'use strict';
// SPDX-License-Identifier: GPL-3.0-or-later

// collect statistics from bind (named) v9.10+
//
// bind statistics documentation at:
// http://jpmens.net/2013/03/18/json-in-bind-9-s-statistics-server/
// https://ftp.isc.org/isc/bind/9.10.3/doc/arm/Bv9ARM.ch06.html#statistics

// example configuration in /etc/netdata/node.d/named.conf
// the module supports auto-detection if bind is running at localhost

/*
{
    "enable_autodetect": true,
    "update_every": 5,
    "servers": [
        {
            "name": "bind1",
            "url": "http://127.0.0.1:8888/json/v1/server",
            "update_every": 1
        },
        {
            "name": "bind2",
            "url": "http://10.0.0.1:8888/xml/v3/server",
            "update_every": 2
        }
    ]
}
*/

// the following is the bind named.conf configuration required

/*
statistics-channels {
        inet 127.0.0.1 port 8888 allow { 127.0.0.1; };
};
*/

require('url');
require('http');
var XML = require('pixl-xml');
var netdata = require('netdata');

if(netdata.options.DEBUG === true) netdata.debug('loaded', __filename, 'plugin');

var named = {
    name: __filename,
    enable_autodetect: true,
    update_every: 1,
    base_priority: 60000,
    charts: {},

    chartFromMembersCreate: function(service, obj, id, title_suffix, units, family, context, type, priority, algorithm, multiplier, divisor) {
        var chart = {
            id: id,                                         // the unique id of the chart
            name: '',                                       // the unique name of the chart
            title: service.name + ' ' + title_suffix,       // the title of the chart
            units: units,                                   // the units of the chart dimensions
            family: family,                                 // the family of the chart
            context: context,                               // the context of the chart
            type: type,                                     // the type of the chart
            priority: priority,                             // the priority relative to others in the same family
            update_every: service.update_every,             // the expected update frequency of the chart
            dimensions: {}
        };

        var found = 0;
        var dims = Object.keys(obj);
        var len = dims.length;
        for(var i = 0; i < len ;i++) {
            var x = dims[i];

            if(typeof(obj[x]) !== 'undefined' && obj[x] !== 0) {
                found++;
                chart.dimensions[x] = {
                    id: x,                  // the unique id of the dimension
                    name: x,                // the name of the dimension
                    algorithm: algorithm,   // the id of the netdata algorithm
                    multiplier: multiplier, // the multiplier
                    divisor: divisor,       // the divisor
                    hidden: false           // is hidden (boolean)
                };
            }
        }

        if(!found)
            return null;

        chart = service.chart(id, chart);
        this.charts[id] = chart;
        return chart;
    },

    chartFromMembers: function(service, obj, id_suffix, title_suffix, units, family, context, type, priority, algorithm, multiplier, divisor) {
        var id = 'named_' + service.name + '.' + id_suffix;
        var chart = this.charts[id];
        var dims, len, x, i;

        if(typeof chart === 'undefined') {
            chart = this.chartFromMembersCreate(service, obj, id, title_suffix, units, family, context, type, priority, algorithm, multiplier, divisor);
            if(chart === null) return false;
        }
        else {
            // check if we need to re-generate the chart
            dims = Object.keys(obj);
            len = dims.length;
            for(i = 0; i < len ;i++) {
                x = dims[i];
                if(typeof(chart.dimensions[x]) === 'undefined') {
                    chart = this.chartFromMembersCreate(service, obj, id, title_suffix, units, family, context, type, priority, algorithm, multiplier, divisor);
                    if(chart === null) return false;
                    break;
                }
            }
        }

        service.begin(chart);

        var found = 0;
        dims = Object.keys(obj);
        len = dims.length;
        for(i = 0; i < len ;i++) {
            x = dims[i];
            if(typeof(chart.dimensions[x]) !== 'undefined') {
                found++;
                service.set(x, obj[x]);
            }
        }

        service.end();

        return (found > 0);
    },

    // an index to map values to different charts
    lookups: {
        nsstats: {},
        resolver_stats: {},
        numfetch: {}
    },

    // transform the XML response of bind
    // to the JSON response of bind
    xml2js: function(service, data_xml) {
        var d = XML.parse(data_xml);
        if(d === null) return null;

        var a, aa, alen, alen2;

        var data = {};
        var len = d.server.counters.length;
        while(len--) {
            a = d.server.counters[len];
            if(typeof a.counter === 'undefined') continue;
            if(a.type === 'opcode') a.type = 'opcodes';
            else if(a.type === 'qtype') a.type = 'qtypes';
            else if(a.type === 'nsstat') a.type = 'nsstats';
            aa = data[a.type] = {};
            alen = 0;
            alen2 = a.counter.length;
            while(alen < alen2) {
                aa[a.counter[alen].name] = parseInt(a.counter[alen]._Data, 10);
                alen++;
            }
        }

        data.views = {};
        var vlen = d.views.view.length;
        while(vlen--) {
            var vname = d.views.view[vlen].name;
            data.views[vname] = { resolver: {} };
            len = d.views.view[vlen].counters.length;
            while(len--) {
                a = d.views.view[vlen].counters[len];
                if(typeof a.counter === 'undefined') continue;
                if(a.type === 'resstats') a.type = 'stats';
                else if(a.type === 'resqtype') a.type = 'qtypes';
                else if(a.type === 'adbstat') a.type = 'adb';
                aa = data.views[vname].resolver[a.type] = {};
                alen = 0;
                alen2 = a.counter.length;
                while(alen < alen2) {
                    aa[a.counter[alen].name] = parseInt(a.counter[alen]._Data, 10);
                    alen++;
                }
            }
        }

        return data;
    },

    processResponse: function(service, data) {
        if(data !== null) {
            var r, x, look, id, chart, keys, len;

            // parse XML or JSON
            // pepending on the URL given
            if(service.request.path.match(/^\/xml/) !== null)
                r = named.xml2js(service, data);
            else
                r = JSON.parse(data);

            if(typeof r === 'undefined' || r === null) {
                service.error("Cannot parse these data: " + data.toString());
                return;
            }

            if(service.added !== true)
                service.commit();

            if(typeof r.nsstats !== 'undefined') {
                // we split the nsstats object to several others
                var global_requests = {}, global_requests_enable = false;
                var global_failures = {}, global_failures_enable = false;
                var global_failures_detail = {}, global_failures_detail_enable = false;
                var global_updates = {}, global_updates_enable = false;
                var protocol_queries = {}, protocol_queries_enable = false;
                var global_queries = {}, global_queries_enable = false;
                var global_queries_success = {}, global_queries_success_enable = false;
                var default_enable = false;
                var RecursClients = 0;

                // RecursClients is an absolute value
                if(typeof r.nsstats['RecursClients'] !== 'undefined') {
                    RecursClients = r.nsstats['RecursClients'];
                    delete r.nsstats['RecursClients'];
                }

                keys = Object.keys(r.nsstats);
                len = keys.length;
                while(len--) {
                    x = keys[len];

                    // we maintain an index of the values found
                    // mapping them to objects splitted

                    look = named.lookups.nsstats[x];
                    if(typeof look === 'undefined') {
                        // a new value, not found in the index
                        // index it:
                        if(x === 'Requestv4') {
                            named.lookups.nsstats[x] = {
                                name: 'IPv4',
                                type: 'global_requests'
                            };
                        }
                        else if(x === 'Requestv6') {
                            named.lookups.nsstats[x] = {
                                name: 'IPv6',
                                type: 'global_requests'
                            };
                        }
                        else if(x === 'QryFailure') {
                            named.lookups.nsstats[x] = {
                                name: 'failures',
                                type: 'global_failures'
                            };
                        }
                        else if(x === 'QryUDP') {
                            named.lookups.nsstats[x] = {
                                name: 'UDP',
                                type: 'protocol_queries'
                            };
                        }
                        else if(x === 'QryTCP') {
                            named.lookups.nsstats[x] = {
                                name: 'TCP',
                                type: 'protocol_queries'
                            };
                        }
                        else if(x === 'QrySuccess') {
                            named.lookups.nsstats[x] = {
                                name: 'queries',
                                type: 'global_queries_success'
                            };
                        }
                        else if(x.match(/QryRej$/) !== null) {
                            named.lookups.nsstats[x] = {
                                name: x,
                                type: 'global_failures_detail'
                            };
                        }
                        else if(x.match(/^Qry/) !== null) {
                            named.lookups.nsstats[x] = {
                                name: x,
                                type: 'global_queries'
                            };
                        }
                        else if(x.match(/^Update/) !== null) {
                            named.lookups.nsstats[x] = {
                                name: x,
                                type: 'global_updates'
                            };
                        }
                        else {
                            // values not mapped, will remain
                            // in the default map
                            named.lookups.nsstats[x] = {
                                name: x,
                                type: 'default'
                            };
                        }

                        look = named.lookups.nsstats[x];
                        // netdata.error('lookup nsstats value: ' + x + ' >>> ' + named.lookups.nsstats[x].type);
                    }

                    switch(look.type) {
                        case 'global_requests': global_requests[look.name] = r.nsstats[x]; delete r.nsstats[x]; global_requests_enable = true; break;
                        case 'global_queries': global_queries[look.name] = r.nsstats[x]; delete r.nsstats[x]; global_queries_enable = true; break;
                        case 'global_queries_success': global_queries_success[look.name] = r.nsstats[x]; delete r.nsstats[x]; global_queries_success_enable = true; break;
                        case 'global_updates': global_updates[look.name] = r.nsstats[x]; delete r.nsstats[x]; global_updates_enable = true; break;
                        case 'protocol_queries': protocol_queries[look.name] = r.nsstats[x]; delete r.nsstats[x]; protocol_queries_enable = true; break;
                        case 'global_failures': global_failures[look.name] = r.nsstats[x]; delete r.nsstats[x]; global_failures_enable = true; break;
                        case 'global_failures_detail': global_failures_detail[look.name] = r.nsstats[x]; delete r.nsstats[x]; global_failures_detail_enable = true; break;
                        default: default_enable = true; break;
                    }
                }

                if(global_requests_enable === true)
                    service.module.chartFromMembers(service, global_requests, 'received_requests', 'Bind, Global Received Requests by IP version', 'requests/s', 'requests', 'named.requests', netdata.chartTypes.stacked, named.base_priority + 1, netdata.chartAlgorithms.incremental, 1, 1);

                if(global_queries_success_enable === true)
                    service.module.chartFromMembers(service, global_queries_success, 'global_queries_success', 'Bind, Global Successful Queries', 'queries/s', 'queries', 'named.queries_success', netdata.chartTypes.line, named.base_priority + 2, netdata.chartAlgorithms.incremental, 1, 1);

                if(protocol_queries_enable === true)
                    service.module.chartFromMembers(service, protocol_queries, 'protocols_queries', 'Bind, Global Queries by IP Protocol', 'queries/s', 'queries', 'named.protocol_queries', netdata.chartTypes.stacked, named.base_priority + 3, netdata.chartAlgorithms.incremental, 1, 1);

                if(global_queries_enable === true)
                    service.module.chartFromMembers(service, global_queries, 'global_queries', 'Bind, Global Queries Analysis', 'queries/s', 'queries', 'named.global_queries', netdata.chartTypes.stacked, named.base_priority + 4, netdata.chartAlgorithms.incremental, 1, 1);

                if(global_updates_enable === true)
                    service.module.chartFromMembers(service, global_updates, 'received_updates', 'Bind, Global Received Updates', 'updates/s', 'updates', 'named.global_updates', netdata.chartTypes.stacked, named.base_priority + 5, netdata.chartAlgorithms.incremental, 1, 1);

                if(global_failures_enable === true)
                    service.module.chartFromMembers(service, global_failures, 'query_failures', 'Bind, Global Query Failures', 'failures/s', 'failures', 'named.global_failures', netdata.chartTypes.line, named.base_priority + 6, netdata.chartAlgorithms.incremental, 1, 1);

                if(global_failures_detail_enable === true)
                    service.module.chartFromMembers(service, global_failures_detail, 'query_failures_detail', 'Bind, Global Query Failures Analysis', 'failures/s', 'failures', 'named.global_failures_detail', netdata.chartTypes.stacked, named.base_priority + 7, netdata.chartAlgorithms.incremental, 1, 1);

                if(default_enable === true)
                    service.module.chartFromMembers(service, r.nsstats, 'nsstats', 'Bind, Other Global Server Statistics', 'operations/s', 'other', 'named.nsstats', netdata.chartTypes.line, named.base_priority + 8, netdata.chartAlgorithms.incremental, 1, 1);

                // RecursClients chart
                id = 'named_' + service.name + '.recursive_clients';
                chart = named.charts[id];

                if(typeof chart === 'undefined') {
                    chart = {
                        id: id,                                         // the unique id of the chart
                        name: '',                                       // the unique name of the chart
                        title: service.name + ' Bind, Current Recursive Clients',       // the title of the chart
                        units: 'clients',                               // the units of the chart dimensions
                        family: 'clients',                              // the family of the chart
                        context: 'named.recursive_clients',             // the context of the chart
                        type: netdata.chartTypes.line,                  // the type of the chart
                        priority: named.base_priority + 1,              // the priority relative to others in the same family
                        update_every: service.update_every,             // the expected update frequency of the chart
                        dimensions: {
                            'clients': {
                                id: 'clients',                              // the unique id of the dimension
                                name: '',                                   // the name of the dimension
                                algorithm: netdata.chartAlgorithms.absolute,// the id of the netdata algorithm
                                multiplier: 1,                              // the multiplier
                                divisor: 1,                                 // the divisor
                                hidden: false                               // is hidden (boolean)
                            }
                        }
                    };

                    chart = service.chart(id, chart);
                    named.charts[id] = chart;
                }

                service.begin(chart);
                service.set('clients', RecursClients);
                service.end();
            }

            if(typeof r.opcodes !== 'undefined')
                service.module.chartFromMembers(service, r.opcodes, 'in_opcodes', 'Bind, Global Incoming Requests by OpCode', 'requests/s', 'requests', 'named.in_opcodes', netdata.chartTypes.stacked, named.base_priority + 9, netdata.chartAlgorithms.incremental, 1, 1);

            if(typeof r.qtypes !== 'undefined')
                service.module.chartFromMembers(service, r.qtypes, 'in_qtypes', 'Bind, Global Incoming Requests by Query Type', 'requests/s', 'requests', 'named.in_qtypes', netdata.chartTypes.stacked, named.base_priority + 10, netdata.chartAlgorithms.incremental, 1, 1);

            if(typeof r.sockstats !== 'undefined')
                service.module.chartFromMembers(service, r.sockstats, 'in_sockstats', 'Bind, Global Socket Statistics', 'operations/s', 'sockets', 'named.in_sockstats', netdata.chartTypes.line, named.base_priority + 11, netdata.chartAlgorithms.incremental, 1, 1);

            if(typeof r.views !== 'undefined') {
                keys = Object.keys(r.views);
                len = keys.length;
                while(len--) {
                    x = keys[len];
                    var resolver = r.views[x].resolver;

                    if(typeof resolver !== 'undefined') {
                        if(typeof resolver.stats !== 'undefined') {
                            var NumFetch = 0;
                            var key = service.name + '.' + x;
                            var rtt = {}, rtt_enable = false;
                            default_enable = false;

                            // NumFetch is an absolute value
                            if(typeof resolver.stats['NumFetch'] !== 'undefined') {
                                named.lookups.numfetch[key] = true;
                                NumFetch = resolver.stats['NumFetch'];
                                delete resolver.stats['NumFetch'];
                            }
                            if(typeof resolver.stats['BucketSize'] !== 'undefined') {
                                delete resolver.stats['BucketSize'];
                            }

                            // split the QryRTT* from the main chart
                            var ykeys = Object.keys(resolver.stats);
                            var ylen = ykeys.length;
                            while(ylen--) {
                                var y = ykeys[ylen];

                                // we maintain an index of the values found
                                // mapping them to objects splitted

                                look = named.lookups.resolver_stats[y];
                                if(typeof look === 'undefined') {
                                    if(y.match(/^QryRTT/) !== null) {
                                        named.lookups.resolver_stats[y] = {
                                            name: y,
                                            type: 'rtt'
                                        };
                                    }
                                    else {
                                        named.lookups.resolver_stats[y] = {
                                            name: y,
                                            type: 'default'
                                        };
                                    }

                                    look = named.lookups.resolver_stats[y];
                                    // netdata.error('lookup resolver stats value: ' + y + ' >>> ' + look.type);
                                }

                                switch(look.type) {
                                    case 'rtt': rtt[look.name] = resolver.stats[y]; delete resolver.stats[y]; rtt_enable = true; break;
                                    default: default_enable = true; break;
                                }
                            }

                            if(rtt_enable)
                                service.module.chartFromMembers(service, rtt, 'view_resolver_rtt_' + x, 'Bind, ' + x + ' View, Resolver Round Trip Timings', 'queries/s', 'view_' + x, 'named.resolver_rtt', netdata.chartTypes.stacked, named.base_priority + 12, netdata.chartAlgorithms.incremental, 1, 1);

                            if(default_enable)
                                service.module.chartFromMembers(service, resolver.stats, 'view_resolver_stats_' + x, 'Bind, ' + x + ' View, Resolver Statistics', 'operations/s', 'view_' + x, 'named.resolver_stats', netdata.chartTypes.line, named.base_priority + 13, netdata.chartAlgorithms.incremental, 1, 1);

                            // NumFetch chart
                            if(typeof named.lookups.numfetch[key] !== 'undefined') {
                                id = 'named_' + service.name + '.view_resolver_numfetch_' + x;
                                chart = named.charts[id];

                                if(typeof chart === 'undefined') {
                                    chart = {
                                        id: id,                                         // the unique id of the chart
                                        name: '',                                       // the unique name of the chart
                                        title: service.name + ' Bind, ' + x + ' View, Resolver Active Queries',     // the title of the chart
                                        units: 'queries',                               // the units of the chart dimensions
                                        family: 'view_' + x,                            // the family of the chart
                                        context: 'named.resolver_active_queries',       // the context of the chart
                                        type: netdata.chartTypes.line,                  // the type of the chart
                                        priority: named.base_priority + 1001,           // the priority relative to others in the same family
                                        update_every: service.update_every,             // the expected update frequency of the chart
                                        dimensions: {
                                            'queries': {
                                                id: 'queries',                              // the unique id of the dimension
                                                name: '',                                   // the name of the dimension
                                                algorithm: netdata.chartAlgorithms.absolute,// the id of the netdata algorithm
                                                multiplier: 1,                              // the multiplier
                                                divisor: 1,                                 // the divisor
                                                hidden: false                               // is hidden (boolean)
                                            }
                                        }
                                    };

                                    chart = service.chart(id, chart);
                                    named.charts[id] = chart;
                                }

                                service.begin(chart);
                                service.set('queries', NumFetch);
                                service.end();
                            }
                        }
                    }

                    if(typeof resolver.qtypes !== 'undefined')
                        service.module.chartFromMembers(service, resolver.qtypes, 'view_resolver_qtypes_' + x, 'Bind, ' + x + ' View, Requests by Query Type', 'requests/s', 'view_' + x, 'named.resolver_qtypes', netdata.chartTypes.stacked, named.base_priority + 14, netdata.chartAlgorithms.incremental, 1, 1);

                    //if(typeof resolver.cache !== 'undefined')
                    //  service.module.chartFromMembers(service, resolver.cache, 'view_resolver_cache_' + x, 'Bind, ' + x + ' View, Cache Entries', 'entries', 'view_' + x, 'named.resolver_cache', netdata.chartTypes.stacked, named.base_priority + 15, netdata.chartAlgorithms.absolute, 1, 1);

                    if(typeof resolver.cachestats['CacheHits'] !== 'undefined' && resolver.cachestats['CacheHits'] > 0) {
                        id = 'named_' + service.name + '.view_resolver_cachehits_' + x;
                        chart = named.charts[id];

                        if(typeof chart === 'undefined') {
                            chart = {
                                id: id,                                         // the unique id of the chart
                                name: '',                                       // the unique name of the chart
                                title: service.name + ' Bind, ' + x + ' View, Resolver Cache Hits',     // the title of the chart
                                units: 'operations/s',                          // the units of the chart dimensions
                                family: 'view_' + x,                            // the family of the chart
                                context: 'named.resolver_cache_hits',           // the context of the chart
                                type: netdata.chartTypes.area,                  // the type of the chart
                                priority: named.base_priority + 1100,           // the priority relative to others in the same family
                                update_every: service.update_every,             // the expected update frequency of the chart
                                dimensions: {
                                    'CacheHits': {
                                        id: 'CacheHits',                            // the unique id of the dimension
                                        name: 'hits',                               // the name of the dimension
                                        algorithm: netdata.chartAlgorithms.incremental,// the id of the netdata algorithm
                                        multiplier: 1,                              // the multiplier
                                        divisor: 1,                                 // the divisor
                                        hidden: false                               // is hidden (boolean)
                                    },
                                    'CacheMisses': {
                                        id: 'CacheMisses',                          // the unique id of the dimension
                                        name: 'misses',                             // the name of the dimension
                                        algorithm: netdata.chartAlgorithms.incremental,// the id of the netdata algorithm
                                        multiplier: -1,                             // the multiplier
                                        divisor: 1,                                 // the divisor
                                        hidden: false                               // is hidden (boolean)
                                    }
                                }
                            };

                            chart = service.chart(id, chart);
                            named.charts[id] = chart;
                        }

                        service.begin(chart);
                        service.set('CacheHits', resolver.cachestats['CacheHits']);
                        service.set('CacheMisses', resolver.cachestats['CacheMisses']);
                        service.end();
                    }

                    // this is wrong, it contains many types of info:
                    // 1. CacheHits, CacheMisses - incremental (added above)
                    // 2. QueryHits, QueryMisses - incremental
                    // 3. DeleteLRU, DeleteTTL - incremental
                    // 4. CacheNodes, CacheBuckets - absolute
                    // 5. TreeMemTotal, TreeMemInUse - absolute
                    // 6. HeapMemMax, HeapMemTotal, HeapMemInUse - absolute
                    //if(typeof resolver.cachestats !== 'undefined')
                    //  service.module.chartFromMembers(service, resolver.cachestats, 'view_resolver_cachestats_' + x, 'Bind, ' + x + ' View, Cache Statistics', 'requests/s', 'view_' + x, 'named.resolver_cache_stats', netdata.chartTypes.line, named.base_priority + 1001, netdata.chartAlgorithms.incremental, 1, 1);

                    //if(typeof resolver.adb !== 'undefined')
                    //  service.module.chartFromMembers(service, resolver.adb, 'view_resolver_adb_' + x, 'Bind, ' + x + ' View, ADB Statistics', 'entries', 'view_' + x, 'named.resolver_adb', netdata.chartTypes.line, named.base_priority + 1002, netdata.chartAlgorithms.absolute, 1, 1);
                }
            }
        }
    },

    // module.serviceExecute()
    // this function is called only from this module
    // its purpose is to prepare the request and call
    // netdata.serviceExecute()
    serviceExecute: function(name, a_url, update_every) {
        if(netdata.options.DEBUG === true) netdata.debug(this.name + ': ' + name + ': url: ' + a_url + ', update_every: ' + update_every);
        var service = netdata.service({
            name: name,
            request: netdata.requestFromURL(a_url),
            update_every: update_every,
            module: this
        });

        service.execute(this.processResponse);
    },

    configure: function(config) {
        var added = 0;

        if(this.enable_autodetect === true) {
            this.serviceExecute('local', 'http://localhost:8888/json/v1/server', this.update_every);
            added++;
        }
        
        if(typeof(config.servers) !== 'undefined') {
            var len = config.servers.length;
            while(len--) {
                if(typeof config.servers[len].update_every === 'undefined')
                    config.servers[len].update_every = this.update_every;

                this.serviceExecute(config.servers[len].name, config.servers[len].url, config.servers[len].update_every);
                added++;
            }
        }

        return added;
    },

    // module.update()
    // this is called repeatedly to collect data, by calling
    // netdata.serviceExecute()
    update: function(service, callback) {
        service.execute(function(serv, data) {
            service.module.processResponse(serv, data);
            callback();
        });
    }
};

module.exports = named;