Add projects

backend/examples/plugin/claude-web-search-router/go/claude_response.go

@@ -0,0 +1,173 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+	"time"
+)
+
+type claudeStreamBuilder struct {
+	model       string
+	messageID   string
+	toolUseID   string
+	index       int
+	inputTokens int
+}
+
+func newClaudeStreamBuilder(model string) *claudeStreamBuilder {
+	model = strings.TrimSpace(model)
+	if model == "" {
+		model = "claude-sonnet-4-6"
+	}
+	now := time.Now().UnixNano()
+	return &claudeStreamBuilder{
+		model:       model,
+		messageID:   fmt.Sprintf("msg_%x", now),
+		toolUseID:   fmt.Sprintf("srvtoolu_%d", now),
+		inputTokens: 85,
+	}
+}
+
+func (b *claudeStreamBuilder) buildStreamWithQuery(query string, hits []claudeWebSearchHit, answer string) []byte {
+	var chunks []string
+	chunks = append(chunks, b.event("message_start", map[string]any{
+		"type": "message_start",
+		"message": map[string]any{
+			"id": b.messageID, "type": "message", "role": "assistant", "content": []any{},
+			"model": b.model, "stop_reason": nil, "stop_sequence": nil,
+			"usage": map[string]any{"input_tokens": b.inputTokens, "output_tokens": 0},
+		},
+	}))
+	chunks = append(chunks, b.blockStart(b.index, map[string]any{
+		"type": "server_tool_use", "id": b.toolUseID, "name": "web_search", "input": map[string]any{},
+	}))
+	partial, _ := json.Marshal(map[string]string{"query": query})
+	chunks = append(chunks, b.event("content_block_delta", map[string]any{
+		"type": "content_block_delta", "index": b.index,
+		"delta": map[string]any{"type": "input_json_delta", "partial_json": string(partial)},
+	}))
+	chunks = append(chunks, b.event("content_block_stop", map[string]any{"type": "content_block_stop", "index": b.index}))
+	b.index++
+
+	resultContent := webSearchResultBlocks(hits)
+	chunks = append(chunks, b.blockStart(b.index, map[string]any{
+		"type": "web_search_tool_result", "tool_use_id": b.toolUseID, "content": resultContent,
+	}))
+	chunks = append(chunks, b.event("content_block_stop", map[string]any{"type": "content_block_stop", "index": b.index}))
+	b.index++
+
+	text := composeAnswerText(answer, hits)
+	outputTokens := estimateTokens(text)
+	chunks = append(chunks, b.blockStart(b.index, map[string]any{"type": "text", "text": ""}))
+	chunks = append(chunks, b.event("content_block_delta", map[string]any{
+		"type": "content_block_delta", "index": b.index,
+		"delta": map[string]any{"type": "text_delta", "text": text},
+	}))
+	chunks = append(chunks, b.event("content_block_stop", map[string]any{"type": "content_block_stop", "index": b.index}))
+
+	chunks = append(chunks, b.event("message_delta", map[string]any{
+		"type":  "message_delta",
+		"delta": map[string]any{"stop_reason": "end_turn", "stop_sequence": nil},
+		"usage": map[string]any{
+			"input_tokens": b.inputTokens, "output_tokens": outputTokens,
+			"server_tool_use": map[string]any{"web_search_requests": 1},
+		},
+	}))
+	chunks = append(chunks, b.event("message_stop", map[string]any{"type": "message_stop"}))
+	return []byte(strings.Join(chunks, ""))
+}
+
+func (b *claudeStreamBuilder) buildMessageJSON(query string, hits []claudeWebSearchHit, answer string) []byte {
+	text := composeAnswerText(answer, hits)
+	content := []map[string]any{
+		{"type": "server_tool_use", "id": b.toolUseID, "name": "web_search", "input": map[string]string{"query": query}},
+		{"type": "web_search_tool_result", "tool_use_id": b.toolUseID, "content": webSearchResultBlocks(hits)},
+		{"type": "text", "text": text},
+	}
+	out := map[string]any{
+		"id": b.messageID, "type": "message", "role": "assistant", "model": b.model,
+		"content": content, "stop_reason": "end_turn", "stop_sequence": nil,
+		"usage": map[string]any{
+			"input_tokens": b.inputTokens, "output_tokens": estimateTokens(text),
+			"server_tool_use": map[string]any{"web_search_requests": 1},
+		},
+	}
+	raw, _ := json.Marshal(out)
+	return raw
+}
+
+func webSearchResultBlocks(hits []claudeWebSearchHit) []map[string]any {
+	resultContent := make([]map[string]any, 0, len(hits))
+	for _, hit := range hits {
+		title := hit.Title
+		if title == "" {
+			title = hostFromURL(hit.URL)
+		}
+		resultContent = append(resultContent, map[string]any{
+			"type": "web_search_result", "title": title, "url": hit.URL, "page_age": nil,
+		})
+	}
+	return resultContent
+}
+
+func (b *claudeStreamBuilder) event(eventType string, data map[string]any) string {
+	raw, _ := json.Marshal(data)
+	return fmt.Sprintf("event: %s\ndata: %s\n\n", eventType, string(raw))
+}
+
+func (b *claudeStreamBuilder) blockStart(index int, block map[string]any) string {
+	return b.event("content_block_start", map[string]any{
+		"type": "content_block_start", "index": index, "content_block": block,
+	})
+}
+
+func composeAnswerText(answer string, hits []claudeWebSearchHit) string {
+	if strings.TrimSpace(answer) != "" {
+		return answer
+	}
+	if len(hits) == 0 {
+		return "No web search results were returned."
+	}
+	var buf strings.Builder
+	for i, hit := range hits {
+		if i > 0 {
+			buf.WriteString("\n\n")
+		}
+		if hit.Title != "" {
+			buf.WriteString(hit.Title)
+			buf.WriteString("\n")
+		}
+		if hit.URL != "" {
+			buf.WriteString(hit.URL)
+			buf.WriteString("\n")
+		}
+		if hit.Snippet != "" {
+			buf.WriteString(hit.Snippet)
+		}
+	}
+	return buf.String()
+}
+
+func hostFromURL(raw string) string {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return ""
+	}
+	withoutScheme := raw
+	if idx := strings.Index(raw, "://"); idx >= 0 {
+		withoutScheme = raw[idx+3:]
+	}
+	if slash := strings.Index(withoutScheme, "/"); slash >= 0 {
+		return withoutScheme[:slash]
+	}
+	return withoutScheme
+}
+
+func estimateTokens(text string) int {
+	n := len([]rune(text)) / 4
+	if n < 1 {
+		return 1
+	}
+	return n
+}