Add a translation assistant to the panel

Each field's original sits beside the field to write, and a translation that
fell behind shows what the original said when it was translated and what it
says now, word by word.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Filament/Pages/TranslationAssistant.php

@@ -0,0 +1,244 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Filament\Pages;
+
+use App\Support\ContentTypes;
+use App\Support\PendingTranslations;
+use App\Support\TextDiff;
+use App\Support\TranslationFreshness;
+use BackedEnum;
+use Filament\Actions\Action;
+use Filament\Forms\Components\RichEditor;
+use Filament\Forms\Components\Textarea;
+use Filament\Forms\Components\TextInput;
+use Filament\Notifications\Notification;
+use Filament\Pages\Page as FilamentPage;
+use Filament\Schemas\Components\Grid;
+use Filament\Schemas\Components\Section;
+use Filament\Schemas\Components\Text;
+use Filament\Schemas\Schema;
+use Filament\Support\Icons\Heroicon;
+use Illuminate\Contracts\Support\Htmlable;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Support\Collection;
+use Illuminate\Support\Facades\Auth;
+use Illuminate\Support\HtmlString;
+use Livewire\Attributes\Url;
+use UnitEnum;
+
+/**
+ * Translating with the original beside you.
+ *
+ * Without a record: what is waiting to be translated, into which language.
+ * With one: each field's original next to the field to write, and for a
+ * translation that fell behind, what the original said when it was translated
+ * and what it says now — the sentence to redo rather than the whole text.
+ */
+class TranslationAssistant extends FilamentPage
+{
+    /**
+     * Rich text, edited as such; everything else is plain.
+     *
+     * @var array<int, string>
+     */
+    public const RICH = ['body', 'description', 'decisions', 'postmortem'];
+
+    /**
+     * Never translated here: an address is not a translation, and changing it
+     * has its own consequences on the record's own form.
+     *
+     * @var array<int, string>
+     */
+    protected const SKIPPED = ['slug', 'featured_image_alt', 'cover_image_alt'];
+
+    protected string $view = 'filament.pages.translation-assistant';
+
+    protected static string|BackedEnum|null $navigationIcon = Heroicon::OutlinedLanguage;
+
+    protected static ?int $navigationSort = 7;
+
+    #[Url]
+    public ?string $type = null;
+
+    #[Url]
+    public ?string $record = null;
+
+    #[Url]
+    public ?string $locale = null;
+
+    public ?array $data = [];
+
+    public static function canAccess(): bool
+    {
+        return Auth::user()?->can('panel.access') ?? false;
+    }
+
+    public static function getNavigationGroup(): string|UnitEnum|null
+    {
+        return __('panel.groups.content');
+    }
+
+    public static function getNavigationLabel(): string
+    {
+        return __('panel.translate.title');
+    }
+
+    public static function urlFor(Model $record, ?string $locale = null): string
+    {
+        $type = array_search($record::class, PendingTranslations::TYPES, true);
+
+        return self::getUrl(array_filter(['type' => $type, 'record' => $record->getKey(), 'locale' => $locale]));
+    }
+
+    public function getTitle(): string|Htmlable
+    {
+        $record = $this->target();
+
+        return $record
+            ? __('panel.translate.title_for', ['title' => ContentTypes::title($record), 'language' => $this->languageName($this->locale)])
+            : __('panel.translate.title');
+    }
+
+    public function mount(): void
+    {
+        $record = $this->target();
+
+        if ($record === null) {
+            return;
+        }
+
+        abort_unless(Auth::user()->can('update', $record), 403);
+
+        $this->form->fill(collect($this->fields($record))
+            ->mapWithKeys(fn (string $field) => [$field => $record->getTranslation($field, $this->locale, false)])
+            ->all());
+    }
+
+    /**
+     * The record being translated, when there is one and the language is one
+     * to translate into.
+     */
+    public function target(): ?Model
+    {
+        $model = PendingTranslations::TYPES[$this->type] ?? null;
+        $locales = array_keys((array) config('locales.supported'));
+
+        if ($model === null || $this->record === null || ! in_array($this->locale, $locales, true) || $this->locale === config('locales.default')) {
+            return null;
+        }
+
+        return $model::query()->find($this->record);
+    }
+
+    /**
+     * @return Collection<int, array<string, mixed>>
+     */
+    public function pending(): Collection
+    {
+        return PendingTranslations::find(Auth::user());
+    }
+
+    /**
+     * @return array<int, string>
+     */
+    public function targetLocales(): array
+    {
+        return array_values(array_diff(array_keys((array) config('locales.supported')), [config('locales.default')]));
+    }
+
+    public function languageName(?string $locale): string
+    {
+        return (string) config("locales.supported.{$locale}.native", $locale);
+    }
+
+    public function form(Schema $schema): Schema
+    {
+        $record = $this->target();
+
+        if ($record === null) {
+            return $schema->statePath('data')->components([]);
+        }
+
+        $source = (string) config('locales.default');
+        $stale = TranslationFreshness::staleFields($record, $this->locale);
+
+        return $schema
+            ->statePath('data')
+            ->components(collect($this->fields($record))->map(function (string $field) use ($record, $source, $stale) {
+                $original = (string) $record->getTranslation($field, $source, false);
+                $rich = in_array($field, self::RICH, true);
+                $label = __("panel.translate.fields.{$field}");
+
+                $input = match (true) {
+                    $rich => RichEditor::make($field)->hiddenLabel(),
+                    mb_strlen($original) > 120 => Textarea::make($field)->hiddenLabel()->rows(4),
+                    default => TextInput::make($field)->hiddenLabel(),
+                };
+
+                $diff = isset($stale[$field]) ? TextDiff::html($stale[$field]['was'], $original) : null;
+
+                return Section::make($label)
+                    ->description(isset($stale[$field])
+                        ? __('panel.translate.stale_since', ['date' => $stale[$field]['since']->isoFormat('LL')])
+                        : null)
+                    ->icon(isset($stale[$field]) ? 'heroicon-o-exclamation-triangle' : null)
+                    ->iconColor('warning')
+                    ->compact()
+                    ->schema(array_filter([
+                        $diff ? Text::make(new HtmlString('<div class="ta-diff"><strong>'.e(__('panel.translate.changed')).'</strong> '.$diff.'</div>')) : null,
+                        Grid::make(['default' => 1, 'lg' => 2])->schema([
+                            Text::make(new HtmlString(
+                                '<div class="ta-source"><span class="ta-lang">'.e($this->languageName($source)).'</span>'
+                                .($rich ? $original : nl2br(e($original))).'</div>'
+                            )),
+                            $input,
+                        ]),
+                    ]));
+            })->values()->all());
+    }
+
+    protected function getHeaderActions(): array
+    {
+        return $this->target() === null ? [] : [
+            Action::make('back')
+                ->label(__('panel.translate.back'))
+                ->color('gray')
+                ->url(self::getUrl()),
+        ];
+    }
+
+    public function save(): void
+    {
+        $record = $this->target();
+
+        abort_unless($record !== null && Auth::user()->can('update', $record), 403);
+
+        foreach ($this->form->getState() as $field => $value) {
+            if (in_array($field, $this->fields($record), true)) {
+                $record->setTranslation($field, $this->locale, (string) ($value ?? ''));
+            }
+        }
+
+        $record->save();
+
+        Notification::make()->title(__('panel.translate.saved'))->success()->send();
+    }
+
+    /**
+     * The fields worth translating on this record: translatable, not an
+     * address, and with something in the original to translate.
+     *
+     * @return array<int, string>
+     */
+    protected function fields(Model $record): array
+    {
+        $source = (string) config('locales.default');
+
+        return array_values(array_filter(
+            array_diff($record->getTranslatableAttributes(), self::SKIPPED),
+            fn (string $field) => filled($record->getTranslation($field, $source, false)),
+        ));
+    }
+}

app/Filament/Resources/Calls/Pages/EditCall.php

@@ -8,6 +8,7 @@ use App\Filament\Concerns\WarnsOfConcurrentEditing;
 use App\Filament\Resources\Calls\CallResource;
 use App\Filament\Support\DuplicateAction;
 use App\Filament\Support\PreviewAction;
+use App\Filament\Support\TranslateAction;
 use Filament\Actions\DeleteAction;
 use Filament\Resources\Pages\EditRecord;
 
@@ -23,6 +24,7 @@ class EditCall extends EditRecord
             // Seeing it on the real site without leaving the form.
             PreviewAction::for('call'),
             DuplicateAction::make(),
+            TranslateAction::make(),
             DeleteAction::make(),
         ];
     }

app/Filament/Resources/Pages/Pages/EditPage.php

@@ -9,6 +9,7 @@ use App\Filament\Concerns\WarnsOfConcurrentEditing;
 use App\Filament\Resources\Pages\PageResource;
 use App\Filament\Support\DuplicateAction;
 use App\Filament\Support\PreviewAction;
+use App\Filament\Support\TranslateAction;
 use Filament\Actions\DeleteAction;
 use Filament\Actions\ForceDeleteAction;
 use Filament\Actions\RestoreAction;
@@ -26,6 +27,7 @@ class EditPage extends EditRecord
             // Seeing it on the real site without leaving the form.
             PreviewAction::for('page'),
             DuplicateAction::make(),
+            TranslateAction::make(),
             DeleteAction::make(),
             ForceDeleteAction::make(),
             RestoreAction::make(),

app/Filament/Resources/Projects/Pages/EditProject.php

@@ -8,6 +8,7 @@ use App\Filament\Concerns\WarnsOfConcurrentEditing;
 use App\Filament\Resources\Projects\ProjectResource;
 use App\Filament\Support\DuplicateAction;
 use App\Filament\Support\PreviewAction;
+use App\Filament\Support\TranslateAction;
 use Filament\Actions\DeleteAction;
 use Filament\Resources\Pages\EditRecord;
 
@@ -23,6 +24,7 @@ class EditProject extends EditRecord
             // Seeing it on the real site without leaving the form.
             PreviewAction::for('project'),
             DuplicateAction::make(),
+            TranslateAction::make(),
             DeleteAction::make(),
         ];
     }

app/Filament/Resources/Services/Pages/EditService.php

@@ -8,6 +8,7 @@ use App\Filament\Concerns\WarnsOfConcurrentEditing;
 use App\Filament\Resources\Services\ServiceResource;
 use App\Filament\Support\DuplicateAction;
 use App\Filament\Support\PreviewAction;
+use App\Filament\Support\TranslateAction;
 use Filament\Actions\DeleteAction;
 use Filament\Resources\Pages\EditRecord;
 
@@ -23,6 +24,7 @@ class EditService extends EditRecord
             // Seeing it on the real site without leaving the form.
             PreviewAction::for('service'),
             DuplicateAction::make(),
+            TranslateAction::make(),
             DeleteAction::make(),
         ];
     }

app/Filament/Support/TranslateAction.php

@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Filament\Support;
+
+use App\Filament\Pages\TranslationAssistant;
+use Filament\Actions\Action;
+use Filament\Actions\ActionGroup;
+use Illuminate\Database\Eloquent\Model;
+
+/**
+ * "Translate into…": this record in the translation assistant, one entry per
+ * language there is to translate into.
+ */
+final class TranslateAction
+{
+    public static function make(): ActionGroup
+    {
+        $default = (string) config('locales.default');
+
+        return ActionGroup::make(collect(config('locales.supported'))
+            ->except($default)
+            ->map(fn (array $meta, string $locale) => Action::make("translate_{$locale}")
+                ->label($meta['native'] ?? $locale)
+                ->url(fn (Model $record) => TranslationAssistant::urlFor($record, $locale)))
+            ->values()
+            ->all())
+            ->label(__('panel.translate.action'))
+            ->icon('heroicon-o-language')
+            ->color('gray')
+            ->button();
+    }
+}