using BakeryErp.Infrastructure.Database;

namespace BakeryErp.Infrastructure.Repositories;

public sealed class SupplierRepository
{
    private readonly DatabaseOptions _options;

    public SupplierRepository(DatabaseOptions options)
    {
        _options = options;
    }

    public IReadOnlyList<LocalSupplier> List()
    {
        return LocalDataStoreFile.Load(_options)
            .Suppliers
            .OrderByDescending(static supplier => supplier.IsActive)
            .ThenBy(static supplier => supplier.Code)
            .ToList();
    }

    public LocalSupplier? Find(Guid id)
    {
        return LocalDataStoreFile.Load(_options)
            .Suppliers
            .FirstOrDefault(supplier => supplier.Id == id);
    }

    public SaveSupplierResult Save(LocalSupplier supplier)
    {
        var store = LocalDataStoreFile.Load(_options);
        var normalizedCode = supplier.Code?.Trim().ToUpperInvariant() ?? string.Empty;
        var normalizedName = supplier.Name?.Trim() ?? string.Empty;

        if (string.IsNullOrWhiteSpace(normalizedCode) || string.IsNullOrWhiteSpace(normalizedName))
        {
            return SaveSupplierResult.ValidationError("供應商代號與名稱為必填。");
        }

        var duplicatedCode = store.Suppliers.Any(existing =>
            existing.Id != supplier.Id &&
            string.Equals(existing.Code, normalizedCode, StringComparison.OrdinalIgnoreCase));
        if (duplicatedCode)
        {
            return SaveSupplierResult.ValidationError("供應商代號已存在，請改用其他代號。");
        }

        var existingSupplier = store.Suppliers.FirstOrDefault(existing => existing.Id == supplier.Id);
        if (existingSupplier is null)
        {
            supplier.Id = supplier.Id == Guid.Empty ? Guid.NewGuid() : supplier.Id;
            supplier.Code = normalizedCode;
            supplier.Name = normalizedName;
            supplier.TaxId = BlankToNull(supplier.TaxId);
            supplier.ContactName = BlankToNull(supplier.ContactName);
            supplier.Phone = BlankToNull(supplier.Phone);
            supplier.Email = BlankToNull(supplier.Email);
            supplier.Address = BlankToNull(supplier.Address);
            supplier.PaymentTermDays = Math.Max(0, supplier.PaymentTermDays);
            supplier.CreatedAt = DateTime.UtcNow;
            supplier.IsActive = true;
            store.Suppliers.Add(supplier);
        }
        else
        {
            existingSupplier.Code = normalizedCode;
            existingSupplier.Name = normalizedName;
            existingSupplier.TaxId = BlankToNull(supplier.TaxId);
            existingSupplier.ContactName = BlankToNull(supplier.ContactName);
            existingSupplier.Phone = BlankToNull(supplier.Phone);
            existingSupplier.Email = BlankToNull(supplier.Email);
            existingSupplier.Address = BlankToNull(supplier.Address);
            existingSupplier.PaymentTermDays = Math.Max(0, supplier.PaymentTermDays);
            existingSupplier.UpdatedAt = DateTime.UtcNow;
        }

        LocalDataStoreFile.Save(_options, store);
        return SaveSupplierResult.Success();
    }

    public void SetActive(Guid id, bool isActive)
    {
        var store = LocalDataStoreFile.Load(_options);
        var supplier = store.Suppliers.FirstOrDefault(existing => existing.Id == id);
        if (supplier is null)
        {
            return;
        }

        supplier.IsActive = isActive;
        supplier.UpdatedAt = DateTime.UtcNow;
        LocalDataStoreFile.Save(_options, store);
    }

    private static string? BlankToNull(string? value)
    {
        return string.IsNullOrWhiteSpace(value) ? null : value.Trim();
    }
}

public sealed record SaveSupplierResult(bool IsSuccess, string? ErrorMessage)
{
    public static SaveSupplierResult Success() => new(true, null);
    public static SaveSupplierResult ValidationError(string message) => new(false, message);
}