using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using RmmAgent.Models;
using RmmAgent.Security;
using System.Net.Http.Json;

namespace RmmAgent.Services;

public class EnrollmentService
{
    private readonly ILogger<EnrollmentService> _logger;
    private readonly IConfiguration _config;
    private readonly ConfigStore _configStore;
    private readonly MachineIdProvider _machineId;
    private readonly InventoryCollector _inventory;

    public EnrollmentService(
        ILogger<EnrollmentService> logger,
        IConfiguration config,
        ConfigStore configStore,
        MachineIdProvider machineId,
        InventoryCollector inventory)
    {
        _logger = logger;
        _config = config;
        _configStore = configStore;
        _machineId = machineId;
        _inventory = inventory;
    }

    public async Task EnrollAsync(CancellationToken ct)
    {
        var serverUrl = _config["Rmm:ServerUrl"]?.TrimEnd('/');
        var token = _config["Rmm:EnrollmentToken"];

        if (string.IsNullOrWhiteSpace(serverUrl) || string.IsNullOrWhiteSpace(token))
            throw new InvalidOperationException("ServerUrl ou EnrollmentToken manquant");

        var sysInfo = _inventory.CollectBasic();
        var machineId = _machineId.GetMachineId();

        using var http = new HttpClient { Timeout = TimeSpan.FromSeconds(60) };

        var payload = new EnrollRequest(
            EnrollmentToken: token!,
            Hostname: Environment.MachineName,
            MachineId: machineId,
            OsName: sysInfo.OsName,
            OsVersion: sysInfo.OsVersion,
            OsBuild: sysInfo.OsBuild,
            CpuModel: sysInfo.CpuModel,
            RamTotalMb: sysInfo.RamTotalMb,
            AgentVersion: typeof(EnrollmentService).Assembly.GetName().Version?.ToString() ?? "1.0.0"
        );

        _logger.LogInformation("Enrollment at {Url} as {Hostname}", serverUrl, payload.Hostname);

        var response = await http.PostAsJsonAsync($"{serverUrl}/agent/enroll", payload, ct);

        if (!response.IsSuccessStatusCode)
        {
            var err = await response.Content.ReadAsStringAsync(ct);
            throw new InvalidOperationException($"Enrollment failed ({response.StatusCode}): {err}");
        }

        var result = await response.Content.ReadFromJsonAsync<EnrollResponse>(cancellationToken: ct);
        if (result is null) throw new InvalidOperationException("Empty enrollment response");

        _configStore.SaveAgentToken(result.AgentToken, result.AgentId);
        _logger.LogInformation("Enrolled as agent {AgentId}", result.AgentId);
    }
}