<?php

declare(strict_types=1);

namespace App\Filament\Resources;

use App\Filament\Resources\BaselineSnapshotResource\Pages;
use App\Models\BaselineProfile;
use App\Models\BaselineSnapshot;
use App\Models\User;
use App\Models\Workspace;
use App\Support\Auth\Capabilities;
use App\Support\Filament\FilterPresets;
use App\Support\Ui\ActionSurface\ActionSurfaceDeclaration;
use App\Support\Ui\ActionSurface\Enums\ActionSurfaceInspectAffordance;
use App\Support\Ui\ActionSurface\Enums\ActionSurfaceProfile;
use App\Support\Ui\ActionSurface\Enums\ActionSurfaceSlot;
use App\Support\Workspaces\WorkspaceContext;
use BackedEnum;
use Filament\Actions\ViewAction;
use Filament\Facades\Filament;
use Filament\Infolists\Components\RepeatableEntry;
use Filament\Infolists\Components\TextEntry;
use Filament\Infolists\Components\ViewEntry;
use Filament\Resources\Resource;
use Filament\Schemas\Components\Section;
use Filament\Schemas\Schema;
use Filament\Tables\Columns\TextColumn;
use Filament\Tables\Filters\SelectFilter;
use Filament\Tables\Table;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Model;
use UnitEnum;

class BaselineSnapshotResource extends Resource
{
    protected static bool $isDiscovered = false;

    protected static bool $isScopedToTenant = false;

    protected static ?string $model = BaselineSnapshot::class;

    protected static ?string $slug = 'baseline-snapshots';

    protected static bool $isGloballySearchable = false;

    protected static string|BackedEnum|null $navigationIcon = 'heroicon-o-camera';

    protected static string|UnitEnum|null $navigationGroup = 'Governance';

    protected static ?string $navigationLabel = 'Baseline Snapshots';

    protected static ?int $navigationSort = 2;

    public static function shouldRegisterNavigation(): bool
    {
        if (Filament::getCurrentPanel()?->getId() !== 'admin') {
            return false;
        }

        return parent::shouldRegisterNavigation();
    }

    public static function canViewAny(): bool
    {
        $user = auth()->user();

        if (! $user instanceof User) {
            return false;
        }

        $workspace = self::resolveWorkspace();

        if (! $workspace instanceof Workspace) {
            return false;
        }

        $resolver = app(\App\Services\Auth\WorkspaceCapabilityResolver::class);

        return $resolver->isMember($user, $workspace)
            && $resolver->can($user, $workspace, Capabilities::WORKSPACE_BASELINES_VIEW);
    }

    public static function canCreate(): bool
    {
        return false;
    }

    public static function canEdit(Model $record): bool
    {
        return false;
    }

    public static function canDelete(Model $record): bool
    {
        return false;
    }

    public static function canView(Model $record): bool
    {
        return self::canViewAny();
    }

    public static function actionSurfaceDeclaration(): ActionSurfaceDeclaration
    {
        return ActionSurfaceDeclaration::forResource(ActionSurfaceProfile::CrudListAndView)
            ->exempt(ActionSurfaceSlot::ListHeader, 'Snapshots are created by capture runs; no list-header actions.')
            ->satisfy(ActionSurfaceSlot::InspectAffordance, ActionSurfaceInspectAffordance::ViewAction->value)
            ->exempt(ActionSurfaceSlot::ListRowMoreMenu, 'Snapshots are immutable; no row actions besides view.')
            ->exempt(ActionSurfaceSlot::ListBulkMoreGroup, 'Snapshots are immutable; no bulk actions.')
            ->exempt(ActionSurfaceSlot::ListEmptyState, 'Empty-state CTA is intentionally omitted; snapshots appear after baseline captures.')
            ->exempt(ActionSurfaceSlot::DetailHeader, 'View page is informational and currently has no header actions.');
    }

    public static function getEloquentQuery(): Builder
    {
        $workspaceId = app(WorkspaceContext::class)->currentWorkspaceId(request());

        return parent::getEloquentQuery()
            ->with('baselineProfile')
            ->when(
                $workspaceId !== null,
                fn (Builder $query): Builder => $query->where('workspace_id', (int) $workspaceId),
            )
            ->when(
                $workspaceId === null,
                fn (Builder $query): Builder => $query->whereRaw('1 = 0'),
            );
    }

    public static function form(Schema $schema): Schema
    {
        return $schema;
    }

    public static function table(Table $table): Table
    {
        return $table
            ->defaultSort('captured_at', 'desc')
            ->paginated(\App\Support\Filament\TablePaginationProfiles::resource())
            ->persistFiltersInSession()
            ->persistSearchInSession()
            ->persistSortInSession()
            ->columns([
                TextColumn::make('id')
                    ->label('Snapshot')
                    ->formatStateUsing(static fn (?int $state): string => $state ? '#'.$state : '—')
                    ->sortable(),
                TextColumn::make('baselineProfile.name')
                    ->label('Baseline')
                    ->wrap()
                    ->searchable()
                    ->placeholder('—'),
                TextColumn::make('captured_at')
                    ->label('Captured')
                    ->since()
                    ->sortable(),
                TextColumn::make('fidelity_summary')
                    ->label('Fidelity')
                    ->getStateUsing(static fn (BaselineSnapshot $record): string => self::fidelitySummary($record))
                    ->wrap(),
                TextColumn::make('snapshot_state')
                    ->label('State')
                    ->badge()
                    ->getStateUsing(static fn (BaselineSnapshot $record): string => self::stateLabel($record))
                    ->color(static fn (BaselineSnapshot $record): string => self::hasGaps($record) ? 'warning' : 'success'),
            ])
            ->filters([
                SelectFilter::make('baseline_profile_id')
                    ->label('Baseline')
                    ->options(static::baselineProfileOptions())
                    ->searchable(),
                SelectFilter::make('snapshot_state')
                    ->label('State')
                    ->options(static::snapshotStateOptions())
                    ->query(fn (Builder $query, array $data): Builder => static::applySnapshotStateFilter($query, $data['value'] ?? null)),
                FilterPresets::dateRange('captured_at', 'Captured', 'captured_at'),
            ])
            ->actions([
                ViewAction::make()->label('View'),
            ])
            ->bulkActions([])
            ->emptyStateHeading('No baseline snapshots')
            ->emptyStateDescription('Capture a baseline snapshot to review evidence fidelity and compare tenants over time.')
            ->emptyStateIcon('heroicon-o-camera');
    }

    public static function infolist(Schema $schema): Schema
    {
        return $schema
            ->schema([
                Section::make('Snapshot')
                    ->schema([
                        TextEntry::make('id')
                            ->label('Snapshot')
                            ->formatStateUsing(static fn (?int $state): string => $state ? '#'.$state : '—'),
                        TextEntry::make('baselineProfile.name')
                            ->label('Baseline'),
                        TextEntry::make('captured_at')
                            ->label('Captured')
                            ->dateTime(),
                        TextEntry::make('snapshot_state')
                            ->label('State')
                            ->badge()
                            ->getStateUsing(static fn (BaselineSnapshot $record): string => self::stateLabel($record))
                            ->color(static fn (BaselineSnapshot $record): string => self::hasGaps($record) ? 'warning' : 'success'),
                        TextEntry::make('fidelity_summary')
                            ->label('Fidelity')
                            ->getStateUsing(static fn (BaselineSnapshot $record): string => self::fidelitySummary($record)),
                        TextEntry::make('evidence_gaps')
                            ->label('Evidence gaps')
                            ->getStateUsing(static fn (BaselineSnapshot $record): int => self::gapsCount($record)),
                        TextEntry::make('snapshot_identity_hash')
                            ->label('Identity hash')
                            ->copyable()
                            ->columnSpanFull(),
                    ])
                    ->columns(2)
                    ->columnSpanFull(),
                Section::make('Summary')
                    ->schema([
                        ViewEntry::make('summary_jsonb')
                            ->label('')
                            ->view('filament.infolists.entries.snapshot-json')
                            ->state(static fn (BaselineSnapshot $record): array => is_array($record->summary_jsonb) ? $record->summary_jsonb : [])
                            ->columnSpanFull(),
                    ])
                    ->columnSpanFull(),
                Section::make('Intune RBAC Role Definition References')
                    ->schema([
                        RepeatableEntry::make('rbac_role_definition_references')
                            ->label('')
                            ->state(static fn (BaselineSnapshot $record): array => self::rbacRoleDefinitionReferences($record))
                            ->schema([
                                TextEntry::make('display_name')
                                    ->label('Role definition'),
                                TextEntry::make('role_source')
                                    ->label('Role source')
                                    ->badge(),
                                TextEntry::make('permission_blocks')
                                    ->label('Permission blocks'),
                                TextEntry::make('identity_strategy')
                                    ->label('Identity')
                                    ->badge(),
                                TextEntry::make('policy_version_reference')
                                    ->label('Baseline evidence'),
                                TextEntry::make('observed_at')
                                    ->label('Observed at')
                                    ->placeholder('—'),
                            ])
                            ->columns(2)
                            ->columnSpanFull(),
                    ])
                    ->visible(static fn (BaselineSnapshot $record): bool => self::rbacRoleDefinitionReferences($record) !== [])
                    ->columnSpanFull(),
            ]);
    }

    public static function getPages(): array
    {
        return [
            'index' => Pages\ListBaselineSnapshots::route('/'),
            'view' => Pages\ViewBaselineSnapshot::route('/{record}'),
        ];
    }

    /**
     * @return array<int, string>
     */
    private static function baselineProfileOptions(): array
    {
        $workspaceId = app(WorkspaceContext::class)->currentWorkspaceId(request());

        if ($workspaceId === null) {
            return [];
        }

        return BaselineProfile::query()
            ->where('workspace_id', (int) $workspaceId)
            ->orderBy('name')
            ->pluck('name', 'id')
            ->all();
    }

    /**
     * @return array<string, string>
     */
    private static function snapshotStateOptions(): array
    {
        return [
            'complete' => 'Complete',
            'with_gaps' => 'Captured with gaps',
        ];
    }

    private static function resolveWorkspace(): ?Workspace
    {
        $workspaceId = app(WorkspaceContext::class)->currentWorkspaceId(request());

        if ($workspaceId === null) {
            return null;
        }

        return Workspace::query()->whereKey($workspaceId)->first();
    }

    private static function summary(BaselineSnapshot $snapshot): array
    {
        return is_array($snapshot->summary_jsonb) ? $snapshot->summary_jsonb : [];
    }

    private static function fidelityCounts(BaselineSnapshot $snapshot): array
    {
        $summary = self::summary($snapshot);
        $counts = $summary['fidelity_counts'] ?? null;
        $counts = is_array($counts) ? $counts : [];

        $content = $counts['content'] ?? 0;
        $meta = $counts['meta'] ?? 0;

        return [
            'content' => is_numeric($content) ? (int) $content : 0,
            'meta' => is_numeric($meta) ? (int) $meta : 0,
        ];
    }

    private static function fidelitySummary(BaselineSnapshot $snapshot): string
    {
        $counts = self::fidelityCounts($snapshot);

        return sprintf('Content %d, Meta %d', (int) ($counts['content'] ?? 0), (int) ($counts['meta'] ?? 0));
    }

    private static function gapsCount(BaselineSnapshot $snapshot): int
    {
        $summary = self::summary($snapshot);
        $gaps = $summary['gaps'] ?? null;
        $gaps = is_array($gaps) ? $gaps : [];

        $count = $gaps['count'] ?? 0;

        return is_numeric($count) ? (int) $count : 0;
    }

    private static function hasGaps(BaselineSnapshot $snapshot): bool
    {
        return self::gapsCount($snapshot) > 0;
    }

    /**
     * @return list<array{
     *   display_name: string,
     *   role_source: string,
     *   permission_blocks: string,
     *   identity_strategy: string,
     *   policy_version_reference: string,
     *   observed_at: ?string
     * }>
     */
    private static function rbacRoleDefinitionReferences(BaselineSnapshot $snapshot): array
    {
        return $snapshot->items()
            ->where('policy_type', 'intuneRoleDefinition')
            ->orderBy('id')
            ->get()
            ->map(static function (\App\Models\BaselineSnapshotItem $item): array {
                $meta = is_array($item->meta_jsonb) ? $item->meta_jsonb : [];
                $policyVersionId = data_get($meta, 'version_reference.policy_version_id');
                $rolePermissionCount = data_get($meta, 'rbac.role_permission_count');
                $identityStrategy = (string) data_get($meta, 'identity.strategy', 'display_name');

                return [
                    'display_name' => (string) data_get($meta, 'display_name', '—'),
                    'role_source' => match (data_get($meta, 'rbac.is_built_in')) {
                        true => 'Built-in',
                        false => 'Custom',
                        default => 'Unknown',
                    },
                    'permission_blocks' => is_numeric($rolePermissionCount)
                        ? (string) ((int) $rolePermissionCount)
                        : '—',
                    'identity_strategy' => $identityStrategy === 'external_id' ? 'Role definition ID' : 'Display name',
                    'policy_version_reference' => is_numeric($policyVersionId)
                        ? 'Policy version #'.((int) $policyVersionId)
                        : 'Metadata only',
                    'observed_at' => data_get($meta, 'evidence.observed_at'),
                ];
            })
            ->all();
    }

    private static function stateLabel(BaselineSnapshot $snapshot): string
    {
        return self::hasGaps($snapshot) ? 'Captured with gaps' : 'Complete';
    }

    private static function applySnapshotStateFilter(Builder $query, mixed $value): Builder
    {
        if (! is_string($value) || trim($value) === '') {
            return $query;
        }

        $gapCountExpression = self::gapCountExpression($query);

        return match ($value) {
            'complete' => $query->whereRaw("{$gapCountExpression} = 0"),
            'with_gaps' => $query->whereRaw("{$gapCountExpression} > 0"),
            default => $query,
        };
    }

    private static function gapCountExpression(Builder $query): string
    {
        return match ($query->getConnection()->getDriverName()) {
            'sqlite' => "COALESCE(CAST(json_extract(summary_jsonb, '$.gaps.count') AS INTEGER), 0)",
            'pgsql' => "COALESCE((summary_jsonb #>> '{gaps,count}')::int, 0)",
            default => "COALESCE(CAST(JSON_EXTRACT(summary_jsonb, '$.gaps.count') AS UNSIGNED), 0)",
        };
    }
}