Method Download

src/Features/Export/ExportController.cs:48–160

([FromQuery] DownloadRequest body)

    }

    [HttpGet("/api/_export/download")]
    public async Task<IActionResult> Download([FromQuery] DownloadRequest body)
    {
        if (!body.StartDate.HasValue || !body.EndDate.HasValue)
        {
            return BadRequest();
        }

        var startDate = body.StartDate.Value;
        var endDate = body.EndDate.Value;

        var (formatName, contentType, fileExtension) = GetFormat(body.Format);
        var appName = UnsafeCharacters().Replace(body.AppName, "").ToLower();
        var fileName = $"{appName}-{body.BuildMode.ToLower()}-{startDate:yyyy-MM-dd}.{fileExtension}";

        var countQuery = $@"SELECT COUNT(*) as event_count
                       FROM events
                       WHERE app_id = '{GetAppId(body.BuildMode, body.AppId)}'
                       AND timestamp BETWEEN '{startDate:yyyy-MM-dd HH:mm:ss}' AND '{endDate:yyyy-MM-dd HH:mm:ss}'
                       FORMAT JSON";

        using var stream = await _queryClient.StreamResponseAsync(countQuery, HttpContext.RequestAborted);
        long eventCount = 0;
        using var reader = new StreamReader(stream);
        var jsonString = await reader.ReadToEndAsync();
        using var doc = JsonDocument.Parse(jsonString);
        var root = doc.RootElement;

        if (root.TryGetProperty("data", out JsonElement data) &&
            data.GetArrayLength() > 0 &&
            data[0].TryGetProperty("event_count", out JsonElement countElement))
        {
            switch (countElement.ValueKind)
            {
                case JsonValueKind.Number:
                    _ = countElement.TryGetInt64(out eventCount);
                    break;
                case JsonValueKind.String:
                    var countString = countElement.GetString();
                    _ = long.TryParse(countString, out eventCount);
                    break;
                default:
                    throw new InvalidOperationException($"Unexpected event_count type: {countElement.ValueKind}");
            }
        }

        if (formatName == "Parquet")
        {
            var query = $@"SELECT timestamp, user_id, session_id,
                              event_name,
                              replace(replace(string_props, '\u0022', '\''), '\u0027', '\'') as string_props,
                              numeric_props,
                              os_name, os_version,
                              locale, app_version, app_build_number,
                              engine_name, engine_version,
                              country_code, {COUNTRY_NAME_COLUMN}, region_name
                       FROM events
                       WHERE app_id = '{GetAppId(body.BuildMode, body.AppId)}'