using Data.SeaHavenIndustries;
using Microsoft.Extensions.Options;
using SeaHaven.DataServices.Interfaces;
using SeaHaven.Services.Configuration;
using SeaHaven.Services.DTOs;
using SeaHaven.Services.Interfaces;
using System.Security.Cryptography;

namespace SeaHaven.Services.Implementation
{
    public class VendorPortalTokenService : IVendorPortalTokenService
    {
        private readonly IVendorDataService _vendorDataService;
        private readonly int _lifetimeDays;

        public VendorPortalTokenService(IVendorDataService vendorDataService, IOptions<VendorPortalOptions> options)
        {
            _vendorDataService = vendorDataService;
            _lifetimeDays = options.Value.TokenLifetimeDays ?? 365;
        }

        public async Task<VendorPortalTokenStateDTO> GetOrCreateActiveTokenAsync(int vendorId, CancellationToken cancellationToken)
        {
            var now = DateTime.UtcNow;
            var existing = await _vendorDataService.GetActiveTokenForVendorAsync(vendorId, cancellationToken);
            if (existing != null) return MapToken(existing);

            var token = new VendorAccessToken
            {
                VendorId = vendorId,
                Token = GenerateToken(),
                IssuedAt = now,
                ExpiresAt = now.AddDays(_lifetimeDays),
                CreatedDate = now
            };
            return MapToken(await _vendorDataService.AddTokenAsync(token, cancellationToken));
        }

        public async Task<VendorPortalSession?> ResolveSessionAsync(string? token, CancellationToken cancellationToken)
        {
            if (string.IsNullOrWhiteSpace(token)) return null;
            var now = DateTime.UtcNow;
            var record = await _vendorDataService.GetTokenWithVendorAsync(token, cancellationToken);

            if (record?.Vendor == null) return null;

            record.LastUsedAt = now;
            await _vendorDataService.SaveChangesAsync(cancellationToken);
            return new VendorPortalSession
            {
                Id = record.Vendor.Id,
                CompanyName = record.Vendor.CompanyName,
                ContactName = record.Vendor.ContactName,
                Email = record.Vendor.Email,
                Phone = record.Vendor.Phone
            };
        }

        public async Task<VendorPortalTokenStateDTO> RotateAsync(int vendorId, CancellationToken cancellationToken)
        {
            var now = DateTime.UtcNow;
            var active = await _vendorDataService.GetRevocableTokensAsync(vendorId, cancellationToken);
            foreach (var t in active) t.RevokedAt = now;
            await _vendorDataService.SaveChangesAsync(cancellationToken);
            return await GetOrCreateActiveTokenAsync(vendorId, cancellationToken);
        }

        public async Task RevokeAllAsync(int vendorId, CancellationToken cancellationToken)
        {
            var now = DateTime.UtcNow;
            var active = await _vendorDataService.GetRevocableTokensAsync(vendorId, cancellationToken);
            foreach (var t in active) t.RevokedAt = now;
            await _vendorDataService.SaveChangesAsync(cancellationToken);
        }

        private static string GenerateToken()
        {
            var bytes = RandomNumberGenerator.GetBytes(32);
            return Convert.ToBase64String(bytes)
                .Replace("+", "-")
                .Replace("/", "_")
                .TrimEnd('=');
        }

        private static VendorPortalTokenStateDTO MapToken(VendorAccessToken token) => new()
        {
            Token = token.Token,
            IssuedAt = token.IssuedAt,
            ExpiresAt = token.ExpiresAt,
            LastUsedAt = token.LastUsedAt
        };
    }
}