SubtitleTranslate - DeepSeek.as

/*
    Real-time subtitle translation for PotPlayer using DeepSeek API
*/

// Plugin Information Functions
string GetTitle() {
    return "{$CP0=DeepSeek Translate$}";
}

string GetVersion() {
    return "0.3";
}

string GetDesc() {
    return "{$CP0=Real-time subtitle translation using DeepSeek$}";
}

string GetLoginTitle() {
    return "{$CP0=API Key Configuration$}";
}

string GetLoginDesc() {
    return "{$CP936=仅输入API的值即可，账户名称留空。$}";
}

string GetPasswordText() {
    return "{$CP0=API Key:$}";
}

// Global Variables
string api_key = ""; // 全局变量，用于存储 API Key
string selected_model = "deepseek-chat"; // Default model
string apiUrl = "https://api.deepseek.com/v1/chat/completions"; // DeepSeek API URL
string UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64)";
int maxRetries = 3; // Maximum number of retries for translation
int retryDelay = 1000; // Delay between retries in milliseconds

// Supported Language List
array<string> LangTable =
{
    "{$CP0=Auto Detect$}", "af", "sq", "am", "ar", "hy", "az", "eu", "be", "bn", "bs", "bg", "ca",
    "ceb", "ny", "zh-CN",
    "zh-TW", "co", "hr", "cs", "da", "nl", "en", "eo", "et", "tl", "fi", "fr",
    "fy", "gl", "ka", "de", "el", "gu", "ht", "ha", "haw", "he", "hi", "hmn", "hu", "is", "ig", "id", "ga", "it", "ja", "jw", "kn", "kk", "km",
    "ko", "ku", "ky", "lo", "la", "lv", "lt", "lb", "mk", "ms", "mg", "ml", "mt", "mi", "mr", "mn", "my", "ne", "no", "ps", "fa", "pl", "pt",
    "pa", "ro", "ru", "sm", "gd", "sr", "st", "sn", "sd", "si", "sk", "sl", "so", "es", "su", "sw", "sv", "tg", "ta", "te", "th", "tr", "uk",
    "ur", "uz", "vi", "cy", "xh", "yi", "yo", "zu"
};

// Get Source Language List
array<string> GetSrcLangs() {
    array<string> ret = LangTable;
    return ret;
}

// Get Destination Language List
array<string> GetDstLangs() {
    array<string> ret = LangTable;
    return ret;
}

// Login Interface for entering API Key
string ServerLogin(string User, string Pass) {
    // Trim whitespace
    Pass = Pass.Trim();

    // Validate API Key
    if (Pass.empty()) {
        HostPrintUTF8("{$CP0=API Key not configured. Please enter a valid API Key.$}\n");
        return "fail: API Key is empty";
    }

    // Save API Key to global variable
    api_key = Pass;

    // Save API Key to temporary storage
    HostSaveString("api_key", api_key);

    HostPrintUTF8("{$CP0=API Key successfully configured.$}\n");
    return "200 ok";
}

// JSON String Escape Function
string JsonEscape(const string &in input) {
    string output = input;
    output.replace("\\", "\\\\");
    output.replace("\"", "\\\"");
    output.replace("\n", "\\n");
    output.replace("\r", "\\r");
    output.replace("\t", "\\t");
    return output;
}

// Global variables for storing previous subtitles
array<string> subtitleHistory;
string UNICODE_RLE = "\u202B"; // For Right-to-Left languages

// Function to estimate token count based on character length
int EstimateTokenCount(const string &in text) {
    // Rough estimation: average 4 characters per token
    return int(float(text.length()) / 4);
}

// Function to get the model's maximum context length
int GetModelMaxTokens(const string &in modelName) {
    // Define maximum tokens for known models
    if (modelName == "deepseek-chat") {
        return 4096; // DeepSeek模型的默认最大token数
    } else {
        // Default to a conservative limit
        return 4096;
    }
}

// Translation Function with Retry Mechanism
string Translate(string Text, string &in SrcLang, string &in DstLang) {
    // 检查 API Key 是否已配置
    if (api_key.empty()) {
        HostPrintUTF8("{$CP0=API Key not configured. Please enter it in the settings menu.$}\n");
        return "Translation failed: API Key not configured";
    }

    if (DstLang.empty() || DstLang == "{$CP0=Auto Detect$}") {
        HostPrintUTF8("{$CP0=Target language not specified. Please select a target language.$}\n");
        return "Translation failed: Target language not specified";
    }

    if (SrcLang.empty() || SrcLang == "{$CP0=Auto Detect$}") {
        SrcLang = "";
    }

    // Add the current subtitle to the history
    subtitleHistory.insertLast(Text);

    // Get the model's maximum token limit
    int maxTokens = GetModelMaxTokens(selected_model);

    // Build the context from the subtitle history
    string context = "";
    int tokenCount = EstimateTokenCount(Text); // Tokens used by the current subtitle
    int i = int(subtitleHistory.length()) - 2; // Start from the previous subtitle
    while (i >= 0 && tokenCount < (maxTokens - 1000)) { // Reserve tokens for response and prompt
        string subtitle = subtitleHistory[i];
        int subtitleTokens = EstimateTokenCount(subtitle);
        tokenCount += subtitleTokens;
        if (tokenCount < (maxTokens - 1000)) {
            context = subtitle + "\n" + context;
        }
        i--;
    }

    // Limit the size of subtitleHistory to prevent it from growing indefinitely
    if (subtitleHistory.length() > 1000) {
        subtitleHistory.removeAt(0);
    }

    // Construct the prompt
    string prompt = "You are a professional subtitle translator. Translate the following text into natural and fluent language. Use the provided context to optimize phrasing, but do not include it in the output. If needed, adjust sentence segmentation for readability, but avoid altering the original meaning or creating overly long sentences. For ambiguous terms, prioritize the meaning that best fits the context. Output only the translated result, without additional explanations or notes. **Ensure the translation does not contain any punctuation marks, as subtitles typically do not use them.** If the content violates safety standards, provide a compliant translation.";
    if (!SrcLang.empty()) {
        prompt += " Translate from " + SrcLang;
    }
    prompt += " to " + DstLang + ". Use the provided context only to maintain coherence, but do not include the context in the output.\n";
    if (!context.empty()) {
        prompt += "Context:\n" + context + "\n";
    }
    prompt += "Subtitle to translate:\n" + Text;


    // JSON escape
    string escapedPrompt = JsonEscape(prompt);

    // Request data
    string requestData = "{\"model\":\"" + selected_model + "\","
                         "\"messages\":[{\"role\":\"user\",\"content\":\"" + escapedPrompt + "\"}],"
                         "\"max_tokens\":1000,\"temperature\":0}";

    string headers = "Authorization: Bearer " + api_key + "\nContent-Type: application/json";

    // Retry mechanism
    int retryCount = 0;
    while (retryCount < maxRetries) {
        // Send request
        string response = HostUrlGetString(apiUrl, UserAgent, headers, requestData);
        if (response.empty()) {
            HostPrintUTF8("{$CP0=Translation request failed. Retrying...$}\n");
            retryCount++;
            HostSleep(retryDelay); // Delay before retrying
            continue;
        }

        // Parse response
        JsonReader Reader;
        JsonValue Root;
        if (!Reader.parse(response, Root)) {
            HostPrintUTF8("{$CP0=Failed to parse API response. Retrying...$}\n");
            retryCount++;
            HostSleep(retryDelay); // Delay before retrying
            continue;
        }

        JsonValue choices = Root["choices"];
        if (choices.isArray() && choices[0]["message"]["content"].isString()) {
            string translatedText = choices[0]["message"]["content"].asString();

            // 处理多行翻译结果：只取最后一行
            translatedText = translatedText.Trim(); // 去除多余的空格
            if (translatedText.find("\n") != -1) {
                array<string> lines = translatedText.split("\n");
                translatedText = lines[lines.length() - 1].Trim(); // 取最后一行
            }

            // 处理 RTL 语言
            if (DstLang == "fa" || DstLang == "ar" || DstLang == "he") {
                translatedText = UNICODE_RLE + translatedText;
            }

            SrcLang = "UTF8";
            DstLang = "UTF8";
            return translatedText;
        }

        // Handle API errors
        if (Root["error"]["message"].isString()) {
            string errorMessage = Root["error"]["message"].asString();
            HostPrintUTF8("{$CP0=API Error: $}" + errorMessage + "\n");
            retryCount++;
            HostSleep(retryDelay); // Delay before retrying
        } else {
            HostPrintUTF8("{$CP0=Translation failed. Retrying...$}\n");
            retryCount++;
            HostSleep(retryDelay); // Delay before retrying
        }
    }

    // If all retries fail, return an error message
    HostPrintUTF8("{$CP0=Translation failed after maximum retries.$}\n");
    return "Translation failed: Maximum retries reached. ";
}

// Plugin Initialization
void OnInitialize() {
    HostPrintUTF8("{$CP0=DeepSeek translation plugin loaded.$}\n");

    // 从持久化存储中加载 API Key
    api_key = HostLoadString("api_key", "");

    if (!api_key.empty()) {
        HostPrintUTF8("{$CP0=Saved API Key loaded.$}\n");
    } else {
        HostPrintUTF8("{$CP0=No saved API Key found. Please configure it in the settings menu.$}\n");
    }
}

// Plugin Finalization
void OnFinalize() {
    HostPrintUTF8("{$CP0=DeepSeek translation plugin unloaded.$}\n");
}