultPagedCommandPageLimit, "自动翻页最多请求页数(默认 50,范围 1-500;仅 --page-all 生效)")
cmd.Flags().Int("max-items", 0, "自动翻页最多返回条数(默认 0 表示不限制;仅 --page-all 生效)")
cmd.Flags().Int("page-delay", defaultPagedCommandDelayMS, "自动翻页每页之间等待毫秒数(默认 200;0 表示不等待;仅 --page-all 生效)")
}
func RunPagedMCPCommand(cmd *cobra.Command, cfg PagedMCPCommandConfig) error {
args, err := cfg.BuildArgs(cmd)
if err != nil {
return err
}
opts, err := readPagedCommandOptions(cmd)
if err != nil {
return err
}
if !opts.pageAll {
return cfg.Fallback(args)
}
if err := validatePagedConfig(cfg); err != nil {
return err
}
if deps.Caller.DryRun() {
return deps.Out.PrintJSON(map[string]any{
"dry_run": true,
"request": map[string]any{
"server": cfg.ServerID,
"name": cfg.ToolName,
"args": args,
},
"paging": map[string]any{
"pageAll": true,
"pageLimit": opts.pageLimit,
"maxItems": opts.maxItems,
"pageDelay": opts.delayMS,
},
})
}
return runPagedMCPCommand(cmd, cfg, opts, args)
}
func readPagedCommandOptions(cmd *cobra.Command) (pagedCommandOptions, error) {
pageAll, _ := cmd.Flags().GetBool("page-all")
opts := pagedCommandOptions{pageAll: pageAll}
if !pageAll {
return opts, nil
}
opts.pageLimit, _ = cmd.Flags().GetInt("page-limit")
if opts.pageLimit < 1 || opts.pageLimit > maxPagedCommandPageLimit {
return opts, fmt.Errorf("--page-limit must be between 1 and 500")
}
opts.maxItems, _ = cmd.Flags().GetInt("max-items")
if opts.maxItems < 0 {
return opts, fmt.Errorf("--max-items must be greater than or equal to 0")
}
opts.delayMS, _ = cmd.Flags().GetInt("page-delay")
if opts.delayMS < 0 {
return opts, fmt.Errorf("--page-delay must be greater than or equal to 0")
}
return opts, nil
}
func validatePagedConfig(cfg PagedMCPCommandConfig) error {
switch {
case strings.TrimSpace(cfg.ServerID) == "":
return fmt.Errorf("paged command server is required")
case strings.TrimSpace(cfg.ToolName) == "":
return fmt.Errorf("paged command tool is required")
case strings.TrimSpace(cfg.ItemPath) == "":
return fmt.Errorf("paged command item path is required")
case strings.TrimSpace(cfg.CursorPath) == "":
return fmt.Errorf("paged command cursor path is required")
case strings.TrimSpace(cfg.HasMorePath) == "":
return fmt.Errorf("paged command hasMore path is required")
case strings.TrimSpace(cfg.CursorArg) == "":
return fmt.Errorf("paged command cursor arg is required")
case cfg.BuildArgs == nil || cfg.Fallback == nil:
return fmt.Errorf("paged command callbacks are required")
default:
return nil
}
}
func runPagedMCPCommand(cmd *cobra.Command, cfg PagedMCPCommandConfig, opts pagedCommandOptions, args map[string]any) error {
var envelope map[string]any
ctx := cmd.Context()
items := newPagedCollection(cfg)
seenCursors := map[string]bool{}
currentCursor := cursorValueKey(args[cfg.CursorArg], cfg.CursorKind)
lastCursor := args[cfg.CursorArg]
hasMore := true
for page := 1; page <= opts.pageLimit && hasMore; page++ {
pageCursor := args[cfg.CursorArg]
seenCursors[currentCursor] = true
text, err := callMCPToolReturnTextOnServer(ctx, cfg.ServerID, cfg.ToolName, args)
if err != nil {
return handlePagedCommandError(cmd, envelope, cfg, items, page, currentCursor, err)
}
parsed, pageItems, nextCursor, more, err := parsePagedCommandPage(text, cfg)
if err != nil {
return handlePagedCommandError(cmd, envelope, cfg, items, page, currentCursor, err)
}
if envelope == nil {
envelope = parsed
}
if err := items.Add(pageItems); err != nil {
return handlePagedCommandError(cmd, envelope, cfg, items, page, currentCursor, err)
}
hasMore = more
if opts.maxItems > 0 && items.Total() > opts.maxItems {
items.Truncate(opts.maxItems)
return writePagedCommandResult(envelope, cfg, items, pagingMetadata{
Truncated: true,
HasMore: true,
LastCursor: pageCursor,
Pages: page,
Total: items.Total(),
TruncatedWithinPage: true,
})
}
lastCursor = nextCursor
if opts.maxItems > 0 && items.Total() == opts.maxItems && hasMore {
return writePagedCommandResult(envelope, cfg, items, pagingMetadata{
Truncated: true,
HasMore: true,
LastCursor: lastCursor,
Pages: page,
Total: items.Total(),
})
}
if !hasMore {
return writePagedCommandResult(envelope, cfg, items, pagingMetadata{
Truncated: false,
HasMore: false,
LastCursor: lastCursor,
Pages: page,
Total: items.Total(),
})
}
nextKey := cursorValueKey(nextCursor, cfg.CursorKind)
if nextKey == "" || nextKey == currentCursor || seenCursors[nextKey] {
err := fmt.Errorf("pagination cursor did not advance: %s", nextKey)
return handlePagedCommandError(cmd, envelope, cfg, items, page+1, nextKey, err)
}
normalizedCursor, err := normalizeCursorArg(nextCursor, cfg.CursorKind)
if err != nil {
return handlePagedCommandError(cmd, envelope, cfg, items, page+1, nextKey, err)
}
currentCursor = nextKey
args[cfg.CursorArg] = normalizedCursor
if opts.delayMS > 0 {
if err := sleepPagedCommandDelay(ctx, time.Duration(opts.delayMS)*time.Millisecond); err != nil {
return handlePagedCommandError(cmd, envelope, cfg, items, page+1, currentCursor, err)
}
}
}
return writePagedCommandResult(envelope, cfg, items, pagingMetadata{
Truncated: hasMore,
HasMore: hasMore,
LastCursor: lastCursor,
Pages: opts.pageLimit,
Total: items.Total(),
})
}
func parsePagedCommandPage(text string, cfg PagedMCPCommandConfig) (map[string]any, []any, any, bool, error) {
var parsed map[string]any
if err := json.Unmarshal([]byte(text), &parsed); err != nil {
return nil, nil, nil, false, fmt.Errorf("parse paged response JSON: %w", err)
}
rawHasMore, ok := getJSONPath(parsed, cfg.HasMorePath)
if !ok {
return nil, nil, nil, false, fmt.Errorf("paged response missing %s", cfg.HasMorePath)
}
hasMore, ok := rawHasMore.(bool)
if !ok {
return nil, nil, nil, false, fmt.Errorf("paged response %s must be boolean", cfg.HasMorePath)
}
rawItems, ok := getJSONPath(parsed, cfg.ItemPath)
if !ok && cfg.AggregationMode == PagedAggregationConversationMessages && !hasMore {
rawItems = []any{}
ok = true
}
if !ok {
return nil, nil, nil, false, fmt.Errorf("paged response missing %s", cfg.ItemPath)
}
items, ok := rawItems.([]any)
if !ok {
return nil, nil, nil, false, fmt.Errorf("paged response %s must be array", cfg.ItemPath)
}
nextCursor, ok := getJSONPath(parsed, cfg.CursorPath)
if hasMore && !ok {
return nil, nil, nil, false, fmt.Errorf("paged response missing %s", cfg.CursorPath)
}
return parsed, items, nextCursor, hasMore, nil
}
type pagingMetadata struct {
Truncated bool
HasMore bool
LastCursor any
Pages int
Total int
TruncatedWithinPage bool
Partial bool
FailedPage int
FailedCursor string
PagesFetched int
ItemsFetched int
Error string
}
func handlePagedCommandError(cmd *cobra.Command, envelope map[string]any, cfg PagedMCPCommandConfig, items *pagedCollection, failedPage int, failedCursor string, err error) error {
if envelope == nil {
return err
}
fmt.Fprintf(cmd.ErrOrStderr(), "pagination stopped at page %d: %v\n", failedPage, err)
if outputErr := writePagedCommandResult(envelope, cfg, items, pagingMetadata{
Truncated: true,
HasMore: true,
LastCursor: failedCursor,
Pages: failedPage - 1,
Total: items.Total(),
Partial: true,
FailedPage: failedPage,
FailedCursor: failedCursor,
PagesFetched: failedPage - 1,
ItemsFetched: items.Total(),
Error: err.Error(),
}); outputErr != nil {
return errors.Join(err, outputErr)
}
return err
}
func writePagedCommandResult(envelope map[string]any, cfg PagedMCPCommandConfig, items *pagedCollection, meta pagingMetadata) error {
_ = setJSONPath(envelope, cfg.ItemPath, items.Values())
_ = setJSONPath(envelope, cfg.HasMorePath, meta.HasMore)
_ = setJSONPath(envelope, cfg.CursorPath, meta.LastCursor)
paging := map[string]any{
"truncated": meta.Truncated,
"hasMore": meta.HasMore,
"lastCursor": meta.LastCursor,
"pages": meta.Pages,
"total": meta.Total,
}
if meta.Partial {
paging["partial"] = true
paging["failedPage"] = meta.FailedPage
paging["failedCursor"] = meta.FailedCursor
paging["pagesFetched"] = meta.PagesFetched
paging["itemsFetched"] = meta.ItemsFetched
paging["error"] = meta.Error
}
if meta.TruncatedWithinPage {
paging["truncatedWithinPage"] = true
paging["resumeCursorReliable"] = false
}
envelope["paging"] = paging
if cfg.ProjectResult != nil {
envelope = cfg.ProjectResult(envelope)
}
return deps.Out.PrintJSON(envelope)
}
func sleepPagedCommandDelay(ctx context.Context, delay time.Duration) error {
select {
case <-ctx.Done():
return ctx.Err()
case <-helperAfter(delay):
return nil
}
}
type pagedCollection struct {
mode PagedAggregationMode
items []any
conversationIndex map[string]int
total int
}
func newPagedCollection(cfg PagedMCPCommandConfig) *pagedCollection {
return &pagedCollection{
mode: cfg.AggregationMode,
conversationIndex: map[string]int{},
}
}
func (c *pagedCollection) Add(items []any) error {
if c.mode != PagedAggregationConversationMessages {
c.items = append(c.items, items...)
c.total = len(c.items)
return nil
}
for _, item := range items {
if err := c.addConversation(item); err != nil {
return err
}
}
return nil
}
func (c *pagedCollection) Values() []any {
if c.items == nil {
return []any{}
}
return c.items
}
func (c *pagedCollection) Total() int {
return c.total
}
func (c *pagedCollection) Truncate(maxItems int) bool {
if maxItems <= 0 || c.total <= maxItems {
return false
}
if c.mode != PagedAggregationConversationMessages {
c.items = c.items[:maxItems]
c.total = len(c.items)
return true
}
c.truncateConversationMessages(maxItems)
return true
}
func (c *pagedCollection) addConversation(item any) error {
conversation, ok := item.(map[string]any)
if !ok {
return fmt.Errorf("paged response conversation item must be object")
}
key, _ := conversation["openConversationId"].(string)
if strings.TrimSpace(key) == "" {
return fmt.Errorf("paged response conversation item missing openConversationId")
}
messages, err := conversationMessages(conversation)
if err != nil {
return err
}
if idx, ok := c.conversationIndex[key]; ok {
existing := c.items[idx].(map[string]any)
existingMessages, err := conversationMessages(existing)
if err != nil {
return err
}
existing["messages"] = append(existingMessages, messages...)
c.total += len(messages)
return nil
}
c.conversationIndex[key] = len(c.items)
c.items = append(c.items, conversation)
c.total += len(messages)
return nil
}
func (c *pagedCollection) truncateConversationMessages(maxItems int) {
remaining := maxItems
for i, item := range c.items {
conversation := item.(map[string]any)
messages, _ := conversationMessages(conversation)
if remaining >= len(messages) {
remaining -= len(messages)
continue
}
if remaining == 0 {
c.items = c.items[:i]
c.total = maxItems
return
}
conversation["messages"] = messages[:remaining]
c.items = c.items[:i+1]
c.total = maxItems
return
}
}
func conversationMessages(conversation map[string]any) ([]any, error) {
raw, ok := conversation["messages"]
if !ok {
return []any{}, nil
}
messages, ok := raw.([]any)
if !ok {
return nil, fmt.Errorf("paged response conversation messages must be array")
}
return messages, nil
}
func getJSONPath(root map[string]any, path string) (any, bool) {
var current any = root
for _, part := range strings.Split(path, ".") {
obj, ok := current.(map[string]any)
if !ok {
return nil, false
}
current, ok = obj[part]
if !ok {
return nil, false
}
}
return current, true
}
func setJSONPath(root map[string]any, path string, value any) bool {
parts := strings.Split(path, ".")
current := root
for _, part := range parts[:len(parts)-1] {
next, ok := current[part].(map[string]any)
if !ok {
return false
}
current = next
}
current[parts[len(parts)-1]] = value
return true
}
func cursorValueKey(value any, kind PagedCursorKind) string {
switch kind {
case PagedCursorInt64:
switch v := value.(type) {
case int64:
return strconv.FormatInt(v, 10)
case int:
return strconv.Itoa(v)
case float64:
return strconv.FormatInt(int64(v), 10)
case string:
return strings.TrimSpace(v)
default:
return ""
}
default:
if value == nil {
return ""
}
return strings.TrimSpace(fmt.Sprint(value))
}
}
func normalizeCursorArg(value any, kind PagedCursorKind) (any, error) {
if kind != PagedCursorInt64 {
if value == nil {
return "", nil
}
return fmt.Sprint(value), nil
}
switch v := value.(type) {
case int64:
return v, nil
case int:
return int64(v), nil
case float64:
converted := int64(v)
if float64(converted) != v {
return nil, fmt.Errorf("paged response cursor must be an integer, got %v", v)
}
return converted, nil
case string:
parsed, err := strconv.ParseInt(strings.TrimSpace(v), 10, 64)
if err == nil {
return parsed, nil
}
return nil, fmt.Errorf("paged response cursor must be a base-10 int64 string, got %q", v)
}
return nil, fmt.Errorf("paged response cursor must be int64-compatible, got %T", value)
}