/* Copyright 2021 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

const measurementPattern = /([+-]?)([0-9]+\.?[0-9]*)(.*)/;

function getInteger({ data, defaultValue, validate }) {
  if (!data) {
    return defaultValue;
  }
  data = data.trim();
  const n = parseInt(data, 10);
  if (!isNaN(n) && validate(n)) {
    return n;
  }
  return defaultValue;
}

function getFloat({ data, defaultValue, validate }) {
  if (!data) {
    return defaultValue;
  }
  data = data.trim();
  const n = parseFloat(data);
  if (!isNaN(n) && validate(n)) {
    return n;
  }
  return defaultValue;
}

function getKeyword({ data, defaultValue, validate }) {
  if (!data) {
    return defaultValue;
  }
  data = data.trim();
  if (validate(data)) {
    return data;
  }
  return defaultValue;
}

function getStringOption(data, options) {
  return getKeyword({
    data,
    defaultValue: options[0],
    validate: k => options.includes(k),
  });
}

function getMeasurement(str, def = "0") {
  def = def || "0";
  if (!str) {
    return getMeasurement(def);
  }
  const match = str.trim().match(measurementPattern);
  if (!match) {
    return getMeasurement(def);
  }
  const [, sign, valueStr, unit] = match;
  const value = parseFloat(valueStr);
  if (isNaN(value)) {
    return getMeasurement(def);
  }
  return {
    value: sign === "-" ? -value : value,
    unit: unit || "pt",
  };
}

function getRatio(data) {
  if (!data) {
    return { num: 1, den: 1 };
  }
  const ratio = data
    .trim()
    .split(/\s*:\s*/)
    .map(x => parseFloat(x))
    .filter(x => !isNaN(x));
  if (ratio.length === 1) {
    ratio.push(1);
  }

  if (ratio.length === 0) {
    return { num: 1, den: 1 };
  }

  const [num, den] = ratio;
  return { num, den };
}

function getRelevant(data) {
  if (!data) {
    return [];
  }
  return data
    .trim()
    .split(/\s+/)
    .map(e => {
      return {
        excluded: e[0] === "-",
        viewname: e.substring(1),
      };
    });
}

function getColor(data, def = [0, 0, 0]) {
  let [r, g, b] = def;
  if (!data) {
    return { r, g, b };
  }
  const color = data
    .trim()
    .split(/\s*,\s*/)
    .map(c => Math.min(Math.max(0, parseInt(c.trim(), 10)), 255))
    .map(c => (isNaN(c) ? 0 : c));

  if (color.length < 3) {
    return { r, g, b };
  }

  [r, g, b] = color;
  return { r, g, b };
}

function getBBox(data) {
  const def = getMeasurement("-1");
  if (!data) {
    return { x: def, y: def, width: def, height: def };
  }
  const bbox = data
    .trim()
    .split(/\s*,\s*/)
    .map(m => getMeasurement(m, "-1"));
  if (bbox.length < 4 || bbox[2].value < 0 || bbox[3].value < 0) {
    return { x: def, y: def, width: def, height: def };
  }

  const [x, y, width, height] = bbox;
  return { x, y, width, height };
}

export {
  getBBox,
  getColor,
  getFloat,
  getInteger,
  getKeyword,
  getMeasurement,
  getRatio,
  getRelevant,
  getStringOption,
};