using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Text.Json.Serialization;
using Microsoft.EntityFrameworkCore;
using NodaTime;
using OtpNet;

namespace DysonNetwork.Common.Models;

public enum AccountStatus
{
    PendingActivation,
    Active,
    Suspended,
    Banned,
    Deleted
}

[Index(nameof(Name), IsUnique = true)]
public class Account : ModelBase
{
    public Guid Id { get; set; }
    [MaxLength(256)] public string Name { get; set; } = string.Empty;
    [MaxLength(256)] public string Nick { get; set; } = string.Empty;
    [MaxLength(32)] public string Language { get; set; } = string.Empty;
    public Instant? ActivatedAt { get; set; }
    public bool IsSuperuser { get; set; } = false;

    public Profile Profile { get; set; } = null!;
    public ICollection<AccountContact> Contacts { get; set; } = new List<AccountContact>();
    public ICollection<Badge> Badges { get; set; } = new List<Badge>();

    [JsonIgnore] public ICollection<AccountAuthFactor> AuthFactors { get; set; } = new List<AccountAuthFactor>();
    [JsonIgnore] public ICollection<AccountConnection> Connections { get; set; } = new List<AccountConnection>();
    [JsonIgnore] public ICollection<AuthSession> Sessions { get; set; } = new List<AuthSession>();
    [JsonIgnore] public ICollection<AuthChallenge> Challenges { get; set; } = new List<AuthChallenge>();

    [JsonIgnore] public ICollection<Relationship> OutgoingRelationships { get; set; } = new List<Relationship>();
    [JsonIgnore] public ICollection<Relationship> IncomingRelationships { get; set; } = new List<Relationship>();

    [JsonIgnore] public ICollection<Subscription> Subscriptions { get; set; } = new List<Subscription>();
    
    public AccountStatus Status { get; set; } = AccountStatus.PendingActivation;
    
    [NotMapped]
    public string? Email => GetPrimaryEmail();
    
    public string? GetPrimaryEmail()
    {
        return Contacts
            .FirstOrDefault(c => c.Type == AccountContactType.Email && c.IsPrimary)
            ?.Content;
    }
    
    public void SetPrimaryEmail(string email)
    {
        // Remove primary flag from existing primary email if any
        foreach (var contact in Contacts.Where(c => c.Type == AccountContactType.Email && c.IsPrimary))
        {
            contact.IsPrimary = false;
        }
        
        // Find or create the email contact
        var emailContact = Contacts.FirstOrDefault(c => 
            c.Type == AccountContactType.Email && 
            string.Equals(c.Content, email, StringComparison.OrdinalIgnoreCase));
            
        if (emailContact == null)
        {
            emailContact = new AccountContact
            {
                Type = AccountContactType.Email,
                Content = email,
                IsPrimary = true
            };
            Contacts.Add(emailContact);
        }
        else
        {
            emailContact.IsPrimary = true;
        }
    }
}

public abstract class Leveling
{
    public static readonly List<int> ExperiencePerLevel =
    [
        0, // Level 0
        100, // Level 1
        250, // Level 2
        500, // Level 3
        1000, // Level 4
        2000, // Level 5
        4000, // Level 6
        8000, // Level 7
        16000, // Level 8
        32000, // Level 9
        64000, // Level 10
        128000, // Level 11
        256000, // Level 12
        512000, // Level 13
        1024000 // Level 14
    ];
}

public class Profile : ModelBase
{
    public Guid Id { get; set; }
    [MaxLength(256)] public string? FirstName { get; set; }
    [MaxLength(256)] public string? MiddleName { get; set; }
    [MaxLength(256)] public string? LastName { get; set; }
    [MaxLength(4096)] public string? Bio { get; set; }
    [MaxLength(1024)] public string? Gender { get; set; }
    [MaxLength(1024)] public string? Pronouns { get; set; }
    [MaxLength(1024)] public string? TimeZone { get; set; }
    [MaxLength(1024)] public string? Location { get; set; }
    public Instant? Birthday { get; set; }
    public Instant? LastSeenAt { get; set; }

    [Column(TypeName = "jsonb")] public VerificationMark? Verification { get; set; }
    [Column(TypeName = "jsonb")] public BadgeReferenceObject? ActiveBadge { get; set; }
    [Column(TypeName = "jsonb")] public SubscriptionReferenceObject? StellarMembership { get; set; }

    public int Experience { get; set; } = 0;
    [NotMapped] public int Level => Leveling.ExperiencePerLevel.Count(xp => Experience >= xp) - 1;

    [NotMapped]
    public double LevelingProgress => Level >= Leveling.ExperiencePerLevel.Count - 1
        ? 100
        : (Experience - Leveling.ExperiencePerLevel[Level]) * 100.0 /
          (Leveling.ExperiencePerLevel[Level + 1] - Leveling.ExperiencePerLevel[Level]);

    // Outdated fields, for backward compability
    [MaxLength(32)] public string? PictureId { get; set; }
    [MaxLength(32)] public string? BackgroundId { get; set; }

    [Column(TypeName = "jsonb")] public CloudFileReferenceObject? Picture { get; set; }
    [Column(TypeName = "jsonb")] public CloudFileReferenceObject? Background { get; set; }

    public Guid AccountId { get; set; }
    [JsonIgnore] public Account Account { get; set; } = null!;
}

public class AccountContact : ModelBase
{
    public Guid Id { get; set; }
    public AccountContactType Type { get; set; }
    public Instant? VerifiedAt { get; set; }
    public bool IsPrimary { get; set; } = false;
    [MaxLength(1024)] public string Content { get; set; } = string.Empty;

    public Guid AccountId { get; set; }
    [JsonIgnore] public Account Account { get; set; } = null!;
}

public enum AccountContactType
{
    Email,
    PhoneNumber,
    Address
}

public class AccountAuthFactor : ModelBase
{
    public Guid Id { get; set; }
    public AccountAuthFactorType Type { get; set; }
    [JsonIgnore] [MaxLength(8196)] public string? Secret { get; set; }

    [JsonIgnore]
    [Column(TypeName = "jsonb")]
    public Dictionary<string, object>? Config { get; set; } = new();

    /// <summary>
    /// The trustworthy stands for how safe is this auth factor.
    /// Basically, it affects how many steps it can complete in authentication.
    /// Besides, users may need to use some high-trustworthy level auth factors when confirming some dangerous operations.
    /// </summary>
    public int Trustworthy { get; set; } = 1;

    [MaxLength(100)]
    public string Name { get; set; } = string.Empty;

    [MaxLength(500)]
    public string? Description { get; set; }

    public bool IsDefault { get; set; }
    public bool IsBackup { get; set; }
    public Instant? LastUsedAt { get; set; }
    public Instant? EnabledAt { get; set; }
    public Instant? ExpiredAt { get; set; }
    public Instant? DisabledAt { get; set; }

    [Column(TypeName = "jsonb")]
    public Dictionary<string, object>? Metadata { get; set; }

    public Guid AccountId { get; set; }
    [JsonIgnore] public Account Account { get; set; } = null!;
    
    // Navigation property for related AuthSessions
    [JsonIgnore]
    public virtual ICollection<AuthSession>? Sessions { get; set; }

    public AccountAuthFactor HashSecret(int cost = 12)
    {
        if (Secret == null) return this;
        Secret = BCrypt.Net.BCrypt.HashPassword(Secret, workFactor: cost);
        return this;
    }

    public bool VerifyPassword(string password)
    {
        if (Secret == null)
            throw new InvalidOperationException("Auth factor with no secret cannot be verified with password.");
        switch (Type)
        {
            case AccountAuthFactorType.Password:
            case AccountAuthFactorType.PinCode:
                return BCrypt.Net.BCrypt.Verify(password, Secret);
            case AccountAuthFactorType.TimedCode:
                var otp = new Totp(Base32Encoding.ToBytes(Secret));
                return otp.VerifyTotp(DateTime.UtcNow, password, out _, new VerificationWindow(previous: 5, future: 5));
            case AccountAuthFactorType.EmailCode:
            case AccountAuthFactorType.InAppCode:
            default:
                throw new InvalidOperationException("Unsupported verification type, use CheckDeliveredCode instead.");
        }
    }

    /// <summary>
    /// This dictionary will be returned to the client and should only be set when it just created.
    /// Useful for passing the client some data to finishing setup and recovery code.
    /// </summary>
    [NotMapped]
    public Dictionary<string, object>? CreatedResponse { get; set; }
}

public enum AccountAuthFactorType
{
    Password,
    EmailCode,
    InAppCode,
    TimedCode,
    PinCode
}