ListViewDropdown — Ajax (Drag and drop)

import { TreeView } from '/_content/CopelandSyst.BootstrapComponents/lib/Bootstrap/dist/treeview/bs-treeview.js';
import { ListView } from '/_content/CopelandSyst.BootstrapComponents/lib/Bootstrap/dist/listview/bs-listview.js';
import { TreeViewDropdown } from '/_content/CopelandSyst.BootstrapComponents/lib/Bootstrap/dist/treeview/bs-treeview-dropdown.js';
import { ListViewDropdown } from '/_content/CopelandSyst.BootstrapComponents/lib/Bootstrap/dist/listview/bs-listview-dropdown.js';

const example = document.getElementById('ajax-example');
const { kind } = example.dataset;
const isDropdown = example.dataset.scenario.startsWith('dropdown-');
const scenario = example.dataset.scenario.replace(/^dropdown-/, '');
const View = isDropdown ? (kind === 'treeview' ? TreeViewDropdown : ListViewDropdown) : (kind === 'treeview' ? TreeView : ListView);
const savesChanges = ['checking', 'reordering', 'renaming'].includes(scenario) || isDropdown && scenario === 'selection';
const endpoint = `/Bcl/ViewExamples/${kind}/${example.dataset.scenario}`;
const token = example.querySelector('[name="__RequestVerificationToken"]').value;
const status = document.getElementById('ajax-status');
const pending = document.getElementById('ajax-pending');
const wire = document.getElementById('ajax-wire');
const server = document.getElementById('ajax-server');
const details = document.getElementById('ajax-details');
const initialElement = document.getElementById('ajax-demo').cloneNode(true);
const controllers = new Set();
let view, seed, ready = false, saving = false, queued = false, paused = false;
let generation = 0, selectionSequence = 0, detailController;
let pendingSubmission;

function report(state, message) {
    example.dataset.state = state;
    status.textContent = message;
    pending.textContent = !savesChanges ? 'This example retrieves data; it does not save local edits.'
        : ready && view.getChangeSet().changes.hasChanges ? 'Local changes are not yet acknowledged.' : 'No unacknowledged changes.';
}

async function request(action, { method = 'GET', body, simulate = true, controller = new AbortController() } = {}) {
    const epoch = generation;
    const url = new URL(`${endpoint}/${action}`, location.origin);
    if (simulate) {
        url.searchParams.set('delay', document.getElementById('ajax-delay').value);
        const fail = document.getElementById('ajax-fail');
        if (fail.checked) { url.searchParams.set('fail', 'true'); fail.checked = false; }
    }
    const sent = { method, url: url.pathname + url.search, body: body ?? null };
    wire.textContent = JSON.stringify({ request: sent, response: 'Pending…' }, null, 2);
    controllers.add(controller);
    try {
        const response = await fetch(url, {
            method, credentials: 'same-origin', signal: controller.signal,
            headers: { 'Content-Type': 'application/json', 'RequestVerificationToken': token },
            body: body === undefined ? undefined : JSON.stringify(body)
        });
        const payload = await response.json();
        if (epoch !== generation) throw new DOMException('Obsolete request', 'AbortError');
        wire.textContent = JSON.stringify({ request: sent, status: response.status, response: payload }, null, 2);
        if (!response.ok) throw Object.assign(new Error(payload.message || `Request failed (${response.status}).`), { status: response.status });
        return payload;
    } finally { controllers.delete(controller); }
}

function dataFromSnapshot(snapshot) {
    const records = new Map(snapshot.items.map(item => [item.id, { ...item.data, id: item.id, ...(kind === 'treeview' ? { children: [] } : {}) }]));
    const roots = [];
    for (const item of [...snapshot.items].sort((a, b) => a.index - b.index)) {
        if (kind === 'treeview' && item.parentId) records.get(item.parentId).children.push(records.get(item.id));
        else roots.push(records.get(item.id));
    }
    return roots;
}

async function restore(reset = false) {
    const epoch = ++generation;
    ++selectionSequence;
    for (const controller of controllers) controller.abort();
    ready = false; saving = false; queued = false; paused = false;
    pendingSubmission = undefined;
    if (isDropdown) { view.setDisabled(true); }
    document.getElementById('ajax-demo').inert = true;
    // Disposing the old instance invalidates deferred lazy-load actions before replacement.
    if (scenario === 'lazy-loading') {
        view.dispose();
        document.getElementById('ajax-demo').replaceWith(initialElement.cloneNode(true));
        document.getElementById('ajax-demo').inert = true;
        view = new View(document.getElementById('ajax-demo'));
    }
    report('loading', reset ? 'Resetting this example…' : 'Loading saved state…');
    try {
        const result = await request(reset ? 'reset' : 'state', { method: reset ? 'POST' : 'GET', simulate: false });
        if (epoch !== generation) return;
        view.replaceData(result.snapshot ? dataFromSnapshot(result.snapshot) : structuredClone(seed));
        if (result.snapshot) view.setState(result.snapshot.state);
        else view.setState({ selection: { ids: [], primaryId: null }, checkedIds: [], focusedId: null });
        view.acceptCurrentState(result.serverRevision);
        document.getElementById('ajax-demo').inert = false; ready = true;
        if (isDropdown) view.setDisabled(false);
        server.textContent = JSON.stringify(result, null, 2);
        if (details) details.textContent = 'Select a notice.';
        report('ready', reset ? 'Example reset.' : 'Ready. Changes are isolated to this example.');
    } catch (error) {
        if (epoch === generation && error.name !== 'AbortError') report('error', error.message);
    }
}

async function save() {
    if (!ready || paused || !savesChanges) return;
    if (saving) { queued = true; return; }
    if (!pendingSubmission && !view.getChangeSet().changes.hasChanges) return;
    const epoch = generation;
    // An uncertain response must retry the same identity, even if later edits exist.
    const submission = pendingSubmission ??= view.createSubmission();
    saving = true; queued = false;
    report('saving', 'Saving this snapshot. Further edits remain available.');
    try {
        const result = await request('save', { method: 'POST', body: submission });
        if (epoch !== generation) return;
        view.acknowledgeChanges(result.acknowledgment);
        pendingSubmission = undefined;
        server.textContent = JSON.stringify(result.snapshot, null, 2);
        report('saved', 'Server acknowledged the submitted snapshot.');
    } catch (error) {
        if (epoch !== generation || error.name === 'AbortError') return;
        // These endpoints reject validation/conflict requests before committing them.
        if ([400, 409, 413, 422].includes(error.status)) pendingSubmission = undefined;
        paused = true;
        report('error', `${error.message} Local edits are retained.`);
    } finally {
        if (epoch === generation) {
            saving = false;
            if (!paused && (queued || view.getChangeSet().changes.hasChanges)) queueMicrotask(save);
        }
    }
}

window.viewAjax = {
    save() { queueMicrotask(save); },
    async selected() {
        if (!ready || scenario !== 'selection' || isDropdown) return;
        const id = view.getSelectedId();
        const sequence = ++selectionSequence;
        const epoch = generation;
        detailController?.abort();
        if (!id) { details.textContent = 'Select a notice.'; report('ready', 'Select a notice.'); return; }
        detailController = new AbortController();
        details.textContent = `Loading details for ${id}…`;
        report('loading', `Loading details for ${id}…`);
        try {
            const result = await request(`details/${encodeURIComponent(id)}`, { controller: detailController });
            if (sequence !== selectionSequence || epoch !== generation) return;
            details.textContent = JSON.stringify(result, null, 2);
            view.acceptCurrentState(view.getSnapshot().serverRevision);
            report('ready', `Details loaded for ${id}.`);
        } catch (error) {
            if (sequence === selectionSequence && epoch === generation && error.name !== 'AbortError') {
                details.textContent = `Details unavailable for ${id}. Retry the request or select another notice.`;
                report('error', error.message);
            }
        }
    },
    async children(event) {
        if (scenario !== 'lazy-loading') return;
        report('loading', `Loading children of ${event.detail.id}…`);
        try {
            const result = await request(`children/${encodeURIComponent(event.detail.id)}`);
            report('ready', `Loaded ${result.length} children. Collapse and expand to use the loaded data.`);
            return result;
        } catch (error) {
            if (error.name !== 'AbortError') report('error', `${error.message} Expand the group again to retry.`);
            throw error;
        }
    }
};

view = View.getOrCreateInstance(document.getElementById('ajax-demo'));
seed = dataFromSnapshot(view.getSnapshot().snapshot);
document.getElementById('ajax-reset').addEventListener('click', () => restore(true));
document.getElementById('ajax-reload').addEventListener('click', () => restore());
document.getElementById('ajax-retry')?.addEventListener('click', () => { paused = false; save(); });
document.getElementById('ajax-retry-details')?.addEventListener('click', () => window.viewAjax.selected());
document.getElementById('ajax-conflict')?.addEventListener('click', async () => {
    try { const result = await request('conflict', { method: 'POST', simulate: false }); report('ready', result.message); }
    catch (error) { if (error.name !== 'AbortError') report('error', error.message); }
});
document.getElementById('ajax-move')?.addEventListener('click', () => {
    const id = view.getSelectedId();
    if (!id) { report('ready', 'Select a notice first.'); return; }
    if (kind === 'treeview') view.moveNode(id, id.startsWith('notice-') ? 'planned' : null, { index: 99 });
    else view.moveItem(id, { index: 99 });
});
restore();

using System.ComponentModel.DataAnnotations;
using System.Security.Cryptography;
using System.Text;
using System.Text.Json;
using CopelandSyst.BootstrapComponents.ViewModels;
using CopelandSyst.Docs.DocsNavigation;
using CopelandSyst.Docs.Models;
using CopelandSyst.Docs.Services;
using Microsoft.AspNetCore.Mvc;

namespace CopelandSyst.Docs.Controllers;

[ResponseCache(NoStore = true, Location = ResponseCacheLocation.None)]
public sealed class ViewExamplesController(ViewDemoStore store) : Controller
{
    [DocsNode("bcl:components:treeview:checking"), HttpGet("/Bcl/TreeView/Ajax/Checking")]
    public IActionResult TreeChecking() => Example("treeview", "checking");
    [DocsNode("bcl:components:treeview:reordering"), HttpGet("/Bcl/TreeView/Ajax/Reordering")]
    public IActionResult TreeReordering() => Example("treeview", "reordering");
    [DocsNode("bcl:components:treeview:renaming"), HttpGet("/Bcl/TreeView/Ajax/Renaming")]
    public IActionResult TreeRenaming() => Example("treeview", "renaming");
    [DocsNode("bcl:components:treeview:selection"), HttpGet("/Bcl/TreeView/Ajax/Selection")]
    public IActionResult TreeSelection() => Example("treeview", "selection");
    [DocsNode("bcl:components:treeview:lazy-loading"), HttpGet("/Bcl/TreeView/Ajax/LazyLoading")]
    public IActionResult TreeLazyLoading() => Example("treeview", "lazy-loading");
    [DocsNode("bcl:components:listview:checking"), HttpGet("/Bcl/ListView/Ajax/Checking")]
    public IActionResult ListChecking() => Example("listview", "checking");
    [DocsNode("bcl:components:listview:reordering"), HttpGet("/Bcl/ListView/Ajax/Reordering")]
    public IActionResult ListReordering() => Example("listview", "reordering");
    [DocsNode("bcl:components:listview:renaming"), HttpGet("/Bcl/ListView/Ajax/Renaming")]
    public IActionResult ListRenaming() => Example("listview", "renaming");
    [DocsNode("bcl:components:listview:selection"), HttpGet("/Bcl/ListView/Ajax/Selection")]
    public IActionResult ListSelection() => Example("listview", "selection");

    [DocsNode("bcl:components:treeview-dropdown:checking"), HttpGet("/Bcl/TreeViewDropdown/Ajax/Checking")]
    public IActionResult TreeDropdownChecking() => Example("treeview", "dropdown-checking");
    [DocsNode("bcl:components:treeview-dropdown:selection"), HttpGet("/Bcl/TreeViewDropdown/Ajax/Selection")]
    public IActionResult TreeDropdownSelection() => Example("treeview", "dropdown-selection");
    [DocsNode("bcl:components:treeview-dropdown:reordering"), HttpGet("/Bcl/TreeViewDropdown/Ajax/Reordering")]
    public IActionResult TreeDropdownReordering() => Example("treeview", "dropdown-reordering");
    [DocsNode("bcl:components:treeview-dropdown:renaming"), HttpGet("/Bcl/TreeViewDropdown/Ajax/Renaming")]
    public IActionResult TreeDropdownRenaming() => Example("treeview", "dropdown-renaming");
    [DocsNode("bcl:components:treeview-dropdown:lazy-loading"), HttpGet("/Bcl/TreeViewDropdown/Ajax/LazyLoading")]
    public IActionResult TreeDropdownLazyLoading() => Example("treeview", "dropdown-lazy-loading");
    [DocsNode("bcl:components:listview-dropdown:checking"), HttpGet("/Bcl/ListViewDropdown/Ajax/Checking")]
    public IActionResult ListDropdownChecking() => Example("listview", "dropdown-checking");
    [DocsNode("bcl:components:listview-dropdown:selection"), HttpGet("/Bcl/ListViewDropdown/Ajax/Selection")]
    public IActionResult ListDropdownSelection() => Example("listview", "dropdown-selection");
    [DocsNode("bcl:components:listview-dropdown:reordering"), HttpGet("/Bcl/ListViewDropdown/Ajax/Reordering")]
    public IActionResult ListDropdownReordering() => Example("listview", "dropdown-reordering");
    [DocsNode("bcl:components:listview-dropdown:renaming"), HttpGet("/Bcl/ListViewDropdown/Ajax/Renaming")]
    public IActionResult ListDropdownRenaming() => Example("listview", "dropdown-renaming");

    private IActionResult Example(string kind, string scenario)
    {
        store.Get(HttpContext); // Issue the browser-isolation cookie before concurrent Ajax requests.
        return View("~/Views/Docs/ViewAjax.cshtml", new ViewAjaxExampleModel(kind, scenario));
    }

    [HttpGet("/Bcl/ViewExamples/{kind}/{scenario}/state")]
    public IActionResult State(string kind, string scenario)
    {
        if (!ViewAjaxExampleModel.IsValid(kind, scenario)) return NotFound();
        var workspace = store.Get(HttpContext);
        lock (workspace.SyncRoot)
        {
            var state = workspace.Get(kind, scenario);
            return Json(new { serverRevision = state.Revision, snapshot = state.Snapshot });
        }
    }

    [HttpPost("/Bcl/ViewExamples/{kind}/{scenario}/save"), ValidateAntiForgeryToken, RequestSizeLimit(131072)]
    public async Task<IActionResult> Save(string kind, string scenario, [FromBody] JsonElement body, int delay = 0, bool fail = false)
    {
        if (!ViewAjaxExampleModel.IsValid(kind, scenario) || !new ViewAjaxExampleModel(kind, scenario).SavesChanges) return NotFound();
        if (await SimulateAsync(delay, fail) is { } failure) return failure;
        if (!ModelState.IsValid || body.ValueKind != JsonValueKind.Object) return BadRequest(new { message = "A JSON submission object is required." });
        BootstrapViewSubmissionModel submission;
        try { submission = BootstrapViewSubmissionModel.Parse(body.GetRawText()); }
        catch (Exception error) when (error is JsonException or ValidationException)
        { return BadRequest(new { message = error.Message }); }
        if (submission.Kind != kind || submission.ControlId != "ajax-demo") return BadRequest(new { message = "Wrong control identity." });
        if (ValidateDomain(submission, scenario) is { } invalid) return UnprocessableEntity(new { message = invalid });
        var workspace = store.Get(HttpContext);
        lock (workspace.SyncRoot)
        {
            var state = workspace.Get(kind, scenario);
            var hash = Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(body.GetRawText())));
            var receiptKey = submission.InstanceId + ":" + submission.SubmissionId;
            if (state.Receipts.TryGetValue(receiptKey, out var receipt))
                return receipt.Hash == hash ? Json(new { acknowledgment = receipt.Ack, snapshot = receipt.Snapshot })
                    : Conflict(new { message = "A submission identity was reused with different data." });
            if (submission.ServerRevision != state.Revision)
                return Conflict(new { message = "The saved revision changed. Reload saved state before applying new edits.", serverRevision = state.Revision });
            state.Snapshot = submission.Snapshot;
            state.Revision = Guid.NewGuid().ToString("N");
            var acknowledgment = new BootstrapViewAcknowledgmentModel
            {
                InstanceId = submission.InstanceId, SubmissionId = submission.SubmissionId,
                Accepted = true, ServerRevision = state.Revision,
            };
            if (state.Receipts.Count >= 32) state.Receipts.Remove(state.Receipts.Keys.First());
            state.Receipts[receiptKey] = (hash, acknowledgment, submission.Snapshot);
            return Json(new { acknowledgment, snapshot = state.Snapshot });
        }
    }

    [HttpPost("/Bcl/ViewExamples/{kind}/{scenario}/reset"), ValidateAntiForgeryToken]
    public IActionResult Reset(string kind, string scenario)
    {
        if (!ViewAjaxExampleModel.IsValid(kind, scenario)) return NotFound();
        var workspace = store.Get(HttpContext);
        lock (workspace.SyncRoot)
        {
            var state = workspace.Get(kind, scenario);
            state.Reset();
            return Json(new { serverRevision = state.Revision, snapshot = state.Snapshot });
        }
    }

    [HttpPost("/Bcl/ViewExamples/{kind}/{scenario}/conflict"), ValidateAntiForgeryToken]
    public IActionResult ConflictExample(string kind, string scenario)
    {
        if (!ViewAjaxExampleModel.IsValid(kind, scenario) || !new ViewAjaxExampleModel(kind, scenario).SavesChanges) return NotFound();
        var workspace = store.Get(HttpContext);
        lock (workspace.SyncRoot)
        {
            var state = workspace.Get(kind, scenario);
            state.Revision = Guid.NewGuid().ToString("N");
            return Json(new { message = "Another editor advanced the server revision. The next local save will conflict." });
        }
    }

    [HttpGet("/Bcl/ViewExamples/{kind}/selection/details/{id}")]
    public async Task<IActionResult> Details(string kind, string id, int delay = 0, bool fail = false)
    {
        if (!ViewAjaxExampleModel.IsValid(kind, "selection")) return NotFound();
        if (await SimulateAsync(delay, fail) is { } failure) return failure;
        var row = ViewAjaxExampleModel.Rows(kind).SingleOrDefault(row => row.Id == id);
        return row is null ? NotFound() : Json(new { id = row.Id, title = row.Label, reference = row.Value,
            owner = "Documentation", summary = "Synthetic notice details retrieved from the server.", loadedAt = DateTimeOffset.UtcNow });
    }

    [HttpGet("/Bcl/ViewExamples/treeview/lazy-loading/children/{id}")]
    [HttpGet("/Bcl/ViewExamples/treeview/dropdown-lazy-loading/children/{id}")]
    public async Task<IActionResult> Children(string id, int delay = 0, bool fail = false)
    {
        if (await SimulateAsync(delay, fail) is { } failure) return failure;
        if (id is not ("operations" or "planned")) return NotFound();
        return Json(ViewAjaxExampleModel.Rows("treeview").Where(row => row.ParentId == id).Select(ViewAjaxExampleModel.Payload));
    }

    private async Task<IActionResult?> SimulateAsync(int delay, bool fail)
    {
        if (delay is < 0 or > 2500) return BadRequest(new { message = "Delay must be between 0 and 2500 milliseconds." });
        if (delay > 0) await Task.Delay(delay, HttpContext.RequestAborted);
        return fail ? StatusCode(503, new { message = "Simulated service failure. The request was not saved; retry when ready." }) : null;
    }

    private static string? ValidateDomain(BootstrapViewSubmissionModel submission, string scenario)
    {
        if (scenario.StartsWith("dropdown-", StringComparison.Ordinal)) scenario = scenario[9..];
        var expected = ViewAjaxExampleModel.Rows(submission.Kind).ToDictionary(row => row.Id);
        if (submission.Snapshot.Items.Count != expected.Count || submission.Snapshot.Items.Any(item => !expected.ContainsKey(item.Id)))
            return "This example permits only its original notice identities.";
        foreach (var item in submission.Snapshot.Items)
        {
            var seed = expected[item.Id];
            if (!item.Data.TryGetValue("data", out var data) || data.ValueKind != JsonValueKind.Object
                || !data.TryGetProperty("code", out var code) || code.ValueKind != JsonValueKind.String || code.GetString() != item.Id
                || !data.TryGetProperty("owner", out var owner) || owner.ValueKind != JsonValueKind.String || owner.GetString() != "Documentation")
                return "Application notice data cannot be changed by this operation.";
            if (!item.Data.TryGetValue("boundValue", out var value) || value.ValueKind != JsonValueKind.String || value.GetString() != seed.Value)
                return "Notice reference values cannot be changed.";
            if (!item.Data.TryGetValue("label", out var label) || label.ValueKind != JsonValueKind.String
                || label.GetString()!.Trim().Length is < 3 or > 80) return "Labels must contain between 3 and 80 characters.";
            if (scenario != "renaming" && label.GetString() != seed.Label) return "This example does not permit renaming.";
            if (scenario != "reordering" && (item.ParentId != seed.ParentId || item.Index != seed.Index)) return "This example does not permit reordering.";
            if (item.ParentId is not null && item.ParentId is not ("operations" or "planned")) return "Only notice groups can receive children.";
        }
        if (scenario != "checking" && (submission.Snapshot.State.CheckedIds.Count > 0 || submission.Snapshot.State.IndeterminateIds.Count > 0))
            return "This example does not permit checking.";
        return null;
    }
}

using CopelandSyst.BootstrapComponents.ViewModels;

namespace CopelandSyst.Docs.Models;

public sealed record ViewDemoRow(string Id, string Label, string? ParentId, int Index, string Value);

public sealed class ViewAjaxExampleModel(string kind, string scenario)
{
    public string Kind { get; } = kind;
    public string Scenario { get; } = scenario;
    public bool IsDropdown => Scenario.StartsWith("dropdown-", StringComparison.Ordinal);
    public string Operation => IsDropdown ? Scenario[9..] : Scenario;
    public string ControlName => (Kind == "treeview" ? "TreeView" : "ListView") + (IsDropdown ? "Dropdown" : "");
    public string Title => Operation switch
    {
        "checking" => "Ajax (Checking)", "reordering" => "Ajax (Drag and drop)",
        "renaming" => "Ajax (Renaming)", "selection" => "Ajax (Selection)",
        "lazy-loading" => "Ajax (Lazy loading)", _ => throw new ArgumentOutOfRangeException(nameof(Scenario)),
    };
    public bool SavesChanges => Operation is "checking" or "reordering" or "renaming" || IsDropdown && Operation == "selection";
    public string Instructions => IsDropdown
        ? Operation == "lazy-loading" ? "Open the picker and expand a group to load its options. Failed loads can be retried; closing the picker preserves loaded data. Reset invalidates pending work."
        : "Open the picker to edit notices. Apply commits the chosen value and queues a background save; Cancel restores the previous value. Reordering and renaming remain independent edits. Delay, failure, retry and revision conflicts exercise the same typed acknowledgment contract as the standalone controls."
        : Operation switch
    {
        "checking" => "Check notices to save their checked state in the background. During a slow save, check another notice: the later edit remains pending until its own acknowledgment.",
        "reordering" => "Drag notices to reorder them. In TreeView, drop a notice inside another group to change its parent. The Move selected button provides the same operation without a pointer. The request records previous and new positions.",
        "renaming" => "Select a notice and press F2, or double-click its label. Commit with Enter or cancel with Escape. The server requires labels between 3 and 80 characters; rejected edits remain local until corrected or discarded.",
        "selection" => "Select notices to fetch their details. With a delay enabled, select another notice before the first request returns: only the latest selection may update the details panel.",
        _ => "Expand a group to request its children. Enable Fail next request to exercise the error/retry path. Reset restores the unloaded groups and invalidates pending responses.",
    };

    public static bool IsValid(string kind, string scenario)
    {
        var operation = scenario.StartsWith("dropdown-", StringComparison.Ordinal) ? scenario[9..] : scenario;
        return kind is "treeview" or "listview"
            && (operation is "checking" or "reordering" or "renaming" or "selection" || kind == "treeview" && operation == "lazy-loading");
    }

    public static IReadOnlyList<ViewDemoRow> Rows(string kind) => kind == "treeview"
        ? [new("operations", "Operations", null, 0, "operations"),
           new("notice-1", "Service maintenance", "operations", 0, "NOTICE-001"),
           new("notice-2", "Access review", "operations", 1, "NOTICE-002"),
           new("planned", "Planned work", null, 1, "planned"),
           new("notice-3", "Release briefing", "planned", 0, "NOTICE-003"),
           new("notice-4", "Policy update", "planned", 1, "NOTICE-004")]
        : [new("notice-1", "Service maintenance", null, 0, "NOTICE-001"),
           new("notice-2", "Access review", null, 1, "NOTICE-002"),
           new("notice-3", "Release briefing", null, 2, "NOTICE-003"),
           new("notice-4", "Policy update", null, 3, "NOTICE-004")];

    public static object Payload(ViewDemoRow row) => new
    {
        id = row.Id, label = row.Label, boundValue = row.Value,
        subtitle = row.Id.StartsWith("notice-", StringComparison.Ordinal) ? "Example notice" : null,
        data = new { code = row.Id, owner = "Documentation" },
    };

    public BootstrapTreeViewModel Tree
    {
        get
        {
            var root = new BootstrapTreeViewModel();
            var rows = Rows("treeview");
            foreach (var group in rows.Where(row => row.ParentId is null))
            {
                var node = ToTreeNode(group);
                node.Expanded = Operation != "lazy-loading";
                if (Operation == "lazy-loading") { node.Lazy = true; node.HasChildren = true; }
                else foreach (var child in rows.Where(row => row.ParentId == group.Id)) node.ChildrenCapture.Add(ToTreeNode(child));
                root.NodesCapture.Add(node);
            }
            return root;
        }
    }

    public BootstrapListViewModel List
    {
        get
        {
            var root = new BootstrapListViewModel();
            foreach (var row in Rows("listview")) root.ItemsCapture.Add(new BootstrapListViewItemModel
            {
                ItemId = row.Id, Label = row.Label, Subtitle = "Example notice", BoundValue = row.Value,
                Data = new { code = row.Id, owner = "Documentation" },
            });
            return root;
        }
    }

    private static BootstrapTreeViewNodeModel ToTreeNode(ViewDemoRow row) => new()
    {
        NodeId = row.Id, Label = row.Label, BoundValue = row.Value,
        Subtitle = row.ParentId is null ? null : "Example notice", Data = new { code = row.Id, owner = "Documentation" },
    };

    public BootstrapTreeViewDropdownModel DropdownTree
    {
        get
        {
            var model = new BootstrapTreeViewDropdownModel();
            foreach (var node in Tree.NodesCapture) model.NodesCapture.Add(node);
            return model;
        }
    }

    public BootstrapListViewDropdownModel DropdownList
    {
        get
        {
            var model = new BootstrapListViewDropdownModel();
            foreach (var item in List.ItemsCapture) model.ItemsCapture.Add(item);
            return model;
        }
    }
}

using CopelandSyst.BootstrapComponents.ViewModels;
using Microsoft.Extensions.Caching.Memory;

namespace CopelandSyst.Docs.Services;

// Synthetic data only. Cookie isolation and revision checks also apply across tabs.
public sealed class ViewDemoStore : IDisposable
{
    private const string CookieName = "CopelandDocs.ViewExamples";
    private readonly MemoryCache cache = new(new MemoryCacheOptions { SizeLimit = 128 });
    private readonly object gate = new();

    public Workspace Get(HttpContext context)
    {
        lock (gate)
        {
            var token = context.Request.Cookies[CookieName];
            if (Guid.TryParseExact(token, "N", out _) && cache.TryGetValue(token!, out Workspace? existing) && existing is not null)
                return existing;
            token = Guid.NewGuid().ToString("N");
            var workspace = new Workspace();
            cache.Set(token, workspace, new MemoryCacheEntryOptions { Size = 1, SlidingExpiration = TimeSpan.FromMinutes(30) });
            context.Response.Cookies.Append(CookieName, token, new CookieOptions
            {
                HttpOnly = true, SameSite = SameSiteMode.Strict, Secure = context.Request.IsHttps,
                IsEssential = true, Path = "/Bcl",
            });
            return workspace;
        }
    }

    public void Dispose() => cache.Dispose();

    public sealed class Workspace
    {
        public object SyncRoot { get; } = new();
        private readonly Dictionary<string, ScenarioState> scenarios = [];
        // Call under SyncRoot. Only allowlisted standalone and dropdown scenarios reach this method.
        public ScenarioState Get(string kind, string scenario)
        {
            var key = kind + ":" + scenario;
            if (!scenarios.TryGetValue(key, out var value)) scenarios[key] = value = new();
            return value;
        }
    }

    public sealed class ScenarioState
    {
        public string Revision { get; set; } = Guid.NewGuid().ToString("N");
        public BootstrapViewSnapshotModel? Snapshot { get; set; }
        public Dictionary<string, (string Hash, BootstrapViewAcknowledgmentModel Ack, BootstrapViewSnapshotModel Snapshot)> Receipts { get; } = [];
        public void Reset()
        {
            Snapshot = null;
            Revision = Guid.NewGuid().ToString("N");
            Receipts.Clear();
        }
    }
}