<?php

namespace Ulmus;

use Ulmus\Common\EntityResolver;

class Repository
{
    const DEFAULT_ALIAS = "this";

    public ? ConnectionAdapter $adapter;

    protected QueryBuilder $queryBuilder;

    protected EntityResolver $entityResolver;

    public string $alias;

    public string $entityClass;

    public function __construct(string $entity, string $alias = self::DEFAULT_ALIAS, ConnectionAdapter $adapter = null) {
        $this->entityClass = $entity;
        $this->alias = $alias;
        $this->entityResolver = Ulmus::resolveEntity($entity);
        $this->adapter = $adapter ?? $this->entityResolver->databaseAdapter() ?? Ulmus::$defaultAdapter;
        $this->queryBuilder = new QueryBuilder( $this->adapter->adapter() );
    }

    public function loadOne() : ? object
    {
        return $this->limit(1)->collectionFromQuery()[0] ?? null;
    }

    public function loadOneFromField($field, $value) : ? object
    {
        return $this->where($field, $value)->loadOne();
    }
    
    public function loadFromPk($value, $primaryKey = "id") : ? object
    {
        return $this->loadOneFromField($primaryKey, $value);
    }
    
    public function loadAll() : EntityCollection
    {
        return $this->collectionFromQuery();
    }

    public function loadFromField($field, $value) : EntityCollection
    {
        return $this->where($field, $value)->collectionFromQuery();
    }
    
    public function count() : int
    {
        $this->select("COUNT(*)")->selectSqlQuery();

        $this->finalizeQuery();

        return Ulmus::runSelectQuery($this->queryBuilder, $this->adapter)->fetchColumn(0);
    }

    public function deleteOne() 
    {
        return $this->limit(1)->deleteSqlQuery()->runQuery();
    }
    
    public function deleteAll() 
    {    
        return $this->deleteSqlQuery()->runQuery();
    }

    public function deleteFromPk($value) : bool
    {
        if ( $value !== 0 && empty($value) ) {
            throw new Exception\EntityPrimaryKeyUnknown("A primary key value has to be defined to delete an item.");
        }
        
        return (bool) $this->wherePrimaryKey($value)->deleteOne()->rowCount();
    }
    
    public function save(object $entity) : bool
    {        
        $dataset = $entity->toArray();
        
        $primaryKeyDefinition = Ulmus::resolveEntity($this->entityClass)->getPrimaryKeyField();

        if ( ! $entity->isLoaded() ) {
            $statement = $this->insertSqlQuery($dataset)->runQuery();
            
            if ( ( 0 !== $statement->lastInsertId ) && 
               ( null !== $primaryKeyDefinition )) {
                $pkField = key($primaryKeyDefinition);
                $entity->$pkField = $statement->lastInsertId;
            }
            
            return true;
        }
        else {
            if ( $primaryKeyDefinition === null ) {
                throw new \Exception(sprintf("No primary key found for entity %s", $this->entityClass));
            }

            if ( [] !== $diff = $this->generateDatasetDiff($entity) ) {
                $pkField = key($primaryKeyDefinition);
                $pkFieldName = $primaryKeyDefinition[$pkField]->name ?? $pkField;
                $this->where($pkFieldName, $dataset[$pkFieldName]);

                $update = $this->updateSqlQuery($diff)->runQuery();
                
                return $update ? (bool) $update->rowCount() : false;
            }
        }
        
        return false;
    }
    
    public function saveAll(EntityCollection $collection) : void 
    {
        foreach($collection as $entity) {
            $this->save($entity);
        }
    }
    
    public function generateDatasetDiff(object $entity) : array
    {
        return array_diff_assoc( array_change_key_case($entity->toArray()), array_change_key_case($entity->entityGetDataset(true)) );
    }
    
    public function yieldAll() : \Generator
    {

    }

    public function select($fields) : self
    {
        $this->queryBuilder->select($fields);
        
        return $this;
    }

    public function insert(array $fieldlist, string $table, string $alias, ? string $schema) : self
    {
        $this->queryBuilder->insert($fieldlist, $this->escapeTable($table), $alias, $schema);
        
        return $this;
    }

    public function values(array $dataset) : self
    {
        $this->queryBuilder->values($dataset);
        
        return $this;
    }
    
    public function update(string $table, string $alias, ? string $schema) : self
    {
        $this->queryBuilder->update($this->escapeTable($table), $alias, $schema);
        
        return $this;
    }
    
    public function set(array $dataset) : self
    {
        $this->queryBuilder->set($dataset);
        
        return $this;
    }
    
    public function delete() : self
    {
        $this->queryBuilder->delete($this->alias);
        
        return $this;
    }

    public function from(string $table, ? string $alias, ? string $schema) : self
    {
        $this->queryBuilder->from($this->escapeTable($table), $alias, $this->escapeDatabase($this->adapter->adapter()->database), $schema ? $this->escapeSchema($schema) : null);
        
        return $this;
    }

    public function join(string $type, $table, $field, $value) : self
    {
        $this->queryBuilder->join($type, $this->escapeTable($table), $field, $value);
        
        return $this;
    }

    public function open(string $condition = Query\Where::CONDITION_AND) : self
    {
        $this->queryBuilder->open($condition);
        
        return $this;
    }

    public function orOpen() : self
    {
        return $this->open(Query\Where::CONDITION_OR);
    }

    public function close() : self
    {
        $this->queryBuilder->close();
        
        return $this;
    }

    public function where($field, $value, string $operator = Query\Where::OPERATOR_EQUAL) : self
    {
        $this->queryBuilder->where($field, $value, $operator, Query\Where::CONDITION_AND);
        
        return $this;
    }

    public function wheres(array $fieldValues, string $operator = Query\Where::OPERATOR_EQUAL) : self
    {
        foreach($fieldValues as $field => $value) {
            if ( is_array($value) ) {
                switch ($value[1]) {
                    case Query\Where::CONDITION_AND:
                        $this->where($field, $value[0], $operator);
                    break;

                    case Query\Where::CONDITION_OR:
                        $this->or($field, $value[0], $operator);
                    break;

                    case Query\Where::CONDITION_NOT:
                        $this->notWhere($field, $value[0], $operator);
                    break;
                }
            }
            else {
                $this->where($field, $value, $operator);
            }
        }
        
        return $this;
    }
    
    public function and($field, $value, string $operator = Query\Where::OPERATOR_EQUAL) : self
    {
        return $this->where($field, $value, $operator);
    }

    public function or($field, $value, string $operator = Query\Where::OPERATOR_EQUAL) : self
    {
        $this->queryBuilder->where($field, $value, $operator, Query\Where::CONDITION_OR);
        
        return $this;
    }

    public function notWhere($field, $value, string $operator = Query\Where::OPERATOR_NOT_EQUAL) : self
    {
        $this->queryBuilder->where($field, $value, $operator, Query\Where::CONDITION_AND, true);
        
        return $this;
    }

    public function orNot($field, $value, string $operator = Query\Where::OPERATOR_NOT_EQUAL) : self
    {
        $this->queryBuilder->notWhere($field, $value, $operator, Query\Where::CONDITION_OR, true);
        
        return $this;
    }

    public function having($field, $value, string $operator = Query\Having::OPERATOR_EQUAL) : self
    {
        $this->queryBuilder->having($field, $value, $operator, Query\Having::CONDITION_AND);
        
        return $this;
    }

    public function orHaving($field, $value, string $operator = Query\Where::OPERATOR_EQUAL) : self
    {
        $this->queryBuilder->having($field, $value, $operator, Query\Having::CONDITION_OR);
        
        return $this;
    }

    public function notHaving($field, $value, string $operator = Query\Where::OPERATOR_NOT_EQUAL) : self
    {
        $this->queryBuilder->having($field, $value, $operator, Query\Having::CONDITION_AND, true);
        
        return $this;
    }

    public function orNotHaving($field, $value, string $operator = Query\Where::OPERATOR_NOT_EQUAL) : self
    {
        $this->queryBuilder->having($field, $value, $operator, Query\Having::CONDITION_OR, true);
        
        return $this;
    }
    
    public function in($field, $value, string $operator = Query\Where::OPERATOR_EQUAL) : self
    {
        $this->queryBuilder->where($field, $value, $operator);
        
        return $this;
    }

    public function orIn($field, $value, string $operator = Query\Where::OPERATOR_EQUAL) : self
    {
        $this->queryBuilder->where($field, $value, $operator, Query\Where::CONDITION_OR);
        
        return $this;
    }

    public function notIn($field, $value) : self
    {
        $this->queryBuilder->where($field, $value, Query\Where::OPERATOR_NOT_EQUAL);
        
        return $this;
    }

    public function orNotIn($field, $value, string $operator = Query\Where::OPERATOR_EQUAL) : self
    {
        return $this->orNot($field, $value, Query\Where::OPERATOR_NOT_EQUAL, Query\Where::CONDITION_OR);
    }

    public function like($field, $value) : self
    {
        $this->where($field, $value, Query\Where::OPERATOR_LIKE);
        
        return $this;
    }

    public function orLike($field, $value) : self
    {
        $this->or($field, $value, Query\Where::OPERATOR_LIKE);
        
        return $this;
    }

    public function notLike($field, $value) : self
    {
        $this->notWhere($field, $value, Query\Where::OPERATOR_LIKE);
        
        return $this;
    }

    public function likes(array $fieldValues, string $condition = Query\Where::CONDITION_AND) : self
    {
        foreach($fieldValues as $field => $value) {
            if ( is_array($value) ) {
                switch ($value[1]) {
                    case Query\Where::CONDITION_AND:
                        $this->like($field, $value[0]);
                    break;

                    case Query\Where::CONDITION_OR:
                        $this->orLike($field, $value[0]);
                    break;

                    case Query\Where::CONDITION_NOT:
                        $this->notLike($field, $value[0]);
                    break;
                }
            }
            else {
                $this->like($field, $value);
            }
        }
        
        return $this;
    }
    
    public function match() : self
    {

    }

    public function notMatch() : self
    {

    }

    public function between() : self
    {

    }

    public function notBetween() : self
    {

    }

    public function groupBy() : self
    {
        return $this;
    }

    public function groups(array $groups) : self
    {
        # foreach($this->groups)
        return $this;
    }
    
    public function orderBy($field, ? string $direction = null) : self
    {
        $this->queryBuilder->orderBy($field, $direction);
        
        return $this;
    }

    public function orders(array $orderList) : self
    {
        foreach($orderList as $field => $direction) {
            $this->queryBuilder->orderBy($field, $direction);
        }
        
        return $this;
    }

    
    public function limit(int $value) : self
    {
        $this->queryBuilder->limit($value);
        
        return $this;
    }

    public function offset(int $value) : self
    {
        $this->queryBuilder->offset($value);
        
        return $this;
    }

    public function commit() : self
    {
        return $this;
    }

    public function rollback() : self
    {
        return $this;
    }

    public function wherePrimaryKey($value) : self
    {
        if ( null === $primaryKeyField = Ulmus::resolveEntity($this->entityClass)->getPrimaryKeyField() ) {
            throw new Exception\EntityPrimaryKeyUnknown("Entity has no field containing attributes 'primary_key'");
        }
        
        $pkField = key($primaryKeyField);
        
        return $this->where($primaryKeyField[$pkField]->name ?? $pkField, $value);
    }
 
    public function filterServerRequest(SearchRequest\SearchRequestInterface $searchRequest) : self 
    {
        $searchRequest->count = $searchRequest->filter( clone $this )
            ->wheres($searchRequest->wheres(), Query\Where::OPERATOR_EQUAL, Query\Where::CONDITION_AND)
            ->likes($searchRequest->likes(), Query\Where::CONDITION_OR)
            ->orders($searchRequest->orders())
            ->groups($searchRequest->groups())
            ->count();
        
        return $searchRequest->filter($this)
            ->wheres($searchRequest->wheres(), Query\Where::OPERATOR_EQUAL, Query\Where::CONDITION_AND)
            ->likes($searchRequest->likes(), Query\Where::CONDITION_OR)
            ->orders($searchRequest->orders())
            ->groups($searchRequest->groups())
            ->offset($searchRequest->offset())
            ->limit($searchRequest->limit());
    }
       
    public function collectionFromQuery(? string $entityClass = null) : EntityCollection
    {
        $class = $entityClass ?: $this->entityClass;

        $entityCollection = new EntityCollection();
        
        $this->selectSqlQuery();
        
        $this->finalizeQuery();

        foreach(Ulmus::iterateQueryBuilder($this->queryBuilder, $this->adapter) as $entityData) {
            $entityCollection->append( ( new $class() )->entityFillFromDataset($entityData) );
        }

        return $entityCollection;
    }

    public function runQuery() : ? \PDOStatement
    {
        $this->finalizeQuery();
        
        return Ulmus::runQuery($this->queryBuilder, $this->adapter);
    }
    
    protected function insertSqlQuery(array $dataset) : self
    {
        if ( null === $this->queryBuilder->getFragment(Query\Insert::class) ) {
            $this->insert(array_keys($dataset), $this->entityResolver->tableName(), $this->alias, $this->entityResolver->schemaName());
        }

        $this->values($dataset);

        return $this;
    }
    
    protected function updateSqlQuery(array $dataset) : self
    {
        if ( null === $this->queryBuilder->getFragment(Query\Update::class) ) {
            $this->update($this->entityResolver->tableName(), $this->alias, $this->entityResolver->schemaName());
        }
        
        $this->set($dataset);

        return $this;
    }
    
    protected function selectSqlQuery() : self
    {
        if ( null === $this->queryBuilder->getFragment(Query\Select::class) ) {
            $this->select("{$this->alias}.*");
        }

        if ( null === $this->queryBuilder->getFragment(Query\From::class) ) {
            $this->from($this->entityResolver->tableName(), $this->alias, $this->entityResolver->schemaName());
        }

        return $this;
    }

    protected function deleteSqlQuery() : self
    {
        if ( null === $this->queryBuilder->getFragment(Query\Delete::class) ) {
            $this->delete();
        }

        if ( null === $this->queryBuilder->getFragment(Query\From::class) ) {
            $this->from($this->entityResolver->tableName(), null, $this->entityResolver->schemaName());
        }

        return $this;
    }
    
    protected function fromRow($row) : self
    {

    }

    protected function fromCollection($rows) : self
    {

    }
    
    public function table()
    {
        return "REFLECT TABLE";
    }
    
    public function escapeTable(string $identifier) : string
    {
        return $this->adapter->adapter()->escapeIdentifier($identifier, Adapter\AdapterInterface::IDENTIFIER_TABLE);
    }
    
    public function escapeDatabase(string $identifier) : string
    {
        return $this->adapter->adapter()->escapeIdentifier($identifier, Adapter\AdapterInterface::IDENTIFIER_DATABASE);
    }
    
    public function escapeSchema(string $identifier) : string
    {
        return $this->adapter->adapter()->escapeIdentifier($identifier, Adapter\AdapterInterface::IDENTIFIER_SCHEMA);
    }
    
    protected function finalizeQuery() : void {}
}