using System;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Text.Json;
using System.Text.Json.Serialization;
using NodaTime;

namespace DysonNetwork.Common.Models;

/// <summary>
/// Represents a connection between an account and an authentication provider
/// </summary>
public class AccountConnection : ModelBase
{
    /// <summary>
    /// The account ID this connection is associated with
    /// </summary>
    public string? AccountId { get; set; }

    /// <summary>
    /// The authentication provider (e.g., "google", "github")
    /// </summary>
    [Required]
    [MaxLength(50)]
    public string Provider { get; set; } = null!;

    /// <summary>
    /// The unique identifier for the user from the provider
    /// </summary>
    [Required]
    [MaxLength(256)]
    public string ProvidedIdentifier { get; set; } = null!;

    /// <summary>
    /// Alias for ProvidedIdentifier for backward compatibility
    /// </summary>
    [NotMapped]
    public string ProviderId
    {
        get => ProvidedIdentifier;
        set => ProvidedIdentifier = value;
    }

    /// <summary>
    /// Display name for the connection
    /// </summary>
    [MaxLength(100)]
    public string? DisplayName { get; set; }

    /// <summary>
    /// OAuth access token from the provider
    /// </summary>
    public string? AccessToken { get; set; }

    /// <summary>
    /// OAuth refresh token from the provider (if available)
    /// </summary>
    public string? RefreshToken { get; set; }

    /// <summary>
    /// When the access token expires (if available)
    /// </summary>
    public Instant? ExpiresAt { get; set; }

    /// <summary>
    /// Raw profile data from the provider
    /// </summary>
    [Column(TypeName = "jsonb")]
    public JsonDocument? ProfileData { get; set; }

    /// <summary>
    /// When the connection was first established
    /// </summary>
    public Instant ConnectedAt { get; set; } = SystemClock.Instance.GetCurrentInstant();

    /// <summary>
    /// Additional metadata about the connection
    /// </summary>
    [Column(TypeName = "jsonb")]
    public JsonDocument? Metadata { get; set; }

    /// <summary>
    /// Gets a value indicating whether the connection is currently active
    /// </summary>
    [NotMapped]
    /// <summary>
    /// When the connection was first established
    /// </summary>
    public Instant CreatedAt { get; set; }

    /// <summary>
    /// When the connection was last used
    /// </summary>
    public Instant? LastUsedAt { get; set; }

    /// <summary>
    /// Navigation property for the associated account
    /// </summary>
    [ForeignKey(nameof(AccountId))]
    [JsonIgnore]
    public virtual Account? Account { get; set; }

    /// <summary>
    /// Updates the connection's tokens and related metadata
    /// </summary>
    /// <param name="accessToken">The new access token</param>
    /// <param name="refreshToken">The new refresh token, if any</param>
    /// <param name="expiresAt">When the access token expires, if any</param>
    public void UpdateTokens(string? accessToken, string? refreshToken, Instant? expiresAt)
    {
        AccessToken = accessToken;
        
        if (!string.IsNullOrEmpty(refreshToken))
        {
            RefreshToken = refreshToken;
        }
        
        if (expiresAt.HasValue)
        {
            ExpiresAt = expiresAt;
        }
        
        LastUsedAt = SystemClock.Instance.GetCurrentInstant();
    }
}