using Disco.Plugins.ADCompare.Features;
using Disco.Plugins.ADCompare.Models;
using Disco.Services.Plugins;
using Newtonsoft.Json;
using System;
using System.Text;
using System.Web.Mvc;

namespace Disco.Plugins.ADCompare.WebHandler
{
    public class ADCompareWebHandler : PluginWebHandler
    {
        public override ActionResult ExecuteAction(string ActionName)
        {
            switch (ActionName?.ToLower())
            {
                case null:
                case "":
                case "index":
                    return Index();
                case "compare":
                    return Compare();
                case "compareuser":
                    return CompareUser();
                case "export":
                    return ExportCsv();
                default:
                    return new HttpNotFoundResult();
            }
        }

        /// <summary>
        /// Landing page with a button to run comparison
        /// </summary>
        private ActionResult Index()
        {
            var html = BuildIndexPage();
            return new ContentResult
            {
                Content = html,
                ContentType = "text/html",
                ContentEncoding = Encoding.UTF8
            };
        }

        /// <summary>
        /// Run full comparison and return results as JSON
        /// </summary>
        private ActionResult Compare()
        {
            var service = new ADCompareService(Database);
            var summary = service.CompareAllUsers();

            return new ContentResult
            {
                Content = JsonConvert.SerializeObject(summary, Formatting.Indented),
                ContentType = "application/json",
                ContentEncoding = Encoding.UTF8
            };
        }

        /// <summary>
        /// Compare a single user - expects ?userId=DOMAIN\username
        /// </summary>
        private ActionResult CompareUser()
        {
            var userId = HostController.Request.QueryString["userId"];
            if (string.IsNullOrWhiteSpace(userId))
            {
                return new HttpStatusCodeResult(400, "userId parameter required");
            }

            var user = Database.Users.Find(userId);
            if (user == null)
            {
                return new HttpStatusCodeResult(404, "User not found in Disco");
            }

            var service = new ADCompareService(Database);
            var result = service.CompareUser(user);

            return new ContentResult
            {
                Content = JsonConvert.SerializeObject(result, Formatting.Indented),
                ContentType = "application/json",
                ContentEncoding = Encoding.UTF8
            };
        }

        /// <summary>
        /// Export comparison results as CSV
        /// </summary>
        private ActionResult ExportCsv()
        {
            var service = new ADCompareService(Database);
            var summary = service.CompareAllUsers();

            var sb = new StringBuilder();
            sb.AppendLine("UserId,DisplayName,FoundInAD,ADDisabled,MismatchedFields,Details");

            foreach (var result in summary.Results)
            {
                var mismatchFields = result.HasMismatches
                    ? string.Join("; ", result.Mismatches.ConvertAll(m => m.FieldName))
                    : "None";

                var details = result.HasMismatches
                    ? string.Join("; ", result.Mismatches.ConvertAll(m =>
                        $"{m.FieldName}: Disco='{m.DiscoValue}' AD='{m.ADValue}'"))
                    : "";

                sb.AppendLine($"\"{CsvEscape(result.UserId)}\",\"{CsvEscape(result.DisplayName)}\",{result.UserFoundInAD},{result.ADAccountDisabled},\"{CsvEscape(mismatchFields)}\",\"{CsvEscape(details)}\"");
            }

            var fileName = $"AD_Compare_{DateTime.Now:yyyyMMdd_HHmmss}.csv";

            HostController.Response.Headers.Add("Content-Disposition", $"attachment; filename=\"{fileName}\"");

            return new ContentResult
            {
                Content = sb.ToString(),
                ContentType = "text/csv",
                ContentEncoding = Encoding.UTF8
            };
        }

        private string CsvEscape(string value)
        {
            if (string.IsNullOrEmpty(value)) return "";
            return value.Replace("\"", "\"\"");
        }

        #region HTML Page Builder

        private string BuildIndexPage()
        {
            var pluginUrl = Url.Action(MVC.API.Disco.Plugin.PluginWebAction(Manifest.Id, null));

            return $@"
<div id='adcompare-container'>
    <h2>AD Compare - User Detail Comparison</h2>
    <p>Compare Active Directory user details against Disco ICT records to identify mismatches.</p>

    <div style='margin: 15px 0;'>
        <button id='btnRunCompare' class='btn btn-primary' onclick='runComparison()'>
            <i class='fa fa-refresh'></i> Run Full Comparison
        </button>
        <button id='btnExport' class='btn btn-default' onclick='exportCsv()' style='margin-left: 10px;' disabled>
            <i class='fa fa-download'></i> Export CSV
        </button>
        <span id='loading' style='display:none; margin-left: 15px;'>
            <i class='fa fa-spinner fa-spin'></i> Comparing users against AD... This may take a moment.
        </span>
    </div>

    <div id='summary' style='display:none; margin: 15px 0; padding: 15px; background: #f5f5f5; border-radius: 4px;'>
        <h4>Summary</h4>
        <div class='row'>
            <div class='col-md-2'><strong>Total Users:</strong> <span id='statTotal'>-</span></div>
            <div class='col-md-2'><strong>In Sync:</strong> <span id='statSync' class='text-success'>-</span></div>
            <div class='col-md-2'><strong>Mismatches:</strong> <span id='statMismatch' class='text-warning'>-</span></div>
            <div class='col-md-2'><strong>Not in AD:</strong> <span id='statNotFound' class='text-danger'>-</span></div>
            <div class='col-md-2'><strong>AD Disabled:</strong> <span id='statDisabled' class='text-muted'>-</span></div>
        </div>
    </div>

    <div style='margin: 10px 0;'>
        <label><input type='checkbox' id='chkIssuesOnly' checked onchange='filterResults()'> Show issues only</label>
        <input type='text' id='txtSearch' placeholder='Search by username or display name...'
               style='margin-left: 15px; padding: 4px 8px; width: 300px;' oninput='filterResults()'>
    </div>

    <table id='resultsTable' class='table table-striped table-condensed' style='display:none;'>
        <thead>
            <tr>
                <th>Status</th>
                <th>User ID</th>
                <th>Display Name</th>
                <th>Mismatched Fields</th>
                <th>Details</th>
            </tr>
        </thead>
        <tbody id='resultsBody'></tbody>
    </table>
</div>

<script>
    var allResults = [];
    var pluginBaseUrl = '{pluginUrl}';

    function runComparison() {{
        document.getElementById('loading').style.display = 'inline';
        document.getElementById('btnRunCompare').disabled = true;
        document.getElementById('resultsTable').style.display = 'none';

        $.ajax({{
            url: pluginBaseUrl + '/Compare',
            method: 'GET',
            dataType: 'json',
            success: function(data) {{
                allResults = data.Results;

                document.getElementById('statTotal').textContent = data.TotalDiscoUsers;
                document.getElementById('statSync').textContent = data.UsersInSync;
                document.getElementById('statMismatch').textContent = data.UsersWithMismatches;
                document.getElementById('statNotFound').textContent = data.UsersNotFoundInAD;
                document.getElementById('statDisabled').textContent = data.ADAccountsDisabled;

                document.getElementById('summary').style.display = 'block';
                document.getElementById('btnExport').disabled = false;

                filterResults();
                document.getElementById('resultsTable').style.display = 'table';
            }},
            error: function(xhr) {{
                alert('Error running comparison: ' + xhr.statusText);
            }},
            complete: function() {{
                document.getElementById('loading').style.display = 'none';
                document.getElementById('btnRunCompare').disabled = false;
            }}
        }});
    }}

    function filterResults() {{
        var issuesOnly = document.getElementById('chkIssuesOnly').checked;
        var searchTerm = document.getElementById('txtSearch').value.toLowerCase();
        var tbody = document.getElementById('resultsBody');
        tbody.innerHTML = '';

        var filtered = allResults.filter(function(r) {{
            if (issuesOnly && r.UserFoundInAD && !r.HasMismatches && !r.ADAccountDisabled) return false;
            if (searchTerm) {{
                var match = (r.UserId || '').toLowerCase().indexOf(searchTerm) >= 0 ||
                            (r.DisplayName || '').toLowerCase().indexOf(searchTerm) >= 0;
                if (!match) return false;
            }}
            return true;
        }});

        filtered.forEach(function(r) {{
            var statusIcon, statusClass;
            if (!r.UserFoundInAD) {{
                statusIcon = '<i class=""fa fa-times-circle text-danger""></i>';
                statusClass = 'danger';
            }} else if (r.ADAccountDisabled) {{
                statusIcon = '<i class=""fa fa-ban text-muted""></i>';
                statusClass = 'warning';
            }} else if (r.HasMismatches) {{
                statusIcon = '<i class=""fa fa-exclamation-triangle text-warning""></i>';
                statusClass = 'warning';
            }} else {{
                statusIcon = '<i class=""fa fa-check-circle text-success""></i>';
                statusClass = '';
            }}

            var fields = r.HasMismatches
                ? r.Mismatches.map(function(m) {{ return m.FieldName; }}).join(', ')
                : (!r.UserFoundInAD ? 'Not found in AD' : (r.ADAccountDisabled ? 'AD Account Disabled' : 'All matched'));

            var details = r.HasMismatches
                ? '<table class=""table table-condensed"" style=""margin:0; font-size:12px;"">' +
                  r.Mismatches.map(function(m) {{
                      return '<tr><td><strong>' + m.FieldName + '</strong></td>' +
                             '<td>Disco: <code>' + escapeHtml(m.DiscoValue) + '</code></td>' +
                             '<td>AD: <code>' + escapeHtml(m.ADValue) + '</code></td></tr>';
                  }}).join('') + '</table>'
                : '';

            var row = '<tr class=""' + statusClass + '"">' +
                      '<td>' + statusIcon + '</td>' +
                      '<td>' + escapeHtml(r.UserId) + '</td>' +
                      '<td>' + escapeHtml(r.DisplayName || '') + '</td>' +
                      '<td>' + fields + '</td>' +
                      '<td>' + details + '</td></tr>';
            tbody.innerHTML += row;
        }});
    }}

    function exportCsv() {{
        window.location.href = pluginBaseUrl + '/Export';
    }}

    function escapeHtml(text) {{
        if (!text) return '';
        var div = document.createElement('div');
        div.appendChild(document.createTextNode(text));
        return div.innerHTML;
    }}
</script>";
        }

        #endregion
    }
}