using System.Security.Claims;
using DysonNetwork.Drive.Data;
using DysonNetwork.Drive.Models;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Http;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using System.Text;

namespace DysonNetwork.Drive.Auth;

public interface IAuthService
{
    Task<string> GenerateJwtToken(Account account);
    Task<Account?> GetAuthenticatedAccountAsync(ClaimsPrincipal user);
    Task<Account?> GetAuthenticatedAccountAsync(HttpContext context);
}

public class AuthService : IAuthService
{
    private readonly IConfiguration _configuration;
    private readonly AppDatabase _db;

    public AuthService(IConfiguration configuration, AppDatabase db)
    {
        _configuration = configuration;
        _db = db;
    }

    public Task<string> GenerateJwtToken(Account account)
    {
        var tokenHandler = new JwtSecurityTokenHandler();
        var key = Encoding.ASCII.GetBytes(_configuration["Jwt:Secret"] ?? throw new InvalidOperationException("JWT Secret not configured"));
        
        var tokenDescriptor = new SecurityTokenDescriptor
        {
            Subject = new ClaimsIdentity(new[] 
            {
                new Claim(ClaimTypes.NameIdentifier, account.Id.ToString()),
                new Claim(ClaimTypes.Name, account.Username),
                new Claim(ClaimTypes.Email, account.Email)
            }),
            Expires = DateTime.UtcNow.AddDays(7),
            SigningCredentials = new SigningCredentials(
                new SymmetricSecurityKey(key), 
                SecurityAlgorithms.HmacSha256Signature)
        };
        
        var token = tokenHandler.CreateToken(tokenDescriptor);
        return Task.FromResult(tokenHandler.WriteToken(token));
    }

    public async Task<Account?> GetAuthenticatedAccountAsync(ClaimsPrincipal user)
    {
        var userIdClaim = user.FindFirst(ClaimTypes.NameIdentifier)?.Value;
        if (string.IsNullOrEmpty(userIdClaim) || !Guid.TryParse(userIdClaim, out var userId))
            return null;

        return await _db.Set<Account>().FindAsync(userId);
    }

    public async Task<Account?> GetAuthenticatedAccountAsync(HttpContext context)
    {
        return await GetAuthenticatedAccountAsync(context.User);
    }
}