<?php

namespace Kletellier\PdoWrapper;

class QueryBuilder
{
    protected Db $db;
    protected array $columns;
    protected array $wheres;
    protected array $orders;
    protected string $table;
    protected string $pk;
    protected ?int $take;
    protected ?int $offset;
    protected string $raw_query;

    public function __construct($table, $pk = "id")
    {
        $this->table = $table;
        $this->pk = $pk;
        $this->db = Db::getInstance();
        $this->reset();
    }

    public function reset()
    {
        $this->columns = [];
        $this->wheres = [];
        $this->orders = [];
        $this->offset = null;
        $this->take = null;
        $this->raw_query = "";
    }

    public function raw(string $query)
    {
        $this->raw_query = $query;
        return $this;
    }

    public function take(?int $nb)
    {
        $this->take = $nb;
        return $this;
    }

    public function offset(?int $offset)
    {
        $this->offset = $offset;
        return $this;
    }

    public function orderBy($columns, $sort = "ASC")
    {
        if (is_array($columns)) {
            foreach ($columns as $column) {
                $this->orders[] = $column . " " . $sort;
            }
        } else {
            $this->orders[] = $columns . " " . $sort;
        }
        return $this;
    }

    public function columns($columns)
    {
        if (is_array($columns)) {
            $this->columns = array_merge($this->columns, $columns);
        }
        if (is_string($columns)) {
            $this->columns[] = $columns;
        }
        return $this;
    }

    public function where($condition, $operator, $value = null)
    {
        if ($value === null) {
            $this->wheres[] = new Expression($condition, "=", $operator);
        } else {
            $this->wheres[] = new Expression($condition, $operator, $value);
        }
        return $this;
    }

    public function whereRaw(string $raw)
    {
        $this->wheres[] = $raw;
        return $this;
    }

    public function find($id): mixed
    {
        $this->reset();
        $expression = new Expression($this->pk, "=", $id);
        $this->wheres = [$expression];
        $this->columns = ["*"];
        $data = $this->getData();
        if (count($data) > 0) {
            return $this->prepareModels($data)[0];
        }
        return null;
    }

    public function get(): mixed
    {
        $data = $this->getData();
        return $this->prepareModels($data);
    }

    public function getPreparedQuery(array $data, $insert = true): Query
    {
        $ret = new Query();

        $columns = implode(",", array_keys($data));
        $query = "";

        if ($insert) {
            $keys = implode(",", str_split(str_repeat("?", count($data))));
            $query = "INSERT INTO " . $this->table . " (" . $columns . ") VALUES (" . $keys . ");";
            foreach ($data as $key => $value) {
                $ret->addData($value);
            }
        } else {
                $query = "UPDATE " . $this->table . " SET ";
                $up = "";
            foreach ($data as $key => $value) {
                if ($up != "") {
                    $up .= ", ";
                }
                $up .= $key . " = ? ";
                $ret->addData($value);
            }
                $query .= $up . " WHERE " . $this->pk . " = ? ;";
                $ret->addData($data[$this->pk]);
        }
        $ret->setQuery($query);
        return $ret;
    }

    private function prepareModels(mixed $data): mixed
    {
        $ret = array();
        foreach ($data as $row) {
            $model = new Model();
            $ret[] = $model->setPk($this->pk)->setTable($this->table)->fillData($row);
        }
        return $ret;
    }

    private function getData(): mixed
    {
        return $this->db->getSelectQuery($this->getQuery());
    }

    private function getConstructedQuery(): Query
    {
        $ret = new Query();
        $ret->setQuery("");
        $ret->setData([]);

        if (count($this->columns) == 0) {
            $this->columns("*");
        }

        $columns = implode(",", $this->columns);
        $where = "";
        foreach ($this->wheres as $expression) {
            $sw = "";
            if ($expression instanceof Expression) {
                $sw = $expression->raw();
                $ret->addData($expression->getValue());
            }
            if ($expression instanceof string) {
                if (trim($expression) !== "") {
                    $sw = "(" . $expression  . ")";
                }
            }
            if ($where != "" && $sw != "") {
                $where .= " AND ";
            }
            $where .= $sw;
        }

        $query = "SELECT " . $columns . " FROM " . $this->table ;
        if ($where != "") {
            $query .= " WHERE " . $where;
        }
        if (count($this->orders) > 0) {
            $query .= " ORDER BY ";
            $iOrder = 0;
            foreach ($this->orders as $order) {
                if ($iOrder > 0) {
                    $query .= ",";
                }
                $query .= $order;
                $iOrder++;
            }
        }
        $query .= $this->getLimit();

        $ret->setQuery($query);
        return $ret;
    }

    private function getLimit(): string
    {
        if ($this->take !== null || $this->offset !== null) {
             $ret = "";
            if ($this->take !== null) {
                $ret = " LIMIT " . $this->take;
            }
            if ($this->offset !== null) {
                $ret .= " OFFSET " . $this->offset;
            }
             return $ret;
        } else {
            return "";
        }
    }

    private function getQuery(): Query
    {
        if ($this->raw_query !== "") {
            $query = new Query();
            $query->setQuery($this->raw_query);
            $query->setData([]);
            return $query;
        } else {
            return $this->getConstructedQuery();
        }
    }
}