449 lines
16 KiB
C#
449 lines
16 KiB
C#
using System.Text.Json;
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using System.Text;
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using DramaLing.Api.Models.Entities;
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namespace DramaLing.Api.Services;
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public interface IGeminiService
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{
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Task<List<GeneratedCard>> GenerateCardsAsync(string inputText, string extractionType, int cardCount);
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Task<SentenceAnalysisResponse> AnalyzeSentenceAsync(string inputText, string userLevel = "A2");
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}
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public class GeminiService : IGeminiService
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{
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private readonly HttpClient _httpClient;
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private readonly IConfiguration _configuration;
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private readonly ILogger<GeminiService> _logger;
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private readonly string _apiKey;
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public GeminiService(HttpClient httpClient, IConfiguration configuration, ILogger<GeminiService> logger)
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{
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_httpClient = httpClient;
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_configuration = configuration;
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_logger = logger;
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_apiKey = Environment.GetEnvironmentVariable("DRAMALING_GEMINI_API_KEY")
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?? _configuration["AI:GeminiApiKey"] ?? "";
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}
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public async Task<List<GeneratedCard>> GenerateCardsAsync(string inputText, string extractionType, int cardCount)
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{
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try
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{
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if (string.IsNullOrEmpty(_apiKey) || _apiKey == "your-gemini-api-key-here")
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{
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throw new InvalidOperationException("Gemini API key not configured");
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}
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var prompt = BuildPrompt(inputText, extractionType, cardCount);
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var response = await CallGeminiApiAsync(prompt);
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return ParseGeneratedCards(response);
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}
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catch (Exception ex)
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{
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_logger.LogError(ex, "Error generating cards with Gemini API");
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throw;
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}
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}
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/// <summary>
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/// 句子分析和翻譯 - 調用 Gemini AI
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/// </summary>
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public async Task<SentenceAnalysisResponse> AnalyzeSentenceAsync(string inputText, string userLevel = "A2")
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{
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try
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{
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if (string.IsNullOrEmpty(_apiKey) || _apiKey == "your-gemini-api-key-here")
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{
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throw new InvalidOperationException("Gemini API key not configured");
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}
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var targetRange = CEFRLevelService.GetTargetLevelRange(userLevel);
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var prompt = $@"
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請分析以下英文句子，提供翻譯和個人化詞彙分析：
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句子：{inputText}
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學習者程度：{userLevel}
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請按照以下JSON格式回應，不要包含任何其他文字：
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{{
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""translation"": ""自然流暢的繁體中文翻譯"",
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""grammarCorrection"": {{
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""hasErrors"": false,
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""originalText"": ""{inputText}"",
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""correctedText"": null,
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""corrections"": []
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}},
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""highValueWords"": [""重要詞彙1"", ""重要詞彙2""],
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""wordAnalysis"": {{
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""單字"": {{
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""translation"": ""中文翻譯"",
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""definition"": ""英文定義"",
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""partOfSpeech"": ""詞性"",
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""pronunciation"": ""音標"",
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""isHighValue"": true,
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""difficultyLevel"": ""CEFR等級"",
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""example"": ""實用的例句展示該詞彙的真實用法"",
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""exampleTranslation"": ""例句的自然中文翻譯""
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}}
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}}
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}}
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要求：
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1. 翻譯要自然流暢，符合中文語法
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2. **基於學習者程度({userLevel})，標記 {targetRange} 等級的詞彙為重點學習**
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3. **為每個詞彙提供實用的例句，展示真實語境和用法**
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4. **例句要有學習價值，避免簡單重複的句型**
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5. 如有語法錯誤請指出並修正
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6. 確保JSON格式正確
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例句要求：
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- 使用真實場景（工作、學習、日常生活）
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- 展示詞彙的實際搭配和用法
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- 適合學習者程度，不要太簡單或太複雜
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- 中文翻譯要自然流暢
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重點學習判定邏輯：
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- 學習者程度: {userLevel}
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- 重點學習範圍: {targetRange}
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- 太簡單的詞彙(≤{userLevel})不要標記為重點學習
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- 太難的詞彙謹慎標記
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- 重點關注適合學習者程度的詞彙
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";
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var response = await CallGeminiApiAsync(prompt);
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return ParseSentenceAnalysisResponse(response);
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}
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catch (Exception ex)
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{
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_logger.LogError(ex, "Error analyzing sentence with Gemini API");
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throw;
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}
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}
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private string BuildPrompt(string inputText, string extractionType, int cardCount)
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{
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var template = extractionType == "vocabulary" ? VocabularyExtractionPrompt : SmartExtractionPrompt;
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return template
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.Replace("{cardCount}", cardCount.ToString())
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.Replace("{inputText}", inputText);
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}
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private async Task<string> CallGeminiApiAsync(string prompt)
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{
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var requestBody = new
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{
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contents = new[]
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{
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new
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{
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parts = new[]
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{
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new { text = prompt }
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}
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}
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}
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};
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var json = JsonSerializer.Serialize(requestBody);
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var content = new StringContent(json, Encoding.UTF8, "application/json");
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var response = await _httpClient.PostAsync(
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$"https://generativelanguage.googleapis.com/v1beta/models/gemini-1.5-flash-latest:generateContent?key={_apiKey}",
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content);
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if (!response.IsSuccessStatusCode)
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{
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var errorContent = await response.Content.ReadAsStringAsync();
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_logger.LogError("Gemini API error: {StatusCode} - {Content}", response.StatusCode, errorContent);
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throw new HttpRequestException($"Gemini API request failed: {response.StatusCode}");
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}
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var responseContent = await response.Content.ReadAsStringAsync();
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var geminiResponse = JsonSerializer.Deserialize<JsonElement>(responseContent);
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if (geminiResponse.TryGetProperty("candidates", out var candidates) &&
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candidates.GetArrayLength() > 0 &&
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candidates[0].TryGetProperty("content", out var contentElement) &&
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contentElement.TryGetProperty("parts", out var parts) &&
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parts.GetArrayLength() > 0 &&
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parts[0].TryGetProperty("text", out var textElement))
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{
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return textElement.GetString() ?? "";
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}
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throw new InvalidOperationException("Invalid response format from Gemini API");
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}
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private List<GeneratedCard> ParseGeneratedCards(string response)
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{
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try
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{
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// 清理回應文本
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var cleanText = response.Trim();
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cleanText = cleanText.Replace("```json", "").Replace("```", "").Trim();
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// 如果不是以 { 開始，嘗試找到 JSON 部分
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if (!cleanText.StartsWith("{"))
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{
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var jsonStart = cleanText.IndexOf("{");
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if (jsonStart >= 0)
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{
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cleanText = cleanText[jsonStart..];
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}
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}
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var jsonResponse = JsonSerializer.Deserialize<JsonElement>(cleanText);
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if (!jsonResponse.TryGetProperty("cards", out var cardsElement) || cardsElement.ValueKind != JsonValueKind.Array)
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{
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throw new InvalidOperationException("Response does not contain cards array");
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}
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var cards = new List<GeneratedCard>();
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foreach (var cardElement in cardsElement.EnumerateArray())
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{
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var card = new GeneratedCard
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{
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Word = GetStringProperty(cardElement, "word"),
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PartOfSpeech = GetStringProperty(cardElement, "part_of_speech"),
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Pronunciation = GetStringProperty(cardElement, "pronunciation"),
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Translation = GetStringProperty(cardElement, "translation"),
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Definition = GetStringProperty(cardElement, "definition"),
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Synonyms = GetArrayProperty(cardElement, "synonyms"),
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Example = GetStringProperty(cardElement, "example"),
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ExampleTranslation = GetStringProperty(cardElement, "example_translation"),
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DifficultyLevel = GetStringProperty(cardElement, "difficulty_level")
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};
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if (!string.IsNullOrEmpty(card.Word) && !string.IsNullOrEmpty(card.Translation))
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{
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cards.Add(card);
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}
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}
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return cards;
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}
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catch (Exception ex)
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{
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_logger.LogError(ex, "Error parsing generated cards response: {Response}", response);
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throw new InvalidOperationException($"Failed to parse AI response: {ex.Message}");
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}
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}
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/// <summary>
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/// 解析 Gemini AI 句子分析響應
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/// </summary>
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private SentenceAnalysisResponse ParseSentenceAnalysisResponse(string response)
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{
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try
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{
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var cleanText = response.Trim().Replace("```json", "").Replace("```", "").Trim();
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if (!cleanText.StartsWith("{"))
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{
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var jsonStart = cleanText.IndexOf("{");
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if (jsonStart >= 0)
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{
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cleanText = cleanText[jsonStart..];
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}
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}
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var jsonResponse = JsonSerializer.Deserialize<JsonElement>(cleanText);
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return new SentenceAnalysisResponse
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{
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Translation = GetStringProperty(jsonResponse, "translation"),
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Explanation = GetStringProperty(jsonResponse, "explanation"),
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HighValueWords = GetArrayProperty(jsonResponse, "highValueWords"),
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WordAnalysis = ParseWordAnalysisFromJson(jsonResponse),
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GrammarCorrection = ParseGrammarCorrectionFromJson(jsonResponse)
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};
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}
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catch (Exception ex)
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{
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_logger.LogError(ex, "Error parsing sentence analysis response: {Response}", response);
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throw new InvalidOperationException($"Failed to parse AI sentence analysis: {ex.Message}");
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}
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}
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private Dictionary<string, WordAnalysisResult> ParseWordAnalysisFromJson(JsonElement jsonResponse)
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{
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var result = new Dictionary<string, WordAnalysisResult>();
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if (jsonResponse.TryGetProperty("wordAnalysis", out var wordAnalysisElement))
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{
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foreach (var property in wordAnalysisElement.EnumerateObject())
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{
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var word = property.Name;
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var analysis = property.Value;
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result[word] = new WordAnalysisResult
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{
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Word = word,
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Translation = GetStringProperty(analysis, "translation"),
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Definition = GetStringProperty(analysis, "definition"),
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PartOfSpeech = GetStringProperty(analysis, "partOfSpeech"),
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Pronunciation = GetStringProperty(analysis, "pronunciation"),
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IsHighValue = analysis.TryGetProperty("isHighValue", out var isHighValueElement) && isHighValueElement.GetBoolean(),
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DifficultyLevel = GetStringProperty(analysis, "difficultyLevel"),
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Example = GetStringProperty(analysis, "example"),
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ExampleTranslation = GetStringProperty(analysis, "exampleTranslation")
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};
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}
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}
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return result;
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}
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private GrammarCorrectionResult ParseGrammarCorrectionFromJson(JsonElement jsonResponse)
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{
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if (jsonResponse.TryGetProperty("grammarCorrection", out var grammarElement))
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{
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return new GrammarCorrectionResult
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{
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HasErrors = grammarElement.TryGetProperty("hasErrors", out var hasErrorsElement) && hasErrorsElement.GetBoolean(),
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OriginalText = GetStringProperty(grammarElement, "originalText"),
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CorrectedText = GetStringProperty(grammarElement, "correctedText"),
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Corrections = new List<GrammarCorrection>() // 簡化
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};
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}
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return new GrammarCorrectionResult
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{
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HasErrors = false,
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OriginalText = "",
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CorrectedText = null,
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Corrections = new List<GrammarCorrection>()
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};
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}
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private static string GetStringProperty(JsonElement element, string propertyName)
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{
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return element.TryGetProperty(propertyName, out var prop) ? prop.GetString() ?? "" : "";
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}
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private static List<string> GetArrayProperty(JsonElement element, string propertyName)
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{
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var result = new List<string>();
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if (element.TryGetProperty(propertyName, out var arrayElement) && arrayElement.ValueKind == JsonValueKind.Array)
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{
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foreach (var item in arrayElement.EnumerateArray())
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{
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result.Add(item.GetString() ?? "");
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}
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}
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return result;
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}
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// Prompt 模板
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private const string VocabularyExtractionPrompt = @"
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從以下英文文本中萃取 {cardCount} 個最重要的詞彙，為每個詞彙生成詞卡資料。
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輸入文本：
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{inputText}
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請按照以下 JSON 格式回應，不要包含任何其他文字或代碼塊標記：
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{
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""cards"": [
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{
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""word"": ""單字原型"",
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""part_of_speech"": ""詞性(n./v./adj./adv.等)"",
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""pronunciation"": ""IPA音標"",
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""translation"": ""繁體中文翻譯"",
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""definition"": ""英文定義(保持A1-A2程度)"",
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""synonyms"": [""同義詞1"", ""同義詞2""],
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""example"": ""例句(使用原文中的句子或生成新句子)"",
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""example_translation"": ""例句中文翻譯"",
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""difficulty_level"": ""CEFR等級(A1/A2/B1/B2/C1/C2)""
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}
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]
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}
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要求：
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1. 選擇最有學習價值的詞彙
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2. 定義要簡單易懂，適合英語學習者
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3. 例句要實用且符合語境
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4. 確保 JSON 格式正確
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5. 同義詞最多2個，選擇常用的";
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private const string SmartExtractionPrompt = @"
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分析以下英文文本，識別片語、俚語和常用表達，生成 {cardCount} 個學習卡片：
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輸入文本：
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{inputText}
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重點關注：
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1. 片語和俚語
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2. 文化相關表達
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3. 語境特定用法
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4. 慣用語和搭配
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請按照相同的 JSON 格式回應...";
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}
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// 支援類型
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public class GeneratedCard
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{
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public string Word { get; set; } = string.Empty;
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public string PartOfSpeech { get; set; } = string.Empty;
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public string Pronunciation { get; set; } = string.Empty;
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public string Translation { get; set; } = string.Empty;
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public string Definition { get; set; } = string.Empty;
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public List<string> Synonyms { get; set; } = new();
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public string Example { get; set; } = string.Empty;
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public string ExampleTranslation { get; set; } = string.Empty;
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public string DifficultyLevel { get; set; } = string.Empty;
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}
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// 新增句子分析相關類型
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public class SentenceAnalysisResponse
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{
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public string Translation { get; set; } = string.Empty;
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public string Explanation { get; set; } = string.Empty;
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public List<string> HighValueWords { get; set; } = new();
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public Dictionary<string, WordAnalysisResult> WordAnalysis { get; set; } = new();
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public GrammarCorrectionResult GrammarCorrection { get; set; } = new();
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}
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public class WordAnalysisResult
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{
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public string Word { get; set; } = string.Empty;
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public string Translation { get; set; } = string.Empty;
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public string Definition { get; set; } = string.Empty;
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public string PartOfSpeech { get; set; } = string.Empty;
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public string Pronunciation { get; set; } = string.Empty;
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public bool IsHighValue { get; set; }
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public string DifficultyLevel { get; set; } = string.Empty;
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public string? Example { get; set; }
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public string? ExampleTranslation { get; set; }
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}
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public class GrammarCorrectionResult
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{
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public bool HasErrors { get; set; }
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public string OriginalText { get; set; } = string.Empty;
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public string? CorrectedText { get; set; }
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public List<GrammarCorrection> Corrections { get; set; } = new();
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}
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public class GrammarCorrection
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{
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public string ErrorType { get; set; } = string.Empty;
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public string Original { get; set; } = string.Empty;
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public string Corrected { get; set; } = string.Empty;
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public string Reason { get; set; } = string.Empty;
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} |