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'use strict';
const chToPath = require('./ch-to-path');
const random = require('./random');
const optionMngr = require('./option-manager');
const opts = optionMngr.options;
const getLineNoise = function (width, height, options) {
const hasColor = options.color;
const noiseLines = [];
const min = options.inverse ? 7 : 1;
const max = options.inverse ? 15 : 9;
let i = -1;
while (++i < options.noise) {
const start = `${random.int(1, 21)} ${random.int(1, height - 1)}`;
const end = `${random.int(width - 21, width - 1)} ${random.int(1, height - 1)}`;
const mid1 = `${random.int((width / 2) - 21, (width / 2) + 21)} ${random.int(1, height - 1)}`;
const mid2 = `${random.int((width / 2) - 21, (width / 2) + 21)} ${random.int(1, height - 1)}`;
const color = hasColor ? random.color() : random.greyColor(min, max);
noiseLines.push(`<path d="M${start} C${mid1},${mid2},${end}" stroke="${color}" fill="none"/>`);
}
return noiseLines;
};
const getText = function (text, width, height, options) {
const len = text.length;
const spacing = (width - 2) / (len + 1);
const min = options.inverse ? 10 : 0;
const max = options.inverse ? 14 : 4;
let i = -1;
const out = [];
while (++i < len) {
const x = spacing * (i + 1);
const y = height / 2;
const charPath = chToPath(text[i], Object.assign({x, y}, options));
const color = options.color ?
random.color(options.background) : random.greyColor(min, max);
out.push(`<path fill="${color}" d="${charPath}"/>`);
}
return out;
};
const createCaptcha = function (text, options) {
text = text || random.captchaText();
options = Object.assign({}, opts, options);
const width = options.width;
const height = options.height;
const bg = options.background;
if (bg) {
options.color = true;
}
const bgRect = bg ?
`<rect width="100%" height="100%" fill="${bg}"/>` : '';
const paths =
[].concat(getLineNoise(width, height, options))
.concat(getText(text, width, height, options))
.sort(() => Math.random() - 0.5)
.join('');
const start = `<svg xmlns="http://www.w3.org/2000/svg" width="${width}" height="${height}" viewBox="0,0,${width},${height}">`;
const xml = `${start}${bgRect}${paths}</svg>`;
return xml;
};
const create = function (options) {
const text = random.captchaText(options);
const data = createCaptcha(text, options);
return {text, data};
};
const createMathExpr = function (options) {
const expr = random.mathExpr(options.mathMin, options.mathMax, options.mathOperator);
const text = expr.text;
const data = createCaptcha(expr.equation, options);
return {text, data};
};
module.exports = createCaptcha;
module.exports.randomText = random.captchaText;
module.exports.create = create;
module.exports.createMathExpr = createMathExpr;
module.exports.options = opts;
module.exports.loadFont = optionMngr.loadFont;