// ============================================================================
// STARTUP RECOVERY Function - Session State Restoration (Issue 1)
// Purpose: Restore session state from database on Node-RED startup/crash recovery
// Trigger: Inject node on startup
// Outputs: 2 (UI notification, database query)
// ============================================================================

// This function should be called on Node-RED startup (via inject node with "inject once after X seconds")
// It queries the session_state table and restores global variables

const mode = msg.mode || "check";

switch (mode) {
    // ========================================================================
    // STEP 1: Query database for session state
    // ========================================================================
    case "check": {
        msg._mode = "query-session-state";
        msg.topic = "SELECT * FROM session_state WHERE session_key = 'current_session';";

        node.warn("[RECOVERY] Checking for existing session state...");

        return [null, msg];
    }

    // ========================================================================
    // STEP 2: Process query results and prompt user
    // ========================================================================
    case "process-results": {
        const results = msg.payload;

        if (!results || results.length === 0) {
            node.warn("[RECOVERY] No session state found in database");
            return [null, null];
        }

        const session = results[0];

        // Check if there's a valid session to restore
        if (!session.work_order_id || session.cycle_count === 0) {
            node.warn("[RECOVERY] Session state exists but is empty - nothing to restore");
            return [null, null];
        }

        // Check if tracking was enabled
        if (!session.tracking_enabled) {
            node.warn("[RECOVERY] Previous session was not actively tracking - restoring state without prompt");

            // Restore the state silently
            global.set("cycleCount", session.cycle_count || 0);
            global.set("productionStartTime", session.production_start_time);
            global.set("operatingTime", Number(session.operating_time) || 0);
            global.set("downtime", Number(session.downtime) || 0);
            global.set("lastUpdateTime", session.last_update_time || Date.now());
            global.set("trackingEnabled", false);
            global.set("scrapPromptIssuedFor", session.scrap_prompt_issued_for || null);
            global.set("currentSessionId", session.current_session_id || null);

            return [null, null];
        }

        // Session was actively tracking - prompt user
        node.warn(`[RECOVERY] Found active session - Work Order: ${session.work_order_id}, Cycles: ${session.cycle_count}`);

        const promptMsg = {
            _mode: "recovery-prompt",
            recoveryPrompt: {
                workOrderId: session.work_order_id,
                cycleCount: session.cycle_count,
                operatingTime: Number(session.operating_time) || 0,
                downtime: Number(session.downtime) || 0,
                timestamp: session.last_update_time,
                sessionData: session
            }
        };

        return [promptMsg, null];
    }

    // ========================================================================
    // STEP 3: User chose to restore session
    // ========================================================================
    case "restore": {
        const sessionData = msg.payload;

        if (!sessionData) {
            node.error("[RECOVERY] No session data provided for restore");
            return [null, null];
        }

        node.warn(`[RECOVERY] Restoring session - Work Order: ${sessionData.work_order_id}, Cycles: ${sessionData.cycle_count}`);

        // Restore all global variables
        global.set("cycleCount", sessionData.cycle_count || 0);
        global.set("productionStartTime", sessionData.production_start_time);
        global.set("operatingTime", Number(sessionData.operating_time) || 0);
        global.set("downtime", Number(sessionData.downtime) || 0);
        global.set("lastUpdateTime", sessionData.last_update_time || Date.now());
        global.set("trackingEnabled", !!sessionData.tracking_enabled);
        global.set("scrapPromptIssuedFor", sessionData.scrap_prompt_issued_for || null);
        global.set("currentSessionId", sessionData.current_session_id || null);

        // Also need to restore activeWorkOrder from work_orders table
        const queryMsg = {
            _mode: "query-work-order",
            topic: `SELECT * FROM work_orders WHERE work_order_id = '${sessionData.work_order_id}';`
        };

        const notificationMsg = {
            _mode: "recovery-success",
            notification: {
                message: `Session restored: ${sessionData.work_order_id} - ${sessionData.cycle_count} cycles`,
                type: "success"
            }
        };

        return [notificationMsg, queryMsg];
    }

    // ========================================================================
    // STEP 4: Set activeWorkOrder from query result
    // ========================================================================
    case "set-work-order": {
        const results = msg.payload;

        if (!results || results.length === 0) {
            node.error("[RECOVERY] Work order not found in database");
            return [null, null];
        }

        const workOrder = results[0];

        // Reconstruct activeWorkOrder object
        const activeOrder = {
            id: workOrder.work_order_id,
            sku: workOrder.sku,
            target: workOrder.target,
            good: workOrder.good_parts,
            scrap: workOrder.scrap_count || 0,
            cycleTime: workOrder.cycle_time,
            theoreticalCycleTime: workOrder.cycle_time,
            progressPercent: workOrder.progress_percent,
            status: workOrder.status,
            lastUpdateIso: new Date().toISOString()
        };

        global.set("activeWorkOrder", activeOrder);

        node.warn(`[RECOVERY] Active work order restored: ${activeOrder.id}`);

        return [null, null];
    }

    // ========================================================================
    // STEP 5: User chose to start fresh
    // ========================================================================
    case "start-fresh": {
        node.warn("[RECOVERY] User chose to start fresh - clearing session state");

        // Clear all global variables
        global.set("cycleCount", 0);
        global.set("productionStartTime", null);
        global.set("operatingTime", 0);
        global.set("downtime", 0);
        global.set("lastUpdateTime", Date.now());
        global.set("trackingEnabled", false);
        global.set("activeWorkOrder", null);
        global.set("scrapPromptIssuedFor", null);
        global.set("currentSessionId", null);

        // Clear session_state in database
        const clearMsg = {
            _mode: "clear-session-state",
            topic: `
                UPDATE session_state
                SET
                    work_order_id = NULL,
                    cycle_count = 0,
                    production_start_time = NULL,
                    operating_time = 0,
                    downtime = 0,
                    last_update_time = NULL,
                    tracking_enabled = 0,
                    machine_state = 0,
                    scrap_prompt_issued_for = NULL,
                    current_session_id = NULL
                WHERE session_key = 'current_session';
            `
        };

        const notificationMsg = {
            _mode: "recovery-cleared",
            notification: {
                message: "Started with fresh session",
                type: "info"
            }
        };

        return [notificationMsg, clearMsg];
    }
}

// Default
return [null, null];