@page "/admin/api-keys/create"
@page "/admin/api-keys/{Id:int}/edit"
@using ScadaLink.Security
@using ScadaLink.Commons.Entities.InboundApi
@using ScadaLink.Commons.Interfaces.Repositories
@attribute [Authorize(Policy = AuthorizationPolicies.RequireAdmin)]
@inject IInboundApiRepository InboundApiRepository
@inject NavigationManager NavigationManager
@inject IJSRuntime JS

<div class="container-fluid mt-3">
    <div class="d-flex align-items-center mb-3">
        <a href="/admin/api-keys" class="btn btn-outline-secondary btn-sm me-2"
           aria-label="Back to API Keys">&larr; Back</a>
        <span class="text-muted me-2">·</span>
        <h4 class="mb-0">
            @if (_saved)
            {
                @:API Key Created
            }
            else if (IsEditMode)
            {
                @:Edit API Key
            }
            else
            {
                @:Add API Key
            }
        </h4>
    </div>

    <ToastNotification @ref="_toast" />

    @if (_loading)
    {
        <LoadingSpinner IsLoading="true" />
    }
    else if (_saved && _newlyCreatedKeyValue != null)
    {
        <div class="alert alert-success">
            <strong>New API Key Created</strong>
            <div class="d-flex align-items-center mt-1">
                <code class="me-2">@_newlyCreatedKeyValue</code>
                <button class="btn btn-outline-secondary btn-sm py-0 px-1" @onclick="CopyKeyToClipboard">Copy</button>
            </div>
            <small class="text-muted d-block mt-1">Save this key now. It will not be shown again in full.</small>
        </div>
        <a href="/admin/api-keys" class="btn btn-primary btn-sm">Back to API Keys</a>
    }
    else if (_errorMessage != null)
    {
        <div class="alert alert-danger">@_errorMessage</div>
    }
    else
    {
        <div class="mb-2">
            <label class="form-label small">Name</label>
            <input type="text" class="form-control form-control-sm" @bind="_formName" />
        </div>
        @if (IsEditMode)
        {
            <div class="mb-2">
                <label class="form-label small">API Method Access</label>
                @if (_allMethods.Count == 0)
                {
                    <div class="form-text">
                        No API methods configured.
                        <a href="/design/external-systems">Create one</a> to grant access.
                    </div>
                }
                else
                {
                    <div class="border rounded p-2" style="max-height: 220px; overflow-y: auto;">
                        @foreach (var method in _allMethods.OrderBy(m => m.Name))
                        {
                            var checkboxId = $"method-access-{method.Id}";
                            <div class="form-check">
                                <input class="form-check-input" type="checkbox" id="@checkboxId"
                                       checked="@_selectedMethodIds.Contains(method.Id)"
                                       @onchange="e => ToggleMethod(method.Id, (bool)e.Value!)" />
                                <label class="form-check-label" for="@checkboxId">@method.Name</label>
                            </div>
                        }
                    </div>
                    <div class="form-text">
                        Callers using this key can invoke any checked method.
                    </div>
                }
            </div>
        }
        @if (_formError != null)
        {
            <div class="text-danger small mt-2">@_formError</div>
        }
        <div class="mt-3">
            <button class="btn btn-success btn-sm me-1" @onclick="SaveKey">Save</button>
            <button class="btn btn-outline-secondary btn-sm" @onclick="GoBack">Cancel</button>
        </div>
    }
</div>

@code {
    [Parameter] public int? Id { get; set; }

    private bool IsEditMode => _editingKey != null;

    private ApiKey? _editingKey;
    private string _formName = string.Empty;
    private string? _formError;
    private string? _errorMessage;
    private string? _newlyCreatedKeyValue;
    private bool _loading = true;
    private bool _saved;

    private List<ApiMethod> _allMethods = new();
    private HashSet<int> _initialMethodIds = new();
    private HashSet<int> _selectedMethodIds = new();

    private ToastNotification _toast = default!;

    protected override async Task OnInitializedAsync()
    {
        try
        {
            if (Id.HasValue)
            {
                _editingKey = await InboundApiRepository.GetApiKeyByIdAsync(Id.Value);
                if (_editingKey == null)
                {
                    _errorMessage = $"API key with ID {Id.Value} not found.";
                }
                else
                {
                    _formName = _editingKey.Name;
                    _allMethods = (await InboundApiRepository.GetAllApiMethodsAsync()).ToList();
                    _initialMethodIds = _allMethods
                        .Where(m => ParseApprovedKeyIds(m.ApprovedApiKeyIds).Contains(_editingKey.Id))
                        .Select(m => m.Id)
                        .ToHashSet();
                    _selectedMethodIds = new HashSet<int>(_initialMethodIds);
                }
            }
        }
        catch (Exception ex)
        {
            _errorMessage = $"Failed to load API key: {ex.Message}";
        }
        _loading = false;
    }

    private async Task SaveKey()
    {
        _formError = null;
        if (string.IsNullOrWhiteSpace(_formName)) { _formError = "Name is required."; return; }

        try
        {
            if (_editingKey != null)
            {
                _editingKey.Name = _formName.Trim();
                await InboundApiRepository.UpdateApiKeyAsync(_editingKey);

                var changedIds = _selectedMethodIds
                    .Except(_initialMethodIds)
                    .Concat(_initialMethodIds.Except(_selectedMethodIds))
                    .ToHashSet();
                foreach (var method in _allMethods.Where(m => changedIds.Contains(m.Id)))
                {
                    var ids = ParseApprovedKeyIds(method.ApprovedApiKeyIds);
                    if (_selectedMethodIds.Contains(method.Id)) ids.Add(_editingKey.Id);
                    else ids.Remove(_editingKey.Id);
                    method.ApprovedApiKeyIds = ids.Count == 0
                        ? null
                        : string.Join(",", ids.OrderBy(x => x));
                    await InboundApiRepository.UpdateApiMethodAsync(method);
                }

                await InboundApiRepository.SaveChangesAsync();
                NavigationManager.NavigateTo("/admin/api-keys");
            }
            else
            {
                var keyValue = GenerateApiKey();
                var key = new ApiKey(_formName.Trim(), keyValue) { IsEnabled = true };
                await InboundApiRepository.AddApiKeyAsync(key);
                await InboundApiRepository.SaveChangesAsync();
                _newlyCreatedKeyValue = keyValue;
                _saved = true;
            }
        }
        catch (Exception ex)
        {
            _formError = $"Save failed: {ex.Message}";
        }
    }

    private void GoBack() => NavigationManager.NavigateTo("/admin/api-keys");

    private void ToggleMethod(int methodId, bool isChecked)
    {
        if (isChecked) _selectedMethodIds.Add(methodId);
        else _selectedMethodIds.Remove(methodId);
    }

    private static HashSet<int> ParseApprovedKeyIds(string? value)
    {
        if (string.IsNullOrWhiteSpace(value))
            return new HashSet<int>();
        return value.Split(',', StringSplitOptions.RemoveEmptyEntries)
            .Select(s => int.TryParse(s.Trim(), out var id) ? id : -1)
            .Where(id => id > 0)
            .ToHashSet();
    }

    private async Task CopyKeyToClipboard()
    {
        if (_newlyCreatedKeyValue == null) return;
        try
        {
            await JS.InvokeVoidAsync("navigator.clipboard.writeText", _newlyCreatedKeyValue);
            _toast.ShowSuccess("Copied to clipboard.");
        }
        catch
        {
            _toast.ShowError("Copy failed.");
        }
    }

    private static string GenerateApiKey()
    {
        var bytes = new byte[32];
        using var rng = System.Security.Cryptography.RandomNumberGenerator.Create();
        rng.GetBytes(bytes);
        return Convert.ToBase64String(bytes).Replace("+", "").Replace("/", "").Replace("=", "")[..40];
    }
}
