import { ifInline, matches } from '../utils'

import regex from '../regex'

import 'whatwg-fetch'

/**

* Takes the location name and returns the coordinates of that location using the Google

* Map API v3. This is an async function so it will return a promise.

* @param {string} location The name of any location

* @return {array} Returns an array in the form [latitude, longitude]

*/

function getCoordinate(location) {

let url = `http://maps.googleapis.com/maps/api/geocode/json?address=${location}&sensor=false`;

return new Promise((resolve) => {

fetch(url)

.then((data) => data.json())

.then((json) => resolve([json.results[0].geometry.location.lat, json.results[0].geometry.location.lng]))

})

}

/**

* Returns the template of the Map widget. The source of the iframe is based on whether the

* mode set in options is 'place', 'streetview' or 'view'.

* @param {string} match The matching string in the form of @(location name).

* @param {number} latitude Latitude of the location

* @param {number} longitude Longitude of the location

* @param {object} options plugin options

* @return {string} Template of the map widget.

*/

function template(match, latitude, longitude, options) {

const location = locationText(match);

return options.template.gmap(latitude, longitude, location, options);

}

/**

* Extracts out the location name from the format @(locationName)

* @param {string} match The string in the supported format. Eg : @(Delhi)

* @return {string} Only the location name removing @ and brackets. Eg: Delhi

*/

function locationText(match) {

return match.split('(')[1].split(')')[0]

}

export default class Gmap {

constructor(input, output, options, embeds) {

this.input = input;

this.output = output;

this.options = options;

this.embeds = embeds;

this.service = 'map';

this.regex = regex.gmap;

}

process() {

let match, promises = [],

allMatches = [];

while ((match = matches(this.regex, this.output)) !== null) {

this.options.served.push(match);

let promise = this.options.mapOptions.mode !== 'place' ? getCoordinate(match[0]) : Promise.resolve([null, null]);

promises.push(promise);

allMatches.push(match)

}

return new Promise((resolve) => {

Promise.all(promises).then((coordinatesArr) => {

for (var i in promises) {

let [latitude, longitude] = coordinatesArr[i];

let text = template((allMatches[i])[0], latitude, longitude, this.options);

if (ifInline(this.options, this.service)) {

this.output = this.output.replace(this.regex, (regexMatch) => {

return `<span class="ejs-location">${locationText(regexMatch)}</span>${text}`

})

} else {

this.embeds.push({

text: text,

index: allMatches[i][0].index

});

this.output = this.output.replace(this.regex, (regexMatch) => {

return `<span class="ejs-location">${locationText(regexMatch)}</span>`

});

}

}

resolve([this.output, this.embeds])

})

})

}

}