using DramaLing.Api.Tests.Integration.Fixtures;
using System.Net;
using System.Net.Http.Json;
using System.Text.Json;

namespace DramaLing.Api.Tests.Integration.EndToEnd;

/// <summary>
/// 使用者資料隔離測試
/// 驗證多用戶環境下的資料安全和隔離機制
/// </summary>
public class DataIsolationTests : IntegrationTestBase
{
    public DataIsolationTests(DramaLingWebApplicationFactory factory) : base(factory)
    {
    }

    [Fact]
    public async Task UserFlashcards_ShouldBeCompletelyIsolated()
    {
        // Arrange
        var user1Client = CreateTestUser1Client();
        var user2Client = CreateTestUser2Client();

        // Act: 兩個用戶分別取得詞卡列表
        var user1Response = await user1Client.GetAsync("/api/flashcards");
        var user2Response = await user2Client.GetAsync("/api/flashcards");

        // Assert
        user1Response.StatusCode.Should().Be(HttpStatusCode.OK);
        user2Response.StatusCode.Should().Be(HttpStatusCode.OK);

        var user1Content = await user1Response.Content.ReadAsStringAsync();
        var user2Content = await user2Response.Content.ReadAsStringAsync();

        var user1Json = JsonSerializer.Deserialize<JsonElement>(user1Content);
        var user2Json = JsonSerializer.Deserialize<JsonElement>(user2Content);

        var user1Flashcards = user1Json.GetProperty("data").EnumerateArray().ToList();
        var user2Flashcards = user2Json.GetProperty("data").EnumerateArray().ToList();

        // 驗證 User1 只能看到自己的詞卡 (hello, beautiful)
        user1Flashcards.Should().HaveCount(2);
        user1Flashcards.Should().Contain(f => f.GetProperty("word").GetString() == "hello");
        user1Flashcards.Should().Contain(f => f.GetProperty("word").GetString() == "beautiful");

        // 驗證 User2 只能看到自己的詞卡 (sophisticated)
        user2Flashcards.Should().HaveCount(1);
        user2Flashcards.Should().Contain(f => f.GetProperty("word").GetString() == "sophisticated");

        // 交叉驗證：確保絕對隔離
        user1Flashcards.Should().NotContain(f => f.GetProperty("word").GetString() == "sophisticated");
        user2Flashcards.Should().NotContain(f => f.GetProperty("word").GetString() == "hello");
        user2Flashcards.Should().NotContain(f => f.GetProperty("word").GetString() == "beautiful");
    }

    [Fact]
    public async Task ReviewData_ShouldBeIsolatedBetweenUsers()
    {
        // Arrange
        var user1Client = CreateTestUser1Client();
        var user2Client = CreateTestUser2Client();

        // Step 1: 用戶1進行複習
        var user1FlashcardId = TestDataSeeder.TestFlashcard1Id;
        await user1Client.PostAsJsonAsync($"/api/flashcards/{user1FlashcardId}/review", new
        {
            confidence = 2,
            wasSkipped = false,
            responseTime = 2000
        });

        // Step 2: 檢查複習記錄隔離
        using var context = GetDbContext();
        var user1Reviews = context.FlashcardReviews
            .Where(r => r.UserId == TestDataSeeder.TestUser1Id)
            .ToList();

        var user2Reviews = context.FlashcardReviews
            .Where(r => r.UserId == TestDataSeeder.TestUser2Id)
            .ToList();

        // Assert: 驗證複習記錄隔離
        user1Reviews.Should().HaveCountGreaterThan(0, "用戶1應該有複習記錄");
        user2Reviews.Should().HaveCount(0, "用戶2不應該有複習記錄（在測試資料中）");

        // 驗證 User1 的複習不會影響 User2 的資料
        user1Reviews.Should().OnlyContain(r => r.UserId == TestDataSeeder.TestUser1Id);
    }

    [Fact]
    public async Task CreateFlashcard_ShouldOnlyBeAccessibleByOwner()
    {
        // Arrange
        var user1Client = CreateTestUser1Client();
        var user2Client = CreateTestUser2Client();

        // Step 1: User1 建立新詞卡
        var newFlashcard = new
        {
            word = "isolation-test",
            translation = "隔離測試",
            definition = "A test for data isolation",
            partOfSpeech = "noun"
        };

        var createResponse = await user1Client.PostAsJsonAsync("/api/flashcards", newFlashcard);
        createResponse.StatusCode.Should().Be(HttpStatusCode.OK);

        var createContent = await createResponse.Content.ReadAsStringAsync();
        var createJson = JsonSerializer.Deserialize<JsonElement>(createContent);
        var newFlashcardId = createJson.GetProperty("data").GetProperty("id").GetString();

        // Step 2: User2 嘗試存取 User1 的詞卡
        var accessResponse = await user2Client.GetAsync($"/api/flashcards/{newFlashcardId}");

        // Assert: User2 應該無法存取 User1 的詞卡
        accessResponse.StatusCode.Should().Be(HttpStatusCode.NotFound, "用戶不應該能存取其他用戶的詞卡");

        // Step 3: User1 應該能正常存取自己的詞卡
        var ownerAccessResponse = await user1Client.GetAsync($"/api/flashcards/{newFlashcardId}");
        ownerAccessResponse.StatusCode.Should().Be(HttpStatusCode.OK, "用戶應該能存取自己的詞卡");
    }

    [Fact]
    public async Task ReviewStats_ShouldBeUserSpecific()
    {
        // Arrange
        var user1Client = CreateTestUser1Client();
        var user2Client = CreateTestUser2Client();

        // Act: 獲取各用戶的複習統計
        var user1StatsResponse = await user1Client.GetAsync("/api/flashcards/review-stats");
        var user2StatsResponse = await user2Client.GetAsync("/api/flashcards/review-stats");

        // Assert
        user1StatsResponse.StatusCode.Should().Be(HttpStatusCode.OK);
        user2StatsResponse.StatusCode.Should().Be(HttpStatusCode.OK);

        var user1StatsContent = await user1StatsResponse.Content.ReadAsStringAsync();
        var user2StatsContent = await user2StatsResponse.Content.ReadAsStringAsync();

        // 統計資料應該不同 (因為用戶有不同的詞卡和複習歷史)
        user1StatsContent.Should().NotBe(user2StatsContent, "不同用戶的統計資料應該不同");

        // 解析並驗證統計資料結構
        var user1Stats = JsonSerializer.Deserialize<JsonElement>(user1StatsContent);
        var user2Stats = JsonSerializer.Deserialize<JsonElement>(user2StatsContent);

        user1Stats.GetProperty("success").GetBoolean().Should().BeTrue();
        user2Stats.GetProperty("success").GetBoolean().Should().BeTrue();
    }

    [Fact]
    public async Task MasteredFlashcards_ShouldOnlyAffectOwner()
    {
        // Arrange
        var user1Client = CreateTestUser1Client();
        var user2Client = CreateTestUser2Client();
        var user1FlashcardId = TestDataSeeder.TestFlashcard1Id;

        // Step 1: User1 標記詞卡為已掌握
        var masteredResponse = await user1Client.PostAsync($"/api/flashcards/{user1FlashcardId}/mastered", null);
        masteredResponse.StatusCode.Should().Be(HttpStatusCode.OK);

        // Step 2: 驗證只影響 User1 的複習間隔
        using var context = GetDbContext();
        var user1Review = context.FlashcardReviews
            .FirstOrDefault(r => r.FlashcardId == user1FlashcardId && r.UserId == TestDataSeeder.TestUser1Id);

        var user2Reviews = context.FlashcardReviews
            .Where(r => r.UserId == TestDataSeeder.TestUser2Id)
            .ToList();

        // Assert
        user1Review.Should().NotBeNull("User1 應該有複習記錄");
        user1Review!.SuccessCount.Should().BeGreaterThan(0, "User1 的成功次數應該增加");

        // User2 的複習記錄不應受影響
        user2Reviews.Should().NotContain(r => r.FlashcardId == user1FlashcardId, "User2 不應該有 User1 詞卡的複習記錄");
    }
}