@page "/audit/log"
@attribute [Authorize(Policy = AuthorizationPolicies.OperationalAudit)]
@using ZB.MOM.WW.ScadaBridge.CentralUI.Components.Audit
@using ZB.MOM.WW.ScadaBridge.CentralUI.Components.Shared
@using ZB.MOM.WW.ScadaBridge.CentralUI.Services
@using ZB.MOM.WW.ScadaBridge.Commons.Types.Audit
@using ZB.MOM.WW.ScadaBridge.Security
@inject IAuditLogQueryService AuditLogQueryService

<PageTitle>Audit Log</PageTitle>

<div class="container-fluid mt-3">
    <h1 class="h4 mb-3">Audit Log</h1>

    @* Trends panel (M6 / K15). A best-effort collapsible Bootstrap card sitting
       above the audit query UI: one KpiTrendChart per AuditLog global metric over
       a 24h (default) / 7d window. Series are fetched independently in the
       code-behind — a failed fetch degrades only that chart to the unavailable
       placeholder and never breaks the filter bar / grid below. *@
    <div class="card mb-3" data-test="audit-trends">
        <div class="card-header d-flex justify-content-between align-items-center">
            <button type="button"
                    class="btn btn-link p-0 text-decoration-none fw-semibold"
                    aria-expanded="@_trendsOpen"
                    @onclick="ToggleTrendsAsync">
                Trends
                <span class="text-muted small">@(_trendsOpen ? "▾" : "▸")</span>
            </button>
            @if (_trendsOpen)
            {
                <div class="btn-group btn-group-sm" role="group" aria-label="Trend window">
                    <button type="button"
                            class="btn @(_windowHours == 24 ? "btn-secondary" : "btn-outline-secondary")"
                            @onclick="() => SetWindowAsync(24)" disabled="@_trendsLoading">
                        24h
                    </button>
                    <button type="button"
                            class="btn @(_windowHours == 168 ? "btn-secondary" : "btn-outline-secondary")"
                            @onclick="() => SetWindowAsync(168)" disabled="@_trendsLoading">
                        7d
                    </button>
                </div>
            }
        </div>
        @if (_trendsOpen)
        {
            <div class="card-body">
                <div class="row g-3">
                    @foreach (var (metric, title, unit) in TrendMetrics)
                    {
                        var series = SeriesFor(metric);
                        <div class="col-12 col-md-4">
                            <KpiTrendChart Points="@series.Points"
                                           Title="@title"
                                           Unit="@unit"
                                           IsAvailable="@series.IsAvailable"
                                           ErrorMessage="@series.ErrorMessage" />
                        </div>
                    }
                </div>
            </div>
        }
    </div>

    @* Filter bar (Bundle B / M7-T2). Apply hands the collapsed filter to the grid.
       Bundle D (M7-T10..T12) threads a query-string instance prefill through
       InitialInstanceSearch — UI-only because the filter contract has no instance column. *@
    <div class="mb-3">
        <AuditFilterBar OnFilterChanged="HandleFilterChanged"
                        InitialInstanceSearch="@_initialInstanceSearch" />
    </div>

    @* Export button (Bundle F / M7-T14). A plain <a download> link triggers the
       streaming CSV endpoint at /api/centralui/audit/export — chosen over a
       SignalR-driven download because the request can stream 100k rows directly
       to the response body without buffering through the Blazor circuit. The
       href reflects the most recently applied filter; before Apply is clicked,
       an unconstrained export is exposed.

       Bundle G (#23 M7-T15) gates the button on the AuditExport policy so an
       OperationalAudit-only operator (read access without bulk export) sees the
       page + filters but cannot trigger the CSV pull. The endpoint itself is
       gated separately, so a hand-crafted URL still 403s — the AuthorizeView
       here is the user-facing affordance, not the authoritative check. *@
    <AuthorizeView Policy="@AuthorizationPolicies.AuditExport">
        <Authorized Context="exportContext">
            <div class="mb-3 d-flex justify-content-end">
                <a class="btn btn-outline-secondary btn-sm"
                   href="@ExportUrl"
                   download
                   role="button"
                   aria-label="Export current view to CSV">
                    Export CSV
                </a>
            </div>
        </Authorized>
    </AuthorizeView>

    @* Results grid (Bundle B / M7-T3). Row clicks emit OnRowSelected for Bundle C's
       drilldown drawer; the grid stays in "no events" mode until the user applies a
       filter so the page does not auto-load the full audit table on first render. *@
    <div>
        <AuditResultsGrid Filter="@_currentFilter" OnRowSelected="HandleRowSelected" />
    </div>
</div>

@* Drilldown drawer (Bundle C / M7-T4..T8). Hosted at the page level so the
   off-canvas overlay sits above the grid / filter bar irrespective of scroll. *@
<AuditDrilldownDrawer Event="@_selectedEvent"
                      IsOpen="@_drawerOpen"
                      OnClose="HandleDrawerClose" />