<?php

declare(strict_types=1);

namespace App\Support;

/**
 * The application's permission catalogue.
 *
 * This is the single source of truth for authorisation. The identity server
 * says *who* someone is; everything they may *do* is decided from this list,
 * via the roles administrators assign in the panel.
 *
 * Adding a permission here and re-running `php artisan db:seed
 * --class=RolePermissionSeeder` (or `php artisan permissions:sync`) makes it
 * available everywhere: policies, the role editor, and the API.
 */
final class Permissions
{
    public const PANEL_ACCESS = 'panel.access';

    /**
     * The CRUD abilities a soft-deleting resource exposes.
     *
     * @var array<int, string>
     */
    public const CRUD_ABILITIES = [
        'view_any', 'view', 'create', 'update', 'delete', 'restore', 'force_delete',
    ];

    /**
     * Resource key => the abilities that resource actually supports.
     *
     * `users` and `roles` are hard-deleted, so they carry no restore or
     * force_delete permission; granting one would be a permission nothing ever
     * checks.
     *
     * @var array<string, array<int, string>>
     */
    public const RESOURCES = [
        'pages' => [...self::CRUD_ABILITIES, 'publish'],
        'categories' => self::CRUD_ABILITIES,
        'projects' => [...self::CRUD_ABILITIES, 'publish'],
        'members' => self::CRUD_ABILITIES,

        // What the collective offers, as opposed to what it has built.
        // Publishing is separate for the same reason it is on projects: an
        // editor may write the offer without putting it on the website.
        'services' => [...self::CRUD_ABILITIES, 'publish'],

        'clients' => self::CRUD_ABILITIES,
        'testimonials' => self::CRUD_ABILITIES,
        'talks' => ['view_any', 'view', 'create', 'update', 'delete'],

        'technologies' => ['view_any', 'view', 'create', 'update', 'delete'],
        'calls' => ['view_any', 'view', 'create', 'update', 'delete'],

        // The inbox holds names, e-mail addresses and messages from people
        // outside the collective, so it is gated more tightly than the content
        // resources — and nobody creates one by hand: they arrive from the
        // public site, which is why there is no `create` here.
        'applications' => ['view_any', 'view', 'update', 'delete', 'restore', 'force_delete'],

        // A broken link is a content problem, not an infrastructure one, so
        // whoever renames a slug is also who fixes what it broke.
        // Derived from the files themselves: nobody creates one by hand, and
        // "update" would mean editing something the processor owns.
        'media' => ['view_any', 'view', 'delete'],

        'redirects' => ['view_any', 'view', 'create', 'update', 'delete'],

        // `sync` is separate from `update` because triggering a sync spends
        // the provider's rate limit, which is a shared resource.
        'repositories' => ['view_any', 'view', 'create', 'update', 'delete', 'sync'],

        'users' => ['view_any', 'view', 'create', 'update', 'delete'],
        'roles' => ['view_any', 'view', 'create', 'update', 'delete'],

        // Taking the public site down is a deliberate, visible act, so it is
        // its own permission rather than part of general settings editing.
        'settings' => ['view', 'update', 'maintenance'],
    ];

    /**
     * Every permission name the application knows about.
     *
     * @return array<int, string>
     */
    public static function all(): array
    {
        return array_merge(...array_values(self::grouped()));
    }

    /**
     * Permissions grouped by resource, for rendering the role editor.
     *
     * @return array<string, array<int, string>>
     */
    public static function grouped(): array
    {
        $groups = ['general' => [self::PANEL_ACCESS]];

        foreach (self::RESOURCES as $resource => $abilities) {
            $groups[$resource] = array_map(
                fn (string $ability) => "{$resource}.{$ability}",
                $abilities,
            );
        }

        return $groups;
    }

    /**
     * Every permission belonging to one resource.
     *
     * @return array<int, string>
     */
    public static function for(string $resource): array
    {
        return self::grouped()[$resource] ?? [];
    }

    /**
     * The roles shipped with the application, and what each one may do.
     *
     * `super_admin` is deliberately absent: it is granted everything by a
     * Gate::before hook in AuthServiceProvider rather than by a permission list,
     * so it can never drift out of date as the catalogue grows.
     *
     * @return array<string, array<int, string>>
     */
    public static function roleDefinitions(): array
    {
        $readOnly = fn (string $resource) => [
            "{$resource}.view_any",
            "{$resource}.view",
        ];

        // Everything you need to write something, and nothing that decides
        // whether the public sees it.
        $authoring = fn (string $resource) => array_values(array_diff(
            self::for($resource),
            ["{$resource}.publish", "{$resource}.force_delete"],
        ));

        return [
            'super_admin' => [],

            'admin' => self::all(),

            'editor' => [
                self::PANEL_ACCESS,
                ...self::for('pages'),
                ...self::for('categories'),
                ...self::for('projects'),
                ...self::for('members'),
                ...self::for('services'),
                ...self::for('clients'),
                ...self::for('testimonials'),
                ...self::for('talks'),
                ...self::for('technologies'),
                ...self::for('calls'),
                ...self::for('media'),
                ...self::for('redirects'),

                // Editors run the calls, so they are the ones who have to
                // answer the people who reply to them.
                ...self::for('applications'),

                ...$readOnly('repositories'),
                ...$readOnly('users'),
                'settings.view',
            ],

            /*
             * Writes content, cannot put it on the site.
             *
             * The role the separate `publish` permissions were always for.
             * Without one, `pages.publish` was a distinction the catalogue
             * made and no shipped role ever exercised — `editor` holds it
             * along with everything else — so the handover it implies had
             * nowhere to happen. This is the other end of it: somebody who
             * finishes a piece of work and asks for a review, because that is
             * the only way they have of putting it live.
             *
             * Also without `force_delete`: erasing something for good is not
             * part of writing it, and the bin makes an ordinary delete
             * recoverable. And without `applications`, for the reason the
             * viewer does not have it either — writing for the site and
             * reading strangers' contact details are different jobs.
             */
            'writer' => [
                self::PANEL_ACCESS,
                ...$authoring('pages'),
                ...$authoring('projects'),
                ...$authoring('services'),

                // Enough to pick one on a form, not to invent one.
                ...$readOnly('categories'),
                ...$readOnly('members'),
                ...$readOnly('clients'),
                ...$readOnly('technologies'),
                ...$readOnly('talks'),
                ...$readOnly('testimonials'),
                ...$readOnly('media'),
                ...$readOnly('calls'),
            ],

            // Deliberately without `applications`: a viewer reads the site's
            // content, not the contact details of the people who wrote in.
            'viewer' => [
                self::PANEL_ACCESS,
                ...$readOnly('pages'),
                ...$readOnly('categories'),
                ...$readOnly('projects'),
                ...$readOnly('members'),
                ...$readOnly('services'),
                ...$readOnly('clients'),
                ...$readOnly('testimonials'),
                ...$readOnly('talks'),
                ...$readOnly('technologies'),
                ...$readOnly('media'),
                ...$readOnly('calls'),
                ...$readOnly('repositories'),
            ],
        ];
    }

    /**
     * Roles that must never be deleted or renamed from the panel, because the
     * application's own bootstrapping depends on them.
     *
     * @return array<int, string>
     */
    public static function protectedRoles(): array
    {
        return array_values(array_unique([
            'super_admin',
            (string) config('pireon.default_role'),
        ]));
    }
}