@page "/design/shared-scripts"
@using ScadaLink.Security
@using ScadaLink.Commons.Entities.Scripts
@using ScadaLink.Commons.Interfaces.Repositories
@using ScadaLink.TemplateEngine
@attribute [Authorize(Policy = AuthorizationPolicies.RequireDesign)]
@inject ITemplateEngineRepository TemplateEngineRepository
@inject SharedScriptService SharedScriptService
@inject AuthenticationStateProvider AuthStateProvider

<div class="container-fluid mt-3">
    <div class="d-flex justify-content-between align-items-center mb-3">
        <h4 class="mb-0">Shared Scripts</h4>
        <button class="btn btn-primary btn-sm" @onclick="ShowAddForm">New Script</button>
    </div>

    <ToastNotification @ref="_toast" />
    <ConfirmDialog @ref="_confirmDialog" />

    @if (_loading)
    {
        <LoadingSpinner IsLoading="true" />
    }
    else if (_errorMessage != null)
    {
        <div class="alert alert-danger">@_errorMessage</div>
    }
    else
    {
        @if (_showForm)
        {
            <div class="card mb-3">
                <div class="card-body">
                    <h6 class="card-title">@(_editingScript == null ? "New Shared Script" : $"Edit: {_editingScript.Name}")</h6>
                    <div class="row g-2">
                        <div class="col-md-4">
                            <label class="form-label small">Name</label>
                            <input type="text" class="form-control form-control-sm" @bind="_formName"
                                   disabled="@(_editingScript != null)" />
                        </div>
                        <div class="col-md-4">
                            <label class="form-label small">Parameters (JSON)</label>
                            <input type="text" class="form-control form-control-sm" @bind="_formParameters"
                                   placeholder='e.g. [{"name":"x","type":"Int32"}]' />
                        </div>
                        <div class="col-md-4">
                            <label class="form-label small">Return Definition (JSON)</label>
                            <input type="text" class="form-control form-control-sm" @bind="_formReturn"
                                   placeholder='e.g. {"type":"Boolean"}' />
                        </div>
                    </div>
                    <div class="mt-2">
                        <label class="form-label small">Code</label>
                        <textarea class="form-control form-control-sm font-monospace" rows="10" @bind="_formCode"
                                  style="font-size: 0.8rem;"></textarea>
                    </div>
                    <div class="mt-2">
                        <button class="btn btn-success btn-sm me-1" @onclick="SaveScript">Save</button>
                        <button class="btn btn-outline-info btn-sm me-1" @onclick="CheckCompilation">Check Syntax</button>
                        <button class="btn btn-outline-secondary btn-sm" @onclick="CancelForm">Cancel</button>
                    </div>
                    @if (_formError != null)
                    {
                        <div class="text-danger small mt-1">@_formError</div>
                    }
                    @if (_syntaxCheckResult != null)
                    {
                        <div class="@(_syntaxCheckPassed ? "text-success" : "text-danger") small mt-1">@_syntaxCheckResult</div>
                    }
                </div>
            </div>
        }

        <table class="table table-sm table-striped table-hover">
            <thead class="table-dark">
                <tr>
                    <th>ID</th>
                    <th>Name</th>
                    <th>Code (preview)</th>
                    <th>Parameters</th>
                    <th>Returns</th>
                    <th style="width: 160px;">Actions</th>
                </tr>
            </thead>
            <tbody>
                @if (_scripts.Count == 0)
                {
                    <tr>
                        <td colspan="6" class="text-muted text-center">No shared scripts configured.</td>
                    </tr>
                }
                @foreach (var script in _scripts)
                {
                    <tr>
                        <td>@script.Id</td>
                        <td><strong>@script.Name</strong></td>
                        <td class="small text-muted font-monospace text-truncate" style="max-width: 300px;">
                            @script.Code[..Math.Min(60, script.Code.Length)]@(script.Code.Length > 60 ? "..." : "")
                        </td>
                        <td class="small text-muted">@(script.ParameterDefinitions ?? "—")</td>
                        <td class="small text-muted">@(script.ReturnDefinition ?? "—")</td>
                        <td>
                            <button class="btn btn-outline-primary btn-sm py-0 px-1 me-1"
                                    @onclick="() => EditScript(script)">Edit</button>
                            <button class="btn btn-outline-danger btn-sm py-0 px-1"
                                    @onclick="() => DeleteScript(script)">Delete</button>
                        </td>
                    </tr>
                }
            </tbody>
        </table>
    }
</div>

@code {
    private async Task<string> GetCurrentUserAsync()
    {
        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
        return authState.User.FindFirst("Username")?.Value ?? "unknown";
    }

    private List<SharedScript> _scripts = new();
    private bool _loading = true;
    private string? _errorMessage;

    private bool _showForm;
    private SharedScript? _editingScript;
    private string _formName = string.Empty;
    private string _formCode = string.Empty;
    private string? _formParameters;
    private string? _formReturn;
    private string? _formError;
    private string? _syntaxCheckResult;
    private bool _syntaxCheckPassed;

    private ToastNotification _toast = default!;
    private ConfirmDialog _confirmDialog = default!;

    protected override async Task OnInitializedAsync()
    {
        await LoadDataAsync();
    }

    private async Task LoadDataAsync()
    {
        _loading = true;
        _errorMessage = null;
        try
        {
            _scripts = (await SharedScriptService.GetAllSharedScriptsAsync()).ToList();
        }
        catch (Exception ex)
        {
            _errorMessage = $"Failed to load shared scripts: {ex.Message}";
        }
        _loading = false;
    }

    private void ShowAddForm()
    {
        _editingScript = null;
        _formName = string.Empty;
        _formCode = string.Empty;
        _formParameters = null;
        _formReturn = null;
        _formError = null;
        _syntaxCheckResult = null;
        _showForm = true;
    }

    private void EditScript(SharedScript script)
    {
        _editingScript = script;
        _formName = script.Name;
        _formCode = script.Code;
        _formParameters = script.ParameterDefinitions;
        _formReturn = script.ReturnDefinition;
        _formError = null;
        _syntaxCheckResult = null;
        _showForm = true;
    }

    private void CancelForm()
    {
        _showForm = false;
        _editingScript = null;
    }

    private void CheckCompilation()
    {
        var syntaxError = ValidateSyntaxLocally(_formCode);
        if (syntaxError == null)
        {
            _syntaxCheckResult = "Syntax check passed.";
            _syntaxCheckPassed = true;
        }
        else
        {
            _syntaxCheckResult = syntaxError;
            _syntaxCheckPassed = false;
        }
    }

    private async Task SaveScript()
    {
        _formError = null;
        _syntaxCheckResult = null;

        try
        {
            if (_editingScript != null)
            {
                var user = await GetCurrentUserAsync();
                var result = await SharedScriptService.UpdateSharedScriptAsync(
                    _editingScript.Id, _formCode, _formParameters?.Trim(), _formReturn?.Trim(), user);
                if (result.IsSuccess)
                {
                    _showForm = false;
                    _toast.ShowSuccess($"Script '{_editingScript.Name}' updated.");
                    await LoadDataAsync();
                }
                else
                {
                    _formError = result.Error;
                }
            }
            else
            {
                var user = await GetCurrentUserAsync();
                var result = await SharedScriptService.CreateSharedScriptAsync(
                    _formName.Trim(), _formCode, _formParameters?.Trim(), _formReturn?.Trim(), user);
                if (result.IsSuccess)
                {
                    _showForm = false;
                    _toast.ShowSuccess($"Script '{_formName}' created.");
                    await LoadDataAsync();
                }
                else
                {
                    _formError = result.Error;
                }
            }
        }
        catch (Exception ex)
        {
            _formError = $"Save failed: {ex.Message}";
        }
    }

    /// <summary>
    /// Basic syntax check: balanced braces/brackets/parens.
    /// Mirrors the internal SharedScriptService.ValidateSyntax logic.
    /// </summary>
    private static string? ValidateSyntaxLocally(string code)
    {
        if (string.IsNullOrWhiteSpace(code)) return "Script code cannot be empty.";
        int brace = 0, bracket = 0, paren = 0;
        foreach (var ch in code)
        {
            switch (ch) { case '{': brace++; break; case '}': brace--; break; case '[': bracket++; break; case ']': bracket--; break; case '(': paren++; break; case ')': paren--; break; }
            if (brace < 0) return "Syntax error: unmatched closing brace '}'.";
            if (bracket < 0) return "Syntax error: unmatched closing bracket ']'.";
            if (paren < 0) return "Syntax error: unmatched closing parenthesis ')'.";
        }
        if (brace != 0) return "Syntax error: unmatched opening brace '{'.";
        if (bracket != 0) return "Syntax error: unmatched opening bracket '['.";
        if (paren != 0) return "Syntax error: unmatched opening parenthesis '('.";
        return null;
    }

    private async Task DeleteScript(SharedScript script)
    {
        var confirmed = await _confirmDialog.ShowAsync(
            $"Delete shared script '{script.Name}'?", "Delete Shared Script");
        if (!confirmed) return;

        try
        {
            var user = await GetCurrentUserAsync();
            var result = await SharedScriptService.DeleteSharedScriptAsync(script.Id, user);
            if (result.IsSuccess)
            {
                _toast.ShowSuccess($"Script '{script.Name}' deleted.");
                await LoadDataAsync();
            }
            else
            {
                _toast.ShowError(result.Error);
            }
        }
        catch (Exception ex)
        {
            _toast.ShowError($"Delete failed: {ex.Message}");
        }
    }
}