<?php

namespace KTXC\Db;

use MongoDB\Collection as MongoCollection;
use MongoDB\InsertOneResult;
use MongoDB\UpdateResult;
use MongoDB\DeleteResult;

/**
 * Wrapper for MongoDB\Collection
 * Provides abstraction layer for MongoDB collection operations
 */
class Collection
{
    private MongoCollection $collection;

    public function __construct(MongoCollection $collection)
    {
        $this->collection = $collection;
        
        // Set type map to return plain arrays instead of objects
        // This converts BSON types to PHP native types
        $this->collection = $collection->withOptions([
            'typeMap' => [
                'root' => 'array',
                'document' => 'array',
                'array' => 'array'
            ]
        ]);
    }

    /**
     * Find documents in the collection
     * 
     * @param array $filter Query filter
     * @param array $options Query options
     * @return Cursor
     */
    public function find(array $filter = [], array $options = []): Cursor
    {
        $filter = $this->convertFilter($filter);
        /** @var \Iterator $cursor */
        $cursor = $this->collection->find($filter, $options);
        return new Cursor($cursor);
    }

    /**
     * Find a single document
     * 
     * @param array $filter Query filter
     * @param array $options Query options
     * @return array|null Returns array with _id as string
     */
    public function findOne(array $filter = [], array $options = []): ?array
    {
        $filter = $this->convertFilter($filter);
        $result = $this->collection->findOne($filter, $options);
        
        if ($result === null) {
            return null;
        }
        
        // Convert to array if it's an object
        if (is_object($result)) {
            $result = (array) $result;
        }
        
        return $this->convertBsonToNative($result);
    }

    /**
     * Insert a single document
     * 
     * @param array|object $document Document to insert
     * @param array $options Insert options
     * @return InsertOneResult
     */
    public function insertOne(array|object $document, array $options = []): InsertOneResult
    {
        $document = $this->convertDocument($document);
        return $this->collection->insertOne($document, $options);
    }

    /**
     * Insert multiple documents
     * 
     * @param array $documents Documents to insert
     * @param array $options Insert options
     */
    public function insertMany(array $documents, array $options = []): mixed
    {
        $documents = array_map(fn($doc) => $this->convertDocument($doc), $documents);
        return $this->collection->insertMany($documents, $options);
    }

    /**
     * Update a single document
     * 
     * @param array $filter Query filter
     * @param array $update Update operations
     * @param array $options Update options
     * @return UpdateResult
     */
    public function updateOne(array $filter, array $update, array $options = []): UpdateResult
    {
        $filter = $this->convertFilter($filter);
        $update = $this->convertDocument($update);
        return $this->collection->updateOne($filter, $update, $options);
    }

    /**
     * Update multiple documents
     * 
     * @param array $filter Query filter
     * @param array $update Update operations
     * @param array $options Update options
     * @return UpdateResult
     */
    public function updateMany(array $filter, array $update, array $options = []): UpdateResult
    {
        $filter = $this->convertFilter($filter);
        $update = $this->convertDocument($update);
        return $this->collection->updateMany($filter, $update, $options);
    }

    /**
     * Delete a single document
     * 
     * @param array $filter Query filter
     * @param array $options Delete options
     * @return DeleteResult
     */
    public function deleteOne(array $filter, array $options = []): DeleteResult
    {
        $filter = $this->convertFilter($filter);
        return $this->collection->deleteOne($filter, $options);
    }

    /**
     * Delete multiple documents
     * 
     * @param array $filter Query filter
     * @param array $options Delete options
     * @return DeleteResult
     */
    public function deleteMany(array $filter, array $options = []): DeleteResult
    {
        $filter = $this->convertFilter($filter);
        return $this->collection->deleteMany($filter, $options);
    }

    /**
     * Count documents matching filter
     * 
     * @param array $filter Query filter
     * @param array $options Count options
     * @return int
     */
    public function countDocuments(array $filter = [], array $options = []): int
    {
        $filter = $this->convertFilter($filter);
        return $this->collection->countDocuments($filter, $options);
    }

    /**
     * Execute aggregation pipeline
     * 
     * @param array $pipeline Aggregation pipeline
     * @param array $options Aggregation options
     * @return Cursor
     */
    public function aggregate(array $pipeline, array $options = []): Cursor
    {
        /** @var \Iterator $cursor */
        $cursor = $this->collection->aggregate($pipeline, $options);
        return new Cursor($cursor);
    }

    /**
     * Create an index
     * 
     * @param array $key Index specification
     * @param array $options Index options
     * @return string Index name
     */
    public function createIndex(array $key, array $options = []): string
    {
        return $this->collection->createIndex($key, $options);
    }

    /**
     * Drop the collection
     */
    public function drop(): array|object|null
    {
        return $this->collection->drop();
    }

    /**
     * Get collection name
     */
    public function getCollectionName(): string
    {
        return $this->collection->getCollectionName();
    }

    /**
     * Get database name
     */
    public function getDatabaseName(): string
    {
        return $this->collection->getDatabaseName();
    }

    /**
     * Convert ObjectId instances in filter to MongoDB ObjectId
     */
    private function convertFilter(array $filter): array
    {
        return $this->convertArray($filter);
    }

    /**
     * Convert ObjectId instances in document to MongoDB ObjectId
     */
    private function convertDocument(array|object $document): array|object
    {
        if (is_array($document)) {
            return $this->convertArray($document);
        }
        return $document;
    }

    /**
     * Recursively convert ObjectId and UTCDateTime instances
     */
    private function convertArray(array $data): array
    {
        foreach ($data as $key => $value) {
            if ($value instanceof ObjectId) {
                $data[$key] = $value->toBSON();
            } elseif ($value instanceof UTCDateTime) {
                $data[$key] = $value->toBSON();
            } elseif (is_array($value)) {
                $data[$key] = $this->convertArray($value);
            }
        }
        return $data;
    }

    /**
     * Get the underlying MongoDB Collection
     * Use sparingly - prefer using wrapper methods
     */
    public function getMongoCollection(): MongoCollection
    {
        return $this->collection;
    }
    
    /**
     * Convert BSON objects to native PHP types
     * Handles ObjectId, UTCDateTime, and other BSON types
     */
    private function convertBsonToNative(mixed $data): mixed
    {
        if (is_array($data)) {
            foreach ($data as $key => $value) {
                $data[$key] = $this->convertBsonToNative($value);
            }
            return $data;
        }
        
        if (is_object($data)) {
            // Convert MongoDB BSON ObjectId to string
            if ($data instanceof \MongoDB\BSON\ObjectId) {
                return (string) $data;
            }
            
            // Convert MongoDB BSON UTCDateTime to string or DateTime
            if ($data instanceof \MongoDB\BSON\UTCDateTime) {
                return (string) $data->toDateTime()->format('c');
            }
            
            // Convert other objects to arrays recursively
            if (method_exists($data, 'bsonSerialize')) {
                return $this->convertBsonToNative($data->bsonSerialize());
            }
            
            return (array) $data;
        }
        
        return $data;
    }
}