// routes/ivantiTodoQueue.js
const express = require('express');
const pool = require('../db');
const { requireAuth, requireGroup } = require('../middleware/auth');
const logAudit = require('../helpers/auditLog');

const VALID_WORKFLOW_TYPES = ['FP', 'Archer', 'CARD', 'GRANITE', 'DECOM'];
const INVENTORY_TYPES     = ['CARD', 'GRANITE', 'DECOM'];
const VALID_STATUSES       = ['pending', 'complete'];

function isValidVendor(vendor) {
    if (typeof vendor !== 'string') return false;
    const trimmed = vendor.trim();
    return trimmed.length > 0 && trimmed.length <= 200;
}

function createIvantiTodoQueueRouter() {
    const router = express.Router();

    /**
     * GET /api/ivanti/todo-queue
     *
     * Returns all todo queue items belonging to the authenticated user.
     *
     * @query None
     * @returns {Array<Object>} Array of queue items with parsed `cves` array
     *   - id {number}
     *   - user_id {number}
     *   - finding_id {string}
     *   - finding_title {string|null}
     *   - cves {Array<string>}
     *   - ip_address {string|null}
     *   - hostname {string|null}
     *   - vendor {string}
     *   - workflow_type {string} One of: FP, Archer, CARD, GRANITE, DECOM
     *   - status {string} pending | complete
     *   - created_at {string}
     *   - updated_at {string}
     */
    router.get('/', requireAuth(), async (req, res) => {
        try {
            const { rows } = await pool.query(
                `SELECT q.*
                 FROM ivanti_todo_queue q
                 WHERE q.user_id = $1
                 ORDER BY q.vendor ASC, q.created_at ASC`,
                [req.user.id]
            );
            const parsed = rows.map((r) => {
                let cves = [];
                if (r.cves_json) {
                    try { cves = JSON.parse(r.cves_json); } catch (e) { cves = []; }
                }
                return { ...r, cves };
            });
            res.json(parsed);
        } catch (err) {
            console.error('Error fetching todo queue:', err);
            res.status(500).json({ error: 'Internal server error.' });
        }
    });

    /**
     * POST /api/ivanti/todo-queue/batch
     *
     * Adds multiple findings to the authenticated user's todo queue in a single transaction.
     * Requires Admin or Standard_User group.
     *
     * @body {Object}
     *   - findings {Array<Object>} 1–200 items, each with:
     *       - finding_id {string} Required, non-empty
     *       - finding_title {string} Optional, max 500 chars
     *       - cves {Array<string>} Optional
     *       - ip_address {string} Optional, max 64 chars
     *       - hostname {string} Optional, max 255 chars
     *   - workflow_type {string} Required. One of: FP, Archer, CARD, GRANITE, DECOM
     *   - vendor {string} Required for FP, Archer, and DECOM workflows; max 200 chars
     * @returns {Object} { items: Array<Object> } — inserted queue items with parsed `cves` array
     * @error 400 Invalid input
     * @error 500 Internal server error
     */
    router.post('/batch', requireAuth(), requireGroup('Admin', 'Standard_User'), async (req, res) => {
        const { findings, workflow_type, vendor } = req.body;

        if (!Array.isArray(findings) || findings.length < 1 || findings.length > 200) {
            return res.status(400).json({ error: 'findings array must contain 1-200 items.' });
        }

        for (let i = 0; i < findings.length; i++) {
            const f = findings[i];
            if (!f || typeof f.finding_id !== 'string' || f.finding_id.trim().length === 0) {
                return res.status(400).json({ error: 'Each finding must have a non-empty finding_id string.' });
            }
        }

        if (!VALID_WORKFLOW_TYPES.includes(workflow_type)) {
            return res.status(400).json({ error: 'workflow_type must be FP, Archer, CARD, GRANITE, or DECOM.' });
        }

        if (!INVENTORY_TYPES.includes(workflow_type)) {
            if (!isValidVendor(vendor)) {
                return res.status(400).json({ error: 'vendor is required for FP and Archer workflows.' });
            }
        }

        if (vendor !== undefined && vendor !== '' && typeof vendor === 'string' && vendor.trim().length > 200) {
            return res.status(400).json({ error: 'vendor must be under 200 chars.' });
        }

        const vendorVal = INVENTORY_TYPES.includes(workflow_type) ? '' : vendor.trim();
        const userId = req.user.id;

        const client = await pool.connect();
        try {
            await client.query('BEGIN');

            const insertedIds = [];
            for (const f of findings) {
                const findingId = f.finding_id.trim();
                const title = f.finding_title && typeof f.finding_title === 'string'
                    ? f.finding_title.slice(0, 500) : null;
                const cvesJson = Array.isArray(f.cves) ? JSON.stringify(f.cves) : null;
                const ipVal = f.ip_address && typeof f.ip_address === 'string'
                    ? f.ip_address.trim().slice(0, 64) : null;
                const hostVal = f.hostname && typeof f.hostname === 'string'
                    ? f.hostname.trim().slice(0, 255) : null;

                const { rows } = await client.query(
                    `INSERT INTO ivanti_todo_queue
                         (user_id, finding_id, finding_title, cves_json, ip_address, hostname, vendor, workflow_type)
                     VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
                     RETURNING id`,
                    [userId, findingId, title, cvesJson, ipVal, hostVal, vendorVal, workflow_type]
                );
                insertedIds.push(rows[0].id);
            }

            await client.query('COMMIT');

            // Fetch all inserted rows
            const { rows: fetchedRows } = await pool.query(
                `SELECT * FROM ivanti_todo_queue WHERE id = ANY($1)`,
                [insertedIds]
            );

            const items = fetchedRows.map((r) => ({
                ...r,
                cves: r.cves_json ? JSON.parse(r.cves_json) : [],
            }));

            logAudit({
                userId: req.user.id,
                username: req.user.username,
                action: 'batch_add_to_queue',
                entityType: 'ivanti_todo_queue',
                entityId: null,
                details: {
                    count: insertedIds.length,
                    workflow_type: workflow_type,
                    finding_ids: findings.map((f) => f.finding_id.trim()),
                },
                ipAddress: req.ip,
            });

            return res.status(201).json({ items });
        } catch (err) {
            await client.query('ROLLBACK');
            console.error('Batch insert error:', err);
            return res.status(500).json({ error: 'Internal server error.' });
        } finally {
            client.release();
        }
    });

    /**
     * POST /api/ivanti/todo-queue
     *
     * Adds a single finding to the authenticated user's todo queue.
     * Requires Admin or Standard_User group.
     *
     * @body {Object}
     *   - finding_id {string} Required, non-empty
     *   - finding_title {string} Optional, max 500 chars
     *   - cves {Array<string>} Optional
     *   - ip_address {string} Optional, max 64 chars
     *   - hostname {string} Optional, max 255 chars
     *   - vendor {string} Required for FP, Archer, and DECOM workflows; max 200 chars
     *   - workflow_type {string} Required. One of: FP, Archer, CARD, GRANITE, DECOM
     * @returns {Object} The created queue item with parsed `cves` array
     * @error 400 Invalid input
     * @error 500 Internal server error
     */
    router.post('/', requireAuth(), requireGroup('Admin', 'Standard_User'), async (req, res) => {
        const { finding_id, finding_title, cves, ip_address, hostname, vendor, workflow_type } = req.body;

        if (!finding_id || typeof finding_id !== 'string' || finding_id.trim().length === 0) {
            return res.status(400).json({ error: 'finding_id is required.' });
        }
        if (!VALID_WORKFLOW_TYPES.includes(workflow_type)) {
            return res.status(400).json({ error: 'workflow_type must be FP, Archer, CARD, GRANITE, or DECOM.' });
        }
        if (!INVENTORY_TYPES.includes(workflow_type) && !isValidVendor(vendor)) {
            return res.status(400).json({ error: 'vendor is required for FP and Archer workflows.' });
        }
        if (vendor !== undefined && vendor !== '' && !isValidVendor(vendor)) {
            return res.status(400).json({ error: 'vendor must be under 200 chars.' });
        }

        const vendorVal = INVENTORY_TYPES.includes(workflow_type) ? '' : vendor.trim();
        const cvesJson  = Array.isArray(cves) ? JSON.stringify(cves) : null;
        const ipVal     = ip_address && typeof ip_address === 'string' ? ip_address.trim().slice(0, 64) : null;
        const hostVal   = hostname && typeof hostname === 'string' ? hostname.trim().slice(0, 255) : null;
        const title     = finding_title && typeof finding_title === 'string'
            ? finding_title.slice(0, 500) : null;

        try {
            const { rows } = await pool.query(
                `INSERT INTO ivanti_todo_queue
                     (user_id, finding_id, finding_title, cves_json, ip_address, hostname, vendor, workflow_type)
                 VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
                 RETURNING *`,
                [req.user.id, finding_id.trim(), title, cvesJson, ipVal, hostVal, vendorVal, workflow_type]
            );

            const result = {
                ...rows[0],
                cves: rows[0].cves_json ? JSON.parse(rows[0].cves_json) : [],
            };
            res.status(201).json(result);
        } catch (err) {
            console.error('Error adding to queue:', err);
            res.status(500).json({ error: 'Internal server error.' });
        }
    });

    /**
     * PUT /api/ivanti/todo-queue/:id
     *
     * Updates an existing queue item owned by the authenticated user.
     * Requires Admin or Standard_User group.
     *
     * @param {string} id — Queue item ID (URL parameter)
     * @body {Object} At least one field required:
     *   - vendor {string} Optional, non-empty, max 200 chars
     *   - workflow_type {string} Optional. One of: FP, Archer, CARD, GRANITE, DECOM
     *   - status {string} Optional. One of: pending, complete
     * @returns {Object} The updated queue item with parsed `cves` array
     * @error 400 Invalid input or no fields to update
     * @error 404 Queue item not found
     * @error 500 Internal server error
     */
    router.put('/:id', requireAuth(), requireGroup('Admin', 'Standard_User'), async (req, res) => {
        const { id } = req.params;
        const { vendor, workflow_type, status } = req.body;

        if (vendor !== undefined && !isValidVendor(vendor)) {
            return res.status(400).json({ error: 'vendor must be a non-empty string (max 200 chars).' });
        }
        if (workflow_type !== undefined && !VALID_WORKFLOW_TYPES.includes(workflow_type)) {
            return res.status(400).json({ error: 'workflow_type must be FP, Archer, CARD, GRANITE, or DECOM.' });
        }
        if (status !== undefined && !VALID_STATUSES.includes(status)) {
            return res.status(400).json({ error: 'status must be pending or complete.' });
        }

        try {
            const { rows: existingRows } = await pool.query(
                'SELECT * FROM ivanti_todo_queue WHERE id = $1 AND user_id = $2',
                [id, req.user.id]
            );
            if (!existingRows[0]) {
                return res.status(404).json({ error: 'Queue item not found.' });
            }

            const updates = [];
            const params = [];
            let paramIndex = 1;

            if (vendor !== undefined) {
                updates.push(`vendor = $${paramIndex++}`);
                params.push(vendor.trim());
            }
            if (workflow_type !== undefined) {
                updates.push(`workflow_type = $${paramIndex++}`);
                params.push(workflow_type);
            }
            if (status !== undefined) {
                updates.push(`status = $${paramIndex++}`);
                params.push(status);
            }

            if (updates.length === 0) {
                return res.status(400).json({ error: 'No fields to update.' });
            }

            updates.push('updated_at = NOW()');
            params.push(id, req.user.id);

            await pool.query(
                `UPDATE ivanti_todo_queue SET ${updates.join(', ')} WHERE id = $${paramIndex++} AND user_id = $${paramIndex}`,
                params
            );

            const { rows } = await pool.query(
                'SELECT * FROM ivanti_todo_queue WHERE id = $1', [id]
            );
            const result = {
                ...rows[0],
                cves: rows[0].cves_json ? JSON.parse(rows[0].cves_json) : [],
            };
            res.json(result);
        } catch (err) {
            console.error(err);
            res.status(500).json({ error: 'Internal server error.' });
        }
    });

    /**
     * POST /api/ivanti/todo-queue/:id/redirect
     *
     * Redirects a completed queue item to a different workflow by creating a new
     * pending queue item with the same finding data but a new workflow type/vendor.
     * Requires Admin or Standard_User group.
     *
     * @param {string} id — Queue item ID of the completed item (URL parameter)
     * @body {Object}
     *   - workflow_type {string} Required. One of: FP, Archer, CARD, GRANITE, DECOM
     *   - vendor {string} Required for FP, Archer, and DECOM workflows; max 200 chars
     * @returns {Object} The newly created queue item with parsed `cves` array
     * @error 400 Invalid input or item not in complete status
     * @error 404 Queue item not found
     * @error 500 Internal server error
     */
    router.post('/:id/redirect', requireAuth(), requireGroup('Admin', 'Standard_User'), async (req, res) => {
        const { id } = req.params;
        const { workflow_type, vendor } = req.body;

        if (!VALID_WORKFLOW_TYPES.includes(workflow_type)) {
            return res.status(400).json({ error: 'workflow_type must be FP, Archer, CARD, GRANITE, or DECOM.' });
        }
        if (!INVENTORY_TYPES.includes(workflow_type)) {
            if (!isValidVendor(vendor)) {
                return res.status(400).json({ error: 'vendor is required for FP and Archer workflows.' });
            }
        }
        if (vendor !== undefined && vendor !== '' && typeof vendor === 'string' && vendor.trim().length > 200) {
            return res.status(400).json({ error: 'vendor must be under 200 chars.' });
        }

        const vendorVal = INVENTORY_TYPES.includes(workflow_type) ? '' : vendor.trim();

        try {
            const { rows: origRows } = await pool.query(
                'SELECT * FROM ivanti_todo_queue WHERE id = $1 AND user_id = $2',
                [id, req.user.id]
            );
            const original = origRows[0];
            if (!original) {
                return res.status(404).json({ error: 'Queue item not found.' });
            }
            if (original.status !== 'complete') {
                return res.status(400).json({ error: 'Only completed queue items can be redirected.' });
            }

            const { rows } = await pool.query(
                `INSERT INTO ivanti_todo_queue
                     (user_id, finding_id, finding_title, cves_json, ip_address, hostname, vendor, workflow_type)
                 VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
                 RETURNING *`,
                [req.user.id, original.finding_id, original.finding_title, original.cves_json, original.ip_address, original.hostname, vendorVal, workflow_type]
            );

            logAudit({
                userId: req.user.id,
                username: req.user.username,
                action: 'queue_item_redirected',
                entityType: 'ivanti_todo_queue',
                entityId: String(original.id),
                details: {
                    original_workflow_type: original.workflow_type,
                    target_workflow_type: workflow_type,
                    new_item_id: rows[0].id,
                    vendor: vendorVal,
                },
                ipAddress: req.ip,
            });

            const result = {
                ...rows[0],
                cves: rows[0].cves_json ? JSON.parse(rows[0].cves_json) : [],
            };
            return res.status(201).json(result);
        } catch (err) {
            console.error('Error redirecting queue item:', err);
            res.status(500).json({ error: 'Internal server error.' });
        }
    });

    /**
     * DELETE /api/ivanti/todo-queue/completed
     *
     * Deletes all completed queue items belonging to the authenticated user.
     * Requires Admin or Standard_User group.
     *
     * @returns {Object} { message: string, deleted: number }
     * @error 500 Internal server error
     */
    router.delete('/completed', requireAuth(), requireGroup('Admin', 'Standard_User'), async (req, res) => {
        try {
            const result = await pool.query(
                "DELETE FROM ivanti_todo_queue WHERE user_id = $1 AND status = 'complete'",
                [req.user.id]
            );
            res.json({ message: 'Completed items cleared.', deleted: result.rowCount });
        } catch (err) {
            console.error('Error clearing completed queue items:', err);
            res.status(500).json({ error: 'Internal server error.' });
        }
    });

    /**
     * DELETE /api/ivanti/todo-queue/:id
     *
     * Deletes a single queue item owned by the authenticated user.
     * Requires Admin or Standard_User group.
     *
     * @param {string} id — Queue item ID (URL parameter)
     * @returns {Object} { message: string }
     * @error 404 Queue item not found
     * @error 500 Internal server error
     */
    router.delete('/:id', requireAuth(), requireGroup('Admin', 'Standard_User'), async (req, res) => {
        const { id } = req.params;

        try {
            const { rows } = await pool.query(
                'SELECT id FROM ivanti_todo_queue WHERE id = $1 AND user_id = $2',
                [id, req.user.id]
            );
            if (!rows[0]) {
                return res.status(404).json({ error: 'Queue item not found.' });
            }

            await pool.query(
                'DELETE FROM ivanti_todo_queue WHERE id = $1 AND user_id = $2',
                [id, req.user.id]
            );
            res.json({ message: 'Queue item deleted.' });
        } catch (err) {
            console.error(err);
            res.status(500).json({ error: 'Internal server error.' });
        }
    });

    return router;
}

module.exports = createIvantiTodoQueueRouter;