using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using DysonNetwork.Common.Models;
using DysonNetwork.Pass.Data;
using DysonNetwork.Pass.Features.Auth.Models;
using Microsoft.EntityFrameworkCore;
using NodaTime;
using Account = DysonNetwork.Common.Models.Account;
using AuthTokens = DysonNetwork.Common.Models.AuthTokens;

namespace DysonNetwork.Pass.Features.Auth.Services;

public class AccountService : IAccountService
{
    private readonly PassDatabase _db;
    private readonly IClock _clock;

    public AccountService(PassDatabase db, IClock clock)
    {
        _db = db;
        _clock = clock;
    }

    public async Task<Account> CreateAccount(Common.Models.OidcUserInfo userInfo)
    {
        if (string.IsNullOrEmpty(userInfo.Email))
            throw new ArgumentException("Email is required for account creation", nameof(userInfo));

        var now = _clock.GetCurrentInstant();
        var account = new Models.Account
        {
            Id = Guid.NewGuid(),
            Email = userInfo.Email,
            Name = userInfo.Name ?? userInfo.Email.Split('@')[0],
            CreatedAt = now,
            UpdatedAt = now,
            Status = "Active"
        };

        _db.Accounts.Add(account);
        await _db.SaveChangesAsync();

        return new Account
        {
            Id = account.Id.ToString(),
            Email = account.Email,
            Name = account.Name,
            CreatedAt = account.CreatedAt,
            UpdatedAt = account.UpdatedAt,
            Status = account.Status
        };
    }

    public async Task<Account?> FindByEmailAsync(string email)
    {
        if (string.IsNullOrEmpty(email))
            return null;

        var account = await _db.Accounts
            .FirstOrDefaultAsync(a => a.Email == email);
        
        if (account == null)
            return null;
            
        return new Account
        {
            Id = account.Id.ToString(),
            Email = account.Email,
            Name = account.Name,
            CreatedAt = account.CreatedAt,
            UpdatedAt = account.UpdatedAt,
            Status = account.Status
        };
    }

    public async Task<Account?> FindByIdAsync(string accountId)
    {
        if (string.IsNullOrEmpty(accountId) || !Guid.TryParse(accountId, out var id))
            return null;

        var account = await _db.Accounts
            .FirstOrDefaultAsync(a => a.Id == id);
            
        if (account == null)
            return null;
            
        return new Account
        {
            Id = account.Id.ToString(),
            Email = account.Email,
            Name = account.Name,
            CreatedAt = account.CreatedAt,
            UpdatedAt = account.UpdatedAt,
            Status = account.Status
        };
    }

    public async Task UpdateAccount(Account account)
    {
        if (!Guid.TryParse(account.Id, out var id))
            throw new ArgumentException("Invalid account ID format", nameof(account));
            
        var existingAccount = await _db.Accounts.FindAsync(id);
        if (existingAccount == null)
            throw new InvalidOperationException($"Account with ID {account.Id} not found");
            
        existingAccount.Name = account.Name;
        existingAccount.Email = account.Email;
        existingAccount.UpdatedAt = _clock.GetCurrentInstant();
        existingAccount.Status = account.Status;
        
        _db.Accounts.Update(existingAccount);
        await _db.SaveChangesAsync();
    }

    public async Task<Account> FindOrCreateAccountAsync(Common.Models.OidcUserInfo userInfo, string provider)
    {
        if (string.IsNullOrEmpty(userInfo.Email))
            throw new ArgumentException("Email is required for account creation", nameof(userInfo));

        // Check if account exists by email
        var account = await FindByEmailAsync(userInfo.Email);
        if (account != null)
            return account;

        // Create new account if not found
        return await CreateAccount(userInfo);
    }

    public async Task<Account?> GetAccountByIdAsync(Guid accountId)
    {
        var account = await _db.Accounts
            .FirstOrDefaultAsync(a => a.Id == accountId);
            
        if (account == null)
            return null;
            
        return new Account
        {
            Id = account.Id.ToString(),
            Email = account.Email,
            Name = account.Name,
            CreatedAt = account.CreatedAt,
            UpdatedAt = account.UpdatedAt,
            Status = account.Status
        };
    }

    public async Task<AuthTokens> GenerateAuthTokensAsync(Account account, string sessionId)
    {
        if (!Guid.TryParse(sessionId, out var sessionGuid))
            throw new ArgumentException("Invalid session ID format", nameof(sessionId));
            
        var now = _clock.GetCurrentInstant();
        var accessTokenLifetime = Duration.FromHours(1);
        var accessTokenExpiry = now.Plus(accessTokenLifetime);

        // In a real implementation, you would generate proper JWT tokens here
        // This is a simplified version for demonstration
        var accessToken = $"access_token_{Guid.NewGuid()}";
        var refreshToken = $"refresh_token_{Guid.NewGuid()}";

        // Create or update the session
        var session = await _db.AuthSessions.FindAsync(sessionGuid);
        if (session != null)
        {
            session.UpdateTokens(accessToken, refreshToken, accessTokenLifetime);
            _db.AuthSessions.Update(session);
            await _db.SaveChangesAsync();
        }

        return new AuthTokens
        {
            AccessToken = accessToken,
            RefreshToken = refreshToken,
            ExpiresIn = (int)accessTokenLifetime.TotalSeconds,
            TokenType = "Bearer"
        };
    }
}