Function normalize_messages

src/server/rest_handler.cpp:26–125

@brief Normalize messages by merging consecutive user messages (like Ollama does) @param messages the original messages @return normalized messages with consecutive user messages merged

///@param messages the original messages
///@return normalized messages with consecutive user messages merged
static json normalize_messages(json messages) {
    if (messages.empty()) return messages;

    json normalized = nlohmann::ordered_json::array();

    for (size_t i = 0; i < messages.size(); i++) {
        auto current_msg = messages[i];
        std::string role = current_msg.value("role", "");

        if (role == "user") {
            json merged_content_array = json::array();

            // Merge all consecutive user messages into array format
            while (i < messages.size() && messages[i].value("role", "") == "user") {
                if (messages[i].contains("content")) {
                    if (messages[i]["content"].is_array()) {
                        for (auto& item : messages[i]["content"]) {
                            merged_content_array.push_back(item);
                        }
                    }
                    else if (messages[i]["content"].is_string()) {
                        std::string text = messages[i]["content"].get<std::string>();
                        if (!text.empty()) {
                            nlohmann::ordered_json text_item;
                            text_item["type"] = "text";
                            text_item["text"] = text;
                            merged_content_array.push_back(text_item);
                        }
                    }
                }
                if (i + 1 < messages.size() && messages[i + 1].value("role", "") == "user") i++;
                else break;
            }

            current_msg["content"] = merged_content_array;
        }
        else if (role == "system") {
            json merged_content_array = json::array();

            // Merge all consecutive system messages into array format
            while (i < messages.size() && messages[i].value("role", "") == "system") {
                if (messages[i].contains("content")) {
                    if (messages[i]["content"].is_array()) {
                        for (auto& item : messages[i]["content"]) {
                            merged_content_array.push_back(item);
                        }
                    }
                    else if (messages[i]["content"].is_string()) {
                        std::string text = messages[i]["content"].get<std::string>();
                        if (!text.empty()) {
                            json text_item;
                            text_item["type"] = "text";
                            text_item["text"] = text;
                            merged_content_array.push_back(text_item);
                        }
                    }
                }
                if (i + 1 < messages.size() && messages[i + 1].value("role", "") == "system") i++;