-- =============================================================================
-- DC_BACKEND_PKG
-- PL/SQL-Schnittstelle zum Quarkus dc-backend (Kubernetes Service dc-backend:8090)
--
-- Voraussetzungen:
--   - APEX_WEB_SERVICE-Berechtigung für das Schema:
--       GRANT EXECUTE ON APEX_240100.APEX_WEB_SERVICE TO <schema>;  -- APEX-Version anpassen
--   - ACL für ausgehende HTTP-Verbindung im selben Namespace:
--       DBMS_NETWORK_ACL_ADMIN.APPEND_HOST_ACE(
--         host => 'dc-backend', lower_port => 8090, upper_port => 8090,
--         ace  => xs$ace_type(privilege_list => xs$name_list('connect','resolve'),
--                             principal_name => '<schema>', principal_type => xs_acl.ptype_db));
--
-- Deployment:
--   sqlplus user/pass@db @"Scripts/DC_BACKEND_PKG.sql"
-- =============================================================================


-- =============================================================================
-- Package Spec
-- =============================================================================
CREATE OR REPLACE PACKAGE DC_BACKEND_PKG AS

    -- Basis-URL des dc-backend Kubernetes Service
    c_base_url  CONSTANT VARCHAR2(200) := 'http://dc-backend:8090';

    -- API-Key (X-API-KEY Header).
    -- Leer = kein Auth (Dev-Modus).
    -- Zur Laufzeit setzen: DC_BACKEND_PKG.g_api_key := 'mein-key';
    g_api_key   VARCHAR2(500) := '';

    -- -------------------------------------------------------------------------
    -- Startet die KI-gestützte Dokumentenprüfung für ein Projekt (asynchron).
    -- Das Projekt muss im Status PENDING sein.
    -- POST /check/{p_project_id} → 202 Accepted
    --
    -- p_project_id   ID des dc_projects-Eintrags
    -- p_status_code  HTTP-Statuscode der Antwort (202 = OK, 409 = nicht PENDING)
    -- p_response     JSON-Antwort des Backend
    -- -------------------------------------------------------------------------
    PROCEDURE start_check(
        p_project_id   IN  NUMBER,
        p_status_code  OUT NUMBER,
        p_response     OUT VARCHAR2
    );

    -- -------------------------------------------------------------------------
    -- Health-Check: prüft ob der dc-backend Service erreichbar ist.
    -- GET /check/health → 200 UP
    --
    -- Rückgabe: TRUE = Service läuft, FALSE = nicht erreichbar
    -- -------------------------------------------------------------------------
    FUNCTION health_check RETURN BOOLEAN;

    -- -------------------------------------------------------------------------
    -- Startet die Prüfung und wirft eine Exception wenn nicht 202 zurückkommt.
    -- Convenience-Wrapper für direkte APEX-Button-Aufrufe.
    -- -------------------------------------------------------------------------
    PROCEDURE start_check_or_raise(
        p_project_id IN NUMBER
    );

    -- -------------------------------------------------------------------------
    -- Fortschritts-Record
    -- -------------------------------------------------------------------------
    TYPE t_project_status IS RECORD (
        status               dc_projects.status%TYPE,
        processing_progress  dc_projects.progress%TYPE,
        is_completed         BOOLEAN,
        is_running           BOOLEAN,
        is_pending           BOOLEAN
    );

    -- -------------------------------------------------------------------------
    -- Liest Status und Fortschritt eines Projekts direkt aus der DB.
    -- Kein REST-Aufruf – sofort und transaktionssicher.
    --
    -- Beispiel:
    --   l_s := DC_BACKEND_PKG.get_status(1);
    --   DBMS_OUTPUT.PUT_LINE(l_s.status || ' ' || l_s.processing_progress || '%');
    -- -------------------------------------------------------------------------
    FUNCTION get_status(
        p_project_id IN NUMBER
    ) RETURN t_project_status;

    -- -------------------------------------------------------------------------
    -- Wartet (polling) bis das Projekt COMPLETED oder ein Timeout erreicht ist.
    -- Wirft eine Exception bei Timeout oder wenn das Projekt nicht gefunden wird.
    --
    -- p_timeout_sec   Max. Wartezeit in Sekunden (Default: 1800 = 30 Min.)
    -- p_interval_sec  Polling-Intervall in Sekunden (Default: 5)
    -- -------------------------------------------------------------------------
    PROCEDURE wait_for_completion(
        p_project_id    IN NUMBER,
        p_timeout_sec   IN NUMBER DEFAULT 1800,
        p_interval_sec  IN NUMBER DEFAULT 5
    );

END DC_BACKEND_PKG;
/


-- =============================================================================
-- Package Body
-- =============================================================================
CREATE OR REPLACE PACKAGE BODY DC_BACKEND_PKG AS

    -- -------------------------------------------------------------------------
    -- Setzt gemeinsame Request-Header (Content-Type + optional API-Key)
    -- -------------------------------------------------------------------------
    PROCEDURE set_headers IS
        l_idx PLS_INTEGER := 1;
    BEGIN
        APEX_WEB_SERVICE.G_REQUEST_HEADERS.DELETE;

        APEX_WEB_SERVICE.G_REQUEST_HEADERS(l_idx).NAME  := 'Content-Type';
        APEX_WEB_SERVICE.G_REQUEST_HEADERS(l_idx).VALUE := 'application/json';
        l_idx := l_idx + 1;

        IF g_api_key IS NOT NULL AND LENGTH(TRIM(g_api_key)) > 0 THEN
            APEX_WEB_SERVICE.G_REQUEST_HEADERS(l_idx).NAME  := 'X-API-KEY';
            APEX_WEB_SERVICE.G_REQUEST_HEADERS(l_idx).VALUE := g_api_key;
        END IF;
    END set_headers;


    -- -------------------------------------------------------------------------
    PROCEDURE start_check(
        p_project_id   IN  NUMBER,
        p_status_code  OUT NUMBER,
        p_response     OUT VARCHAR2
    ) IS
        l_url      VARCHAR2(500);
        l_response CLOB;
    BEGIN
        l_url := c_base_url || '/check/' || TO_CHAR(p_project_id);

        set_headers();

        l_response := APEX_WEB_SERVICE.MAKE_REST_REQUEST(
            p_url         => l_url,
            p_http_method => 'POST',
            p_body        => '{}'   -- leerer Body, projectId ist im Pfad
        );

        p_status_code := APEX_WEB_SERVICE.G_STATUS_CODE;
        p_response    := SUBSTR(l_response, 1, 4000);

    EXCEPTION
        WHEN OTHERS THEN
            p_status_code := -1;
            p_response    := 'Verbindungsfehler: ' || SQLERRM;
    END start_check;


    -- -------------------------------------------------------------------------
    FUNCTION health_check RETURN BOOLEAN IS
        l_url      VARCHAR2(500);
        l_response CLOB;
        l_status   NUMBER;
    BEGIN
        l_url := c_base_url || '/check/health';

        set_headers();

        l_response := APEX_WEB_SERVICE.MAKE_REST_REQUEST(
            p_url         => l_url,
            p_http_method => 'GET'
        );

        l_status := APEX_WEB_SERVICE.G_STATUS_CODE;
        RETURN l_status = 200;

    EXCEPTION
        WHEN OTHERS THEN
            RETURN FALSE;
    END health_check;


    -- -------------------------------------------------------------------------
    PROCEDURE start_check_or_raise(
        p_project_id IN NUMBER
    ) IS
        l_status   NUMBER;
        l_response VARCHAR2(4000);
    BEGIN
        start_check(
            p_project_id  => p_project_id,
            p_status_code => l_status,
            p_response    => l_response
        );

        IF l_status = 202 THEN
            -- OK: Verarbeitung wurde gestartet
            NULL;
        ELSIF l_status = 409 THEN
            RAISE_APPLICATION_ERROR(-20100,
                'Projekt ' || p_project_id || ' ist nicht im Status PENDING.');
        ELSIF l_status = 401 THEN
            RAISE_APPLICATION_ERROR(-20101,
                'Ungültiger API-Key für dc-backend.');
        ELSIF l_status = -1 THEN
            RAISE_APPLICATION_ERROR(-20102,
                'dc-backend nicht erreichbar: ' || l_response);
        ELSE
            RAISE_APPLICATION_ERROR(-20103,
                'Unerwarteter HTTP-Status ' || l_status || ': ' || l_response);
        END IF;
    END start_check_or_raise;


    -- -------------------------------------------------------------------------
    FUNCTION get_status(
        p_project_id IN NUMBER
    ) RETURN t_project_status IS
        l_rec t_project_status;
    BEGIN
        SELECT status, progress
          INTO l_rec.status, l_rec.processing_progress
          FROM dc_projects
         WHERE id = p_project_id;

        l_rec.is_completed := l_rec.status = 'COMPLETED';
        l_rec.is_running   := l_rec.status = 'IN_PROGRESS';
        l_rec.is_pending   := l_rec.status = 'PENDING';
        RETURN l_rec;

    EXCEPTION
        WHEN NO_DATA_FOUND THEN
            RAISE_APPLICATION_ERROR(-20110,
                'Projekt ' || p_project_id || ' nicht gefunden.');
    END get_status;


    -- -------------------------------------------------------------------------
    PROCEDURE wait_for_completion(
        p_project_id    IN NUMBER,
        p_timeout_sec   IN NUMBER DEFAULT 1800,
        p_interval_sec  IN NUMBER DEFAULT 5
    ) IS
        l_start  TIMESTAMP := SYSTIMESTAMP;
        l_status t_project_status;
    BEGIN
        LOOP
            l_status := get_status(p_project_id);

            EXIT WHEN l_status.is_completed;

            IF EXTRACT(SECOND FROM (SYSTIMESTAMP - l_start))
             + EXTRACT(MINUTE FROM (SYSTIMESTAMP - l_start)) * 60
             + EXTRACT(HOUR   FROM (SYSTIMESTAMP - l_start)) * 3600
               > p_timeout_sec
            THEN
                RAISE_APPLICATION_ERROR(-20111,
                    'Timeout nach ' || p_timeout_sec || 's – Projekt ' ||
                    p_project_id || ' noch im Status ' || l_status.status ||
                    ' (' || l_status.processing_progress || '%).');
            END IF;

            DBMS_SESSION.SLEEP(p_interval_sec);
        END LOOP;
    END wait_for_completion;


END DC_BACKEND_PKG;
/


-- =============================================================================
-- Schnelltest (optional, auskommentiert)
-- =============================================================================
/*
-- Health-Check
BEGIN
    IF DC_BACKEND_PKG.health_check() THEN
        DBMS_OUTPUT.PUT_LINE('dc-backend: UP');
    ELSE
        DBMS_OUTPUT.PUT_LINE('dc-backend: NICHT ERREICHBAR');
    END IF;
END;
/

-- Prüfung starten (Projekt-ID anpassen)
DECLARE
    l_status   NUMBER;
    l_response VARCHAR2(4000);
BEGIN
    DC_BACKEND_PKG.start_check(
        p_project_id  => 1,
        p_status_code => l_status,
        p_response    => l_response
    );
    DBMS_OUTPUT.PUT_LINE('Status: ' || l_status);
    DBMS_OUTPUT.PUT_LINE('Response: ' || l_response);
END;
/
*/