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

namespace HrynCo.NotificationService.DAL.EF.Repositories;

internal sealed class EmailChannelRepository : EfRepository<NotificationDbContext, EmailChannelEntity>, IEmailChannelRepository
{
    public EmailChannelRepository(NotificationDbContext dbContext) : base(dbContext)
    {
    }

    public async Task<IReadOnlyList<EmailChannel>> GetAllAsync(CancellationToken ct = default)
    {
        var entities = await DbSet
            .AsNoTracking()
            .OrderBy(x => x.ServiceName)
            .ThenBy(x => x.Priority)
            .ToListAsync(ct);

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

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

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

    public async Task<IReadOnlyList<ChannelWithUsage>> GetAllWithUsageSummaryAsync(
        DateOnly today, CancellationToken ct = default)
    {
        var rows = await DbSet
            .AsNoTracking()
            .OrderBy(c => c.ServiceName)
            .ThenBy(c => c.Priority)
            .Select(c => new
            {
                Channel = c,
                DailySent = c.UsageRecords
                    .Where(u => u.Date == today)
                    .Sum(u => (int?)u.SentCount) ?? 0,
                MonthlySent = c.UsageRecords
                    .Where(u => u.Date.Year == today.Year && u.Date.Month == today.Month)
                    .Sum(u => (int?)u.SentCount) ?? 0
            })
            .ToListAsync(ct);

        return rows
            .Select(r => new ChannelWithUsage(MapToDomain(r.Channel), r.DailySent, r.MonthlySent))
            .ToList();
    }

    public async Task<EmailChannel?> GetByIdAsync(Guid id, CancellationToken ct = default)
    {
        EmailChannelEntity? entity = await DbSet.AsNoTracking().FirstOrDefaultAsync(x => x.Id == id, ct);
        return entity is null ? null : MapToDomain(entity);
    }

    public Task AddAsync(EmailChannel channel, CancellationToken ct = default)
    {
        return base.AddAsync(MapToEntity(channel), ct);
    }

    public Task UpdateAsync(EmailChannel channel, CancellationToken ct = default)
    {
        EmailChannelEntity entity = MapToEntity(channel);
        entity.Updated = DateTimeOffset.UtcNow;
        Update(entity);
        return Task.CompletedTask;
    }

    public async Task DeleteAsync(EmailChannel channel, CancellationToken ct = default)
    {
        EmailChannelEntity? entity = await DbSet.FindAsync([channel.Id], ct);
        if (entity is not null)
        {
            Delete(entity);
        }
    }

    private static EmailChannel MapToDomain(EmailChannelEntity e)
    {
        return new EmailChannel
        {
            Id = e.Id,
            ServiceName = e.ServiceName,
            Priority = e.Priority,
            EmailChannelType = e.EmailChannelType,
            Settings = DeserializeSettings(e.EmailChannelType, e.SettingsJson),
            DailyLimit = e.DailyLimit,
            MonthlyLimit = e.MonthlyLimit,
            WarnThresholdPercent = e.WarnThresholdPercent,
            IsActive = e.IsActive,
            Created = e.Created,
            Updated = e.Updated
        };
    }

    private static EmailChannelEntity MapToEntity(EmailChannel p)
    {
        return new EmailChannelEntity
        {
            Id = p.Id,
            ServiceName = p.ServiceName,
            Priority = p.Priority,
            EmailChannelType = p.EmailChannelType,
            SettingsJson = JsonSerializer.Serialize(p.Settings, p.Settings.GetType()),
            DailyLimit = p.DailyLimit,
            MonthlyLimit = p.MonthlyLimit,
            WarnThresholdPercent = p.WarnThresholdPercent,
            IsActive = p.IsActive,
            Created = p.Created,
            Updated = p.Updated
        };
    }

    private static EmailChannelSettings DeserializeSettings(EmailChannelType type, string json)
    {
        return type switch
        {
            EmailChannelType.Smtp => JsonSerializer.Deserialize<SmtpChannelSettings>(json)
                                 ?? throw new InvalidOperationException(
                                     "Failed to deserialize SMTP EmailChannel settings."),
            _ => throw new InvalidOperationException($"Unknown or undefined email channel type: {type}")
        };
    }
}