/**
 * kw
 * @author oldj
 * @blog http://oldj.net
 */

'use strict';

function kw2re(kw) {
    // 模糊搜索
    let r;
    let m;
    let flag = [];

    if (kw === '/') {
        return;
    } else if ((m = kw.match(/^\/([^\/]+)\/?(\w*)$/))) {
        if (m[2].indexOf('i') > -1) {
            flag.push('i');
        }
        // if (m[2].indexOf('g') > -1) {
        flag.push('g');
        // }
        try {
            r = new RegExp(m[1], flag.join(''));
        } catch (e) {
        }
    } else if (kw.indexOf('*') > -1) {
        try {
            r = new RegExp(kw.replace(/\*/g, '.*'), 'ig');
        } catch (e) {
        }
    }

    return r;
}

exports.findPositions = function (kw, code) {
    if (!kw || kw === '/') return;

    let r = kw2re(kw);
    if (!r) {
        try {
            r = new RegExp(kw
                    .replace(/([\.\?\*\+\^\$\(\)\-\[\]\{\}])/g, '\\$1')
                , 'ig');
        } catch (e) {
            console.log(e);
            return;
        }
    }
    let indexes = [];

    let lines = code.split('\n');

    lines.map((ln, idx) => {
        let match;
        let max_loop = 30;
        while (match = r.exec(ln)) {
            indexes.push([
                {line: idx, ch: match.index},
                {line: idx, ch: match.index + match[0].length},
            ]);
            max_loop--;
            if (max_loop < 0) break;
        }
    });

    return indexes;
};

exports.kw2re = kw2re;