suttacentral-api/src/sutta-central-id.js

SuttaCentral API cached proxy

(function(exports) {
    const fs = require('fs');
    const path = require('path');
    const { logger, } = require('log-instance');
    const SRC_PATH = __dirname;
    const UID_EXPANSION_PATH = path.join(SRC_PATH, 'uid_expansion.json');
    const SUTTAIDS_PATH = path.join(SRC_PATH, 'sutta-ids.json');

    var suttaIds;
    var uid_expansion;

    class SuttaCentralId { 
        constructor(scid=null) {
            this.scid = scid;
        }

        static initialize(){
            if (suttaIds) {
                return;
            }
            if (fs.existsSync(SUTTAIDS_PATH)) {
                logger.info(`SuttaCentralId.initialize() loading:${SUTTAIDS_PATH}`);
                suttaIds = JSON.parse(fs.readFileSync(SUTTAIDS_PATH))
                    .sort(SuttaCentralId.compareLow);
            }
            if (fs.existsSync(UID_EXPANSION_PATH)) {
                logger.info(`SuttaCentralId.initialize() loading:${UID_EXPANSION_PATH}`);
                uid_expansion = JSON.parse(fs.readFileSync(UID_EXPANSION_PATH));
            }
        }

        static get supportedSuttas() {
            SuttaCentralId.initialize();
            return suttaIds;
        }

        static normalizeSuttaId(id) {
            SuttaCentralId.initialize();
            if (typeof id !== 'string') {
                if (id.scid) {
                    id = id.scid;
                } else {
                    throw new Error(`expected string:${JSON.stringify(id)}`);
                }
            }
            id = id.trim();
            var sutta_uid = null;
            if (/[^0-9][1-9]/.test(id)) {
                var tokens = id.toLowerCase().split(' ');
                if (tokens.length > 1) {
                    var matches = uid_expansion.filter(ue => 
                        0 === ue.acro.toLowerCase().localeCompare(tokens[0]));
                    if (matches.length > 0) {
                        sutta_uid = `${matches[0].uid}${tokens.slice(1).join('')}`;
                    }
                }
                sutta_uid = sutta_uid || id;
            }
            sutta_uid = sutta_uid && suttaIds.filter(sid => {
                return SuttaCentralId.compareLow(sid, sutta_uid) <= 0 &&
                    0 <= SuttaCentralId.compareHigh(sid, sutta_uid);
            })[0] || sutta_uid;
            return sutta_uid;
        }

        static scidRegExp(pat) {
            if (!pat) {
                return /.*/;
            }

            var pat = pat.replace(/\./g, "\\.");
            var pat = pat.replace(/\*/g, ".*");
            var pat = pat.replace(/\?/g, ".");
            var pat = pat.replace(/[$^]/g, "\\$&");
            return new RegExp(pat);
        }

        static compareLow(a,b) {
            var aprefix = a.substring(0,a.search(/[0-9]/));
            var bprefix = b.substring(0,b.search(/[0-9]/));
            var cmp = aprefix.localeCompare(bprefix);
            if (cmp === 0) {
                var adig = a.replace(/[^0-9]*([0-9]*.?[0-9]*).*/,"$1").split('.');
                var bdig = b.replace(/[^0-9]*([0-9]*.?[0-9]*).*/,"$1").split('.');
                var cmp = Number(adig[0]) - Number(bdig[0]);
                if (cmp === 0 && adig.length>1 && bdig.length>1) {
                    cmp = Number(adig[1]) - Number(bdig[1]);
                }
            }
            return cmp;
        }

        static compareHigh(a,b) {
            var aprefix = a.substring(0,a.search(/[0-9]/));
            var bprefix = b.substring(0,b.search(/[0-9]/));
            var cmp = aprefix.localeCompare(bprefix);
            if (cmp === 0) {
                var adig = a.replace(/[0-9]+-/ug,'')
                    .replace(/[^0-9]*([0-9]+)/,"$1")
                    .split('.');
                var bdig = b.replace(/[0-9]+-/ug,'')
                    .replace(/[^0-9]*([0-9]+)/,"$1")
                    .split('.');
                var cmp = Number(adig[0]) - Number(bdig[0]);
                if (cmp === 0) {
                    var alast = Number(adig[adig.length-1]);
                    var blast = Number(bdig[bdig.length-1]);
                    cmp = alast - blast;
                }
            }
            return cmp;
        }

        get groups() {
            var tokens = this.scid && this.scid.split(':');
            return tokens && tokens[1] ? tokens[1].split('.') : null;
        }

        get sutta() {
            return this.scid && this.scid.split(':')[0] ;
        }

        get parent() {
            var groups = this.groups;
            if (groups == null) {
                return new SuttaCentralId();
            }
            !groups.pop() && groups.pop();
            if (groups.length === 0) {
                return new SuttaCentralId(`${this.sutta}:`);
            }
            return new SuttaCentralId(`${this.sutta}:${groups.join('.')}.`);
        }

        toString() {
            return this.scid;
        }

    }

    module.exports = exports.SuttaCentralId = SuttaCentralId;
})(typeof exports === "object" ? exports : (exports = {}));