import * as util from './utils.js'

// emojis:

// javascript: a string escape: "\u{1-6 Ns}" where N is a hex digit

// or String.fromCodePoint(codePoint)

// html: an entity: &....; where ... is text, decimal or hex number

// ©: © © © "&#..." decimal, "&#x..."

// ↣: ↣ ↣ ↣

// Lion: <no text> &#129409; &#x1F981;

// Good emoji list: https://www.w3schools.com/charsets/ref_emoji.asp

//

// examples:

// In html: <p>&copy; &#129409; &#x1F981; </p>

// In javascript: console.log("\u{1F981}", String.fromCodePoint(0x1F981))

const defaultSize = 100

export function emoji2ctx(codePoint, size = defaultSize) {

}

export function emoji2can(codePoint, size = defaultSize) {

const ctx = emoji2ctx(codePoint, size)

return ctx.canvas

}

export function downloadEmoji(

}

// ============ emojis, codePoints & codeUnits ============

// Here we convert between numbers (codePoints) and emojis.

// Emojis are simply utf16 strings. CodePoints are numbers up to 32 bits

// We often use the hex form of codePoints due to emoji docs using hex

// Ex: for U+1F469 we would use 0x1F469 for the codePoint

// For codePoints > 16 bits, emojis create two 16 bit "surrogate pairs" codeUnits

// High-surrogate codeUnits takes values from range 0xD800 to 0xDBFF

// Low-surrogate codeUnits takes values from range 0xDC00 to 0xDFFF

// You seldom need to use the codeUnits, just recognise them

export const emoji2codePoint = emoji => emoji.codePointAt(0)

export const codePoint2emoji = codePoint => String.fromCodePoint(codePoint)

// Note "\u{1F469}" will also create an emoji using a unicode \ escape string

// HTML uses a different syntax, "entities", for emojis. See initial notes.

export const text2entity = text => `&${text};`

export const int2entity = int => `&#${int};`

export const hex2entity = hex => `&#x${hex.toString(16).toUpperCase()};`

// It is possible to have several emojies combine to create a single emoji

// Paste this into the browser's console: 2 folks and a heart!

// "\u{1F469}\u{200D}\u{2764}\u{FE0F}\u{200D}\u{1F48B}\u{200D}\u{1F468}"

// In html:

// <p>&#9757;&#127999; Dark</p>

// creates a hand with a skin tone

// See: https://unicode.org/emoji/charts/emoji-zwj-sequences.html

// Both arrays can be used by JS or HTML via codePoints2emoji or codePoints2entity

// [0x261D, 0x1F3FC]

// [0x1F469, 0x200D, 0x2764, 0xFE0F, 0x200D, 0x1F48B, 0x200D, 0x1F468]

export function codePoints2emoji(array) {

return array.map(point => codePoint2emoji(point)).join('')

}

export function codePoints2entity(array) {

return array.map(point => hex2entity(point)).join('')

}

// let foo = codePoints2emoji([0x261d, 0x1f3ff])

// foo => '☝🏿'

// and foo.length = 3! The first emoji needs only 16 bits while the 2nd 32, or 2 codeUnits

// This: [0x1F469, 0x200D, 0x2764, 0xFE0F, 0x200D, 0x1F48B, 0x200D, 0x1F468]

// produces '👩‍❤️‍💋‍👨' with a length of 11, 8 codePoints with 3 large (32 bit) ones