package main

import (
	"bytes"
	"fmt"
	"math"
	"os"
	"os/exec"
	"sort"
	"text/template"
)

type Outter struct {
	MetaData    map[string]interface{} // 记录source/data下的所有文件
	Posts       []Post                 // 记录文章
	Pages       []Page                 // 记录页面
	Theme       Theme                  // 记录主题模板文件
	Config      Config                 // 全局配置
	Paginate    bool                   // 是否开启了分页
	PageTotal   int                    // 页面总数
	PageCurrent int                    // 当前分页
}

type PostOutter struct {
	Post   Post
	Config Config
}

type PageOutter struct {
	Page     Page
	Config   Config
	PostData []PostData
}

type PostData struct {
	Key   string
	Posts []Post
}

// check 检测目标
func (o *Outter) check() {
	if !isExist("./dist") {
		if err := mkdir("./dist"); err != nil {
			sfault("create dist directory failed: %v", err)
		}
	}

	if err := exec.Command("rm", "-rf", "./dist/*").Run(); err != nil {
		sfault("clear dist directory failed: %v", err)
	}
}

func (o *Outter) createDir(fp string) error {
	if !isExist(fp) {
		if err := mkdir(fp); err != nil {
			sfault("create %s directory failed: %v", fp, err)
		}
	}
	return nil
}

// sourceCopy 资源拷贝 将主题的资源拷贝到目标文件夹中
func (o *Outter) sourceCopy() {
	themePath := fmt.Sprintf("./themes/%s/", o.Config.Theme)
	destPath := "./dist/"
	cmd := exec.Command("cp", "-r", themePath+"css", destPath)
	if err := cmd.Run(); err != nil {
		sfault("copy theme css source failed: %v", err)
	}
	cmd = exec.Command("cp", "-r", themePath+"js", destPath)
	if err := cmd.Run(); err != nil {
		sfault("copy theme js source failed: %v", err)
	}
	cmd = exec.Command("cp", "-r", themePath+"images", destPath)
	if err := cmd.Run(); err != nil {
		sfault("copy theme images source failed: %v", err)
	}
}

// generate 文件生成
func (o *Outter) generate() {
	o.check()
	o.sourceCopy()
	o.generateIndex()
	o.generatePost()
	o.generatePage()
	o.generateArchives()
	o.generateTags()
}

var funcMap = template.FuncMap{
	"getSource": getSource,
	"add":       add,
	"sum":       sum,
}

// generateIndex 首页生成
func (o *Outter) generateIndex() {
	indexTemplate := template.New("index")

	funcMap["title"] = func() string {
		return o.Config.Title
	}

	indexTemplate.Funcs(funcMap)

	indexTemplate, err := indexTemplate.Parse(string(o.Theme.IndexLayout))
	if err != nil {
		sfault("parse index layout failed: %v", err)
	}

	// 首页文件
	var buffer = bytes.Buffer{}

	// 没开分页
	if !o.Config.Site.Paginate {
		err = indexTemplate.Execute(&buffer, o)
		if err != nil {
			sfault("generate index page failed: %v", err)
		}
		var filename = "./dist/index.html"
		if err := os.WriteFile(filename, buffer.Bytes(), os.ModePerm); err != nil {
			sfault("write index file failed: %v", err)
		}
		sout("index generate success...")
		return
	}

	// 分页数据不规范
	if o.Config.Site.PageSize < 1 {
		sfault("page size must > 1")
	}

	var pageSize = int(math.Ceil(float64(len(o.Posts)) / float64(o.Config.Site.PageSize)))
	o.PageTotal = pageSize
	o.Paginate = true
	var posts = make([]Post, len(o.Posts))
	copy(posts, o.Posts)
	for i := 0; i < pageSize; i++ {
		rightBorder := int(o.Config.Site.PageSize) * (i + 1)
		if rightBorder > len(posts) {
			rightBorder = len(posts)
		}
		leftBorder := int(o.Config.Site.PageSize) * (i)
		o.Posts = make([]Post, rightBorder-leftBorder)
		copy(o.Posts, posts[leftBorder:rightBorder])
		o.PageCurrent = i + 1

		err = indexTemplate.Execute(&buffer, o)
		if err != nil {
			sfault("generate index page failed: %v", err)
		}
		// 第一页 主页
		if i == 0 {
			// 第一次的时候创建目录
			dir := "./dist/page"
			if err := o.createDir(dir); err != nil {
				sfault("create index page failed: %v", err)
				return
			}
			var filename = "./dist/index.html"
			if err := os.WriteFile(filename, buffer.Bytes(), os.ModePerm); err != nil {
				sfault("write index file failed: %v", err)
			}
		}
		fPage := fmt.Sprintf("./dist/page/%d.html", i+1)
		if err := os.WriteFile(fPage, buffer.Bytes(), os.ModePerm); err != nil {
			sfault("write index file failed: %v", err)
		}
		buffer.Reset()
	}
	sout("index generate success...")
	o.Posts = make([]Post, len(posts))
	copy(o.Posts, posts)
}

func (o *Outter) generatePost() {
	postTemplate := template.New("post")
	var postBuffer = new(bytes.Buffer)
	for _, post := range o.Posts {
		instance := PostOutter{
			Post:   post,
			Config: o.Config,
		}
		funcMap["title"] = func() string {
			return instance.Post.Title
		}
		funcMap["post_name"] = func() string {
			return o.Config.Title
		}
		postTemplate.Funcs(funcMap)
		postTemplate, err := postTemplate.Parse(string(o.Theme.PostLayout))
		if err != nil {
			sfault("generate post page failed: %v", err)
		}
		// 入buffer
		if err := postTemplate.Execute(postBuffer, instance); err != nil {
			sfault("generate post page failed: %v", err)
		}
		// buffer写文件
		var catDir = fmt.Sprintf("./dist/%s", post.Category)
		if !isExist(catDir) {
			if err := mkdir(catDir); err != nil {
				sfault("create directory failed: %v", err)
			}
		}
		var filename = fmt.Sprintf("%s/%s.html", catDir, post.FileBasename)
		if err := os.WriteFile(filename, postBuffer.Bytes(), os.ModePerm); err != nil {
			sfault("write file failed: %v", err)
		}
		postBuffer.Reset()
	}

	sout("post generate success...")
}

func (o *Outter) generatePage() {
	pageTemplate := template.New("page")
	var pageBuffer = new(bytes.Buffer)
	for _, page := range o.Pages {
		instance := PageOutter{
			Page:   page,
			Config: o.Config,
		}
		funcMap["title"] = func() string {
			return page.Title
		}
		funcMap["page_name"] = func() string {
			return o.Config.Title
		}
		pageTemplate.Funcs(funcMap)
		pageTemplate, err := pageTemplate.Parse(string(o.Theme.PageLayout))
		if err != nil {
			sfault("generate page page failed: %v", err)
		}
		// 入buffer
		if err := pageTemplate.Execute(pageBuffer, instance); err != nil {
			sfault("generate page page failed: %v", err)
		}
		// buffer写文件
		var filename = fmt.Sprintf("./dist/%s.html", page.Link)
		if err := os.WriteFile(filename, pageBuffer.Bytes(), os.ModePerm); err != nil {
			sfault("write page content failed: %v", err)
		}
		pageBuffer.Reset()
	}

	sout("page generate success...")
}

func (o *Outter) generateArchives() {
	archiveTemplate := template.New("archive")
	var archiveBuffer = new(bytes.Buffer)
	// 按时间归档
	var m = make(map[string][]Post)
	for _, post := range o.Posts {
		newPost := post
		newPost.MD = ""
		m[int2String(post.CreatedAt.Year())] = append(m[int2String(post.CreatedAt.Year())], newPost)
	}

	var postData []PostData
	for year, posts := range m {
		postData = append(postData, PostData{
			Key:   year,
			Posts: posts,
		})
	}

	sort.Slice(postData, func(i, j int) bool {
		return postData[i].Key > postData[j].Key
	})

	var instance = PageOutter{
		Page: Page{
			Title: "Archives",
			Link:  "archives",
		},
		Config:   o.Config,
		PostData: postData,
	}
	funcMap["title"] = func() string {
		return instance.Page.Title
	}
	funcMap["page_name"] = func() string {
		return o.Config.Title
	}
	archiveTemplate.Funcs(funcMap)
	archiveTemplate, err := archiveTemplate.Parse(string(o.Theme.ArchiveLayout))
	if err != nil {
		sfault("generate archive page failed: %v", err)
	}

	// 入buffer
	if err := archiveTemplate.Execute(archiveBuffer, instance); err != nil {
		sfault("generate archive page failed: %v", err)
	}
	// buffer写文件
	var filename = fmt.Sprintf("./dist/%s.html", instance.Page.Link)
	if err := os.WriteFile(filename, archiveBuffer.Bytes(), os.ModePerm); err != nil {
		sfault("write archive page failed: %v", err)
	}
	archiveBuffer.Reset()

	sout("archives generate success...")
}

func (o *Outter) generateTags() {
	tagsTemplate := template.New("tags")
	var tagsBuffer = new(bytes.Buffer)

	// 按标签归档
	var mTag = make(map[string][]Post)
	for _, post := range o.Posts {
		for _, tag := range post.Tags {
			newPost := post
			newPost.MD = ""
			mTag[tag] = append(mTag[tag], newPost)
		}
	}

	for tag, posts := range mTag {
		// 按时间归档
		var m = make(map[string][]Post)
		for _, post := range posts {
			newPost := post
			newPost.MD = ""
			m[int2String(post.CreatedAt.Year())] = append(m[int2String(post.CreatedAt.Year())], newPost)
		}

		var postData []PostData
		for year, _posts := range m {
			postData = append(postData, PostData{
				Key:   year,
				Posts: _posts,
			})
		}

		sort.Slice(postData, func(i, j int) bool {
			return postData[i].Key > postData[j].Key
		})

		var instance = PageOutter{
			Page: Page{
				Title: tag,
				Link:  tag,
			},
			Config:   o.Config,
			PostData: postData,
		}

		funcMap["title"] = func() string {
			return instance.Page.Title
		}
		funcMap["page_name"] = func() string {
			return o.Config.Title
		}
		tagsTemplate.Funcs(funcMap)
		tagsTemplate, err := tagsTemplate.Parse(string(o.Theme.TagLayout))
		if err != nil {
			sfault("generate tags page failed: %v", err)
		}

		// 入buffer
		if err := tagsTemplate.Execute(tagsBuffer, instance); err != nil {
			sfault("generate tags page failed: %v", err)
		}
		// 创建tag文件夹
		var tagDir = "./dist/tags"
		if !isExist(tagDir) {
			if err := mkdir(tagDir); err != nil {
				sfault("create tag directory failed: %v", err)
			}
		}
		// buffer写文件
		var filename = fmt.Sprintf("%s/%s.html", tagDir, instance.Page.Link)
		if err := os.WriteFile(filename, tagsBuffer.Bytes(), os.ModePerm); err != nil {
			sfault("write tag content failed: %v", err)
		}
		tagsBuffer.Reset()
	}

	sout("tags generate success...")
}

func getSource(data interface{}, key string) interface{} {
	meta, ok := data.(map[string]interface{})
	if !ok {
		return nil
	}
	return meta[key]
}

func add(a, b int) int {
	return a + b
}

func sum(a, b int) int {
	return a - b
}