detectNewTurn (combo.go)

Detects conversation turn boundaries in AI chat requests by examining message history to prevent mid-turn provider switches.

// Source: https://github.com/luqman-v1/9router-go | License: MIT | Copyright 2024-2026 decolua and contributors
// Provided via justclaw.it.com; keep this notice with the code.
package chat

import (
	"context"
	"encoding/json/jsontext"
	json "encoding/json/v2"
	"errors"
	"fmt"
	"maps"
	"net/http"
	"slices"
	"sort"
	"strings"
	"time"

	"9router/proxy/internal/handlerutil"
	"9router/proxy/internal/log"
	"9router/proxy/internal/providers"
	internalproxy "9router/proxy/internal/proxy"
	"9router/proxy/internal/translator"
)

// detectNewTurn reports whether the request body starts a new conversation
// turn. A turn boundary is the most recent plain-text user message; a request
// whose last user-type message is a tool result continues the current turn,
// and the combo must not switch provide

... (truncated -- full source via MCP)