<?php

declare(strict_types=1);

function isLoggedIn(): bool
{
    return !empty($_SESSION['user_email']);
}

function requireAuth(): void
{
    if (!isLoggedIn()) {
        $return = $_SERVER['REQUEST_URI'] ?? '/';
        header('Location: /login' . ($return !== '/' ? '?return_to=' . urlencode($return) : ''), true, 302);
        exit;
    }
}

function currentUserEmail(): ?string
{
    return $_SESSION['user_email'] ?? null;
}

function currentUserName(): string
{
    if (!isLoggedIn()) {
        return '';
    }
    if (isset($_SESSION['user_display_name']) && $_SESSION['user_display_name'] !== '') {
        return $_SESSION['user_display_name'];
    }
    $name = authorDisplayName(currentUserEmail() ?? '');
    $_SESSION['user_display_name'] = $name;
    return $name;
}

function authorDisplayName(string $email): string
{
    return authorProfile($email)['name'];
}

function authorProfileUrl(string $email): string
{
    return authorProfile($email)['url'];
}

function authorProfile(string $email): array
{
    static $cache = [];
    $key = strtolower(trim($email));
    if ($key === '') {
        return ['name' => '', 'url' => ''];
    }
    if (array_key_exists($key, $cache)) {
        return $cache[$key];
    }
    $pdo = dbPdo();
    if ($pdo) {
        try {
            $st = $pdo->prepare('SELECT display_name, profile_url FROM user_profiles WHERE email = :e');
            $st->execute([':e' => $key]);
            $row = $st->fetch(PDO::FETCH_ASSOC);
            if ($row) {
                $cache[$key] = [
                    'name' => ($row['display_name'] !== '') ? $row['display_name'] : explode('@', $key)[0],
                    'url'  => $row['profile_url'] ?? '',
                ];
                return $cache[$key];
            }
        } catch (\Throwable) {
        }
    }
    $cache[$key] = ['name' => explode('@', $key)[0], 'url' => ''];
    return $cache[$key];
}

function dbPdo(): ?PDO
{
    static $pdo    = null;
    static $failed = false;
    if ($failed) {
        return null;
    }
    if ($pdo !== null) {
        return $pdo;
    }
    $dsn  = $_ENV['DB_DSN']  ?? (getenv('DB_DSN') ?: '');
    $user = $_ENV['DB_USER'] ?? (getenv('DB_USER') ?: '');
    $pass = $_ENV['DB_PASS'] ?? (getenv('DB_PASS') ?: '');
    if (!$dsn) {
        $failed = true;
        return null;
    }
    try {
        $pdo = new PDO($dsn, $user ?: null, $pass ?: null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
    } catch (\Throwable) {
        $failed = true;
        return null;
    }
    return $pdo;
}

function currentUserRoles(): array
{
    if (!isLoggedIn()) {
        return [];
    }
    if (isset($_SESSION['user_roles'])) {
        return $_SESSION['user_roles'];
    }
    $pdo = dbPdo();
    if (!$pdo) {
        $_SESSION['user_roles'] = [];
        return [];
    }
    try {
        $st = $pdo->prepare(
            'SELECT r.name FROM roles r
             JOIN user_roles ur ON ur.role_id = r.id
             WHERE ur.user_email = :e'
        );
        $st->execute([':e' => strtolower(currentUserEmail() ?? '')]);
        $_SESSION['user_roles'] = $st->fetchAll(PDO::FETCH_COLUMN) ?: [];
    } catch (\Throwable) {
        $_SESSION['user_roles'] = [];
    }
    return $_SESSION['user_roles'];
}

function hasRole(string $role): bool
{
    return in_array($role, currentUserRoles(), true);
}

// Capacités connues — clé => label affiché dans l'admin
const KNOWN_CAPABILITIES = [
    'propose_articles'      => 'Proposer des articles',
    'validate_articles_all' => 'Valider des articles',
    'validate_articles_own' => 'Valider ses articles uniquement',
    'publish_articles_all'  => 'Publier des articles',
    'publish_articles_own'  => 'Publier ses articles uniquement',
    'edit_articles_all'     => 'Modifier des articles',
    'edit_articles_own'     => 'Modifier ses articles uniquement',
    'rate_articles'         => 'Noter des articles',
    'view_previews'         => 'Lire des avant-premières',
    'view_drafts_all'       => 'Voir tous les brouillons',
    'view_drafts_own'       => 'Voir ses brouillons',
    'view_sources_all'      => 'Voir les sources (tous les articles)',
    'view_sources_own'      => 'Voir les sources de ses articles',
];

// Groupes pour l'interface d'administration
const CAPABILITY_GROUPS = [
    'Articles' => [
        'propose_articles',
        'validate_articles_all',
        'validate_articles_own',
        'publish_articles_all',
        'publish_articles_own',
        'edit_articles_all',
        'edit_articles_own',
    ],
    'Accès & lecture' => [
        'rate_articles',
        'view_previews',
        'view_drafts_all',
        'view_drafts_own',
        'view_sources_all',
        'view_sources_own',
    ],
];

function currentUserCapabilities(): array
{
    if (!isLoggedIn()) {
        return [];
    }
    if (isset($_SESSION['user_capabilities'])) {
        return $_SESSION['user_capabilities'];
    }
    $pdo = dbPdo();
    if (!$pdo) {
        $_SESSION['user_capabilities'] = [];
        return [];
    }
    try {
        $st = $pdo->prepare(
            'SELECT DISTINCT rc.capability
             FROM role_capabilities rc
             JOIN user_roles ur ON ur.role_id = rc.role_id
             WHERE ur.user_email = :e'
        );
        $st->execute([':e' => strtolower(currentUserEmail() ?? '')]);
        $_SESSION['user_capabilities'] = $st->fetchAll(PDO::FETCH_COLUMN) ?: [];
    } catch (\Throwable) {
        $_SESSION['user_capabilities'] = [];
    }
    return $_SESSION['user_capabilities'];
}

function hasCapability(string $cap): bool
{
    if (isAdmin()) {
        return true;
    }
    return in_array($cap, currentUserCapabilities(), true);
}

function canDoOnArticle(string $baseCap, array $article): bool
{
    if (isAdmin()) {
        return true;
    }
    if (hasCapability($baseCap . '_all')) {
        return true;
    }
    if (hasCapability($baseCap . '_own')) {
        $owner = strtolower($article['author'] ?? '');
        return $owner !== '' && $owner === strtolower(currentUserEmail() ?? '');
    }
    return false;
}

function isAdmin(): bool
{
    $email = currentUserEmail();
    if (!$email) {
        return false;
    }
    // Fallback bootstrap : var d'env
    $rawAdmin = $_ENV['ADMIN_EMAIL'] ?? (getenv('ADMIN_EMAIL') ?: '');
    $allowed  = array_filter(array_map('trim', explode(',', (string)$rawAdmin)));
    if (in_array(strtolower($email), array_map('strtolower', $allowed), true)) {
        return true;
    }
    return hasRole('admin');
}

function ssoLogoutUrl(): string
{
    $issuer   = rtrim((string)($_ENV['OIDC_ISSUER'] ?? (getenv('OIDC_ISSUER') ?: '')), '/');
    $clientId = (string)($_ENV['OIDC_CLIENT_ID'] ?? (getenv('OIDC_CLIENT_ID') ?: ''));
    $baseUrl  = rtrim((string)($_ENV['APP_URL'] ?? (getenv('APP_URL') ?: '/')), '/');

    $params = [
        'client_id'                => $clientId,
        'post_logout_redirect_uri' => $baseUrl . '/',
    ];
    if (!empty($_SESSION['oidc']['id_token'])) {
        $params['id_token_hint'] = $_SESSION['oidc']['id_token'];
    }

    if (!$issuer) {
        return $baseUrl . '/';
    }

    return $issuer . '/protocol/openid-connect/logout?' . http_build_query($params);
}