// Atlas InfoSec Action Plans Routes
// Proxies CRUD operations to the Atlas API and maintains a local SQLite cache
// for fast badge rendering on the ReportingPage.

const express = require('express');
const { requireGroup } = require('../middleware/auth');
const logAudit = require('../helpers/auditLog');
const { isConfigured, atlasGet, atlasPut, atlasPatch, atlasPost } = require('../helpers/atlasApi');

const VALID_PLAN_TYPES = ['decommission', 'remediation', 'false_positive', 'risk_acceptance', 'scan_exclusion'];
const DATE_PATTERN = /^\d{4}-\d{2}-\d{2}$/;

// ---------------------------------------------------------------------------
// DB helpers — promise wrappers for callback-based SQLite API
// ---------------------------------------------------------------------------
function dbRun(db, sql, params = []) {
    return new Promise((resolve, reject) => {
        db.run(sql, params, function (err) { if (err) reject(err); else resolve(this); });
    });
}

function dbGet(db, sql, params = []) {
    return new Promise((resolve, reject) => {
        db.get(sql, params, (err, row) => { if (err) reject(err); else resolve(row); });
    });
}

function dbAll(db, sql, params = []) {
    return new Promise((resolve, reject) => {
        db.all(sql, params, (err, rows) => { if (err) reject(err); else resolve(rows || []); });
    });
}

// ---------------------------------------------------------------------------
// Router factory
// ---------------------------------------------------------------------------
function createAtlasRouter(db, requireAuth) {
    const router = express.Router();

    // -----------------------------------------------------------------------
    // GET /status
    // Return all cached Atlas rows for badge rendering.
    // Auth: any authenticated user
    // -----------------------------------------------------------------------
    router.get('/status', requireAuth(db), async (req, res) => {
        if (!isConfigured) {
            return res.status(503).json({ error: 'Atlas API is not configured. Check ATLAS_API_URL, ATLAS_API_USER, and ATLAS_API_PASS environment variables.' });
        }

        try {
            const rows = await dbAll(db,
                `SELECT host_id, has_action_plan, plan_count, synced_at FROM atlas_action_plans_cache`
            );
            res.json(rows);
        } catch (err) {
            console.error('[Atlas] Error fetching status:', err.message);
            res.status(500).json({ error: 'Failed to fetch Atlas status.' });
        }
    });

    // -----------------------------------------------------------------------
    // POST /sync
    // Sync Atlas action plan data for all hosts found in the Ivanti cache.
    // Auth: Admin or Standard_User
    // -----------------------------------------------------------------------
    router.post('/sync', requireAuth(db), requireGroup('Admin', 'Standard_User'), async (req, res) => {
        if (!isConfigured) {
            return res.status(503).json({ error: 'Atlas API is not configured. Check ATLAS_API_URL, ATLAS_API_USER, and ATLAS_API_PASS environment variables.' });
        }

        try {
            // 1. Read Ivanti findings cache and extract unique non-null hostIds
            const cacheRow = await dbGet(db, `SELECT findings_json FROM ivanti_findings_cache WHERE id = 1`);
            if (!cacheRow || !cacheRow.findings_json) {
                return res.json({ synced: 0, withPlans: 0, failed: 0 });
            }

            let findings;
            try {
                findings = JSON.parse(cacheRow.findings_json);
            } catch (parseErr) {
                return res.status(500).json({ error: 'Failed to parse Ivanti findings cache.' });
            }

            const hostIdSet = new Set();
            for (const f of findings) {
                if (f.hostId != null && typeof f.hostId === 'number' && f.hostId > 0) {
                    hostIdSet.add(f.hostId);
                }
            }
            const hostIds = [...hostIdSet];

            if (hostIds.length === 0) {
                return res.json({ synced: 0, withPlans: 0, failed: 0 });
            }

            // 2. Process hosts in batches of 5 concurrent requests
            let synced = 0;
            let withPlans = 0;
            let failed = 0;
            const BATCH_SIZE = 5;

            for (let i = 0; i < hostIds.length; i += BATCH_SIZE) {
                const batch = hostIds.slice(i, i + BATCH_SIZE);
                const results = await Promise.allSettled(
                    batch.map(async (hostId) => {
                        const result = await atlasGet('/hosts/' + hostId + '/action-plans');
                        return { hostId, result };
                    })
                );

                for (const settled of results) {
                    if (settled.status === 'rejected') {
                        failed++;
                        console.warn('[Atlas Sync] Request failed for host:', settled.reason?.message || settled.reason);
                        continue;
                    }

                    const { hostId, result } = settled.value;

                    if (result.status >= 200 && result.status < 300) {
                        let allPlans = [];
                        let activePlans = [];
                        try {
                            const parsed = JSON.parse(result.body);
                            // Atlas returns { active: [...], inactive: [...] }
                            if (parsed && typeof parsed === 'object' && !Array.isArray(parsed)) {
                                activePlans = Array.isArray(parsed.active) ? parsed.active : [];
                                const inactive = Array.isArray(parsed.inactive) ? parsed.inactive : [];
                                allPlans = [...activePlans, ...inactive];
                            } else if (Array.isArray(parsed)) {
                                allPlans = parsed;
                                activePlans = parsed;
                            }
                        } catch (e) {
                            allPlans = [];
                            activePlans = [];
                        }

                        // Badge counts only active plans — inactive are historical
                        const planCount = activePlans.length;
                        const hasActionPlan = planCount > 0 ? 1 : 0;

                        try {
                            await dbRun(db,
                                `INSERT INTO atlas_action_plans_cache (host_id, has_action_plan, plan_count, plans_json, synced_at)
                                 VALUES (?, ?, ?, ?, datetime('now'))
                                 ON CONFLICT(host_id) DO UPDATE SET
                                     has_action_plan = excluded.has_action_plan,
                                     plan_count = excluded.plan_count,
                                     plans_json = excluded.plans_json,
                                     synced_at = excluded.synced_at`,
                                [hostId, hasActionPlan, planCount, JSON.stringify(allPlans)]
                            );
                        } catch (dbErr) {
                            console.error('[Atlas Sync] DB upsert failed for host', hostId, ':', dbErr.message);
                        }

                        synced++;
                        if (hasActionPlan) withPlans++;
                    } else {
                        failed++;
                        console.warn(`[Atlas Sync] Non-2xx response for host ${hostId}: status ${result.status}`);
                    }
                }
            }

            // 3. Log audit entry
            logAudit(db, {
                userId: req.user.id,
                username: req.user.username,
                action: 'ATLAS_SYNC',
                entityType: 'atlas_action_plans',
                entityId: null,
                details: { synced, withPlans, failed, totalHosts: hostIds.length },
                ipAddress: req.ip
            });

            res.json({ synced, withPlans, failed });
        } catch (err) {
            console.error('[Atlas Sync] Unexpected error:', err.message);
            res.status(500).json({ error: 'Atlas sync failed: ' + err.message });
        }
    });

    // -----------------------------------------------------------------------
    // GET /hosts/:hostId/action-plans
    // Proxy to Atlas API — returns live action plan data for a single host.
    // Auth: any authenticated user
    // -----------------------------------------------------------------------
    router.get('/hosts/:hostId/action-plans', requireAuth(db), async (req, res) => {
        if (!isConfigured) {
            return res.status(503).json({ error: 'Atlas API is not configured. Check ATLAS_API_URL, ATLAS_API_USER, and ATLAS_API_PASS environment variables.' });
        }

        const hostId = parseInt(req.params.hostId, 10);
        if (!Number.isInteger(hostId) || hostId <= 0) {
            return res.status(400).json({ error: 'hostId must be a positive integer' });
        }

        try {
            const result = await atlasGet('/hosts/' + hostId + '/action-plans');

            if (result.status >= 200 && result.status < 300) {
                let body;
                try {
                    body = JSON.parse(result.body);
                } catch (e) {
                    body = result.body;
                }
                res.status(result.status).json(body);
            } else {
                // Forward non-2xx Atlas responses to the client
                let errorBody;
                try {
                    errorBody = JSON.parse(result.body);
                } catch (e) {
                    errorBody = { error: result.body };
                }
                res.status(result.status).json(errorBody);
            }
        } catch (err) {
            console.error('[Atlas] GET action-plans failed for host', hostId, ':', err.message);
            res.status(502).json({ error: 'Failed to reach Atlas API: ' + err.message });
        }
    });

    // -----------------------------------------------------------------------
    // PUT /hosts/:hostId/action-plans
    // Create a new action plan for a host.
    // Auth: Admin or Standard_User
    // -----------------------------------------------------------------------
    router.put('/hosts/:hostId/action-plans', requireAuth(db), requireGroup('Admin', 'Standard_User'), async (req, res) => {
        if (!isConfigured) {
            return res.status(503).json({ error: 'Atlas API is not configured. Check ATLAS_API_URL, ATLAS_API_USER, and ATLAS_API_PASS environment variables.' });
        }

        const hostId = parseInt(req.params.hostId, 10);
        if (!Number.isInteger(hostId) || hostId <= 0) {
            return res.status(400).json({ error: 'hostId must be a positive integer' });
        }

        const { plan_type, commit_date } = req.body || {};

        if (!plan_type || !VALID_PLAN_TYPES.includes(plan_type)) {
            return res.status(400).json({ error: 'plan_type must be one of: ' + VALID_PLAN_TYPES.join(', ') });
        }

        if (!commit_date || !DATE_PATTERN.test(commit_date)) {
            return res.status(400).json({ error: 'commit_date must be a valid YYYY-MM-DD date string' });
        }

        try {
            const result = await atlasPut('/hosts/' + hostId + '/action-plans', req.body);

            logAudit(db, {
                userId: req.user.id,
                username: req.user.username,
                action: 'ATLAS_CREATE_PLAN',
                entityType: 'atlas_action_plan',
                entityId: String(hostId),
                details: { hostId, plan_type, commit_date },
                ipAddress: req.ip
            });

            if (result.status >= 200 && result.status < 300) {
                let body;
                try {
                    body = JSON.parse(result.body);
                } catch (e) {
                    body = result.body;
                }
                res.status(result.status).json(body);
            } else {
                let errorBody;
                try {
                    errorBody = JSON.parse(result.body);
                } catch (e) {
                    errorBody = { error: result.body };
                }
                res.status(result.status).json(errorBody);
            }
        } catch (err) {
            console.error('[Atlas] PUT action-plans failed for host', hostId, ':', err.message);
            res.status(502).json({ error: 'Failed to reach Atlas API: ' + err.message });
        }
    });

    // -----------------------------------------------------------------------
    // PATCH /hosts/:hostId/action-plans
    // Update an existing action plan for a host.
    // Auth: Admin or Standard_User
    // -----------------------------------------------------------------------
    router.patch('/hosts/:hostId/action-plans', requireAuth(db), requireGroup('Admin', 'Standard_User'), async (req, res) => {
        if (!isConfigured) {
            return res.status(503).json({ error: 'Atlas API is not configured. Check ATLAS_API_URL, ATLAS_API_USER, and ATLAS_API_PASS environment variables.' });
        }

        const hostId = parseInt(req.params.hostId, 10);
        if (!Number.isInteger(hostId) || hostId <= 0) {
            return res.status(400).json({ error: 'hostId must be a positive integer' });
        }

        const { action_plan_id, updates } = req.body || {};

        if (!action_plan_id || typeof action_plan_id !== 'string' || action_plan_id.trim() === '') {
            return res.status(400).json({ error: 'action_plan_id is required and must be a non-empty string' });
        }

        if (!updates || typeof updates !== 'object' || Array.isArray(updates)) {
            return res.status(400).json({ error: 'updates is required and must be an object' });
        }

        try {
            const result = await atlasPatch('/hosts/' + hostId + '/action-plans', req.body);

            logAudit(db, {
                userId: req.user.id,
                username: req.user.username,
                action: 'ATLAS_UPDATE_PLAN',
                entityType: 'atlas_action_plan',
                entityId: String(hostId),
                details: { hostId, action_plan_id },
                ipAddress: req.ip
            });

            if (result.status >= 200 && result.status < 300) {
                let body;
                try {
                    body = JSON.parse(result.body);
                } catch (e) {
                    body = result.body;
                }
                res.status(result.status).json(body);
            } else {
                let errorBody;
                try {
                    errorBody = JSON.parse(result.body);
                } catch (e) {
                    errorBody = { error: result.body };
                }
                res.status(result.status).json(errorBody);
            }
        } catch (err) {
            console.error('[Atlas] PATCH action-plans failed for host', hostId, ':', err.message);
            res.status(502).json({ error: 'Failed to reach Atlas API: ' + err.message });
        }
    });

    // -----------------------------------------------------------------------
    // POST /hosts/bulk-action-plans
    // Create action plans for multiple hosts at once.
    // Auth: Admin or Standard_User
    // -----------------------------------------------------------------------
    router.post('/hosts/bulk-action-plans', requireAuth(db), requireGroup('Admin', 'Standard_User'), async (req, res) => {
        if (!isConfigured) {
            return res.status(503).json({ error: 'Atlas API is not configured. Check ATLAS_API_URL, ATLAS_API_USER, and ATLAS_API_PASS environment variables.' });
        }

        const { host_ids, plan_type, commit_date } = req.body || {};

        if (!Array.isArray(host_ids) || host_ids.length === 0) {
            return res.status(400).json({ error: 'host_ids must be a non-empty array of positive integers' });
        }

        for (const id of host_ids) {
            if (!Number.isInteger(id) || id <= 0) {
                return res.status(400).json({ error: 'host_ids must be a non-empty array of positive integers' });
            }
        }

        if (!plan_type || !VALID_PLAN_TYPES.includes(plan_type)) {
            return res.status(400).json({ error: 'plan_type must be one of: ' + VALID_PLAN_TYPES.join(', ') });
        }

        if (!commit_date || !DATE_PATTERN.test(commit_date)) {
            return res.status(400).json({ error: 'commit_date must be a valid YYYY-MM-DD date string' });
        }

        try {
            const result = await atlasPost('/hosts/create-bulk-action-plans', req.body);

            if (result.status >= 200 && result.status < 300) {
                let body;
                try {
                    body = JSON.parse(result.body);
                } catch (e) {
                    body = result.body;
                }
                res.status(result.status).json(body);
            } else {
                let errorBody;
                try {
                    errorBody = JSON.parse(result.body);
                } catch (e) {
                    errorBody = { error: result.body };
                }
                res.status(result.status).json(errorBody);
            }
        } catch (err) {
            console.error('[Atlas] POST bulk-action-plans failed:', err.message);
            res.status(502).json({ error: 'Failed to reach Atlas API: ' + err.message });
        }
    });

    return router;
}

module.exports = createAtlasRouter;