@page "/stock/new"
@page "/stock/{Id:int}"
@inject StockItemService StockItemService
@inject MaterialService MaterialService
@inject NavigationManager Navigation
@using CutList.Core.Formatting

<PageTitle>@(IsNew ? "Add Stock Item" : "Edit Stock Item")</PageTitle>

<h1>@(IsNew ? "Add Stock Item" : $"{stockItem.Material?.DisplayName} - {ArchUnits.FormatFromInches((double)stockItem.LengthInches)}")</h1>

@if (loading)
{
    <p><em>Loading...</em></p>
}
else
{
    <div class="row">
        <div class="col-lg-6 mb-4">
            <div class="card">
                <div class="card-header">
                    <h5 class="mb-0">Stock Item Details</h5>
                </div>
                <div class="card-body">
                    <EditForm Model="stockItem" OnValidSubmit="SaveStockItemAsync">
                        <DataAnnotationsValidator />

                        <div class="mb-3">
                            <label class="form-label">Material</label>
                            <select class="form-select" @bind="stockItem.MaterialId" disabled="@(!IsNew)">
                                <option value="0">-- Select Material --</option>
                                @foreach (var material in materials)
                                {
                                    <option value="@material.Id">@material.DisplayName</option>
                                }
                            </select>
                        </div>

                        <div class="mb-3">
                            <label class="form-label">Length</label>
                            <LengthInput @bind-Value="stockItem.LengthInches" />
                        </div>

                        <div class="mb-3">
                            <label class="form-label">Name (optional)</label>
                            <InputText class="form-control" @bind-Value="stockItem.Name" placeholder="Custom display name" />
                        </div>

                        <div class="mb-3">
                            <label class="form-label">Notes (optional)</label>
                            <InputText class="form-control" @bind-Value="stockItem.Notes" placeholder="Internal notes" />
                        </div>

                        @if (!string.IsNullOrEmpty(errorMessage))
                        {
                            <div class="alert alert-danger">@errorMessage</div>
                        }

                        <div class="d-flex gap-2">
                            <button type="submit" class="btn btn-primary" disabled="@saving">
                                @if (saving)
                                {
                                    <span class="spinner-border spinner-border-sm me-1"></span>
                                }
                                @(IsNew ? "Create Stock Item" : "Save Changes")
                            </button>
                            <a href="stock" class="btn btn-outline-secondary">@(IsNew ? "Cancel" : "Back to List")</a>
                        </div>
                    </EditForm>
                </div>
            </div>
        </div>

        @if (!IsNew)
        {
            <div class="col-lg-6 mb-4">
                <div class="card">
                    <div class="card-header d-flex justify-content-between align-items-center">
                        <h5 class="mb-0">
                            Inventory
                            <span class="badge @(stockItem.QuantityOnHand > 0 ? "bg-success" : "bg-secondary") ms-2">@stockItem.QuantityOnHand on hand</span>
                        </h5>
                        <button class="btn btn-sm btn-primary" @onclick="ShowStockForm">Add/Adjust Stock</button>
                    </div>
                    <div class="card-body">
                        @if (showStockForm)
                        {
                            <div class="border rounded p-3 mb-3 bg-light">
                                <h6>Stock Transaction</h6>
                                <div class="row g-2">
                                    <div class="col-md-4">
                                        <label class="form-label">Type</label>
                                        <select class="form-select" @bind="stockTransactionType">
                                            <option value="add">Receive Stock</option>
                                            <option value="adjust">Set Quantity</option>
                                            <option value="scrap">Scrap/Waste</option>
                                        </select>
                                    </div>
                                    <div class="col-md-4">
                                        <label class="form-label">@(stockTransactionType == "adjust" ? "New Quantity" : "Quantity")</label>
                                        <input type="number" class="form-control" @bind="stockQuantity" min="0" />
                                    </div>
                                    <div class="col-md-4">
                                        <label class="form-label">Notes</label>
                                        <InputText class="form-control" @bind-Value="stockNotes" />
                                    </div>
                                </div>
                                @if (!string.IsNullOrEmpty(stockFormErrorMessage))
                                {
                                    <div class="alert alert-danger mt-2 mb-0">@stockFormErrorMessage</div>
                                }
                                <div class="mt-3 d-flex gap-2">
                                    <button class="btn btn-primary btn-sm" @onclick="SaveStockTransactionAsync" disabled="@savingStockTransaction">
                                        @if (savingStockTransaction)
                                        {
                                            <span class="spinner-border spinner-border-sm me-1"></span>
                                        }
                                        Save
                                    </button>
                                    <button class="btn btn-outline-secondary btn-sm" @onclick="CancelStockForm">Cancel</button>
                                </div>
                            </div>
                        }

                        @if (transactions.Count == 0)
                        {
                            <p class="text-muted">No transaction history yet.</p>
                        }
                        else
                        {
                            <table class="table table-sm">
                                <thead>
                                    <tr>
                                        <th>Date</th>
                                        <th>Type</th>
                                        <th>Qty</th>
                                        <th>Notes</th>
                                    </tr>
                                </thead>
                                <tbody>
                                    @foreach (var txn in transactions)
                                    {
                                        <tr>
                                            <td>@txn.CreatedAt.ToLocalTime().ToString("MM/dd/yy HH:mm")</td>
                                            <td>
                                                <span class="badge @GetTransactionBadgeClass(txn.Type)">@txn.Type</span>
                                            </td>
                                            <td class="@(txn.Quantity >= 0 ? "text-success" : "text-danger")">
                                                @(txn.Quantity >= 0 ? "+" : "")@txn.Quantity
                                            </td>
                                            <td>@(txn.Notes ?? "-")</td>
                                        </tr>
                                    }
                                </tbody>
                            </table>
                        }
                    </div>
                </div>
            </div>
        }
    </div>
}

@code {
    [Parameter]
    public int? Id { get; set; }

    private StockItem stockItem = new();
    private List<Material> materials = new();
    private List<StockTransaction> transactions = new();
    private bool loading = true;
    private bool saving;
    private string? errorMessage;

    // Stock transaction form
    private bool showStockForm;
    private bool savingStockTransaction;
    private string stockTransactionType = "add";
    private int stockQuantity;
    private string? stockNotes;
    private string? stockFormErrorMessage;

    private bool IsNew => !Id.HasValue;

    protected override async Task OnInitializedAsync()
    {
        materials = await MaterialService.GetAllAsync();

        if (Id.HasValue)
        {
            var existing = await StockItemService.GetByIdAsync(Id.Value);
            if (existing == null)
            {
                Navigation.NavigateTo("stock");
                return;
            }
            stockItem = existing;
            transactions = await StockItemService.GetTransactionHistoryAsync(Id.Value, 20);
        }
        loading = false;
    }

    private string GetTransactionBadgeClass(StockTransactionType type) => type switch
    {
        StockTransactionType.Received => "bg-success",
        StockTransactionType.Used => "bg-primary",
        StockTransactionType.Adjustment => "bg-warning text-dark",
        StockTransactionType.Scrapped => "bg-danger",
        StockTransactionType.Returned => "bg-info",
        _ => "bg-secondary"
    };

    private void ShowStockForm()
    {
        stockTransactionType = "add";
        stockQuantity = 0;
        stockNotes = null;
        stockFormErrorMessage = null;
        showStockForm = true;
    }

    private void CancelStockForm()
    {
        showStockForm = false;
        stockFormErrorMessage = null;
    }

    private async Task SaveStockTransactionAsync()
    {
        stockFormErrorMessage = null;
        savingStockTransaction = true;

        try
        {
            if (stockQuantity <= 0 && stockTransactionType != "adjust")
            {
                stockFormErrorMessage = "Quantity must be greater than zero";
                return;
            }

            if (stockTransactionType == "adjust" && stockQuantity < 0)
            {
                stockFormErrorMessage = "Quantity cannot be negative";
                return;
            }

            switch (stockTransactionType)
            {
                case "add":
                    await StockItemService.AddStockAsync(Id!.Value, stockQuantity, stockNotes);
                    break;
                case "adjust":
                    await StockItemService.AdjustStockAsync(Id!.Value, stockQuantity, stockNotes);
                    break;
                case "scrap":
                    await StockItemService.ScrapStockAsync(Id!.Value, stockQuantity, stockNotes);
                    break;
            }

            // Refresh
            var updated = await StockItemService.GetByIdAsync(Id!.Value);
            if (updated != null)
            {
                stockItem = updated;
            }
            transactions = await StockItemService.GetTransactionHistoryAsync(Id!.Value, 20);
            showStockForm = false;
        }
        finally
        {
            savingStockTransaction = false;
        }
    }

    private async Task SaveStockItemAsync()
    {
        errorMessage = null;
        saving = true;

        try
        {
            if (stockItem.MaterialId == 0)
            {
                errorMessage = "Please select a material";
                return;
            }

            if (stockItem.LengthInches <= 0)
            {
                errorMessage = "Length must be greater than zero";
                return;
            }

            var exists = await StockItemService.ExistsAsync(
                stockItem.MaterialId,
                stockItem.LengthInches,
                IsNew ? null : stockItem.Id);

            if (exists)
            {
                errorMessage = "A stock item with this material and length already exists";
                return;
            }

            try
            {
                if (IsNew)
                {
                    var created = await StockItemService.CreateAsync(stockItem);
                    Navigation.NavigateTo($"stock/{created.Id}");
                }
                else
                {
                    await StockItemService.UpdateAsync(stockItem);
                }
            }
            catch (Microsoft.EntityFrameworkCore.DbUpdateException)
            {
                errorMessage = "A stock item with this material and length already exists (it may have been previously deleted).";
            }
        }
        finally
        {
            saving = false;
        }
    }
}