@page "/"
@inject DashboardService Dash

<PageTitle>MeterVault — Overview</PageTitle>

<MudText Typo="Typo.h4" Class="mb-4">Overview</MudText>

@if (_summary is null)
{
    <MudProgressLinear Indeterminate="true" Color="Color.Primary" />
}
else
{
    <MudGrid>
        <MudItem xs="12" sm="4">
            <MudPaper Class="pa-4" Elevation="2">
                <MudText Typo="Typo.overline" Color="Color.Secondary">This month</MudText>
                <MudText Typo="Typo.h5">@Format.Euro(_summary.Month.Current)</MudText>
                <DeltaChip Kpi="_summary.Month" />
            </MudPaper>
        </MudItem>
        <MudItem xs="12" sm="4">
            <MudPaper Class="pa-4" Elevation="2">
                <MudText Typo="Typo.overline" Color="Color.Secondary">This year</MudText>
                <MudText Typo="Typo.h5">@Format.Euro(_summary.Year.Current)</MudText>
                <DeltaChip Kpi="_summary.Year" />
            </MudPaper>
        </MudItem>
        <MudItem xs="12" sm="4">
            <MudPaper Class="pa-4" Elevation="2">
                <MudText Typo="Typo.overline" Color="Color.Secondary">Latest month with data</MudText>
                <MudText Typo="Typo.h5">@Format.Euro(_summary.LatestMonthCost)</MudText>
            </MudPaper>
        </MudItem>

        <MudItem xs="12" md="6">
            <MudPaper Class="pa-4" Elevation="2" Style="height:100%">
                <MudText Typo="Typo.h6" Class="mb-2">What costs most (this year)</MudText>
                @if (_breakdown is { Count: > 0 })
                {
                    <CategoryDonut Slices="_breakdown" />
                    <MudSimpleTable Dense="true" Hover="true" Class="mt-2">
                        <tbody>
                            @foreach (var slice in _breakdown)
                            {
                                <tr>
                                    <td>@slice.Name</td>
                                    <td style="text-align:right">@Format.Euro(slice.Cost)</td>
                                </tr>
                            }
                        </tbody>
                    </MudSimpleTable>
                }
                else
                {
                    <MudText Typo="Typo.body2" Color="Color.Secondary">No cost data yet — import a sheet or add tariffs.</MudText>
                }
            </MudPaper>
        </MudItem>

        <MudItem xs="12" md="6">
            <MudPaper Class="pa-4" Elevation="2" Style="height:100%">
                <MudText Typo="Typo.h6" Class="mb-2">What cost more / less (year vs last year)</MudText>
                <MudSimpleTable Dense="true" Hover="true">
                    <thead>
                        <tr><th>Category</th><th style="text-align:right">Now</th><th style="text-align:right">Prev</th><th style="text-align:right">Δ</th></tr>
                    </thead>
                    <tbody>
                        @foreach (var row in _difference)
                        {
                            <tr>
                                <td>@row.Name</td>
                                <td style="text-align:right">@Format.Euro(row.Current)</td>
                                <td style="text-align:right">@Format.Euro(row.Previous)</td>
                                <td style="text-align:right" class="@(row.Delta >= 0 ? "mv-up" : "mv-down")">
                                    @Format.DirectionIcon(Math.Sign(row.Delta)) @Format.Euro(Math.Abs(row.Delta))
                                </td>
                            </tr>
                        }
                    </tbody>
                </MudSimpleTable>
            </MudPaper>
        </MudItem>
    </MudGrid>
}

@code {
    private DashboardSummary? _summary;
    private IReadOnlyList<CategorySlice> _breakdown = [];
    private IReadOnlyList<DifferenceRow> _difference = [];

    protected override async Task OnInitializedAsync()
    {
        var asOf = DateOnly.FromDateTime(DateTime.UtcNow);
        _summary = await Dash.GetSummaryAsync(asOf);

        var yearStart = new DateOnly(asOf.Year, 1, 1);
        _breakdown = await Dash.GetCategoryBreakdownAsync(yearStart, asOf.AddMonths(1));
        _difference = await Dash.GetCategoryDifferenceAsync(yearStart, yearStart.AddYears(-1), asOf.AddMonths(1));
    }
}