<?php
declare(strict_types=1);

/**
 * Admin user management helpers.
 *
 * Every read here explicitly selects columns and leaves password_hash
 * out, so it can never accidentally end up in a JSON response or a
 * data-* attribute the way a full row dump would.
 */

require_once __DIR__ . '/db.php';

function get_all_users(): array {
    $pdo = get_db();
    $stmt = $pdo->query("SELECT id, username, role, is_enabled, created_at FROM users ORDER BY username ASC");
    return $stmt->fetchAll() ?: [];
}

function get_user_by_id(int $id): ?array {
    $pdo = get_db();
    $stmt = $pdo->prepare("SELECT id, username, role, is_enabled, created_at FROM users WHERE id = ?");
    $stmt->execute([$id]);
    $res = $stmt->fetch();
    return $res ?: null;
}

function count_users(): int {
    $pdo = get_db();
    return (int) $pdo->query("SELECT COUNT(*) FROM users")->fetchColumn();
}

function count_enabled_users(): int {
    $pdo = get_db();
    return (int) $pdo->query("SELECT COUNT(*) FROM users WHERE is_enabled = 1")->fetchColumn();
}

function toggle_user_enabled(int $id): bool {
    $pdo = get_db();
    $stmt = $pdo->prepare("UPDATE users SET is_enabled = CASE WHEN is_enabled = 1 THEN 0 ELSE 1 END WHERE id = ?");
    return $stmt->execute([$id]);
}

function username_exists(string $username, ?int $excludeId = null): bool {
    $pdo = get_db();
    if ($excludeId !== null) {
        $stmt = $pdo->prepare("SELECT 1 FROM users WHERE username = ? AND id != ?");
        $stmt->execute([$username, $excludeId]);
    } else {
        $stmt = $pdo->prepare("SELECT 1 FROM users WHERE username = ?");
        $stmt->execute([$username]);
    }
    return (bool) $stmt->fetchColumn();
}

function create_user(string $username, string $password, string $role): int {
    $pdo = get_db();
    $hash = password_hash($password, PASSWORD_DEFAULT);
    $stmt = $pdo->prepare("INSERT INTO users (username, password_hash, role) VALUES (?, ?, ?)");
    $stmt->execute([$username, $hash, $role]);
    return (int) $pdo->lastInsertId();
}

function set_user_password(int $id, string $newPassword): bool {
    $pdo = get_db();
    $hash = password_hash($newPassword, PASSWORD_DEFAULT);
    $stmt = $pdo->prepare("UPDATE users SET password_hash = ? WHERE id = ?");
    return $stmt->execute([$hash, $id]);
}

function verify_user_password(int $id, string $password): bool {
    $pdo = get_db();
    $stmt = $pdo->prepare("SELECT password_hash FROM users WHERE id = ?");
    $stmt->execute([$id]);
    $hash = $stmt->fetchColumn();
    return is_string($hash) && password_verify($password, $hash);
}

function delete_user(int $id): bool {
    $pdo = get_db();
    $stmt = $pdo->prepare("DELETE FROM users WHERE id = ?");
    return $stmt->execute([$id]);
}