<template>
    <Split v-model="split" min="5px">
        <template #left>
            <div class="split-left" :class="hiddenSplitLeft">
                <LeftSidebar v-model:rootFolderPath="rootFolderPath" v-model:currentFilePath="currentFilePath">
                </LeftSidebar>
            </div>
        </template>
        <template #trigger>
            <div ref="splitTrigger" class="split-trigger"></div>
        </template>
        <template #right>
            <div ref="splitRight" class="split-right">
                <MainEditor ref="mainEditor" v-model:markdownCode="markdownCode"
                    v-model:leftSidebarState="leftSidebarState" :save="writeFileContent">
                </MainEditor>
            </div>
        </template>
    </Split>
</template>

<script setup>
import LeftSidebar from './components/LeftSidebar.vue'
import MainEditor from './components/MainEditor.vue'
import { ref, watch, useTemplateRef, nextTick, onMounted, onUnmounted } from "vue";
import { invoke } from "@tauri-apps/api/core";
import { readTextFile, writeTextFile, exists } from '@tauri-apps/plugin-fs';
import { Message } from 'view-ui-plus'

// 原始示例数据，仅供参考
const greetMsg = ref("");
const name = ref("");
async function greet() {
    // Learn more about Tauri commands at https://tauri.app/develop/calling-rust/
    greetMsg.value = await invoke("greet", { name: name.value });
}

// 使用 Split 组件动态控制页面左右布局
const defaultSplit = 0.15; // 默认左侧边栏和右侧区域的比例为 1.5:8.5
const split = ref(defaultSplit);
const splitTrigger = useTemplateRef('splitTrigger');
const splitRight = useTemplateRef('splitRight');
const splitRightWidth = ref(0);
const hiddenSplitLeft = ref('');
const leftSidebarState = ref('open');
watch(split, (newSplit) => {
    splitRightWidth.value = splitRight.value.offsetWidth;
    // 当 split 小于某个值时，隐藏左边布局
    if (newSplit < 0.05) {
        leftSidebarState.value = 'close';
        if (hiddenSplitLeft.value == '') {
            hiddenSplitLeft.value = 'hidden';
        }
    } else {
        leftSidebarState.value = 'open';
        if (hiddenSplitLeft.value == 'hidden') {
            hiddenSplitLeft.value = '';
        }
    }
})
watch(leftSidebarState, (state) => {
    if (state == 'open') {
        split.value = defaultSplit;
    } else {
        split.value = 0;
    }
})

// 监听根目录路径。如果之前已经选过目录，初始界面直接加载该目录
const rootFolderPath = ref(localStorage.getItem('rootPathOfFolderTree') || "");
watch(rootFolderPath, (newRootPath) => {
    localStorage.setItem('rootPathOfFolderTree', newRootPath);
})

// <FolderTree> 完成文件树渲染后，点击文件得到 currentFilePath
const currentFilePath = ref(localStorage.getItem('currentSelectedFilePath') || "");
// 读取 currentFilePath 的文件内容，填充到 MarkdownEditor 之中
watch(currentFilePath, async (newFilePath) => {
    localStorage.setItem('currentSelectedFilePath', newFilePath);
    await readFileContent(newFilePath);
})

const mainEditor = ref(null);
const markdownCode = ref("# Hello Markdown");
watch(markdownCode, (newMarkdownCode) => {
    console.log("code be updated");
})
async function readFileContent(filePath) {
    try {
        let fileContent = '';
        if (window.__TAURI_INTERNALS__ === undefined) {
            fileContent = "# this is " + filePath;
        } else {
            fileContent = await readTextFile(filePath);
        }
        markdownCode.value = fileContent;
        currentFilePath.value = filePath;
        Message.success('已读取文件内容，并加载到编辑器中:' + filePath);
    } catch (err) {
        Message.error('文件读取失败:' + err);
    }
}
async function writeFileContent(markdownCode) {
    // 如果未选择任何文件，则不触发写文件事件
    if (currentFilePath.value.length == 0) {
        Message.warning('当前编辑器暂未关联目标文件，请在左侧打开目录并选择一个文件')
        return;
    }
    try {
        if (window.__TAURI_INTERNALS__ === undefined) {
            // TODO 调用接口更新 currentFilePath 文件内容
            Message.warning('暂未实现接口');
        } else {
            const exist = await exists(currentFilePath.value);
            if (!exist) {
                throw new Error(currentFilePath.value + " 文件不存在.");
            }
            await writeTextFile(currentFilePath.value, markdownCode);
        }
        Message.success('文件更新成功:' + currentFilePath.value);
    } catch (err) {
        Message.error('文件更新失败:' + err);
    }
}

const resizeHandler = () => {
    // splitRight 的宽度为视口宽度右边百分比，再减去 splitTrigger 的宽度
    splitRightWidth.value = window.innerWidth * (1 - split.value) - splitTrigger.value.offsetWidth;
}
onMounted(async () => {
    // 使用 nextTick 确保页面组件已完成挂载和渲染
    await nextTick();
    resizeHandler();
    // 监听页面宽度和高度，调整 markdown 编辑器的高宽度
    window.addEventListener('resize', resizeHandler);
    // 打开上一次选择的文件的内容
    if (currentFilePath.value.length > 0) {
        await readFileContent(currentFilePath.value);
    }
});
onUnmounted(() => {
    window.removeEventListener('resize', resizeHandler);
});
</script>

<style>
body {
    overflow: hidden;
    /* 禁用所有方向滚动 */
}

.split-left {
    height: 100vh;
    border-right: 1px solid #dcdee2;
    overflow-x: hidden;
    overflow-y: auto;
    scrollbar-width: none;
}

.split-trigger {
    width: 2px;
    height: 100vh;
    background-color: #e6e6e6;
}

.split-trigger:hover {
    cursor: ew-resize;
}

.split-right {
    margin-left: 2px;
}

.hidden {
    display: none;
}
</style>
