@page "/clusters/{ClusterId}/drivers/new"
@page "/clusters/{ClusterId}/drivers/{DriverInstanceId}"
@* Per Q1 of the AdminUI rebuild plan — JSON editor only, typed driver editors deferred.
   DriverInstance is the keystone for everything downstream (Equipment, Tag, VirtualTag,
   ScriptedAlarm all reference DriverInstanceId), so this is the second edit page after
   Namespace. *@
@attribute [Microsoft.AspNetCore.Authorization.Authorize]
@rendermode RenderMode.InteractiveServer
@using Microsoft.AspNetCore.Components.Forms
@using Microsoft.EntityFrameworkCore
@using System.ComponentModel.DataAnnotations
@using ZB.MOM.WW.OtOpcUa.Configuration
@using ZB.MOM.WW.OtOpcUa.Configuration.Entities
@inject IDbContextFactory<OtOpcUaConfigDbContext> DbFactory
@inject NavigationManager Nav

<div class="d-flex justify-content-between align-items-center mb-3">
    <h4 class="mb-0">@(IsNew ? "New driver instance" : "Edit driver instance") &middot; <span class="mono">@ClusterId</span></h4>
    <a href="/clusters/@ClusterId/drivers" class="btn btn-outline-secondary btn-sm">Cancel</a>
</div>

<ClusterNav ClusterId="@ClusterId" ActiveTab="drivers" />

@if (!_loaded)
{
    <p>Loading…</p>
}
else if (!IsNew && _existing is null)
{
    <section class="panel notice rise" style="animation-delay:.02s">
        Driver instance <span class="mono">@DriverInstanceId</span> was not found in cluster <span class="mono">@ClusterId</span>.
    </section>
}
else
{
    <EditForm Model="_form" OnValidSubmit="SubmitAsync" FormName="driverEdit">
        <DataAnnotationsValidator />
        <section class="panel rise" style="animation-delay:.02s">
            <div class="panel-head">@(IsNew ? "Identity" : $"Edit {_form.DriverInstanceId}")</div>
            <div style="padding:1rem">
                <div class="row">
                    <div class="col-md-6 mb-3">
                        <label class="form-label" for="instId">DriverInstanceId</label>
                        <InputText id="instId" @bind-Value="_form.DriverInstanceId" disabled="@(!IsNew)"
                                   class="form-control form-control-sm mono"
                                   placeholder="drv-modbus-line3-01" />
                    </div>
                    <div class="col-md-6 mb-3">
                        <label class="form-label" for="name">Display name</label>
                        <InputText id="name" @bind-Value="_form.Name" class="form-control form-control-sm"
                                   placeholder="Line 3 Modbus" />
                    </div>
                </div>
                <div class="row">
                    <div class="col-md-6 mb-3">
                        <label class="form-label" for="dtype">Driver type</label>
                        <InputSelect id="dtype" @bind-Value="_form.DriverType" disabled="@(!IsNew)"
                                     class="form-select form-select-sm">
                            <option value="ModbusTcp">ModbusTcp</option>
                            <option value="AbCip">AbCip</option>
                            <option value="AbLegacy">AbLegacy</option>
                            <option value="S7">S7</option>
                            <option value="TwinCat">TwinCat</option>
                            <option value="Focas">Focas</option>
                            <option value="OpcUaClient">OpcUaClient</option>
                            <option value="Galaxy">Galaxy</option>
                            <option value="Historian.Wonderware">Historian.Wonderware</option>
                        </InputSelect>
                        <div class="form-text">Cannot be changed after creation — drives the actor type that owns this instance.</div>
                    </div>
                    <div class="col-md-6 mb-3">
                        <label class="form-label" for="ns">Namespace</label>
                        <InputSelect id="ns" @bind-Value="_form.NamespaceId" class="form-select form-select-sm">
                            @foreach (var ns in _namespaces)
                            {
                                <option value="@ns.NamespaceId">@ns.NamespaceId (@ns.Kind)</option>
                            }
                        </InputSelect>
                    </div>
                </div>
                <div class="mb-3">
                    <label class="form-label" for="enabled">Enabled</label>
                    <div class="form-check form-switch">
                        <InputCheckbox id="enabled" @bind-Value="_form.Enabled" class="form-check-input" />
                        <label class="form-check-label" for="enabled">Spawn this driver in deployments</label>
                    </div>
                </div>
            </div>
        </section>

        <section class="panel rise mt-3" style="animation-delay:.08s">
            <div class="panel-head">Driver config (JSON)</div>
            <div style="padding:1rem">
                <InputTextArea @bind-Value="_form.DriverConfig" rows="12"
                               class="form-control form-control-sm mono"
                               placeholder='{ "endpoint": "10.0.0.42:502", "slaveId": 1 }' />
                <div class="form-text">Schemaless per driver type — validated server-side at deploy time. JSON is reformatted on save.</div>
            </div>
        </section>

        <section class="panel rise mt-3" style="animation-delay:.14s">
            <div class="panel-head">Resilience overrides (optional)</div>
            <div style="padding:1rem">
                <InputTextArea @bind-Value="_form.ResilienceConfig" rows="6"
                               class="form-control form-control-sm mono"
                               placeholder='Leave blank to use tier defaults' />
                <div class="form-text">Polly pipeline overrides per docs/v2/driver-stability.md — bulkhead, retry counts, breaker thresholds. Null = use the driver type's tier defaults.</div>
            </div>
        </section>

        @if (!string.IsNullOrWhiteSpace(_error))
        {
            <div class="panel notice mt-3" style="border-color:var(--alert)">@_error</div>
        }

        <div class="mt-3 d-flex gap-2">
            <button type="submit" class="btn btn-primary" disabled="@_busy">
                @if (_busy) { <span class="spinner-border spinner-border-sm me-1"></span> }
                @(IsNew ? "Create" : "Save changes")
            </button>
            <a href="/clusters/@ClusterId/drivers" class="btn btn-outline-secondary">Cancel</a>
            @if (!IsNew)
            {
                <button type="button" class="btn btn-outline-danger ms-auto" @onclick="DeleteAsync" disabled="@_busy">
                    Delete
                </button>
            }
        </div>
    </EditForm>
}

@code {
    [Parameter] public string ClusterId { get; set; } = "";
    [Parameter] public string? DriverInstanceId { get; set; }

    private bool IsNew => string.IsNullOrEmpty(DriverInstanceId);

    private FormModel _form = new();
    private DriverInstance? _existing;
    private List<Namespace> _namespaces = new();
    private bool _loaded;
    private bool _busy;
    private string? _error;

    protected override async Task OnInitializedAsync()
    {
        await using var db = await DbFactory.CreateDbContextAsync();
        _namespaces = await db.Namespaces.AsNoTracking()
            .Where(n => n.ClusterId == ClusterId)
            .OrderBy(n => n.NamespaceId)
            .ToListAsync();

        if (IsNew)
        {
            _form = new FormModel
            {
                DriverInstanceId = "",
                Name = "",
                DriverType = "ModbusTcp",
                NamespaceId = _namespaces.FirstOrDefault()?.NamespaceId ?? "",
                Enabled = true,
                DriverConfig = "{}",
            };
        }
        else
        {
            _existing = await db.DriverInstances.AsNoTracking()
                .FirstOrDefaultAsync(d => d.ClusterId == ClusterId && d.DriverInstanceId == DriverInstanceId);
            if (_existing is not null)
            {
                _form = new FormModel
                {
                    DriverInstanceId = _existing.DriverInstanceId,
                    Name = _existing.Name,
                    DriverType = _existing.DriverType,
                    NamespaceId = _existing.NamespaceId,
                    Enabled = _existing.Enabled,
                    DriverConfig = _existing.DriverConfig,
                    ResilienceConfig = _existing.ResilienceConfig,
                    RowVersion = _existing.RowVersion,
                };
            }
        }
        _loaded = true;
    }

    private async Task SubmitAsync()
    {
        _busy = true;
        _error = null;
        try
        {
            var normalizedConfig = NormalizeJson(_form.DriverConfig);
            if (normalizedConfig is null)
            {
                _error = "DriverConfig is not valid JSON.";
                return;
            }
            var normalizedResilience = NormalizeOptionalJson(_form.ResilienceConfig);
            if (!string.IsNullOrWhiteSpace(_form.ResilienceConfig) && normalizedResilience is null)
            {
                _error = "ResilienceConfig is not valid JSON. Leave blank to use defaults.";
                return;
            }

            await using var db = await DbFactory.CreateDbContextAsync();
            if (IsNew)
            {
                if (await db.DriverInstances.AnyAsync(d => d.DriverInstanceId == _form.DriverInstanceId))
                {
                    _error = $"Driver instance '{_form.DriverInstanceId}' already exists.";
                    return;
                }
                db.DriverInstances.Add(new DriverInstance
                {
                    DriverInstanceId = _form.DriverInstanceId,
                    ClusterId = ClusterId,
                    NamespaceId = _form.NamespaceId,
                    Name = _form.Name,
                    DriverType = _form.DriverType,
                    Enabled = _form.Enabled,
                    DriverConfig = normalizedConfig,
                    ResilienceConfig = normalizedResilience,
                });
            }
            else
            {
                var entity = await db.DriverInstances.FirstOrDefaultAsync(
                    d => d.ClusterId == ClusterId && d.DriverInstanceId == DriverInstanceId);
                if (entity is null)
                {
                    _error = "Row no longer exists.";
                    return;
                }
                db.Entry(entity).Property(e => e.RowVersion).OriginalValue = _form.RowVersion;
                entity.NamespaceId = _form.NamespaceId;
                entity.Name = _form.Name;
                entity.Enabled = _form.Enabled;
                entity.DriverConfig = normalizedConfig;
                entity.ResilienceConfig = normalizedResilience;
            }
            await db.SaveChangesAsync();
            Nav.NavigateTo($"/clusters/{ClusterId}/drivers");
        }
        catch (DbUpdateConcurrencyException)
        {
            _error = "Another user changed this driver instance while you were editing. Reload to see the latest values, then re-apply your changes.";
        }
        catch (Exception ex)
        {
            _error = ex.Message;
        }
        finally
        {
            _busy = false;
        }
    }

    private async Task DeleteAsync()
    {
        if (IsNew) return;
        _busy = true;
        _error = null;
        try
        {
            await using var db = await DbFactory.CreateDbContextAsync();
            var entity = await db.DriverInstances.FirstOrDefaultAsync(
                d => d.ClusterId == ClusterId && d.DriverInstanceId == DriverInstanceId);
            if (entity is null)
            {
                Nav.NavigateTo($"/clusters/{ClusterId}/drivers");
                return;
            }
            db.Entry(entity).Property(e => e.RowVersion).OriginalValue = _form.RowVersion;
            db.DriverInstances.Remove(entity);
            await db.SaveChangesAsync();
            Nav.NavigateTo($"/clusters/{ClusterId}/drivers");
        }
        catch (DbUpdateConcurrencyException)
        {
            _error = "Another user changed this driver instance while you were viewing it. Reload before deleting.";
        }
        catch (Exception ex)
        {
            _error = $"Delete failed: {ex.Message}. (Likely because equipment/tags still reference this driver — remove them first.)";
        }
        finally
        {
            _busy = false;
        }
    }

    private static string? NormalizeJson(string? input)
    {
        if (string.IsNullOrWhiteSpace(input)) return null;
        try
        {
            using var doc = System.Text.Json.JsonDocument.Parse(input);
            return System.Text.Json.JsonSerializer.Serialize(doc.RootElement);
        }
        catch { return null; }
    }

    private static string? NormalizeOptionalJson(string? input) =>
        string.IsNullOrWhiteSpace(input) ? null : NormalizeJson(input);

    private sealed class FormModel
    {
        [Required, RegularExpression("^[A-Za-z0-9_-]+$", ErrorMessage = "Use letters, digits, dash, underscore.")]
        public string DriverInstanceId { get; set; } = "";
        [Required]
        public string Name { get; set; } = "";
        [Required]
        public string DriverType { get; set; } = "ModbusTcp";
        [Required]
        public string NamespaceId { get; set; } = "";
        public bool Enabled { get; set; } = true;
        [Required]
        public string DriverConfig { get; set; } = "{}";
        public string? ResilienceConfig { get; set; }
        public byte[] RowVersion { get; set; } = [];
    }
}