// Export CDR (Call Detail Records) from a CodeB tenant to CSV for BI ingest.
// European Digital Identity Wallet-enabled tenants use the same key surface.
// [compliance-archive-cookbook 2026-07-23]
//
// Endpoint live-verified in signal.ashx:
//   GET signal.ashx?cdrlog=1&date=YYYY-MM-DD&limit=N

using System;
using System.IO;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;

class ExportCdr
{
    static readonly string[] Cols = new[]{
        "recordedUtc","startUtc","endUtc","direction","trunk",
        "callingNumber","calledNumber","durationSec","answered","outcome","releaseReason"};

    static string CsvCell(string v)
    {
        if (v == null) return "";
        return (v.IndexOfAny(new[]{',','"','\n'}) >= 0)
            ? "\"" + v.Replace("\"","\"\"") + "\""
            : v;
    }

    static async Task Main()
    {
        var tenant = Environment.GetEnvironmentVariable("CODEB_TENANT") ?? "https://<CODEB_TENANT_HOST>";
        var apiKey = Environment.GetEnvironmentVariable("CODEB_API_KEY");
        var date   = Environment.GetEnvironmentVariable("DATE") ?? DateTime.UtcNow.AddDays(-1).ToString("yyyy-MM-dd");
        var outF   = Environment.GetEnvironmentVariable("OUT_FILE") ?? $"cdr-{date}.csv";
        if (string.IsNullOrEmpty(apiKey)) { Console.Error.WriteLine("CODEB_API_KEY not set"); Environment.Exit(2); }

        using var http = new HttpClient { BaseAddress = new Uri(tenant) };
        http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);
        var body = await http.GetStringAsync($"/signal.ashx?cdrlog=1&date={date}&limit=5000");
        using var doc = JsonDocument.Parse(body);
        if (!doc.RootElement.TryGetProperty("events", out var events)) return;

        using var sw = new StreamWriter(outF, false, new UTF8Encoding(false));
        sw.WriteLine(string.Join(",", Cols));
        int n = 0;
        foreach (var e in events.EnumerateArray())
        {
            var sb = new StringBuilder();
            for (int i = 0; i < Cols.Length; i++)
            {
                if (i > 0) sb.Append(',');
                sb.Append(CsvCell(e.TryGetProperty(Cols[i], out var v) ? v.ToString() : ""));
            }
            sw.WriteLine(sb.ToString());
            n++;
        }
        Console.WriteLine($"[done] {n} rows -> {outF}");
    }
}