autobus-api_old/AutobusApi.Application/Common/Mappings/MappingExtensions.cs

using System.Reflection;
using System.Linq.Dynamic.Core;
using System.Text;
using AutobusApi.Application.Common.Models;
using AutoMapper;
using AutoMapper.QueryableExtensions;
using Microsoft.EntityFrameworkCore;
using System.Dynamic;

namespace AutobusApi.Application.Common.Mappings;

public static class MappingExtensions
{
    public static Task<PaginatedList<T>> PaginatedListAsync<T>(
            this IQueryable<T> queryable,
            int pageNumber,
            int pageSize)
        where T : class
    {
        return PaginatedList<T>.CreateAsync(queryable.AsNoTracking(), pageNumber, pageSize);
    }

    public static Task<List<T>> ProjectToListAsync<T>(
            this IQueryable queryable,
            IConfigurationProvider configuration)
        where T : class
    {
        return queryable.ProjectTo<T>(configuration).AsNoTracking().ToListAsync();
    }

    public static IQueryable<T> ApplySort<T>(
        this IQueryable<T> entities,
        string? orderByQueryString)
    {
        if (!entities.Any() || String.IsNullOrWhiteSpace(orderByQueryString))
        {
            return entities;
        }

        var orderParams = orderByQueryString.Trim().Split(",");
        var propertyInfos = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
        var orderQueryBuilder = new StringBuilder();

        foreach (var param in orderParams)
        {
            if (string.IsNullOrWhiteSpace(param))
            {
                continue;
            }

            var propertyFromQueryName = param[0] == '-' || param[0] == '+' ? param.Substring(1) : param;
            var objectProperty = propertyInfos.FirstOrDefault(pi =>
                pi.Name.Equals(propertyFromQueryName, StringComparison.InvariantCultureIgnoreCase));

            if (objectProperty == null)
            {
                continue;
            }

            var sortingOrder = param[0] == '-' ? "descending" : "ascending";

            orderQueryBuilder.Append($"{objectProperty.Name} {sortingOrder}, ");
        }

        var orderQuery = orderQueryBuilder.ToString().TrimEnd(',', ' ');

        return entities.OrderBy(orderQuery);
    }






    public static IQueryable<ExpandoObject> ShapeData<T>(
        this IQueryable<T> entities,
        string? fieldsString)
    {
        var allProperties = GetAllProperties<T>();
        var requiredProperties = GetRequiredProperties(fieldsString, allProperties);
        return FetchData(entities, requiredProperties);
    }
    
    public static ExpandoObject ShapeData<T>(
        this T entity,
        string? fieldsString)
    {
        var allProperties = GetAllProperties<T>();
        var requiredProperties = GetRequiredProperties(fieldsString, allProperties);
        return FetchDataForEntity(entity, requiredProperties);
    }

    private static IEnumerable<PropertyInfo> GetAllProperties<T>()
    {
        return typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
    }
    
    private static IEnumerable<PropertyInfo> GetRequiredProperties(
        string? fieldsString,
        IEnumerable<PropertyInfo> properties)
    {
        var requiredProperties = new List<PropertyInfo>();

        if (!string.IsNullOrWhiteSpace(fieldsString))
        {
            var fields = fieldsString.Split(',', StringSplitOptions.RemoveEmptyEntries);

            foreach (var field in fields)
            {
                var property = properties.FirstOrDefault(pi => pi.Name.Equals(field.Trim(), StringComparison.InvariantCultureIgnoreCase));

                if (property == null)
                    continue;

                requiredProperties.Add(property);
            }
        }
        else
        {
            requiredProperties = properties.ToList();
        }

        return requiredProperties;
    }
    
    private static IQueryable<ExpandoObject> FetchData<T>(
        IQueryable<T> entities,
        IEnumerable<PropertyInfo> requiredProperties)
    {
        var shapedData = new List<ExpandoObject>();

        foreach (var entity in entities)
        {
            var shapedObject = FetchDataForEntity(entity, requiredProperties);
            shapedData.Add(shapedObject);
        }

        return shapedData.AsQueryable();
    }
    
    private static ExpandoObject FetchDataForEntity<T>(
        T entity,
        IEnumerable<PropertyInfo> requiredProperties)
    {
        var shapedObject = new ExpandoObject();

        foreach (var property in requiredProperties)
        {
            var objectPropertyValue = property.GetValue(entity);
            shapedObject.TryAdd(property.Name, objectPropertyValue);
        }

        return shapedObject;
    }

}