using System.Text.Json;
using HrynCo.NotificationService.DAL.Abstract.Providers;
using HrynCo.NotificationService.DAL.Abstract.Repositories;
using HrynCo.NotificationService.DAL.EF.Core;
using HrynCo.NotificationService.DAL.EF.Entities;
using Microsoft.EntityFrameworkCore;

namespace HrynCo.NotificationService.DAL.EF.Repositories;

internal sealed class ProviderRepository : EfRepository<ProviderEntity>, IProviderRepository
{
    public ProviderRepository(NotificationDbContext dbContext) : base(dbContext)
    {
    }

    public async Task<IReadOnlyList<Provider>> GetByServiceAsync(string serviceName, CancellationToken ct = default)
    {
        List<ProviderEntity> entities = await DbSet
            .Where(x => x.ServiceName == serviceName)
            .OrderBy(x => x.Priority)
            .ToListAsync(ct);

        return entities.Select(MapToDomain).ToList();
    }

    public async Task<Provider?> GetByIdAsync(Guid id, CancellationToken ct = default)
    {
        ProviderEntity? entity = await DbSet.FindAsync([id], ct);
        return entity is null ? null : MapToDomain(entity);
    }

    public Task AddAsync(Provider provider, CancellationToken ct = default) =>
        base.AddAsync(MapToEntity(provider), ct);

    public Task UpdateAsync(Provider provider, CancellationToken ct = default)
    {
        ProviderEntity entity = MapToEntity(provider);
        entity.Updated = DateTimeOffset.UtcNow;
        return base.UpdateAsync(entity, ct);
    }

    public async Task DeleteAsync(Provider provider, CancellationToken ct = default)
    {
        ProviderEntity? entity = await DbSet.FindAsync([provider.Id], ct);
        if (entity is not null)
            await base.DeleteAsync(entity, ct);
    }

    private static Provider MapToDomain(ProviderEntity e) => new()
    {
        Id = e.Id,
        ServiceName = e.ServiceName,
        Priority = e.Priority,
        ProviderType = e.ProviderType,
        Settings = DeserializeSettings(e.ProviderType, e.SettingsJson),
        DailyLimit = e.DailyLimit,
        MonthlyLimit = e.MonthlyLimit,
        WarnThresholdPercent = e.WarnThresholdPercent,
        IsActive = e.IsActive,
        Created = e.Created,
        Updated = e.Updated
    };

    private static ProviderEntity MapToEntity(Provider p) => new()
    {
        Id = p.Id,
        ServiceName = p.ServiceName,
        Priority = p.Priority,
        ProviderType = p.ProviderType,
        SettingsJson = JsonSerializer.Serialize(p.Settings),
        DailyLimit = p.DailyLimit,
        MonthlyLimit = p.MonthlyLimit,
        WarnThresholdPercent = p.WarnThresholdPercent,
        IsActive = p.IsActive,
        Created = p.Created,
        Updated = p.Updated
    };

    private static ProviderSettings DeserializeSettings(ProviderType type, string json) => type switch
    {
        ProviderType.Smtp => JsonSerializer.Deserialize<SmtpProviderSettings>(json)
            ?? throw new InvalidOperationException("Failed to deserialize SMTP provider settings."),
        _ => throw new InvalidOperationException($"Unknown provider type: {type}")
    };
}