<?php

/*
	SQLite database wrapper class.

	By default, foreign keys are enabled and the database is in WAL mode. In general
	these defaults should be perfect for most use cases.
 */

class Database
{
    private PDO $c;
    private int $queries = 0;
    private array $log = [];
	private float $time = 0;
	private string $path = '';

    public function __construct(string $path, array $opts = [])
    {
        $opts = !empty($opts) ? $opts : [
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
        ];

        try {
            $this->c = new PDO("sqlite:$path", null, null, $opts);
            $this->c->exec('PRAGMA foreign_keys = ON;'); // Enable foreign keys
            $this->c->exec('PRAGMA journal_mode = WAL;'); // Enable WAL
			$this->path = $path;
        } catch (PDOException $e) {
            throw $e;
        }
    }

	public function do(string $query, array $params = []): PDOStatement|false
	{
		$start = microtime(true);

		try {
			$stmt = $this->c->prepare($query);
			$stmt->execute($params);
			$this->record($query, $start);
			return $stmt;
		} catch (PDOException $e) {
			print_r($query);
			throw $e;
		}
	}

	public function q(string $query): PDOStatement|false
	{
		$start = microtime(true);

		try {
			$stmt = $this->c->query($query);
			$this->record($query, $start);
			return $stmt;
		} catch (PDOException $e) {
			print_r($query);
			throw $e;
		}
	}

	private function record(string $query, float $start): void
	{
		$time = microtime(true) - $start;
		$this->queries++;
		$this->log[] = [$query, $time];
		$this->time += $time;
	}

	public function queries(): int
	{
		return $this->queries;
	}

	public function log(): array
	{
		return $this->log;
	}

	public function time(): float
	{
		return $this->time;
	}

	public function path(): string
	{
		return $this->path;
	}

	public function lastInsertID(): int
	{
		return $this->c->lastInsertId();
	}

	public function insertFromCSV(string $table, string $path): PDOStatement|false
	{
		// open the file
		$handle = fopen($path, 'r');
		if ($handle === false) return false;

		// reduce the column names to lower case with underscores
		$columns = array_map(function ($column) {
			return strtolower(str_replace(' ', '_', $column));
		}, fgetcsv($handle));

		// set up the query
		$query = "INSERT INTO $table (" . implode(',', $columns) . ') VALUES ';

		// read the rows and add them to the query
		while (($row = fgetcsv($handle)) !== false) {
			// go through the row and put strings into single quotes
			$row = array_map(function ($column) {
				if (is_numeric($column)) return $column;
				return "'" . str_replace("'", "''", $column) . "'";
			}, $row);

			// add the row to the query
			$query .= '(' . implode(',', $row) . '),';
		}

		// remove the trailing comma
		$query = rtrim($query, ',') . ';';

		// execute the insert
		return $this->q($query);
	}
}