<?php
include("../db.php");

$table = isset($_GET['table']) ? $_GET['table'] : '';
$result = [
    'instruction' => ['min' => '-', 'max' => '-', 'avg' => '-'],
    'input'       => ['min' => '-', 'max' => '-', 'avg' => '-'],
    'output'      => ['min' => '-', 'max' => '-', 'avg' => '-']
];

if ($table && preg_match('/^[a-zA-Z0-9_]+$/', $table)) {
    $sql = "SELECT 
                MIN(CHAR_LENGTH(instruction)) as min_instruction,
                MAX(CHAR_LENGTH(instruction)) as max_instruction,
                AVG(CHAR_LENGTH(instruction)) as avg_instruction,
                MIN(CHAR_LENGTH(input)) as min_input,
                MAX(CHAR_LENGTH(input)) as max_input,
                AVG(CHAR_LENGTH(input)) as avg_input,
                MIN(CHAR_LENGTH(output)) as min_output,
                MAX(CHAR_LENGTH(output)) as max_output,
                AVG(CHAR_LENGTH(output)) as avg_output
            FROM `$table`";
    $res = mysqli_query($conn, $sql);
    if ($res && $row = mysqli_fetch_assoc($res)) {
        $result['instruction'] = [
            'min' => $row['min_instruction'] !== null ? $row['min_instruction'] : '-',
            'max' => $row['max_instruction'] !== null ? $row['max_instruction'] : '-',
            'avg' => $row['avg_instruction'] !== null ? round($row['avg_instruction'], 2) : '-'
        ];
        $result['input'] = [
            'min' => $row['min_input'] !== null ? $row['min_input'] : '-',
            'max' => $row['max_input'] !== null ? $row['max_input'] : '-',
            'avg' => $row['avg_input'] !== null ? round($row['avg_input'], 2) : '-'
        ];
        $result['output'] = [
            'min' => $row['min_output'] !== null ? $row['min_output'] : '-',
            'max' => $row['max_output'] !== null ? $row['max_output'] : '-',
            'avg' => $row['avg_output'] !== null ? round($row['avg_output'], 2) : '-'
        ];
    }
}

header('Content-Type: application/json');
echo json_encode($result);