<?php

namespace App\Services\Import;

use App\Models\Import;
use App\Models\ImportEntity;
use App\Models\ImportEvent;
use App\Models\ImportRow;
use App\Services\Import\Contracts\EntityHandlerInterface;
use App\Services\Import\DateNormalizer;
use App\Services\Import\DecimalNormalizer;
use Illuminate\Contracts\Auth\Authenticatable;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Storage;

/**
 * ImportServiceV2 - Generic, database-driven import processor.
 *
 * Refactored from ImportProcessor to use entity handlers and config from import_entities table.
 * 
 * PHASE 6: EntityResolutionService is integrated via handler constructors.
 * Each handler (PersonHandler, ContractHandler, ClientCaseHandler) instantiates
 * the service and uses it to prevent duplicate Person creation.
 */
class ImportServiceV2
{
    protected array $handlers = [];

    protected array $entityConfigs = [];

    protected array $templateMeta = [];

    protected bool $paymentsImport = false;

    protected bool $historyImport = false;

    protected ?string $contractKeyMode = null;

    /**
     * Process an import using v2 architecture.
     */
    public function process(Import $import, ?Authenticatable $user = null): array
    {
        $started = now();
        $total = 0;
        $skipped = 0;
        $imported = 0;
        $invalid = 0;

        try {
            // Load template meta flags
            $this->loadTemplateMeta($import);

            // Load entity configurations and handlers
            $this->loadEntityConfigurations();

            // Only CSV/TSV supported for now
            if (! in_array($import->source_type, ['csv', 'txt'])) {
                ImportEvent::create([
                    'import_id' => $import->id,
                    'user_id' => $user?->getAuthIdentifier(),
                    'event' => 'processing_skipped',
                    'level' => 'warning',
                    'message' => 'Only CSV/TXT supported in v2 processor.',
                ]);
                $import->update(['status' => 'completed', 'finished_at' => now()]);

                return compact('total', 'imported', 'skipped', 'invalid');
            }

            $import->update(['status' => 'processing', 'started_at' => $started]);

            $filePath = $import->path;
            if (! Storage::disk($import->disk ?? 'local')->exists($filePath)) {
                throw new \RuntimeException("File not found: {$filePath}");
            }

            // Check if this is a retry (import_rows already exist)
            $isRetry = ImportRow::where('import_id', $import->id)->exists();

            $fullPath = Storage::disk($import->disk ?? 'local')->path($filePath);
            $fh = fopen($fullPath, 'r');

            if (! $fh) {
                throw new \RuntimeException("Could not open file: {$filePath}");
            }

            $meta = $import->meta ?? [];
            $hasHeader = (bool) ($meta['has_header'] ?? true);
            $delimiter = $meta['forced_delimiter'] ?? $meta['detected_delimiter'] ?? ',';

            $mappings = $this->loadMappings($import);
            $header = null;
            $rowNum = 0;

            // Read header if present
            if ($hasHeader) {
                $header = fgetcsv($fh, 0, $delimiter);
                $rowNum++;
            }

            // If retry mode, only process failed/invalid rows
            if ($isRetry) {
                $failedRows = ImportRow::where('import_id', $import->id)
                    ->whereIn('status', ['invalid', 'failed'])
                    ->orderBy('row_number')
                    ->get();

                foreach ($failedRows as $importRow) {
                    $total++;
                    
                    try {
                        $rawAssoc = $importRow->raw_data;
                        $mapped = $importRow->mapped_data;

                        // Process entities in priority order within a transaction
                        $context = ['import' => $import, 'user' => $user, 'import_row' => $importRow];
                        
                        DB::beginTransaction();
                        try {
                            $results = $this->processRow($import, $mapped, $rawAssoc, $context);
                            
                            // If processing succeeded, commit the transaction
                            if ($results['status'] === 'imported' || $results['status'] === 'skipped') {
                                DB::commit();
                            } else {
                                DB::rollBack();
                            }
                        } catch (\Throwable $e) {
                            DB::rollBack();
                            throw $e;
                        }

                        // Collect entity details from results
                        $entityData = $this->collectEntityDetails($results);
                        $entityDetails = $entityData['details'];
                        $hasErrors = $entityData['hasErrors'];
                        $hasWarnings = $entityData['hasWarnings'];

                        // Handle different result statuses
                        if ($results['status'] === 'imported') {
                            $imported++;
                            $importRow->update([
                                'status' => 'imported',
                                'entity_type' => $results['entity_type'] ?? null,
                                'entity_id' => $results['entity_id'] ?? null,
                            ]);
                            $this->createRowProcessedEvent($import, $user, $importRow->row_number, $entityDetails, $hasWarnings, $rawAssoc);
                        } elseif ($results['status'] === 'skipped') {
                            $skipped++;
                            $importRow->update(['status' => 'skipped']);
                            $this->createRowSkippedEvent($import, $user, $importRow->row_number, $entityDetails, $rawAssoc);
                        } else {
                            $invalid++;
                            $importRow->update([
                                'status' => 'invalid',
                                'errors' => $results['errors'] ?? ['Processing failed'],
                            ]);
                            $this->createRowFailedEvent(
                                $import,
                                $user,
                                $importRow->row_number,
                                $results['errors'] ?? ['Processing failed'],
                                $entityDetails,
                                $rawAssoc
                            );
                        }
                    } catch (\Throwable $e) {
                        $invalid++;
                        $this->handleRowException($import, $user, $importRow->row_number, $e);
                    }
                }
                
                fclose($fh);
            } else {
                // Normal mode: process all rows from CSV
                while (($row = fgetcsv($fh, 0, $delimiter)) !== false) {
                $rowNum++;
                $total++;

                try {
                    $rawAssoc = $this->buildRowAssoc($row, $header);

                    // Skip empty rows
                    if ($this->rowIsEffectivelyEmpty($rawAssoc)) {
                        $skipped++;
                        continue;
                    }

                    $mapped = $this->applyMappings($rawAssoc, $mappings);

                    $rawSha1 = sha1(json_encode($rawAssoc));
                    $importRow = ImportRow::create([
                        'import_id' => $import->id,
                        'row_number' => $rowNum,
                        'record_type' => $this->determineRecordType($mapped),
                        'raw_data' => $rawAssoc,
                        'mapped_data' => $mapped,
                        'status' => 'valid',
                        'raw_sha1' => $rawSha1,
                    ]);

                    // Process entities in priority order within a transaction
                    $context = ['import' => $import, 'user' => $user, 'import_row' => $importRow];
                    
                    DB::beginTransaction();
                    try {
                        $results = $this->processRow($import, $mapped, $rawAssoc, $context);
                        
                        // If processing succeeded, commit the transaction
                        if ($results['status'] === 'imported' || $results['status'] === 'skipped') {
                            DB::commit();
                        } else {
                            DB::rollBack();
                        }
                    } catch (\Throwable $e) {
                        DB::rollBack();
                        throw $e;
                    }

                    // Collect entity details from results
                    $entityData = $this->collectEntityDetails($results);
                    $entityDetails = $entityData['details'];
                    $hasErrors = $entityData['hasErrors'];
                    $hasWarnings = $entityData['hasWarnings'];

                    // Handle different result statuses
                    if ($results['status'] === 'imported') {
                        $imported++;
                        $importRow->update([
                            'status' => 'imported',
                            'entity_type' => $results['entity_type'] ?? null,
                            'entity_id' => $results['entity_id'] ?? null,
                        ]);
                        $this->createRowProcessedEvent($import, $user, $rowNum, $entityDetails, $hasWarnings, $rawAssoc);
                    } elseif ($results['status'] === 'skipped') {
                        $skipped++;
                        $importRow->update(['status' => 'skipped']);
                        $this->createRowSkippedEvent($import, $user, $rowNum, $entityDetails, $rawAssoc);
                    } else {
                        $invalid++;
                        $importRow->update([
                            'status' => 'invalid',
                            'errors' => $results['errors'] ?? ['Processing failed'],
                        ]);
                        $this->createRowFailedEvent(
                            $import,
                            $user,
                            $rowNum,
                            $results['errors'] ?? ['Processing failed'],
                            $entityDetails,
                            $rawAssoc
                        );
                    }
                } catch (\Throwable $e) {
                    $invalid++;
                    $this->handleRowException($import, $user, $rowNum, $e);
                }
                }

                fclose($fh);
            }

            $this->finalizeImport($import, $user, $total, $imported, $skipped, $invalid);
        } catch (\Throwable $e) {
            $this->handleFatalException($import, $user, $e);
            throw $e;
        }

        return compact('total', 'imported', 'skipped', 'invalid');
    }

    /**
     * Load entity configurations from database.
     */
    protected function loadEntityConfigurations(): void
    {
        $entities = ImportEntity::where('is_active', true)
            ->orderBy('priority', 'desc')
            ->get();

        foreach ($entities as $entity) {
            $this->entityConfigs[$entity->canonical_root] = $entity;

            // Instantiate handler if specified
            if ($entity->handler_class && class_exists($entity->handler_class)) {
                $this->handlers[$entity->canonical_root] = new $entity->handler_class($entity);
            }
        }
    }

    /**
     * Load mappings for import.
     */
    protected function loadMappings(Import $import)
    {
        return DB::table('import_mappings')
            ->where('import_id', $import->id)
            ->orderBy('position')
            ->get();
    }

    /**
     * Build associative array from row.
     */
    protected function buildRowAssoc(array $row, ?array $header): array
    {
        if ($header) {
            $result = [];
            foreach ($header as $idx => $col) {
                $result[$col] = $row[$idx] ?? null;
            }

            return $result;
        }

        return array_combine(range(0, count($row) - 1), $row);
    }

    /**
     * Check if row is effectively empty.
     */
    protected function rowIsEffectivelyEmpty(array $raw): bool
    {
        foreach ($raw as $val) {
            if (! is_null($val) && trim((string) $val) !== '') {
                return false;
            }
        }

        return true;
    }

    /**
     * Apply mappings to raw data.
     */
    protected function applyMappings(array $raw, $mappings): array
    {
        $mapped = [];
        
        // Group mappings by target field to handle concatenation
        $groupedMappings = [];
        foreach ($mappings as $mapping) {
            $targetField = $mapping->target_field;
            if (!isset($groupedMappings[$targetField])) {
                $groupedMappings[$targetField] = [];
            }
            $groupedMappings[$targetField][] = $mapping;
        }
        
        foreach ($groupedMappings as $targetField => $fieldMappings) {
            // Special handling for meta fields: contracts.meta or other_entity.meta
            if (str_ends_with($targetField, '.meta')) {
                $this->applyMetaMappings($mapped, $targetField, $fieldMappings, $raw);
                continue;
            }
            
            // Group by group number from options
            $valuesByGroup = [];
            
            foreach ($fieldMappings as $mapping) {
                $sourceCol = $mapping->source_column;
                
                if (!isset($raw[$sourceCol])) {
                    continue;
                }
                
                $value = $raw[$sourceCol];
                
                // Apply transform
                if ($mapping->transform) {
                    $value = $this->applyTransform($value, $mapping->transform);
                }
                
                // Get group from options
                $options = $mapping->options ? json_decode($mapping->options, true) : [];
                $group = $options['group'] ?? null;
                
                // Group values by their group number
                if ($group !== null) {
                    // Same group = concatenate
                    if (!isset($valuesByGroup[$group])) {
                        $valuesByGroup[$group] = [];
                    }
                    $valuesByGroup[$group][] = $value;
                } else {
                    // No group = each gets its own group
                    $valuesByGroup[] = [$value];
                }
            }
            
            // Now set the values
            foreach ($valuesByGroup as $values) {
                if (count($values) === 1) {
                    // Single value - set directly
                    $this->setNestedValue($mapped, $targetField, $values[0]);
                } else {
                    // Multiple values in same group - concatenate with newline
                    $concatenated = implode("\n", array_filter($values, fn($v) => !empty($v) && trim((string)$v) !== ''));
                    if (!empty($concatenated)) {
                        $this->setNestedValue($mapped, $targetField, $concatenated);
                    }
                }
            }
        }

        return $mapped;
    }
    
    /**
     * Apply meta mappings with special structure: entity.meta[group][key] = {title, value, type}
     */
    protected function applyMetaMappings(array &$mapped, string $targetField, array $fieldMappings, array $raw): void
    {
        // Extract entity from target field: contracts.meta -> contracts
        $entity = str_replace('.meta', '', $targetField);
        
        foreach ($fieldMappings as $mapping) {
            $sourceCol = $mapping->source_column;
            
            if (!isset($raw[$sourceCol])) {
                continue;
            }
            
            $value = $raw[$sourceCol];
            
            // Apply transform
            if ($mapping->transform) {
                $value = $this->applyTransform($value, $mapping->transform);
            }
            
            // Get options
            $options = $mapping->options ? json_decode($mapping->options, true) : [];
            $metaKey = $options['key'] ?? null;
            $metaType = $options['type'] ?? 'string';
            $group = $options['group'] ?? '1';
            
            if (!$metaKey) {
                continue;
            }
            
            // Coerce value based on type
            $coerced = $value;
            if ($metaType === 'number') {
                if (is_string($coerced)) {
                    $norm = DecimalNormalizer::normalize($coerced);
                    $coerced = is_numeric($norm) ? (float) $norm : $coerced;
                }
            } elseif ($metaType === 'boolean') {
                if (is_string($coerced)) {
                    $lc = strtolower(trim($coerced));
                    if (in_array($lc, ['1', 'true', 'yes', 'y'], true)) {
                        $coerced = true;
                    } elseif (in_array($lc, ['0', 'false', 'no', 'n'], true)) {
                        $coerced = false;
                    }
                } else {
                    $coerced = (bool) $coerced;
                }
            } elseif ($metaType === 'date') {
                $coerced = is_scalar($coerced) ? $this->normalizeDate((string) $coerced) : null;
            } else {
                // string or unspecified: cast scalars to string
                if (is_scalar($coerced)) {
                    $coerced = (string) $coerced;
                }
            }
            
            // Initialize structure if needed
            if (!isset($mapped[$entity])) {
                $mapped[$entity] = [];
            }
            if (!isset($mapped[$entity]['meta']) || !is_array($mapped[$entity]['meta'])) {
                $mapped[$entity]['meta'] = [];
            }
            if (!isset($mapped[$entity]['meta'][$group])) {
                $mapped[$entity]['meta'][$group] = [];
            }
            
            // Store as structure with title, value and type
            $entry = [
                'title' => $sourceCol,
                'value' => $coerced,
            ];
            if ($metaType) {
                $entry['type'] = $metaType;
            }
            
            $mapped[$entity]['meta'][$group][$metaKey] = $entry;
        }
    }

    /**
     * Apply transform to value.
     */
    protected function applyTransform(mixed $value, string $transform): mixed
    {
        return match (strtolower($transform)) {
            'trim' => is_string($value) ? trim($value) : $value,
            'upper' => is_string($value) ? strtoupper($value) : $value,
            'lower' => is_string($value) ? strtolower($value) : $value,
            'date' => $this->normalizeDate($value),
            default => $value,
        };
    }

    /**
     * Normalize date value.
     */
    protected function normalizeDate(mixed $value): ?string
    {
        if (empty($value)) {
            return null;
        }

        try {
            return DateNormalizer::toDate((string) $value);
        } catch (\Throwable $e) {
            return null;
        }
    }

    /**
     * Set nested value in array using dot notation.
     * If the key already exists, convert to array and append the new value.
     */
    protected function setNestedValue(array &$array, string $key, mixed $value): void
    {
        $keys = explode('.', $key);
        $current = &$array;

        foreach ($keys as $i => $k) {
            if ($i === count($keys) - 1) {
                // If key already exists, convert to array and append
                if (isset($current[$k])) {
                    // Convert existing single value to array if needed
                    if (!is_array($current[$k])) {
                        $current[$k] = [$current[$k]];
                    }
                    // Append new value
                    $current[$k][] = $value;
                } else {
                    // Set as single value
                    $current[$k] = $value;
                }
            } else {
                if (! isset($current[$k]) || ! is_array($current[$k])) {
                    $current[$k] = [];
                }
                $current = &$current[$k];
            }
        }
    }

    /**
     * Determine record type from mapped data.
     */
    protected function determineRecordType(array $mapped): string
    {
        if (isset($mapped['payment'])) {
            return 'payment';
        }
        if (isset($mapped['activity'])) {
            return 'activity';
        }
        if (isset($mapped['contract'])) {
            return 'contract';
        }
        if (isset($mapped['account'])) {
            return 'account';
        }

        return 'contact';
    }

    /**
     * Process a single row through all entity handlers.
     */
    protected function processRow(Import $import, array $mapped, array $raw, array $context): array
    {
        $entityResults = [];
        $lastEntityType = null;
        $lastEntityId = null;
        $hasErrors = false;

        // Process entities in configured priority order
        foreach ($this->entityConfigs as $root => $config) {
            // Check if this entity exists in mapped data (support aliases)
            $mappedKey = $this->findMappedKey($mapped, $root, $config);
            
            if (!$mappedKey || !isset($mapped[$mappedKey])) {
                continue;
            }

            $handler = $this->handlers[$root] ?? null;

            if (! $handler) {
                continue;
            }

            try {
                // Validate before processing
                $validation = $handler->validate($mapped[$mappedKey]);
                if (! $validation['valid']) {
                    $entityResults[$root] = [
                        'action' => 'invalid',
                        'errors' => $validation['errors'],
                        'level' => 'error',
                    ];
                    $hasErrors = true;
                    
                    // Don't stop processing, continue to other entities to collect all errors
                    continue;
                }

                // Pass previous results as context
                $result = $handler->process($import, $mapped[$mappedKey], $raw, array_merge($context, $entityResults));

                $entityResults[$root] = $result;

                // Track last successful entity for row status
                if (in_array($result['action'] ?? null, ['inserted', 'updated'])) {
                    $lastEntityType = $handler->getEntityClass();
                    $lastEntityId = $result['entity']?->id ?? null;
                }

                // Post-contract actions (segment attachment, activity creation)
                if ($root === 'contract' && in_array($result['action'] ?? null, ['inserted', 'updated', 'reactivated'])) {
                    try {
                        $this->postContractActions($import, $result['entity'], $context);
                    } catch (\Throwable $e) {
                        Log::warning('Post-contract action failed', [
                            'import_id' => $import->id,
                            'contract_id' => $result['entity']->id ?? null,
                            'error' => $e->getMessage(),
                        ]);
                    }
                }
            } catch (\Throwable $e) {
                $hasErrors = true;
                
                Log::error("Handler failed for entity {$root}", [
                    'import_id' => $import->id,
                    'error' => $e->getMessage(),
                    'trace' => $e->getTraceAsString(),
                ]);

                $entityResults[$root] = [
                    'action' => 'failed',
                    'level' => 'error',
                    'errors' => [$e->getMessage()],
                    'exception' => [
                        'message' => $e->getMessage(),
                        'file' => basename($e->getFile()),
                        'line' => $e->getLine(),
                        'class' => get_class($e),
                    ],
                ];
                
                // Continue to process other entities to collect all errors
                continue;
            }
        }

        // If we had errors, return invalid status
        if ($hasErrors) {
            $allErrors = [];
            foreach ($entityResults as $root => $result) {
                if (isset($result['errors'])) {
                    $allErrors[] = "{$root}: " . implode(', ', $result['errors']);
                }
            }
            
            return [
                'status' => 'invalid',
                'errors' => $allErrors,
                'results' => $entityResults,
            ];
        }

        return [
            'status' => $lastEntityId ? 'imported' : 'skipped',
            'entity_type' => $lastEntityType,
            'entity_id' => $lastEntityId,
            'results' => $entityResults,
        ];
    }
    
    /**
     * Find the key in mapped data that corresponds to this canonical root.
     */
    protected function findMappedKey(array $mapped, string $canonicalRoot, $config): ?string
    {
        // First check canonical_root itself
        if (isset($mapped[$canonicalRoot])) {
            return $canonicalRoot;
        }
        
        // Then check key (e.g., 'contracts', 'person_addresses')
        if (isset($mapped[$config->key])) {
            return $config->key;
        }
        
        // Then check aliases
        $aliases = $config->aliases ?? [];
        foreach ($aliases as $alias) {
            if (isset($mapped[$alias])) {
                return $alias;
            }
        }
        
        return null;
    }
    /**
     * Load template meta flags for special processing modes.
     */
    protected function loadTemplateMeta(Import $import): void
    {
        $this->templateMeta = optional($import->template)->meta ?? [];
        $this->paymentsImport = (bool) ($this->templateMeta['payments_import'] ?? false);
        $this->historyImport = (bool) ($this->templateMeta['history_import'] ?? false);
        $this->contractKeyMode = $this->templateMeta['contract_key_mode'] ?? null;
    }

    /**
     * Collect entity details from processing results.
     */
    protected function collectEntityDetails(array $results): array
    {
        $entityDetails = [];
        $hasErrors = false;
        $hasWarnings = false;

        if (isset($results['results']) && is_array($results['results'])) {
            foreach ($results['results'] as $entityKey => $result) {
                $action = $result['action'] ?? 'unknown';
                $message = $result['message'] ?? null;
                $count = $result['count'] ?? 1;
                
                $detail = [
                    'entity' => $entityKey,
                    'action' => $action,
                    'count' => $count,
                ];
                
                if ($message) {
                    $detail['message'] = $message;
                }
                
                if ($action === 'invalid' || isset($result['errors'])) {
                    $detail['level'] = 'error';
                    $detail['errors'] = $result['errors'] ?? [];
                    $hasErrors = true;
                } elseif ($action === 'skipped') {
                    $detail['level'] = 'warning';
                    $hasWarnings = true;
                } else {
                    $detail['level'] = 'info';
                }
                
                if (isset($result['exception'])) {
                    $detail['exception'] = $result['exception'];
                    $hasErrors = true;
                }
                
                $entityDetails[] = $detail;
            }
        }

        return [
            'details' => $entityDetails,
            'hasErrors' => $hasErrors,
            'hasWarnings' => $hasWarnings,
        ];
    }

    /**
     * Create a success event for a processed row.
     */
    protected function createRowProcessedEvent(
        Import $import,
        ?Authenticatable $user,
        int $rowNum,
        array $entityDetails,
        bool $hasWarnings,
        array $rawData = []
    ): void {
        ImportEvent::create([
            'import_id' => $import->id,
            'user_id' => $user?->getAuthIdentifier(),
            'event' => 'row_processed',
            'level' => $hasWarnings ? 'warning' : 'info',
            'message' => "Row {$rowNum} processed successfully",
            'context' => [
                'row' => $rowNum,
                'entity_details' => $entityDetails,
                'raw_data' => $rawData,
            ],
        ]);
    }

    /**
     * Create a skip event for a skipped row.
     */
    protected function createRowSkippedEvent(
        Import $import,
        ?Authenticatable $user,
        int $rowNum,
        array $entityDetails,
        array $rawData = []
    ): void {
        ImportEvent::create([
            'import_id' => $import->id,
            'user_id' => $user?->getAuthIdentifier(),
            'event' => 'row_skipped',
            'level' => 'warning',
            'message' => "Row {$rowNum} skipped",
            'context' => [
                'row' => $rowNum,
                'entity_details' => $entityDetails,
                'raw_data' => $rawData,
            ],
        ]);
    }

    /**
     * Create a failure event for a failed row.
     */
    protected function createRowFailedEvent(
        Import $import,
        ?Authenticatable $user,
        int $rowNum,
        array $errors,
        array $entityDetails,
        array $rawData = []
    ): void {
        ImportEvent::create([
            'import_id' => $import->id,
            'user_id' => $user?->getAuthIdentifier(),
            'event' => 'row_failed',
            'level' => 'error',
            'message' => "Row {$rowNum} failed: " . implode(', ', $errors),
            'context' => [
                'row' => $rowNum,
                'errors' => $errors,
                'entity_details' => $entityDetails,
                'raw_data' => $rawData,
            ],
        ]);
    }

    /**
     * Handle row processing exception.
     */
    protected function handleRowException(
        Import $import,
        ?Authenticatable $user,
        int $rowNum,
        \Throwable $e
    ): void {
        Log::error('ImportServiceV2 row processing failed', [
            'import_id' => $import->id,
            'row' => $rowNum,
            'error' => $e->getMessage(),
            'trace' => $e->getTraceAsString(),
        ]);

        ImportEvent::create([
            'import_id' => $import->id,
            'user_id' => $user?->getAuthIdentifier(),
            'event' => 'row_failed',
            'level' => 'error',
            'message' => "Row {$rowNum} exception: {$e->getMessage()}",
            'context' => [
                'row' => $rowNum,
                'exception' => [
                    'message' => $e->getMessage(),
                    'file' => $e->getFile(),
                    'line' => $e->getLine(),
                ],
            ],
        ]);
    }

    /**
     * Finalize import with completion event.
     */
    protected function finalizeImport(
        Import $import,
        ?Authenticatable $user,
        int $total,
        int $imported,
        int $skipped,
        int $invalid
    ): void {
        // If there are any invalid rows, mark import as failed, not completed
        $status = $invalid > 0 ? 'failed' : 'completed';
        $eventLevel = $invalid > 0 ? 'error' : 'info';
        $eventName = $invalid > 0 ? 'processing_failed' : 'processing_completed';
        
        $import->update([
            'status' => $status,
            'finished_at' => now(),
            'total_rows' => $total,
            'imported_rows' => $imported,
            'valid_rows' => $imported,
            'invalid_rows' => $invalid,
        ]);

        ImportEvent::create([
            'import_id' => $import->id,
            'user_id' => $user?->getAuthIdentifier(),
            'event' => $eventName,
            'level' => $eventLevel,
            'message' => "Processed {$total} rows: {$imported} imported, {$skipped} skipped, {$invalid} invalid",
        ]);
    }

    /**
     * Handle fatal processing exception.
     */
    protected function handleFatalException(
        Import $import,
        ?Authenticatable $user,
        \Throwable $e
    ): void {
        Log::error('ImportServiceV2 processing failed', [
            'import_id' => $import->id,
            'error' => $e->getMessage(),
            'trace' => $e->getTraceAsString(),
        ]);

        $import->update(['status' => 'failed', 'finished_at' => now()]);

        ImportEvent::create([
            'import_id' => $import->id,
            'user_id' => $user?->getAuthIdentifier(),
            'event' => 'processing_failed',
            'level' => 'error',
            'message' => $e->getMessage(),
        ]);
    }

    /**
     * Post-contract actions: attach segment, create activity with decision.
     * Matches ImportProcessor::postContractActions() behavior.
     */
    protected function postContractActions(Import $import, $contract, array $context = []): void
    {
        $meta = $import->meta ?? [];
        $segmentId = (int) ($meta['segment_id'] ?? 0);
        $decisionId = (int) ($meta['decision_id'] ?? 0);
        $templateName = (string) ($meta['template_name'] ?? optional($import->template)->name ?? '');
        $actionId = (int) ($meta['action_id'] ?? 0);

        // Attach segment to contract as the main (active) segment if provided
        if ($segmentId > 0) {
            // Ensure the segment exists on the client case and is active
            $ccSeg = \DB::table('client_case_segment')
                ->where('client_case_id', $contract->client_case_id)
                ->where('segment_id', $segmentId)
                ->first();
            if (! $ccSeg) {
                \DB::table('client_case_segment')->insert([
                    'client_case_id' => $contract->client_case_id,
                    'segment_id' => $segmentId,
                    'active' => true,
                    'created_at' => now(),
                    'updated_at' => now(),
                ]);
            } elseif (! $ccSeg->active) {
                \DB::table('client_case_segment')
                    ->where('id', $ccSeg->id)
                    ->update(['active' => true, 'updated_at' => now()]);
            }

            // Deactivate all other segments for this contract to make this the main one
            \DB::table('contract_segment')
                ->where('contract_id', $contract->id)
                ->where('segment_id', '!=', $segmentId)
                ->update(['active' => false, 'updated_at' => now()]);

            // Upsert the selected segment as active for this contract
            $pivot = \DB::table('contract_segment')
                ->where('contract_id', $contract->id)
                ->where('segment_id', $segmentId)
                ->first();
            if ($pivot) {
                if (! $pivot->active) {
                    \DB::table('contract_segment')
                        ->where('id', $pivot->id)
                        ->update(['active' => true, 'updated_at' => now()]);
                }
            } else {
                \DB::table('contract_segment')->insert([
                    'contract_id' => $contract->id,
                    'segment_id' => $segmentId,
                    'active' => true,
                    'created_at' => now(),
                    'updated_at' => now(),
                ]);
            }
        }

        // Create activity if decision provided
        if ($decisionId > 0) {
            \App\Models\Activity::create([
                'decision_id' => $decisionId,
                'action_id' => $actionId > 0 ? $actionId : null,
                'contract_id' => $contract->id,
                'client_case_id' => $contract->client_case_id,
                'note' => trim('Imported via template'.($templateName ? ': '.$templateName : '')),
            ]);
        }
    }
}