using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace LD_SysInfo.Services
{
    /// <summary>
    /// Scheduled task that collects Windows update history using osquery
    /// and sends it to the backend API
    /// </summary>
    public class PatchComplianceTask : ScheduledTask
    {
        private readonly AppConfig _config;
        private readonly ApiClient _apiClient;

        public override string TaskName => "PatchCompliance";

        public override TimeSpan Interval =>
            TimeSpan.FromHours(_config.PatchCompliance.CheckIntervalHours);

        public PatchComplianceTask(AppConfig config, ApiClient apiClient)
        {
            _config = config;
            _apiClient = apiClient;

            // Initialize LastRun from config if available
            LastRun = _config.PatchCompliance.LastCheckTime;
        }

        public override bool ShouldRun()
        {
            // Don't run if disabled in config
            if (!_config.PatchCompliance.Enabled)
                return false;

            return base.ShouldRun();
        }

        public override async Task ExecuteAsync()
        {
            try
            {
                // Query windows_update_history from osquery
                var updates = OsqueryService.Query(@"
                    SELECT
                        date,
                        title,
                        update_id
                    FROM windows_update_history
                    ORDER BY date DESC;
                ");

                if (!updates.Any())
                {
                    LogInfo("No Windows update history found.");
                    return;
                }

                // Transform to API-friendly format
                var patchData = updates.Select(u => new
                {
                    date = u.GetValueOrDefault("date"),
                    title = u.GetValueOrDefault("title"),
                    updateId = u.GetValueOrDefault("update_id")
                }).ToList();

                LogInfo($"Collected {patchData.Count} Windows updates.");

                // Send to API
                await _apiClient.PostPatchComplianceAsync(patchData);

                // Update config with last check time
                _config.PatchCompliance.LastCheckTime = DateTime.Now;
                SaveConfig();

                LogInfo("Patch compliance data sent successfully.");
            }
            catch (Exception ex)
            {
                LogError($"PatchComplianceTask failed: {ex.Message}");
                throw;
            }
        }

        private void SaveConfig()
        {
            try
            {
                var configPath = System.IO.Path.Combine(AppContext.BaseDirectory, "config.json");
                var json = Newtonsoft.Json.JsonConvert.SerializeObject(_config, Newtonsoft.Json.Formatting.Indented);
                System.IO.File.WriteAllText(configPath, json);
            }
            catch (Exception ex)
            {
                LogError($"Failed to save config: {ex.Message}");
            }
        }

        private void LogInfo(string message)
        {
            if (!_config.EnableLogging) return;

            try
            {
                var logDir = System.IO.Path.Combine(
                    Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
                    "PSG-Oversight"
                );
                System.IO.Directory.CreateDirectory(logDir);
                var logPath = System.IO.Path.Combine(logDir, "patch_compliance.log");
                System.IO.File.AppendAllText(logPath, $"[{DateTime.Now}] INFO: {message}\n");
            }
            catch { }
        }

        private void LogError(string message)
        {
            try
            {
                var logDir = System.IO.Path.Combine(
                    Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
                    "PSG-Oversight"
                );
                System.IO.Directory.CreateDirectory(logDir);
                var logPath = System.IO.Path.Combine(logDir, "patch_compliance.log");
                System.IO.File.AppendAllText(logPath, $"[{DateTime.Now}] ERROR: {message}\n");
            }
            catch { }
        }
    }
}