<?php
/**
 * SearchController
 *
 * Handles all data-fetching logic for the public search and répertoire pages.
 *
 * Entry points:
 *  - public/search.php     calls handleSearch()     — text-query results
 *  - public/repertoire.php calls handleRepertoire()  — filter index + HTMX swaps
 *
 * Responsibilities:
 *  - Rate-limit enforcement (returns early HTTP 429 response when needed)
 *  - GET parameter sanitisation and validation
 *  - Database queries (search + index listings)
 *  - OG / meta tag assembly
 *  - HTMX partial response for repertoire filter swaps
 *
 * The class has NO output side-effects; all template rendering stays in the
 * respective public/*.php files so the view layer remains easy to inspect.
 * Exception: renderRepertoirePartial() exits early for HTMX requests.
 */
class SearchController
{
    private const RATE_LIMIT_MAX = 30;
    private const RATE_LIMIT_WINDOW = 60; // seconds
    private const ITEMS_PER_PAGE = 30;

    private Database $db;
    private RateLimit $rateLimit;

    public function __construct(Database $db, RateLimit $rateLimit)
    {
        $this->db = $db;
        $this->rateLimit = $rateLimit;
    }

    // ── Factory ───────────────────────────────────────────────────────────────

    /**
     * Convenience factory: builds dependencies, checks rate limit (sends 429
     * and exits if exceeded), then returns a ready-to-use controller instance.
     */
    public static function create(): self
    {
        require_once APP_ROOT . "/src/Database.php";
        require_once APP_ROOT . "/src/RateLimit.php";

        $rateLimit = new RateLimit(
            self::RATE_LIMIT_MAX,
            self::RATE_LIMIT_WINDOW,
        );

        if (!$rateLimit->check()) {
            self::sendRateLimitResponse($rateLimit);
        }

        $rateLimit->sendHeaders();

        // Probabilistic cleanup (1-in-100 requests) to prune stale entries
        if (rand(1, 100) === 1) {
            $rateLimit->cleanup();
        }

        return new self(Database::getInstance(), $rateLimit);
    }

    // ── Entry points ──────────────────────────────────────────────────────────

    /**
     * Handle the search results page (public/search.php).
     * Requires a ?query= parameter; always returns search-result view variables.
     *
     * @return array<string, mixed>
     */
    public function handleSearch(): array
    {
        $searchParams = $this->collectSearchParams();
        $page = isset($_GET["page"]) ? max(1, (int) $_GET["page"]) : 1;
        $offset = ($page - 1) * self::ITEMS_PER_PAGE;
        $validationError = null;

        $results = [];
        $totalItems = 0;
        $totalPages = 0;
        $years = [];
        $orientations = [];
        $apPrograms = [];

        try {
            $results = $this->db->searchTheses(
                $searchParams,
                self::ITEMS_PER_PAGE,
                $offset,
            );
            $totalItems = $this->db->countSearchResults($searchParams);
            $totalPages = (int) ceil($totalItems / self::ITEMS_PER_PAGE);
            $years = $this->db->getAvailableYears();
            $orientations = $this->db->getAllOrientations();
            $apPrograms = $this->db->getAllAPPrograms();
        } catch (InvalidArgumentException $e) {
            $validationError = $e->getMessage();
        } catch (Exception $e) {
            error_log("SearchController: " . $e->getMessage());
            $validationError = "Une erreur est survenue.";
        }

        // Preserve all active params, strip 'page' (pagination partial adds it)
        $baseParams = array_diff_key($_GET, ["page" => ""]);

        $query = $_GET["query"] ?? "";

        return [
            "searchParams" => $searchParams,
            "page" => $page,
            "totalItems" => $totalItems,
            "totalPages" => $totalPages,
            "results" => $results,
            "validationError" => $validationError,
            "baseParams" => $baseParams,

            // Filter dropdowns
            "years" => $years,
            "orientations" => $orientations,
            "apPrograms" => $apPrograms,

            // Page meta
            "searchBarValue" => $query,
            "pageTitle" =>
                $query !== ""
                    ? "Recherche : " . $query . " – XAMXAM"
                    : "Recherche – XAMXAM",
            "metaDescription" =>
                "Résultats de recherche dans le répertoire des TFE de l'erg.",
            "ogTags" => [
                "type" => "website",
                "title" => "Recherche – XAMXAM",
                "description" =>
                    "Résultats de recherche dans le répertoire des TFE de l'erg.",
                "url" => "https://xamxam.erg.be/search",
                "site_name" => "XAMXAM – ERG",
            ],
            "currentNav" => "repertoire",
            "extraCss" => ["/assets/css/repertoire.css"],
            "bodyClass" => "search-body",
        ];
    }

    /**
     * Handle the répertoire index page (public/repertoire.php).
     * Serves the filter-column index; HTMX partial swaps are handled here too.
     *
     * @return array<string, mixed>
     */
    public function handleRepertoire(): array
    {
        $isHtmx = !empty($_SERVER["HTTP_HX_REQUEST"]);
        $activeFilters = $this->collectFilterParams();
        $repData = null;
        $validationError = null;

        try {
            $repData = $this->db->getRepertoireFilterData($activeFilters);
        } catch (InvalidArgumentException $e) {
            $validationError = $e->getMessage();
        } catch (Exception $e) {
            error_log("SearchController: " . $e->getMessage());
            $validationError = "Une erreur est survenue.";
        }

        // HTMX partial: render just the index div and exit
        if ($isHtmx && $repData !== null) {
            $this->renderRepertoirePartial($repData, $activeFilters);
        }

        return [
            "repData" => $repData,
            "activeFilters" => $activeFilters,
            "isHtmx" => $isHtmx,
            "validationError" => $validationError,

            // Page meta
            "searchBarValue" => "",
            "pageTitle" => "Répertoire – XAMXAM",
            "metaDescription" =>
                "Parcourez le répertoire des mémoires de fin d'études (TFE) de l'erg – École de Recherches Graphiques de Bruxelles.",
            "ogTags" => [
                "type" => "website",
                "title" => "Répertoire – XAMXAM",
                "description" =>
                    "Parcourez le répertoire des mémoires de fin d'études (TFE) de l'erg – École de Recherches Graphiques de Bruxelles.",
                "url" => "https://xamxam.erg.be/repertoire",
                "site_name" => "XAMXAM – ERG",
            ],
            "currentNav" => "repertoire",
            "extraCss" => ["/assets/css/repertoire.css"],
            "bodyClass" => "search-body",
        ];
    }

    // ── Private helpers ───────────────────────────────────────────────────────

    /**
     * Render the repertoire index partial and exit (for HTMX swaps).
     * Never returns.
     */
    /**
     * HTMX endpoint: returns a popover snippet for a student name.
     * Renders directly and exits.
     */
    public function handleStudentPreview(): never {
        $name = trim($_GET['name'] ?? '');
        header('Content-Type: text/html; charset=UTF-8');

        if ($name === '') {
            echo '';
            exit();
        }

        $theses = $this->db->getThesesByAuthorName($name);

        if (empty($theses)) {
            echo '';
            exit();
        }

        header('Cache-Control: public, max-age=300');
        include APP_ROOT . '/templates/partials/student-preview.php';
        exit();
    }

    private function renderRepertoirePartial(
        array $repData,
        array $activeFilters,
    ): never {
        header("Content-Type: text/html; charset=UTF-8");
        $isHtmx = true;
        include APP_ROOT . "/templates/partials/repertoire-index.php";
        exit();
    }

    /**
     * Collect and sanitise repertoire filter params from $_GET.
     * Params: fy[] (years), ap[] (AP programs), or[] (orientations),
     *         fi[] (finality types), kw[] (keywords)
     *
     * @return array{years:int[], ap:string[], or:string[], fi:string[], kw:string[]}
     */
    private function collectFilterParams(): array
    {
        $sanitiseStrings = function (mixed $raw, int $maxLen = 100): array {
            if (!is_array($raw)) {
                return [];
            }
            $out = [];
            foreach ($raw as $v) {
                $v = trim((string) $v);
                if ($v !== "" && strlen($v) <= $maxLen) {
                    $out[] = $v;
                }
            }
            return array_values(array_unique($out));
        };

        $years = [];
        if (!empty($_GET["fy"]) && is_array($_GET["fy"])) {
            foreach ($_GET["fy"] as $y) {
                $y = (int) $y;
                if ($y >= 1900 && $y <= 2100) {
                    $years[] = $y;
                }
            }
            $years = array_values(array_unique($years));
        }

        return [
            "years" => $years,
            "ap" => $sanitiseStrings($_GET["ap"] ?? []),
            "or" => $sanitiseStrings($_GET["or"] ?? []),
            "fi" => $sanitiseStrings($_GET["fi"] ?? []),
            "kw" => $sanitiseStrings($_GET["kw"] ?? []),
        ];
    }

    /**
     * Sanitise and collect valid text search parameters from $_GET.
     *
     * @return array<string, mixed>
     */
    private function collectSearchParams(): array
    {
        $params = [];

        if (!empty($_GET["query"])) {
            $params["query"] = trim((string) $_GET["query"]);
        }
        if (!empty($_GET["year"])) {
            $params["year"] = (int) $_GET["year"];
        }
        if (!empty($_GET["orientation"])) {
            $params["orientation"] = (string) $_GET["orientation"];
        }
        if (!empty($_GET["ap_program"])) {
            $params["ap_program"] = (string) $_GET["ap_program"];
        }
        if (!empty($_GET["keyword"])) {
            $params["keyword"] = (string) $_GET["keyword"];
        }

        return $params;
    }

    // ── Rate-limit response ───────────────────────────────────────────────────

    /**
     * Send a 429 response and exit.  Never returns.
     */
    private static function sendRateLimitResponse(RateLimit $rateLimit): never
    {
        http_response_code(429);
        header("Retry-After: " . $rateLimit->getResetTime());
        $retrySeconds = (int) $rateLimit->getResetTime();

        echo <<<HTML
        <!DOCTYPE html>
        <html lang="fr">
        <head>
            <meta charset="UTF-8">
            <meta name="viewport" content="width=device-width, initial-scale=1">
            <title>Trop de requêtes – XAMXAM</title>
            <style>
                *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
                body {
                    background: #0d0d0d;
                    color: #e0e0e0;
                    font-family: 'Helvetica Neue', Arial, sans-serif;
                    min-height: 100vh;
                    display: flex;
                    align-items: center;
                    justify-content: center;
                    padding: 2rem;
                }
                .box { max-width: 520px; text-align: center; }
                .box__logo {
                    font-size: 1.1rem; font-weight: 700;
                    letter-spacing: .12em; text-transform: uppercase;
                    color: #fff; margin-bottom: 2.5rem;
                }
                .box__title { font-size: 1.6rem; font-weight: 300; margin-bottom: 1rem; }
                .box__text  { font-size: .95rem; color: #999; line-height: 1.7; }
            </style>
        </head>
        <body>
            <div class="box">
                <div class="box__logo">XAMXAM</div>
                <h1 class="box__title">Trop de requêtes</h1>
                <p class="box__text">Vous avez effectué trop de recherches en peu de temps.<br>
                Réessayez dans {$retrySeconds} secondes.</p>
            </div>
        </body>
        </html>
        HTML;
        exit();
    }
}