Approval Workflow Logic

-- On rejection: update entity status
UPDATE procurement.purchase_requests
SET status = 'REJECTED',
    rejection_count = rejection_count + 1,
    last_rejected_at = NOW(),
    last_rejected_by = @rejecterId,
    updated_at = NOW()
WHERE id = @prId;

-- On re-submission after revision:
-- 1. Entity status → PENDING_APPROVAL
-- 2. Create fresh approval records (new cycle)
-- 3. Previous approval records kept with approval_cycle number for audit

public class ApprovalService
{
    public async Task SubmitForApprovalAsync(string entityType, long entityId, decimal amount)
    {
        // 1. Get applicable matrix
        var matrix = await GetApprovalMatrixAsync(entityType, amount);

        // 2. Get approval levels
        var levels = await _context.ApprovalLevels
            .Where(l => l.MatrixId == matrix.Id)
            .OrderBy(l => l.LevelNumber)
            .ToListAsync();

        // 3. Create approval records
        foreach (var level in levels)
        {
            var approverId = await ResolveApprover(level);
            var delegateId = await CheckDelegation(approverId, entityType);

            await CreateApprovalRecord(entityType, entityId, level.LevelNumber,
                                        delegateId ?? approverId);
        }

        // 4. Notify first level approver
        await NotifyApprover(entityType, entityId, 1);
    }

    public async Task ProcessApprovalAsync(string entityType, long entityId,
                                             int level, bool approved, string remarks)
    {
        // 1. Update approval record
        await UpdateApprovalRecord(entityType, entityId, level, approved, remarks);

        // 2. Check final status
        var status = await CalculateFinalStatus(entityType, entityId);

        // 3. Update entity
        await UpdateEntityStatus(entityType, entityId, status);

        // 4. Notify next level or complete
        if (status == "PENDING" && approved)
            await NotifyApprover(entityType, entityId, level + 1);
        else
            await NotifyOriginator(entityType, entityId, status);
    }
}