using System.Text.Json;
using Microsoft.EntityFrameworkCore;
using ProposalSystem.Application.DTOs;
using ProposalSystem.Application.Interfaces;
using ProposalSystem.Domain.Entities;
using ProposalSystem.Infrastructure.Data;

namespace ProposalSystem.Infrastructure.Services;

public class CustomerService : ICustomerService
{
    private readonly ProposalDbContext _db;

    public CustomerService(ProposalDbContext db)
    {
        _db = db;
    }

    public async Task<IReadOnlyList<CustomerResponse>> SearchAsync(string? query, CancellationToken ct = default)
    {
        var q = _db.Customers.AsQueryable();

        if (!string.IsNullOrWhiteSpace(query))
        {
            var search = query.ToLower();
            q = q.Where(c => c.Name.ToLower().Contains(search));
        }

        var customers = await q
            .OrderBy(c => c.Name)
            .Take(50)
            .ToListAsync(ct);

        return customers.Select(c => new CustomerResponse(
            c.Id,
            c.Name,
            DeserializeAddresses(c.Addresses),
            c.CreatedAt
        )).ToList();
    }

    public async Task<CustomerResponse> CreateAsync(CreateCustomerRequest request, CancellationToken ct = default)
    {
        var now = DateTime.UtcNow;
        var customer = new Customer
        {
            Id = Guid.NewGuid(),
            Name = request.Name,
            Addresses = request.Addresses != null ? JsonSerializer.Serialize(request.Addresses) : null,
            CreatedAt = now,
            UpdatedAt = now,
        };

        _db.Customers.Add(customer);
        await _db.SaveChangesAsync(ct);

        return new CustomerResponse(
            customer.Id,
            customer.Name,
            request.Addresses ?? new List<string>(),
            customer.CreatedAt
        );
    }

    private static List<string> DeserializeAddresses(string? json)
    {
        if (string.IsNullOrEmpty(json)) return new List<string>();
        return JsonSerializer.Deserialize<List<string>>(json) ?? new List<string>();
    }
}