// routes/ivantiTodoQueue.js
const express = require('express');

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

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

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

    // GET /api/ivanti/todo-queue
    // Fetch current user's queue items, ordered by vendor then created_at
    router.get('/', requireAuth(db), (req, res) => {
        db.all(
            `SELECT * FROM ivanti_todo_queue
             WHERE user_id = ?
             ORDER BY vendor ASC, created_at ASC`,
            [req.user.id],
            (err, rows) => {
                if (err) {
                    console.error('Error fetching todo queue:', err);
                    return res.status(500).json({ error: 'Internal server error.' });
                }
                // Parse cves_json back to array for each row
                const parsed = rows.map((r) => ({
                    ...r,
                    cves: r.cves_json ? JSON.parse(r.cves_json) : [],
                }));
                res.json(parsed);
            }
        );
    });

    // POST /api/ivanti/todo-queue
    // Add a finding to the queue
    router.post('/', requireAuth(db), (req, res) => {
        const { finding_id, finding_title, cves, 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 (!isValidVendor(vendor)) {
            return res.status(400).json({ error: 'vendor is required (max 200 chars).' });
        }
        if (!VALID_WORKFLOW_TYPES.includes(workflow_type)) {
            return res.status(400).json({ error: 'workflow_type must be FP or Archer.' });
        }

        const cvesJson = Array.isArray(cves) ? JSON.stringify(cves) : null;
        const title    = finding_title && typeof finding_title === 'string'
            ? finding_title.slice(0, 500)
            : null;

        db.run(
            `INSERT INTO ivanti_todo_queue
                 (user_id, finding_id, finding_title, cves_json, vendor, workflow_type)
             VALUES (?, ?, ?, ?, ?, ?)`,
            [req.user.id, finding_id.trim(), title, cvesJson, vendor.trim(), workflow_type],
            function (err) {
                if (err) {
                    console.error('Error adding to queue:', err);
                    return res.status(500).json({ error: 'Internal server error.' });
                }
                db.get(
                    'SELECT * FROM ivanti_todo_queue WHERE id = ?',
                    [this.lastID],
                    (err2, row) => {
                        if (err2 || !row) {
                            return res.status(201).json({ id: this.lastID, message: 'Added to queue.' });
                        }
                        res.status(201).json({ ...row, cves: row.cves_json ? JSON.parse(row.cves_json) : [] });
                    }
                );
            }
        );
    });

    // PUT /api/ivanti/todo-queue/:id
    // Update vendor, workflow_type, or status — scoped to current user
    router.put('/:id', requireAuth(db), (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 or Archer.' });
        }
        if (status !== undefined && !VALID_STATUSES.includes(status)) {
            return res.status(400).json({ error: 'status must be pending or complete.' });
        }

        db.get(
            'SELECT * FROM ivanti_todo_queue WHERE id = ? AND user_id = ?',
            [id, req.user.id],
            (err, existing) => {
                if (err) {
                    console.error(err);
                    return res.status(500).json({ error: 'Internal server error.' });
                }
                if (!existing) {
                    return res.status(404).json({ error: 'Queue item not found.' });
                }

                const updates = [];
                const params  = [];

                if (vendor !== undefined) {
                    updates.push('vendor = ?');
                    params.push(vendor.trim());
                }
                if (workflow_type !== undefined) {
                    updates.push('workflow_type = ?');
                    params.push(workflow_type);
                }
                if (status !== undefined) {
                    updates.push('status = ?');
                    params.push(status);
                }

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

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

                db.run(
                    `UPDATE ivanti_todo_queue SET ${updates.join(', ')} WHERE id = ? AND user_id = ?`,
                    params,
                    function (err2) {
                        if (err2) {
                            console.error(err2);
                            return res.status(500).json({ error: 'Internal server error.' });
                        }
                        db.get(
                            'SELECT * FROM ivanti_todo_queue WHERE id = ?',
                            [id],
                            (err3, row) => {
                                if (err3 || !row) {
                                    return res.json({ message: 'Queue item updated.' });
                                }
                                res.json({ ...row, cves: row.cves_json ? JSON.parse(row.cves_json) : [] });
                            }
                        );
                    }
                );
            }
        );
    });

    // DELETE /api/ivanti/todo-queue/completed
    // Bulk-delete all completed items for the current user
    // IMPORTANT: This route must be registered BEFORE DELETE /:id
    router.delete('/completed', requireAuth(db), (req, res) => {
        db.run(
            "DELETE FROM ivanti_todo_queue WHERE user_id = ? AND status = 'complete'",
            [req.user.id],
            function (err) {
                if (err) {
                    console.error('Error clearing completed queue items:', err);
                    return res.status(500).json({ error: 'Internal server error.' });
                }
                res.json({ message: 'Completed items cleared.', deleted: this.changes });
            }
        );
    });

    // DELETE /api/ivanti/todo-queue/:id
    // Delete a single item — scoped to current user
    router.delete('/:id', requireAuth(db), (req, res) => {
        const { id } = req.params;

        db.get(
            'SELECT id FROM ivanti_todo_queue WHERE id = ? AND user_id = ?',
            [id, req.user.id],
            (err, row) => {
                if (err) {
                    console.error(err);
                    return res.status(500).json({ error: 'Internal server error.' });
                }
                if (!row) {
                    return res.status(404).json({ error: 'Queue item not found.' });
                }

                db.run(
                    'DELETE FROM ivanti_todo_queue WHERE id = ? AND user_id = ?',
                    [id, req.user.id],
                    function (err2) {
                        if (err2) {
                            console.error(err2);
                            return res.status(500).json({ error: 'Internal server error.' });
                        }
                        res.json({ message: 'Queue item deleted.' });
                    }
                );
            }
        );
    });

    return router;
}

module.exports = createIvantiTodoQueueRouter;