using DXPBLL.Common;
using DXPBLL.VendorPo;
using DXPDAL.Common;
using DXPDAL.Kyc;
using DXPDAL.VendorPo;
using GB5Shared.Telemetry;

namespace DXPBLL.VendorInvoice;

public class VendorInvoiceBLL : IVendorInvoiceBLL
{
    private readonly IVendorPoDAL          _VendorPoDAL;
    private readonly IPartyKycDAL          _KycDAL;
    private readonly IMmIntegrationService _MmIntegration;
    private readonly IDXPSystemContext     _SystemContext;
    private readonly IDXPHubNotifier       _HubNotifier;

    public VendorInvoiceBLL(
        IVendorPoDAL vendorPoDAL,
        IPartyKycDAL kycDAL,
        IMmIntegrationService mmIntegration,
        IDXPSystemContext systemContext,
        IDXPHubNotifier hubNotifier)
    {
        _VendorPoDAL   = vendorPoDAL;
        _KycDAL        = kycDAL;
        _MmIntegration = mmIntegration;
        _SystemContext = systemContext;
        _HubNotifier   = hubNotifier;
    }

    public async Task<(string Message, VendorPoDTO? Invoice)> SubmitInvoiceAsync(
        int dxpPartyId, int poMMHeadId, int localPartyId, int ouId, int invoiceBizTransactionTypeId,
        int dxpPartyBranchLinkId, string? invoiceRemarks,
        int tenantId, string databaseName, byte databaseType, int actingDxpUserId,
        CancellationToken ct)
    {
        var tenantLogin = _SystemContext.GetTenantLogin(tenantId, databaseName, databaseType, localPartyId, actingDxpUserId);

        var links = await _VendorPoDAL.GetPartyOuLinksAsync(localPartyId, tenantLogin, ct).ConfigureAwait(false);
        if (!links.Any(l => l.OUId == ouId))
            throw new InvalidOperationException("This party is not linked to the requested Organization Unit.");

        // GST invoicing requires a verified GSTIN — reject unverified/rejected/missing KYC rather
        // than let an unverified vendor submit a document Compliance would later have to untangle.
        var systemLogin = _SystemContext.GetSystemLogin(actingDxpUserId);
        var kyc = await _KycDAL.GetActiveByBranchLinkAsync(dxpPartyBranchLinkId, systemLogin, ct).ConfigureAwait(false);
        if (kyc is null || kyc.VerificationStatus != 2)
            throw new InvalidOperationException("KYC for this branch must be verified before submitting an invoice.");

        var po = await _VendorPoDAL.GetPoHeaderAsync(poMMHeadId, localPartyId, tenantLogin, ct).ConfigureAwait(false)
            ?? throw new InvalidOperationException("Purchase Order not found for this party.");
        var poDetails = (await _VendorPoDAL.GetPoDetailsAsync(poMMHeadId, tenantLogin, ct).ConfigureAwait(false)).ToList();
        if (poDetails.Count == 0)
            throw new InvalidOperationException("Purchase Order has no line items to invoice.");

        GB5Trace.Step("submit-dxp-invoice", new { poMMHeadId, invoiceBizTransactionTypeId });

        // Same generic MM document-save pattern as AsnBLL — see its comments for the full
        // rationale (metadata-driven BizTransactionType, response-is-a-message-not-an-id, etc.).
        // Phase 1 invoices the full PO-ordered quantity/rate per line; partial/adjusted invoicing
        // is a Phase 2 enhancement.
        var request = new MmDocumentSaveRequestDTO
        {
            BizTransactionTypeId  = invoiceBizTransactionTypeId,
            OUId                  = ouId,
            PartyId               = localPartyId,
            MMHeadReferenceNumber = po.MMHeadNumber,
            MMHeadReferenceDate   = po.MMHeadDate,
            MMHeadRemarks         = invoiceRemarks,
            MMDetailArray = poDetails.Select(d => new MmDocumentDetailSaveRequestDTO
            {
                MMDetailSlNo                = d.MMDetailSlNo,
                ItemId                      = d.ItemId,
                MMDetailTransactionQuantity = d.MMDetailTransactionQuantity,
                TransactionUOMId            = d.TransactionUOMId,
                MMDetailRate                = d.MMDetailRate
            }).ToList()
        };

        var outcome = await _MmIntegration.SaveMmDocumentAsync(request, tenantLogin, ct).ConfigureAwait(false);
        if (!outcome.Success)
        {
            GB5Trace.MarkFailed("submit-dxp-invoice-mm-save-failed", new InvalidOperationException(outcome.Error));
            return ($"Invoice submission failed: {outcome.Error}", null);
        }

        var invoice = await _VendorPoDAL.FindNewlyCreatedDocumentAsync(
            po.MMHeadNumber, invoiceBizTransactionTypeId, localPartyId, tenantLogin, ct).ConfigureAwait(false);

        if (invoice != null)
        {
            await _HubNotifier.NotifyAsync(new DXPNotificationDTO
            {
                EventType       = DXPNotificationEventTypes.InvoiceSubmitted,
                DxpPartyId      = dxpPartyId,
                MMHeadId        = invoice.MMHeadId,
                ReferenceNumber = invoice.MMHeadNumber,
                Message         = $"Invoice {invoice.MMHeadNumber} submitted for PO {po.MMHeadNumber}.",
                OccurredOn      = DateTime.UtcNow
            }, ct).ConfigureAwait(false);
        }

        return ($"Invoice submitted successfully{(invoice != null ? $" with number {invoice.MMHeadNumber}" : string.Empty)}.", invoice);
    }
}