<template>
  <div class="vue-easymde" ref="easymdeRef">
    <textarea
      class="vue-simplemde-textarea"
      :name="name"
      :value="modelValue"
      @input="handleInput($event.target.value)"
    />
  </div>
</template>

<script setup lang="ts">
import {ref, watch, onMounted, onDeactivated, onBeforeUnmount, nextTick, shallowReactive} from 'vue'
import type { ShallowReactive } from 'vue'

import EasyMDE from 'easymde'
import {marked} from 'marked'

const props = defineProps({
	modelValue: String,
	name: String,
	previewClass: String,
	autoinit: {
		type: Boolean,
		default: true,
	},
	highlight: {
		type: Boolean,
		default: false,
	},
	sanitize: {
		type: Boolean,
		default: false,
	},
	configs: {
		type: Object,
		default: () => ({}),
	},
	previewRender: {
		type: Function,
	},
})

const emit = defineEmits(['update:modelValue', 'blur', 'initialized'])

const isValueUpdateFromInner = ref(false)
let easymde: ShallowReactive<EasyMDE> | undefined

onMounted(() => {
	if (props.autoinit) initialize()
})

onDeactivated(() => {
	if (!easymde) return
	const isFullScreen = easymde.codemirror.getOption('fullScreen')
	if (isFullScreen) easymde.toggleFullScreen()
})

onBeforeUnmount(() => {
	if (easymde) {
		easymde.toTextArea()
		easymde.cleanup()
		easymde = undefined
	}
})

const easymdeRef = ref<HTMLElement | null>(null)

function initialize() {
	const configs = Object.assign({
		element: easymdeRef.value?.firstElementChild,
		initialValue: props.modelValue,
		previewRender: props.previewRender,
		renderingConfig: {},
	}, props.configs)

	// Synchronize the values of value and initialValue
	if (configs.initialValue) {
		emit('update:modelValue', configs.initialValue)
	}

	// Determine whether to enable code highlighting
	if (props.highlight) {
		configs.renderingConfig.codeSyntaxHighlighting = true
	}

	// Set whether to render the input html
	marked.setOptions({ sanitize: props.sanitize })

	// Instantiated editor
	easymde = shallowReactive(new EasyMDE(configs))

	// Add a custom previewClass
	const className = props.previewClass || ''
	addPreviewClass(className)

	// Binding event
	bindingEvents()

	nextTick(() => emit('initialized', easymde))
}

function addPreviewClass(className: string) {
	const wrapper = easymde.codemirror.getWrapperElement()
	const preview = document.createElement('div')
	wrapper.nextSibling.className += ` ${className}`
	preview.className = `editor-preview ${className}`
	wrapper.appendChild(preview)
}

function bindingEvents() {
	easymde.codemirror.on('change', handleCodemirrorInput)
	easymde.codemirror.on('blur', handleCodemirrorBlur)
}

function handleCodemirrorInput(instance, changeObj)  {
	if (changeObj.origin === 'setValue') {
		return
	}
	const val = easymde.value()
	handleInput(val)
}

function handleCodemirrorBlur() {
	const val = easymde.value()
	isValueUpdateFromInner.value = true
	emit('blur', val)
}

function handleInput(val) {
	isValueUpdateFromInner.value = true
	emit('update:modelValue', val)
}

watch(
	() => props.modelValue,
	(val) => {
		if (isValueUpdateFromInner.value) {
			isValueUpdateFromInner.value = false
		} else {
			easymde.value(val)
		}
	},
)
</script>

<style lang="scss">
.EasyMDEContainer {
    display: block;
}

.EasyMDEContainer.sided--no-fullscreen {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
}

.EasyMDEContainer .CodeMirror {
    box-sizing: border-box;
    height: auto;
    border: 1px solid #ddd;
    border-bottom-left-radius: 4px;
    border-bottom-right-radius: 4px;
    padding: 10px;
    font: inherit;
    z-index: 0;
    word-wrap: break-word;
}

.EasyMDEContainer .CodeMirror-scroll {
    cursor: text;
}

.EasyMDEContainer .CodeMirror-fullscreen {
    background: #fff;
    position: fixed !important;
    top: 50px;
    left: 0;
    right: 0;
    bottom: 0;
    height: auto;
    z-index: 8;
    border-right: none !important;
    border-bottom-right-radius: 0 !important;
}

.EasyMDEContainer .CodeMirror-sided {
    width: 50% !important;
}

.EasyMDEContainer.sided--no-fullscreen .CodeMirror-sided {
    border-right: none!important;
    border-bottom-right-radius: 0px;
    position: relative;
    flex: 1 1 auto;
}

.EasyMDEContainer .CodeMirror-placeholder {
    opacity: .5;
}

.EasyMDEContainer .CodeMirror-focused .CodeMirror-selected {
    background: #d9d9d9;
}

.editor-toolbar {
    position: relative;
    user-select: none;
    padding: 9px 10px;
    border-top: 1px solid #bbb;
    border-left: 1px solid #bbb;
    border-right: 1px solid #bbb;
    border-top-left-radius: 4px;
    border-top-right-radius: 4px;
}

.editor-toolbar.fullscreen {
    width: 100%;
    height: 50px;
    padding-top: 10px;
    padding-bottom: 10px;
    box-sizing: border-box;
    background: #fff;
    border: 0;
    position: fixed;
    top: 0;
    left: 0;
    opacity: 1;
    z-index: 9;
}

.editor-toolbar.fullscreen::before {
    width: 20px;
    height: 50px;
    background: linear-gradient(to right, rgba(255, 255, 255, 1) 0%, rgba(255, 255, 255, 0) 100%);
    position: fixed;
    top: 0;
    left: 0;
    margin: 0;
    padding: 0;
}

.editor-toolbar.fullscreen::after {
    width: 20px;
    height: 50px;
    background: linear-gradient(to right, rgba(255, 255, 255, 0) 0%, rgba(255, 255, 255, 1) 100%);
    position: fixed;
    top: 0;
    right: 0;
    margin: 0;
    padding: 0;
}

.EasyMDEContainer.sided--no-fullscreen .editor-toolbar {
    width: 100%;
}

.editor-toolbar button, .editor-toolbar .easymde-dropdown {
    background: transparent;
    display: inline-block;
    text-align: center;
    text-decoration: none !important;
    height: 30px;
    margin: 0;
    padding: 0;
    border: 1px solid transparent;
    border-radius: 3px;
    cursor: pointer;
}

.editor-toolbar button {
    width: 30px;
}

.editor-toolbar button.active,
.editor-toolbar button:hover {
    background: #fcfcfc;
    border-color: #95a5a6;
}

.editor-toolbar i.separator {
    display: inline-block;
    width: 0;
    border-left: 1px solid #d9d9d9;
    border-right: 1px solid #fff;
    color: transparent;
    text-indent: -10px;
    margin: 0 6px;
}

.editor-toolbar button:after {
    font-family: Arial, "Helvetica Neue", Helvetica, sans-serif;
    font-size: 65%;
    vertical-align: text-bottom;
    position: relative;
    top: 2px;
}

.editor-toolbar button.heading-1:after {
    content: "1";
}

.editor-toolbar button.heading-2:after {
    content: "2";
}

.editor-toolbar button.heading-3:after {
    content: "3";
}

.editor-toolbar button.heading-bigger:after {
    content: "▲";
}

.editor-toolbar button.heading-smaller:after {
    content: "▼";
}

.editor-toolbar.disabled-for-preview button:not(.no-disable) {
    opacity: .6;
    pointer-events: none;
}

@media only screen and (max-width: 700px) {
    .editor-toolbar i.no-mobile {
        display: none;
    }
}

.editor-statusbar {
    padding: 8px 10px;
    font-size: 12px;
    color: #959694;
    text-align: right;
}

.EasyMDEContainer.sided--no-fullscreen .editor-statusbar {
    width: 100%;
}

.editor-statusbar span {
    display: inline-block;
    min-width: 4em;
    margin-left: 1em;
}

.editor-statusbar .lines:before {
    content: 'lines: '
}

.editor-statusbar .words:before {
    content: 'words: '
}

.editor-statusbar .characters:before {
    content: 'characters: '
}

.editor-preview-full {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: 7;
    overflow: auto;
    display: none;
    box-sizing: border-box;
}

.editor-preview-side {
    position: fixed;
    bottom: 0;
    width: 50%;
    top: 50px;
    right: 0;
    z-index: 9;
    overflow: auto;
    display: none;
    box-sizing: border-box;
    border: 1px solid #ddd;
    word-wrap: break-word;
}

.editor-preview-active-side {
    display: block
}

.EasyMDEContainer.sided--no-fullscreen .editor-preview-active-side {
    flex: 1 1 auto;
    height: auto;
    position: static;
}

.editor-preview-active {
    display: block
}

.editor-preview {
    padding: 10px;
    background: #fafafa;
}

.editor-preview > p {
    margin-top: 0
}

.editor-preview pre {
    background: #eee;
    margin-bottom: 10px;
}

.editor-preview table td,
.editor-preview table th {
    border: 1px solid #ddd;
    padding: 5px;
}

.cm-s-easymde .cm-tag {
    color: #63a35c;
}

.cm-s-easymde .cm-attribute {
    color: #795da3;
}

.cm-s-easymde .cm-string {
    color: #183691;
}

.cm-s-easymde .cm-header-1 {
    font-size: 200%;
    line-height: 200%;
}

.cm-s-easymde .cm-header-2 {
    font-size: 160%;
    line-height: 160%;
}

.cm-s-easymde .cm-header-3 {
    font-size: 125%;
    line-height: 125%;
}

.cm-s-easymde .cm-header-4 {
    font-size: 110%;
    line-height: 110%;
}

.cm-s-easymde .cm-comment {
    background: rgba(0, 0, 0, .05);
    border-radius: 2px;
}

.cm-s-easymde .cm-link {
    color: #7f8c8d;
}

.cm-s-easymde .cm-url {
    color: #aab2b3;
}

.cm-s-easymde .cm-quote {
    color: #7f8c8d;
    font-style: italic;
}

.editor-toolbar .easymde-dropdown {
    position: relative;
    background: linear-gradient(to bottom right, #fff 0%, #fff 84%, #333 50%, #333 100%);
    border-radius: 0;
    border: 1px solid #fff;
}

.editor-toolbar .easymde-dropdown:hover {
    background: linear-gradient(to bottom right, #fff 0%, #fff 84%, #333 50%, #333 100%);
}

.easymde-dropdown-content {
    display: block;
    visibility: hidden;
    position: absolute;
    background-color: #f9f9f9;
    box-shadow: 0 8px 16px 0 rgba(0, 0, 0, 0.2);
    padding: 8px;
    z-index: 2;
    top: 30px;
}

.easymde-dropdown:active .easymde-dropdown-content,
.easymde-dropdown:focus .easymde-dropdown-content {
    visibility: visible;
}

span[data-img-src]::after{
    content: '';
    background-image: var(--bg-image);
    display: block;
    max-height: 100%;
    max-width: 100%;
    background-size: contain;
    height: 0;
    padding-top: var(--height);
    width: var(--width);
    background-repeat: no-repeat;
}
</style>

<style lang="scss" scoped>
.vue-easymde .markdown-body {
	padding: 0.5em
}

.vue-easymde .editor-preview-active,
.vue-easymde .editor-preview-active-side {
	display: block;
}
</style>
