@page "/meters"
@inject Microsoft.EntityFrameworkCore.IDbContextFactory<MeterVault.Infrastructure.Persistence.MeterVaultDbContext> DbFactory
@inject ISnackbar Snackbar
@inject IDialogService DialogService
@inject NavigationManager Nav
@using Microsoft.EntityFrameworkCore
@using MudBlazor

<PageTitle>MeterVault — @S.Nav_Meters</PageTitle>

<div class="d-flex align-center justify-space-between mb-4 flex-wrap" style="gap:1rem">
    <MudText Typo="Typo.h4">@S.Common_Meters</MudText>
    <MudButton Variant="Variant.Filled" Color="Color.Primary" StartIcon="@Icons.Material.Filled.Add" OnClick="@(() => _editor!.OpenNewAsync())">
        @S.Meters_AddMeter
    </MudButton>
</div>

@if (_meters is null)
{
    <MudProgressLinear Indeterminate="true" Color="Color.Primary" />
}
else
{
    @* The whole row opens the meter — on a phone this table collapses to cards, where a name link
       is a small target between edit and delete. Grouped by energy type, because that is how people
       look for a meter ("the water one"), not by the order they were created in. *@
    <MudTable Items="_meters" Dense="true" Hover="true" Elevation="2" Filter="Matches"
              GroupBy="_byEnergyType" OnRowClick="@((TableRowClickEventArgs<Meter> e) => Nav.NavigateTo(MeterLinks.Detail(e.Item!.Id)))"
              RowClass="cursor-pointer">
        <ToolBarContent>
            <MudTextField T="string" @bind-Value="_search" Immediate="true" Placeholder="@S.Meters_SearchPlaceholder"
                          Adornment="Adornment.Start" AdornmentIcon="@Icons.Material.Filled.Search" Clearable="true"
                          Class="mt-0" Style="max-width:420px" />
        </ToolBarContent>
        <HeaderContent>
            <MudTh>@S.Common_Name</MudTh>
            <MudTh>@S.Common_Mode</MudTh>
            <MudTh>@S.Common_Unit</MudTh>
            <MudTh>@S.Meters_Sources</MudTh>
            <MudTh>@S.Common_LastSeen</MudTh>
            <MudTh>@S.Meters_Active</MudTh>
            <MudTh Style="text-align:right">@S.Common_Actions</MudTh>
        </HeaderContent>
        <GroupHeaderTemplate>
            <MudTh colspan="7" Class="mud-table-cell-custom-group">
                <MudText Typo="Typo.subtitle2">@context.Key</MudText>
            </MudTh>
        </GroupHeaderTemplate>
        <RowTemplate>
            <MudTd DataLabel="@S.Common_Name">
                @* The link stays a real link (keyboard, open in new tab) but must not also fire the row's
                   click, or one tap pushes the same page onto the history twice. *@
                <span @onclick:stopPropagation="true"><MudLink Href="@MeterLinks.Detail(context.Id)">@context.Name</MudLink></span>
                @if (!context.IsActive)
                {
                    <MudChip T="string" Size="Size.Small" Color="Color.Warning" Class="ml-2">@S.MeterDetail_Retired</MudChip>
                }
            </MudTd>
            <MudTd DataLabel="@S.Common_Mode" HideSmall="true">@context.Mode.Display()</MudTd>
            <MudTd DataLabel="@S.Common_Unit" HideSmall="true">@context.Unit</MudTd>
            <MudTd DataLabel="@S.Meters_Sources" HideSmall="true">@context.Sources.Count</MudTd>
            <MudTd DataLabel="@S.Common_LastSeen" HideSmall="true">
                @{
                    var lastSeen = context.Sources.Where(s => s.LastSeenAt != null).Select(s => s.LastSeenAt).DefaultIfEmpty(null).Max();
                }
                @(lastSeen?.ToString("yyyy-MM-dd HH:mm") ?? "—")
            </MudTd>
            <MudTd DataLabel="@S.Meters_Active" HideSmall="true">@(context.IsActive ? S.Meters_Yes : S.Meters_No)</MudTd>
            <MudTd DataLabel="@S.Common_Actions" Style="text-align:right">
                @* Buttons inside a clickable row must not also open the meter. *@
                <div class="d-inline-flex" @onclick:stopPropagation="true">
                    @if (MeterLinks.QuickEntry(context.Id, context.Mode) is { } entry)
                    {
                        <MudTooltip Text="@(context.Mode == MeterMode.ConsumableBalance ? S.MeterDetail_RecordTankLevel : S.MeterDetail_AddReading)">
                            <MudIconButton Icon="@(context.Mode == MeterMode.ConsumableBalance ? Icons.Material.Filled.Straighten : Icons.Material.Filled.EditNote)"
                                           Size="Size.Small" Color="Color.Primary" Href="@entry"
                                           aria-label="@(context.Mode == MeterMode.ConsumableBalance ? S.MeterDetail_RecordTankLevel : S.MeterDetail_AddReading)" />
                        </MudTooltip>
                    }
                    <MudIconButton Icon="@Icons.Material.Filled.Edit" Size="Size.Small" OnClick="@(() => _editor!.OpenAsync(context.Id))" aria-label="@S.MeterDetail_EditMeter" />
                    <MudIconButton Icon="@Icons.Material.Filled.Delete" Size="Size.Small" Color="Color.Error" OnClick="@(() => DeleteAsync(context))" aria-label="@S.Common_Delete" />
                </div>
            </MudTd>
        </RowTemplate>
        <NoRecordsContent>
            @if (_meters.Count > 0)
            {
                <MudText Typo="Typo.body2" Color="Color.Secondary">@Loc.F(S.Meters_NoSearchMatch, _search)</MudText>
            }
        </NoRecordsContent>
    </MudTable>

    @if (_meters.Count == 0)
    {
        <MudAlert Severity="Severity.Info" Class="mt-4">
            @S.Meters_EmptyBefore <MudLink Href="/import">@S.Nav_Import</MudLink> @S.Meters_EmptyAfter
        </MudAlert>
    }
}

<MeterEditor @ref="_editor" Saved="OnSavedAsync" SwapInsteadRequested="@(id => Nav.NavigateTo(MeterLinks.Event(id, MeterEventType.MeterSwap)))" />

@code {
    private List<Meter>? _meters;
    private MeterEditor? _editor;
    private string? _search;

    private readonly TableGroupDefinition<Meter> _byEnergyType = new()
    {
        Indentation = false,
        Expandable = false,
        Selector = m => m.EnergyType?.DisplayName ?? "—",
    };

    protected override Task OnInitializedAsync() => LoadAsync();

    private async Task LoadAsync()
    {
        await using var db = await DbFactory.CreateDbContextAsync();
        var meters = await db.Meters
            .AsNoTracking()
            .Include(m => m.EnergyType)
            .Include(m => m.Sources)
            .ToListAsync();

        // Grouping follows item order, so sort by the group label first. Retired meters sink to the
        // bottom of their group: their history still counts, but nobody reads them any more.
        _meters = meters
            .OrderBy(m => m.EnergyType?.DisplayName, StringComparer.CurrentCultureIgnoreCase)
            .ThenBy(m => !m.IsActive)
            .ThenBy(m => m.Name, StringComparer.CurrentCultureIgnoreCase)
            .ToList();
    }

    private bool Matches(Meter meter)
    {
        if (string.IsNullOrWhiteSpace(_search))
        {
            return true;
        }

        var term = _search.Trim();
        return Contains(meter.Name) || Contains(meter.SerialNumber) || Contains(meter.Location)
            || Contains(meter.EnergyType?.DisplayName) || Contains(meter.Mode.Display());

        bool Contains(string? value) => value?.Contains(term, StringComparison.CurrentCultureIgnoreCase) == true;
    }

    /// <summary>A new meter goes straight to its own page, where adding readings or a source is the next step.</summary>
    private async Task OnSavedAsync((int MeterId, bool Created) saved)
    {
        if (saved.Created)
        {
            Nav.NavigateTo(MeterLinks.Detail(saved.MeterId));
            return;
        }

        await LoadAsync();
    }

    private async Task DeleteAsync(Meter meter)
    {
        await using var db = await DbFactory.CreateDbContextAsync();
        var readings = await db.Readings.CountAsync(r => r.MeterId == meter.Id);
        var consumption = await db.Consumption.CountAsync(c => c.MeterId == meter.Id);
        var message = readings + consumption > 0
            ? Loc.F(S.Meters_DeleteConfirmWithData, meter.Name, readings, consumption)
            : Loc.F(S.Meters_DeleteConfirm, meter.Name);

        if (!await Confirm.DeleteAsync(DialogService, S.Meters_DeleteTitle, message))
        {
            return;
        }

        await using var tx = await db.Database.BeginTransactionAsync();
        // reading/consumption FKs are Restrict — remove them first; events/sources/tank/members cascade.
        await db.Consumption.Where(c => c.MeterId == meter.Id).ExecuteDeleteAsync();
        await db.Readings.Where(r => r.MeterId == meter.Id).ExecuteDeleteAsync();
        await db.Meters.Where(m => m.Id == meter.Id).ExecuteDeleteAsync();
        await tx.CommitAsync();

        Snackbar.Add(S.Common_Deleted, Severity.Success);
        await LoadAsync();
    }
}