<?php

// Auteur : Cédrix pour a5l.fr
// Projet : scripts-bash/ytdll

// Version 2024.07.07-14.31
// Version initiale


class TableManager {
    private $pdo;
    private $database;

    // SGBD PostGreSQL 16

    public function __construct(Database $database) {
        $this->database = $database;
        $this->pdo = $this->database->getPDO();
    }

    public function getTableColumns($tableName) {
        if (!$this->tableExists($tableName)) {
            return []; // Retourne un tableau vide si la table n'existe pas
        }

        $query = "SELECT column_name, data_type FROM information_schema.columns WHERE table_name = :table_name AND table_schema = :table_schema";
        $stmt = $this->pdo->prepare($query);
        $stmt->execute([
            ':table_name' => $tableName
        ]);
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    }

    private function tableExists($tableName) {
        $schema = $this->database->getDefaultSchema();

        $query = "SELECT COUNT(*) FROM information_schema.tables WHERE table_name = :table_name AND table_schema = :table_schema";
        $stmt = $this->pdo->prepare($query);
        echo "Vérification de l'existence de la table : $tableName\n";
        $stmt->execute([
            ':table_name' => $tableName,
            ':table_schema' => $schema
        ]);
        return $stmt->fetchColumn() > 0;
    }

    public function processTables($tables) {
        foreach ($tables as $table) {
            $this->processTable($table);
        }
    }

    private function processTable($table) {
        $tableName = $table['name'];
        $columns = $table['columns'];
        $existingColumns = $this->getTableColumns($tableName);

        if (empty($existingColumns) && !$this->tableExists($tableName)) {
            $this->createTable($tableName, $columns);
            return;
        }

        $existingColumnsMap = [];
        foreach ($existingColumns as $column) {
            $existingColumnsMap[$column['column_name']] = $column['data_type'];
        }

        foreach ($columns as $column) {
            $columnName = $column['name'];
            $columnType = $column['type'];

            if (isset($existingColumnsMap[$columnName])) {
                if ($existingColumnsMap[$columnName] !== $columnType) {
                    $this->alterColumnType($tableName, $columnName, $columnType);
                }
                unset($existingColumnsMap[$columnName]);
            } else {
                $this->addColumn($tableName, $columnName, $columnType);
            }
        }

        foreach ($existingColumnsMap as $columnName => $columnType) {
            $this->dropColumn($tableName, $columnName);
        }
    }

    public function createTable($tableName, $columns) {
        $columnsSql = [];
        foreach ($columns as $column) {
            $columnsSql[] = "{$column['name']} {$column['type']}";
        }
        $columnsSql = implode(", ", $columnsSql);
        $sql = "CREATE TABLE $tableName ($columnsSql)";
        $this->pdo->exec($sql);
    }

    public function dropTable($tableName) {
        $sql = "DROP TABLE IF EXISTS $tableName";
        $this->pdo->exec($sql);
    }

    private function alterColumnType($tableName, $columnName, $columnType) {
        $sql = "ALTER TABLE $tableName ALTER COLUMN $columnName TYPE $columnType USING $columnName::$columnType";
        $this->pdo->exec($sql);
    }

    private function addColumn($tableName, $columnName, $columnType) {
        $sql = "ALTER TABLE $tableName ADD COLUMN $columnName $columnType";
        $this->pdo->exec($sql);
    }

    private function dropColumn($tableName, $columnName) {
        $sql = "ALTER TABLE $tableName DROP COLUMN $columnName";
        $this->pdo->exec($sql);
    }
}