using System.Text.Json.Serialization;

// ---------- POST /analyze 的请求 ----------
public sealed class AnalyzeRequest
{
    [JsonPropertyName("text")]
    public required string Text { get; init; }

    [JsonPropertyName("language")]
    public required string Language { get; init; }

    // 只找这几类实体。留空表示全找，但会明显变慢。
    [JsonPropertyName("entities")]
    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public string[]? Entities { get; init; }

    // 低于这个分数的结果直接丢弃。
    [JsonPropertyName("score_threshold")]
    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public double? ScoreThreshold { get; init; }
}

// ---------- analyzer 返回的每一条 ----------
public sealed class AnalyzerResult
{
    [JsonPropertyName("entity_type")]
    public required string EntityType { get; init; }

    [JsonPropertyName("start")]
    public int Start { get; init; }

    [JsonPropertyName("end")]
    public int End { get; init; }

    [JsonPropertyName("score")]
    public double Score { get; init; }
}

public sealed class OperatorConfig
{
    [JsonPropertyName("type")]
    public required string Type { get; init; }

    // 各 operator 自己的参数，序列化时会平铺到同一层
    [JsonExtensionData]
    public Dictionary<string, object>? Params { get; init; }
}

public sealed class AnonymizeRequest
{
    [JsonPropertyName("text")]
    public required string Text { get; init; }

    [JsonPropertyName("analyzer_results")]
    public required IReadOnlyList<AnalyzerResult> AnalyzerResults { get; init; }

    // key 是实体类型，或者 "DEFAULT" 表示兜底规则
    [JsonPropertyName("anonymizers")]
    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public Dictionary<string, OperatorConfig>? Anonymizers { get; init; }
}

public sealed class AnonymizeResponse
{
    [JsonPropertyName("text")]
    public required string Text { get; init; }

    [JsonPropertyName("items")]
    public IReadOnlyList<AnonymizedItem> Items { get; init; } = [];
}

public sealed class AnonymizedItem
{
    [JsonPropertyName("entity_type")] public required string EntityType { get; init; }
    [JsonPropertyName("start")]       public int Start { get; init; }
    [JsonPropertyName("end")]         public int End { get; init; }
    [JsonPropertyName("text")]        public string? Text { get; init; }
    [JsonPropertyName("operator")]    public string? Operator { get; init; }
}

public interface IPiiScrubber
{
    Task<string> ScrubAsync(string text, CancellationToken ct = default);
}

internal sealed class PresidioScrubber(
    IHttpClientFactory httpClientFactory,
    ILogger<PresidioScrubber> logger) : IPiiScrubber
{
    // 默认规则：手机号遮蔽前 7 位，人名换成占位符，其余一律换成类型名
    private static readonly Dictionary<string, OperatorConfig> DefaultOperators = new()
    {
        ["PHONE_NUMBER"] = new OperatorConfig
        {
            Type = "mask",
            Params = new Dictionary<string, object>
            {
                ["masking_char"] = "*",
                ["chars_to_mask"] = 7,
                ["from_end"] = false,
            },
        },
        ["PERSON"] = new OperatorConfig
        {
            Type = "replace",
            Params = new Dictionary<string, object> { ["new_value"] = "[某用户]" },
        },
        ["DEFAULT"] = new OperatorConfig { Type = "replace" },
    };

    public async Task<string> ScrubAsync(string text, CancellationToken ct = default)
    {
        if (string.IsNullOrWhiteSpace(text))
            return text;

        // 第一步：找
        var analyzer = httpClientFactory.CreateClient("presidio-analyzer");
        var analyzeResponse = await analyzer.PostAsJsonAsync("/analyze",
            new AnalyzeRequest
            {
                Text = text,
                Language = "en",
                ScoreThreshold = 0.5,
            }, ct);

        analyzeResponse.EnsureSuccessStatusCode();
        var findings = await analyzeResponse.Content
            .ReadFromJsonAsync<List<AnalyzerResult>>(ct) ?? [];

        // 什么都没找到，就别白跑第二趟了
        if (findings.Count == 0)
            return text;

        logger.LogDebug("Presidio 命中 {Count} 个实体，类型：{Types}",
            findings.Count,
            string.Join(", ", findings.Select(f => f.EntityType).Distinct()));

        // 第二步：改
        var anonymizer = httpClientFactory.CreateClient("presidio-anonymizer");
        var anonymizeResponse = await anonymizer.PostAsJsonAsync("/anonymize",
            new AnonymizeRequest
            {
                Text = text,
                AnalyzerResults = findings,
                Anonymizers = DefaultOperators,
            }, ct);

        anonymizeResponse.EnsureSuccessStatusCode();
        var result = await anonymizeResponse.Content
            .ReadFromJsonAsync<AnonymizeResponse>(ct);

        return result?.Text ?? text;
    }
}

// Program.cs
builder.Services.AddHttpClient("presidio-analyzer", client =>
    {
        client.BaseAddress = new Uri(builder.Configuration["Presidio:AnalyzerUrl"]!);
        client.Timeout = TimeSpan.FromSeconds(30);   // 冷启动会慢，别设太短
    })
    .AddStandardResilienceHandler();                 // 重试 + 熔断 + 超时

builder.Services.AddHttpClient("presidio-anonymizer", client =>
    {
        client.BaseAddress = new Uri(builder.Configuration["Presidio:AnonymizerUrl"]!);
        client.Timeout = TimeSpan.FromSeconds(10);
    })
    .AddStandardResilienceHandler();

builder.Services.AddSingleton<IPiiScrubber, PresidioScrubber>();

app.MapPost("/tickets", async (TicketDto dto, IPiiScrubber scrubber, ILogger<Program> log) =>
{
    var safe = await scrubber.ScrubAsync(dto.Description);
    log.LogInformation("收到工单：{Description}", safe);
    return Results.Ok();
});

var text = "🎉 联系我 13800138000";
// Python 那边看到的长度：14
// C# 的 text.Length：15   ← 🎉 占了两个 UTF-16 单元

Entities = ["PHONE_NUMBER", "EMAIL_ADDRESS"],

var hotline = new[] { "400-820-8820" };
findings = findings
    .Where(f => !hotline.Contains(text[f.Start..f.End]))
    .ToList();