<?php

namespace Database\Seeders;

use Illuminate\Database\Seeder;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\File;
use RuntimeException;

class TerritoryReferenceSeeder extends Seeder
{
    private const SOURCE_CHECKSUM = '964a187ad32ea553b9e112cd159caa90b900050c42b7329594a75bcd798a96ff';

    private const RECORDS_CHECKSUM = '630b574a3bfc5fa80dfb8d68314d7a2c413c86c3b1aa9e71603b393523b81c3c';

    private const EXPECTED_COUNTS = [
        'country' => 1,
        'province' => 11,
        'district' => 148,
        'admin_post' => 437,
        'locality' => 1324,
    ];

    public function run(): void
    {
        $data = json_decode(File::get(database_path('data/territory-locations.json')), true, 512, JSON_THROW_ON_ERROR);
        if (! is_array($data) || ! is_array($data['records'] ?? null)) {
            throw new RuntimeException('Territory reference dataset is malformed.');
        }

        $records = $data['records'];

        $actualCounts = array_count_values(array_column($records, 'location_type'));
        ksort($actualCounts);
        $expectedCounts = self::EXPECTED_COUNTS;
        ksort($expectedCounts);

        if (($data['source_system'] ?? null) !== 'cartografia-workbook'
            || ($data['source_sha256'] ?? null) !== self::SOURCE_CHECKSUM
            || ($data['source_version'] ?? null) !== 3
            || ! is_string($data['records_sha256'] ?? null)
            || ! hash_equals(self::RECORDS_CHECKSUM, $data['records_sha256'])
            || ! hash_equals(self::RECORDS_CHECKSUM, hash('sha256', json_encode($records, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR)))
            || $actualCounts !== $expectedCounts) {
            throw new RuntimeException('Territory reference dataset failed its source or completeness checks.');
        }

        $counts = DB::transaction(function () use ($records): array {
            DB::select('SELECT pg_advisory_xact_lock(280926, 150000)');

            $seen = [];
            $types = [];
            $counts = ['created' => 0, 'unchanged' => 0, 'made_public' => 0];

            foreach ($records as $record) {
                $this->validateRecord($record, $seen, $types);

                $externalId = self::SOURCE_CHECKSUM.':'.$record['id'];
                $existing = DB::table('geo_locations')->where('id', $record['id'])->first();
                $externalMatch = DB::table('geo_locations')
                    ->where('source_system', 'cartografia-workbook')
                    ->where('external_id', $externalId)
                    ->first();

                if ($externalMatch && (! $existing || $externalMatch->id !== $existing->id)) {
                    throw new RuntimeException('Territory external identifier collision: '.$record['id']);
                }

                if ($existing) {
                    if ($existing->source_system !== 'cartografia-workbook' || $existing->external_id !== $externalId) {
                        throw new RuntimeException('Territory ID belongs to another source: '.$record['id']);
                    }

                    foreach (['name', 'parent_id', 'location_type', 'code', 'source_code'] as $field) {
                        if ($record[$field] !== $existing->{$field}) {
                            throw new RuntimeException('Territory reference differs from packaged source: '.$record['id']);
                        }
                    }

                    if ($existing->deleted_at !== null) {
                        throw new RuntimeException('Packaged territory reference is archived: '.$record['id']);
                    }

                    if ($existing->data_classification === 'internal') {
                        DB::table('geo_locations')->where('id', $record['id'])->update([
                            'data_classification' => 'public',
                            'updated_at' => now(),
                        ]);
                        $counts['made_public']++;
                    } elseif ($existing->data_classification === 'public') {
                        $counts['unchanged']++;
                    } else {
                        throw new RuntimeException('Territory reference has an unexpected classification: '.$record['id']);
                    }

                    continue;
                }

                DB::table('geo_locations')->insert([
                    ...$record,
                    'source_system' => 'cartografia-workbook',
                    'external_id' => $externalId,
                    'version_no' => 1,
                    'data_classification' => 'public',
                    'created_at' => now(),
                    'updated_at' => now(),
                    'deleted_at' => null,
                ]);
                $counts['created']++;
            }

            return $counts;
        });

        $this->command->info(sprintf(
            'Referências territoriais: %d criadas, %d já existentes, %d classificadas como públicas.',
            $counts['created'],
            $counts['unchanged'],
            $counts['made_public'],
        ));
    }

    /** @param array<string, mixed> $record
     * @param  array<string, bool>  $seen
     * @param  array<string, string>  $types
     *
     * @param-out array<string, bool> $seen
     * @param-out array<string, string> $types
     */
    private function validateRecord(array $record, array &$seen, array &$types): void
    {
        $id = $record['id'] ?? null;
        if (! is_string($id) || $id === '') {
            throw new RuntimeException('Territory reference is missing a valid id.');
        }
        foreach (['id', 'name', 'location_type', 'code', 'source_code'] as $field) {
            if (! isset($record[$field]) || $record[$field] === '') {
                throw new RuntimeException('Territory reference is missing '.$field.'.');
            }
        }

        $type = $record['location_type'];
        $parentTypes = [
            'country' => null,
            'province' => 'country',
            'district' => 'province',
            'admin_post' => 'district',
            'locality' => 'admin_post',
        ];

        if (! is_string($type) || ! array_key_exists($type, $parentTypes) || isset($seen[$id])) {
            throw new RuntimeException('Territory reference has an invalid type or duplicate ID.');
        }

        $expectedParent = $parentTypes[$type];

        if ($expectedParent === null) {
            if ($record['parent_id'] !== null) {
                throw new RuntimeException('Country reference cannot have a parent.');
            }
        } elseif (! is_string($record['parent_id'] ?? null) || ($types[$record['parent_id']] ?? null) !== $expectedParent) {
            throw new RuntimeException('Territory reference has a missing or invalid parent: '.$id);
        }

        $seen[$id] = true;
        $types[$id] = $type;
    }
}