using Microsoft.EntityFrameworkCore;
using LittleShop.Data;
using LittleShop.Models;
using LittleShop.DTOs;

namespace LittleShop.Services;

public class VariantCollectionService : IVariantCollectionService
{
    private readonly LittleShopContext _context;

    public VariantCollectionService(LittleShopContext context)
    {
        _context = context;
    }

    public async Task<IEnumerable<VariantCollectionDto>> GetAllVariantCollectionsAsync()
    {
        return await _context.VariantCollections
            .OrderByDescending(vc => vc.CreatedAt)
            .Select(vc => new VariantCollectionDto
            {
                Id = vc.Id,
                Name = vc.Name,
                PropertiesJson = vc.PropertiesJson,
                IsActive = vc.IsActive,
                CreatedAt = vc.CreatedAt,
                UpdatedAt = vc.UpdatedAt
            })
            .ToListAsync();
    }

    public async Task<VariantCollectionDto?> GetVariantCollectionByIdAsync(Guid id)
    {
        var collection = await _context.VariantCollections
            .FirstOrDefaultAsync(vc => vc.Id == id);

        if (collection == null) return null;

        return new VariantCollectionDto
        {
            Id = collection.Id,
            Name = collection.Name,
            PropertiesJson = collection.PropertiesJson,
            IsActive = collection.IsActive,
            CreatedAt = collection.CreatedAt,
            UpdatedAt = collection.UpdatedAt
        };
    }

    public async Task<VariantCollectionDto> CreateVariantCollectionAsync(CreateVariantCollectionDto createDto)
    {
        var collection = new VariantCollection
        {
            Id = Guid.NewGuid(),
            Name = createDto.Name,
            PropertiesJson = string.IsNullOrWhiteSpace(createDto.PropertiesJson) ? "[]" : createDto.PropertiesJson,
            IsActive = true,
            CreatedAt = DateTime.UtcNow,
            UpdatedAt = DateTime.UtcNow
        };

        _context.VariantCollections.Add(collection);
        await _context.SaveChangesAsync();

        return new VariantCollectionDto
        {
            Id = collection.Id,
            Name = collection.Name,
            PropertiesJson = collection.PropertiesJson,
            IsActive = collection.IsActive,
            CreatedAt = collection.CreatedAt,
            UpdatedAt = collection.UpdatedAt
        };
    }

    public async Task<bool> UpdateVariantCollectionAsync(Guid id, UpdateVariantCollectionDto updateDto)
    {
        var collection = await _context.VariantCollections.FindAsync(id);
        if (collection == null) return false;

        if (!string.IsNullOrEmpty(updateDto.Name))
        {
            collection.Name = updateDto.Name;
        }

        if (updateDto.PropertiesJson != null)
        {
            collection.PropertiesJson = string.IsNullOrWhiteSpace(updateDto.PropertiesJson) ? "[]" : updateDto.PropertiesJson;
        }

        if (updateDto.IsActive.HasValue)
        {
            collection.IsActive = updateDto.IsActive.Value;
        }

        collection.UpdatedAt = DateTime.UtcNow;
        await _context.SaveChangesAsync();
        return true;
    }

    public async Task<bool> DeleteVariantCollectionAsync(Guid id)
    {
        var collection = await _context.VariantCollections.FindAsync(id);
        if (collection == null) return false;

        collection.IsActive = false;
        collection.UpdatedAt = DateTime.UtcNow;
        await _context.SaveChangesAsync();
        return true;
    }
}