<?php

namespace b8\Database;

use b8\Database;

class Map
{
    protected $_db     = null;
    protected $_tables = [];

    public function __construct(Database $db)
    {
        $this->_db = $db;
    }

    public function generate()
    {
        $tables = $this->_getTables();


        foreach ($tables as $table) {
            $this->_tables[$table] = [];
            $this->_tables[$table]['php_name'] = $this->_generatePhpName($table);
        }

        $this->_getRelationships();
        $this->_getColumns();
        $this->_getIndexes();

        return $this->_tables;
    }

    protected function _getTables()
    {
        $details = $this->_db->getDetails();

        $rtn = [];

        foreach ($this->_db->query('SHOW TABLES')->fetchAll(\PDO::FETCH_ASSOC) as $tbl) {
            $rtn[] = $tbl['Tables_in_' . $details['db']];
        }

        return $rtn;
    }

    protected function _getRelationships()
    {
        foreach ($this->_tables as $table => $t) {
            $res = $this->_db->query('SHOW CREATE TABLE `' . $table . '`')->fetchAll(\PDO::FETCH_ASSOC);

            foreach ($res as $r) {
                $str = $r['Create Table'];

                $matches = [];
                if (preg_match_all('/CONSTRAINT\s+\`([a-zA-Z0-9_]+)\`\s+FOREIGN\s+KEY\s+\(\`([a-zA-Z0-9_]+)\`\)\s+REFERENCES\s+\`([a-zA-Z0-9_]+)\`\s+\(\`([a-zA-Z0-9_]+)\`\)(\s+ON (DELETE|UPDATE) (SET NULL|NO ACTION|CASCADE|RESTRICT))?(\s+ON (DELETE|UPDATE) (SET NULL|NO ACTION|CASCADE|RESTRICT))?/',
                    $str, $matches)) {
                    for ($i = 0; $i < count($matches[0]); $i++) {
                        $fromTable = $table;
                        $fromCol   = $matches[2][$i];
                        $toTable   = $matches[3][$i];
                        $toCol     = $matches[4][$i];
                        $fkName    = $matches[1][$i];
                        $fk        = [];

                        if (isset($matches[6][$i])) {
                            $fk[$matches[6][$i]] = $matches[7][$i];
                        }

                        if (isset($matches[9][$i])) {
                            $fk[$matches[9][$i]] = $matches[10][$i];
                        }

                        $fk['UPDATE'] = empty($fk['UPDATE']) ? '' : $fk['UPDATE'];
                        $fk['DELETE'] = empty($fk['DELETE']) ? '' : $fk['DELETE'];

                        if (isset($this->_tables[$fromTable]) && isset($this->_tables[$toTable])) {
                            $phpName = $this->_generateFkName($fromCol, $this->_tables[$fromTable]['php_name']);

                            $this->_tables[$fromTable]['relationships']['toOne'][$fromCol] = [
                                'fk_name' => $fkName,
                                'fk_delete' => $fk['DELETE'],
                                'fk_update' => $fk['UPDATE'],
                                'table_php_name' => $this->_tables[$toTable]['php_name'],
                                'from_col_php' => $this->_generatePhpName($fromCol),
                                'from_col' => $fromCol,
                                'php_name' => $phpName,
                                'table' => $toTable,
                                'col' => $toCol,
                                'col_php' => $this->_generatePhpName($toCol)
                            ];

                            $phpName = $this->_generateFkName(
                                $fromCol,
                                $this->_tables[$fromTable]['php_name']
                            ) . $this->_tables[$fromTable]['php_name'] . 's';
                            $this->_tables[$toTable]['relationships']['toMany'][] = [
                                'from_col_php' => $this->_generatePhpName($fromCol),
                                'php_name'     => $phpName,
                                'thisCol'      => $toCol,
                                'table'        => $fromTable,
                                'table_php'    => $this->_generatePhpName($fromTable),
                                'fromCol'      => $fromCol,
                                'col_php'      => $this->_generatePhpName($toCol)
                            ];
                        }
                    }
                }
            }
        }
    }

    protected function _getColumns()
    {
        foreach ($this->_tables as $key => &$val) {
            $cols = [];
            foreach ($this->_db->query('DESCRIBE `' . $key . '`')->fetchAll(\PDO::FETCH_ASSOC) as $column) {
                $col = $this->_processColumn([], $column, $val);
                $cols[$col['name']] = $col;
            }

            $val['columns'] = $cols;
        }

    }

    protected function _getIndexes()
    {
        foreach ($this->_tables as $key => &$val) {
            $indexes = [];

            foreach ($this->_db->query('SHOW INDEXES FROM `' . $key . '`')->fetchAll(\PDO::FETCH_ASSOC) as $idx) {
                if (!isset($indexes[$idx['Key_name']])) {
                    $indexes[$idx['Key_name']]            = [];
                    $indexes[$idx['Key_name']]['name']    = $idx['Key_name'];
                    $indexes[$idx['Key_name']]['unique']  = ($idx['Non_unique'] == '0') ? true : false;
                    $indexes[$idx['Key_name']]['columns'] = [];
                }

                $indexes[$idx['Key_name']]['columns'][$idx['Seq_in_index']] = $idx['Column_name'];
            }

            $indexes = array_map(function ($idx) {
                ksort($idx['columns']);
                $idx['columns'] = implode(', ', $idx['columns']);

                return $idx;
            }, $indexes);

            $val['indexes'] = $indexes;
        }
    }

    protected function _processColumn($col, $column, &$table)
    {
        $col['name']     = $column['Field'];
        $col['php_name'] = $this->_generatePhpName($col['name']);
        $matches         = [];

        preg_match('/^([a-zA-Z]+)(\()?([0-9\,]+)?(\))?/', $column['Type'], $matches);

        $col['type'] = strtolower($matches[1]);

        if (isset($matches[3])) {
            $col['length'] = $matches[3];
        }

        $col['null'] = strtolower($column['Null']) == 'yes' ? true : false;
        $col['auto'] = strtolower($column['Extra']) == 'auto_increment' ? true : false;

        if ($column['Default'] == 'NULL' || is_null($column['Default'])) {
            $col['default_is_null'] = true;
        } else {
            $col['default_is_null'] = false;
            $col['default'] = $column['Default'];
        }

        if (!empty($column['Key'])) {
            if ($column['Key'] == 'PRI') {
                $col['is_primary_key'] = true;
                $table['primary_key']  = ['column' => $col['name'], 'php_name' => $col['php_name']];
            }

            if ($column['Key'] == 'PRI' || $column['Key'] == 'UNI') {
                $col['unique_indexed'] = true;
            } else {
                $col['many_indexed'] = true;
            }
        }

        $col['validate'] = [];

        if (!$col['null']) {
            $col['validate_null'] = true;
        }

        switch ($col['type']) {
            case 'tinyint':
            case 'smallint':
            case 'int':
            case 'mediumint':
            case 'bigint':
                $col['php_type'] = 'int';
                $col['to_php'] = '_sqlToInt';
                $col['validate_int'] = true;
                break;

            case 'float':
            case 'decimal':
                $col['php_type'] = 'float';
                $col['to_php'] = '_sqlToFloat';
                $col['validate_float'] = true;
                break;

            case 'datetime':
            case 'date':
                $col['php_type'] = 'DateTime';
                $col['to_php'] = '_sqlToDateTime';
                $col['to_sql'] = '_dateTimeToSql';
                $col['validate_date'] = true;
                break;

            case 'varchar':
            case 'text':
            default:
                $col['php_type'] = 'string';
                $col['validate_string'] = true;
                break;
        }

        return $col;
    }

    protected function _generatePhpName($sqlName)
    {
        $rtn = $sqlName;
        $rtn = str_replace('_', ' ', $rtn);
        $rtn = ucwords($rtn);
        $rtn = str_replace(' ', '', $rtn);

        return $rtn;
    }

    protected function _generateFkName($sqlName, $tablePhpName)
    {
        $fkMethod = substr($sqlName, 0, strripos($sqlName, '_'));

        if (empty($fkMethod)) {
            $fkMethod = (substr(strtolower($sqlName), -2) == 'id') ? substr($sqlName, 0, -2) : $tablePhpName;
        }

        $fkMethod = str_replace('_', ' ', $fkMethod);
        $fkMethod = ucwords($fkMethod);
        $fkMethod = str_replace(' ', '', $fkMethod);

        return $fkMethod;
    }
}