using MiniExcelLibs;
using Admin.NET.Plugin.AiDOP.Entity.DataPlatform;

namespace Admin.NET.Plugin.AiDOP.DataPlatform.FileImport;

public sealed class MdpExcelTemplateService : ITransient
{
    public async Task<IActionResult> BuildAsync(MdpEntity entity, IReadOnlyList<MdpFieldMapping> mappings)
    {
        var cols = mappings
            .Where(m => !m.TargetField.Equals("tenant_id", StringComparison.OrdinalIgnoreCase)
                        && !m.SourceField.StartsWith("CONST:", StringComparison.OrdinalIgnoreCase)
                        && !m.SourceField.StartsWith("TO_JSON", StringComparison.OrdinalIgnoreCase)
                        && !m.SourceField.StartsWith("COALESCE", StringComparison.OrdinalIgnoreCase))
            .OrderBy(m => m.SortOrder)
            .ToList();
        if (cols.Count == 0 && !string.IsNullOrWhiteSpace(entity.BizKeyExpr))
        {
            var i = 0;
            cols = entity.BizKeyExpr.Split(',', StringSplitOptions.TrimEntries)
                .Select(name => new MdpFieldMapping { SourceField = name, TargetField = name, IsRequired = 1, SortOrder = ++i * 10 })
                .ToList();
        }

        var headers = new Dictionary<string, object?>();
        foreach (var c in cols)
        {
            var title = c.IsRequired == 1 ? $"{c.SourceField} ★" : c.SourceField;
            headers[title] = null;
        }

        var memory = new MemoryStream();
        await memory.SaveAsAsync(new[] { headers }, sheetName: ReadSheet(entity));
        memory.Seek(0, SeekOrigin.Begin);
        return new FileStreamResult(memory, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
        {
            FileDownloadName = $"{entity.EntityCode}-template.xlsx"
        };
    }

    public static string ReadSheet(MdpEntity entity)
    {
        if (string.IsNullOrWhiteSpace(entity.FileConfigJson))
            return "数据";
        try
        {
            using var doc = System.Text.Json.JsonDocument.Parse(entity.FileConfigJson);
            if (doc.RootElement.TryGetProperty("sheetName", out var s))
                return s.GetString() ?? "数据";
        }
        catch { /* ignore */ }
        return "数据";
    }
}