<?php

namespace App\Models;

use App\Models\Traits\AdjustsQuantity;
use App\Models\Traits\CompanyableTrait;
use App\Models\Traits\HasOrders;
use App\Models\Traits\HasUploads;
use App\Models\Traits\Loggable;
use App\Models\Traits\Searchable;
use App\Presenters\ComponentPresenter;
use App\Presenters\Presentable;
use Illuminate\Database\Eloquent\Casts\Attribute;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\BelongsToMany;
use Illuminate\Database\Eloquent\Relations\Relation;
use Illuminate\Database\Eloquent\SoftDeletes;
use Illuminate\Database\Query\Builder;
use Illuminate\Support\Facades\Gate;
use Watson\Validating\ValidatingTrait;

/**
 * Model for Components.
 *
 * @version v1.0
 */
class Component extends SnipeModel
{
    use HasFactory;

    protected $presenter = ComponentPresenter::class;

    use AdjustsQuantity;
    use CompanyableTrait;
    use HasOrders;
    use HasUploads;
    use Loggable, Presentable;
    use SoftDeletes;

    protected $casts = [
        'purchase_date' => 'datetime',
    ];

    protected $table = 'components';

    /**
     * Category validation rules
     */
    public $rules = [
        'name' => 'required|max:191',
        'qty' => 'required|integer|min:1',
        'category_id' => 'required|integer|exists:categories,id',
        'supplier_id' => 'nullable|integer|exists:suppliers,id',
        'company_id' => 'integer|nullable|exists:companies,id|fmcs_company',
        'location_id' => 'exists:locations,id|nullable|fmcs_location',
        'min_amt' => 'integer|min:0|nullable',
        'purchase_date' => 'date_format:Y-m-d|nullable',
        'purchase_cost' => 'numeric|nullable|gte:0|max:99999999999999999.99',
        'manufacturer_id' => 'integer|exists:manufacturers,id|nullable',
        'default_supplier_id' => 'nullable|integer|exists:suppliers,id',
        'default_purchase_cost' => 'numeric|nullable|gte:0|max:99999999999999999.99',
    ];

    /**
     * Whether the model should inject it's identifier to the unique
     * validation rules before attempting validation. If this property
     * is not set in the model it will default to true.
     *
     * @var bool
     */
    protected $injectUniqueIdentifier = true;

    use ValidatingTrait;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    // supplier_id / purchase_date / purchase_cost are intentionally
    // absent. See Accessory::$fillable for the full rationale.
    // default_supplier_id / default_purchase_cost are parent-level
    // "template" values that seed the adjust-quantity modal.
    protected $fillable = [
        'category_id',
        'company_id',
        'location_id',
        'manufacturer_id',
        'model_number',
        'name',
        'min_amt',
        'qty',
        'serial',
        'notes',
        'default_supplier_id',
        'default_purchase_cost',
    ];

    use Searchable;

    /**
     * The attributes that should be included when searching the model.
     *
     * @var array
     */
    protected $searchableAttributes = [
        'name',
        'serial',
        'notes',
        'model_number',
    ];

    /**
     * The relations and their attributes that should be included when searching the model.
     *
     * @var array
     */
    protected $searchableRelations = [
        'category' => ['name'],
        'company' => ['name'],
        'location' => ['name'],
        // Search by the parent's "typical supplier" template — see the
        // Accessory model for the rationale.
        'defaultSupplier' => ['name'],
        'manufacturer' => ['name'],
        'adminuser' => ['first_name', 'last_name', 'display_name'],
        // See Accessory::$searchableRelations. Search hits order_number
        // through the HasOrders trait's orders() HasManyThrough into
        // the Orders table so historical order references still match.
        'orders' => ['order_number'],
    ];

    public static function booted()
    {
        static::saving(function ($model) {
            // We use 'sum_unconstrained_assets' as a 'cache' of the count of the sum of unconstrained assets, but
            // Eloquent will gladly try to save the value of that attribute in the case where we populate it ourselves.
            // But when it gets populated by 'withSum()' - it seems to work fine due to some Eloquent magic I am not
            // aware of. During a save, the quantity may have changed or other aspects may have changed, so
            // "invalidating the 'cache'" seems like a fair choice here.
            unset($model->sum_unconstrained_assets);
        });
    }

    public function isDeletable()
    {
        return Gate::allows('delete', $this)
            && ($this->numCheckedOut() === 0)
            && ($this->deleted_at == '');
    }

    /**
     * Establishes the component -> location relationship
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since  [v3.0]
     *
     * @return Relation
     */
    public function location()
    {
        return $this->belongsTo(Location::class, 'location_id');
    }

    /**
     * Establishes the component -> assets relationship
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since  [v3.0]
     *
     * @return Relation
     */
    public function assets()
    {
        return $this->belongsToMany(Asset::class, 'components_assets')->withPivot('id', 'assigned_qty', 'created_at', 'created_by', 'note');
    }

    /**
     * Per-pivot line cost for components-assets. Pulls the per-unit
     * price from the last acquisition (with the same default_* fallback
     * that lastOrderDefaults() applies) and multiplies by pivot qty.
     */
    protected function calculatedPurchaseCost(): Attribute
    {
        return Attribute::make(
            get: function ($value) {
                $unitPurchaseCost = $this->lastOrderDefaults()['unit_cost'] ?? null;
                $assignedQty = $this->pivot?->assigned_qty;

                if ($unitPurchaseCost === null) {
                    return $assignedQty !== null ? 0.0 : null;
                }

                if ($assignedQty !== null) {
                    return (float) $unitPurchaseCost * (int) $assignedQty;
                }

                return (float) $unitPurchaseCost;
            }
        );
    }

    /**
     * Establishes the component -> company relationship
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since  [v3.0]
     *
     * @return Relation
     */
    public function company()
    {
        return $this->belongsTo(Company::class, 'company_id');
    }

    /**
     * Establishes the component -> category relationship
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since  [v3.0]
     *
     * @return Relation
     */
    public function category()
    {
        return $this->belongsTo(Category::class, 'category_id');
    }

    /**
     * Establishes the item -> supplier relationship
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since  [v6.1.1]
     *
     * @return Relation
     */
    // No `supplier()` relation, no `supplier_id` / `purchase_date` /
    // `purchase_cost` accessors — see Accessory model for rationale.
    // Callers use `$component->orders` or `$component->lastOrderDefaults()`.

    /**
     * Parent-level "typical supplier" template — see Accessory model.
     */
    public function defaultSupplier(): BelongsTo
    {
        return $this->belongsTo(Supplier::class, 'default_supplier_id');
    }

    /**
     * Establishes the item -> manufacturer relationship
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since  [v3.0]
     *
     * @return Relation
     */
    public function manufacturer()
    {
        return $this->belongsTo(Manufacturer::class, 'manufacturer_id');
    }

    /**
     * Determine whether this asset requires acceptance by the assigned user
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since [v4.0]
     *
     * @return bool
     */
    public function requireAcceptance()
    {
        return $this->category?->require_acceptance ?? false;
    }

    /**
     * Establishes the component -> action logs relationship
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since  [v3.0]
     *
     * @return Relation
     */
    public function assetlog()
    {
        return $this->hasMany(Actionlog::class, 'item_id')->where('item_type', self::class)->orderBy('created_at', 'desc')->withTrashed();
    }

    /**
     * Check how many items within a component are checked out
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since  [v5.0]
     *
     * @return int
     */
    public function numCheckedOut(bool $recalculate = false)
    {
        /**
         * WARNING: This method caches the result, so if you're doing something
         * that is going to change the number of checked-out items, make sure to pass
         * 'true' as the first parameter to force this to recalculate the number of checked-out
         * items!!!!!
         */

        // In case there are elements checked out to assets that belong to a different company
        // than this asset and full multiple company support is on we'll remove the global scope,
        // so they are included in the count.

        // the 'sum' query returns NULL when there are zero checkouts - which can inadvertently re-trigger the following query
        // for un-checked-out components. So we have to do this very careful process of fetching the 'attributes'
        // of the component, then see if sum_unconstrained_assets exists as an attribute. If it doesn't, we run the
        // query. But if it *does* exist as an attribute - even a null - we skip the query, because that means that this
        // component was fetched using withCount() - and that count *is* accurate, even if null. We just do a quick
        // null-coalesce at the end to zero for the null case.
        $raw_attributes = $this->getAttributes();
        if (! array_key_exists('sum_unconstrained_assets', $raw_attributes) || $recalculate) {
            // This part should *only* run if the component was fetched *without* withCount() (or you've asked to recalculate)
            // NOTE: doing this will add a 'pseudo-attribute' to the component in question, so we need to _remove_ this
            // before we save - so that gets handled in the 'saving' callback defined in the 'booted' method, above.
            $this->sum_unconstrained_assets = $this->unconstrainedAssets()->sum('assigned_qty') ?? 0;
        }

        return $this->sum_unconstrained_assets ?? 0;
    }

    /**
     * AdjustsQuantity trait hook: units currently assigned to assets.
     * Passes true to numCheckedOut to force a fresh count instead of
     * trusting the cached sum_unconstrained_assets attribute, since the
     * adjust-quantity flow can be entered without withCount() priming
     * that value.
     */
    public function currentlyInUseCount(): int
    {
        return (int) $this->numCheckedOut(true);
    }

    /**
     * @return BelongsToMany
     *
     * This allows us to get the assets with assigned components without the company restriction
     */
    public function unconstrainedAssets()
    {

        return $this->belongsToMany(Asset::class, 'components_assets')
            ->withPivot('id', 'assigned_qty', 'created_at', 'created_by', 'note')
            ->withoutGlobalScope(new CompanyableScope);

    }

    public function percentRemaining()
    {
        $totalQuantity = (int) $this->qty;

        if ($totalQuantity <= 0) {
            return 0;
        }

        $availableQuantity = max(0, min($this->numRemaining(), $totalQuantity));

        return ($availableQuantity / $totalQuantity) * 100;
    }

    /**
     * Determine whether to send a checkin/checkout email based on
     * asset model category
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since [v4.0]
     *
     * @return bool
     */
    public function checkin_email()
    {
        return $this->category?->checkin_email;
    }

    /**
     * Get the list of checkouts for this License
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since  [v2.0]
     *
     * @return Relation
     */
    public function checkouts()
    {
        return $this->assetlog()->where('action_type', '=', 'checkout')
            ->orderBy('created_at', 'desc')
            ->withTrashed();
    }

    /**
     * Check how many items within a component are remaining
     *
     * @author [A. Gianotto] [<snipe@snipe.net>]
     *
     * @since  [v3.0]
     *
     * @return int
     */
    public function numRemaining()
    {
        return $this->qty - $this->numCheckedOut();
    }

    /**
     * -----------------------------------------------
     * BEGIN MUTATORS
     * -----------------------------------------------
     **/

    /**
     * This sets a value for qty if no value is given. The database does not allow this
     * field to be null, and in the other areas of the code, we set a default, but the importer
     * does not.
     *
     * This simply checks that there is a value for quantity, and if there isn't, set it to 0.
     *
     * @author A. Gianotto <snipe@snipe.net>
     *
     * @since  v6.3.4
     *
     * @return void
     */
    public function setQtyAttribute($value)
    {
        $this->attributes['qty'] = (! $value) ? 0 : intval($value);
    }

    /**
     * -----------------------------------------------
     * BEGIN QUERY SCOPES
     * -----------------------------------------------
     **/

    /**
     * Query builder scope to order on company
     *
     * @param  Builder  $query  Query builder instance
     * @param  string  $order  Order
     * @return Builder Modified query builder
     */
    public function scopeOrderCategory($query, $order)
    {
        return $query->join('categories', 'components.category_id', '=', 'categories.id')->orderBy('categories.name', $order);
    }

    /**
     * Query builder scope to order on company
     *
     * @param  Builder  $query  Query builder instance
     * @param  string  $order  Order
     * @return Builder Modified query builder
     */
    public function scopeOrderLocation($query, $order)
    {
        return $query->leftJoin('locations', 'components.location_id', '=', 'locations.id')->orderBy('locations.name', $order);
    }

    /**
     * Query builder scope to order on company
     *
     * @param  Builder  $query  Query builder instance
     * @param  string  $order  Order
     * @return Builder Modified query builder
     */
    public function scopeOrderCompany($query, $order)
    {
        return $query->leftJoin('companies', 'components.company_id', '=', 'companies.id')->orderBy('companies.name', $order);
    }

    /**
     * Query builder scope to order on supplier
     *
     * @param  Builder  $query  Query builder instance
     * @param  text  $order  Order
     * @return Builder Modified query builder
     */
    public function scopeOrderSupplier($query, $order)
    {
        return $query->leftJoin('suppliers', 'components.default_supplier_id', '=', 'suppliers.id')->orderBy('suppliers.name', $order);
    }

    /**
     * Query builder scope to order on manufacturer
     *
     * @param  Builder  $query  Query builder instance
     * @param  text  $order  Order
     * @return Builder Modified query builder
     */
    public function scopeOrderManufacturer($query, $order)
    {
        return $query->leftJoin('manufacturers', 'components.manufacturer_id', '=', 'manufacturers.id')->orderBy('manufacturers.name', $order);
    }

    public function scopeOrderByCreatedBy($query, $order)
    {
        return $query->leftJoin('users as admin_sort', 'components.created_by', '=', 'admin_sort.id')->select('components.*')->orderBy('admin_sort.first_name', $order)->orderBy('admin_sort.last_name', $order);
    }

    /**
     * Query builder scope to sort by the calculated `% remaining` column.
     *
     * Mirrors Component::percentRemaining(): (qty - numCheckedOut) / qty * 100.
     * sum_unconstrained_assets is added by withSum() in the API index()
     * as the total checked-out quantity. Guards against division by zero
     * for components with qty of 0.
     *
     * PostgreSQL note: references a SELECT-list alias inside a compound
     * ORDER BY expression, which PostgreSQL rejects per SQL standard.
     * Snipe-IT officially supports MySQL/MariaDB and tests on SQLite
     * (both allow this); moving to PostgreSQL would require inlining
     * the subquery or wrapping the query in an outer SELECT.
     */
    public function scopeOrderPercentRemaining($query, $order)
    {
        $direction = strtolower($order) === 'asc' ? 'asc' : 'desc';

        return $query->orderByRaw('CASE WHEN components.qty = 0 THEN 0 ELSE ((components.qty - COALESCE(sum_unconstrained_assets, 0)) * 100.0 / components.qty) END '.$direction);
    }
}
