feat(gemini-web): squash all features and fixes for gemini-web

internal/client/gemini-web/prompt.go

@@ -0,0 +1,130 @@
+package geminiwebapi
+
+import (
+	"math"
+	"regexp"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/tidwall/gjson"
+)
+
+var (
+	reThink     = regexp.MustCompile(`(?s)^\s*<think>.*?</think>\s*`)
+	reXMLAnyTag = regexp.MustCompile(`(?s)<\s*[^>]+>`)
+)
+
+// NormalizeRole converts a role to a standard format (lowercase, 'model' -> 'assistant').
+func NormalizeRole(role string) string {
+	r := strings.ToLower(role)
+	if r == "model" {
+		return "assistant"
+	}
+	return r
+}
+
+// NeedRoleTags checks if a list of messages requires role tags.
+func NeedRoleTags(msgs []RoleText) bool {
+	for _, m := range msgs {
+		if strings.ToLower(m.Role) != "user" {
+			return true
+		}
+	}
+	return false
+}
+
+// AddRoleTag wraps content with a role tag.
+func AddRoleTag(role, content string, unclose bool) string {
+	if role == "" {
+		role = "user"
+	}
+	if unclose {
+		return "<|im_start|>" + role + "\n" + content
+	}
+	return "<|im_start|>" + role + "\n" + content + "\n<|im_end|>"
+}
+
+// BuildPrompt constructs the final prompt from a list of messages.
+func BuildPrompt(msgs []RoleText, tagged bool, appendAssistant bool) string {
+	if len(msgs) == 0 {
+		if tagged && appendAssistant {
+			return AddRoleTag("assistant", "", true)
+		}
+		return ""
+	}
+	if !tagged {
+		var sb strings.Builder
+		for i, m := range msgs {
+			if i > 0 {
+				sb.WriteString("\n")
+			}
+			sb.WriteString(m.Text)
+		}
+		return sb.String()
+	}
+	var sb strings.Builder
+	for _, m := range msgs {
+		sb.WriteString(AddRoleTag(m.Role, m.Text, false))
+		sb.WriteString("\n")
+	}
+	if appendAssistant {
+		sb.WriteString(AddRoleTag("assistant", "", true))
+	}
+	return strings.TrimSpace(sb.String())
+}
+
+// RemoveThinkTags strips <think>...</think> blocks from a string.
+func RemoveThinkTags(s string) string {
+	return strings.TrimSpace(reThink.ReplaceAllString(s, ""))
+}
+
+// SanitizeAssistantMessages removes think tags from assistant messages.
+func SanitizeAssistantMessages(msgs []RoleText) []RoleText {
+	out := make([]RoleText, 0, len(msgs))
+	for _, m := range msgs {
+		if strings.ToLower(m.Role) == "assistant" {
+			out = append(out, RoleText{Role: m.Role, Text: RemoveThinkTags(m.Text)})
+		} else {
+			out = append(out, m)
+		}
+	}
+	return out
+}
+
+// AppendXMLWrapHintIfNeeded appends an XML wrap hint to messages containing XML-like blocks.
+func AppendXMLWrapHintIfNeeded(msgs []RoleText, disable bool) []RoleText {
+	if disable {
+		return msgs
+	}
+	const xmlWrapHint = "\nFor any xml block, e.g. tool call, always wrap it with: \n`````xml\n...\n`````\n"
+	out := make([]RoleText, 0, len(msgs))
+	for _, m := range msgs {
+		t := m.Text
+		if reXMLAnyTag.MatchString(t) {
+			t = t + xmlWrapHint
+		}
+		out = append(out, RoleText{Role: m.Role, Text: t})
+	}
+	return out
+}
+
+// EstimateTotalTokensFromRawJSON estimates token count by summing text parts.
+func EstimateTotalTokensFromRawJSON(rawJSON []byte) int {
+	totalChars := 0
+	contents := gjson.GetBytes(rawJSON, "contents")
+	if contents.Exists() {
+		contents.ForEach(func(_, content gjson.Result) bool {
+			content.Get("parts").ForEach(func(_, part gjson.Result) bool {
+				if t := part.Get("text"); t.Exists() {
+					totalChars += utf8.RuneCountInString(t.String())
+				}
+				return true
+			})
+			return true
+		})
+	}
+	if totalChars <= 0 {
+		return 0
+	}
+	return int(math.Ceil(float64(totalChars) / 4.0))
+}