package main

import (
	"fmt"
	"os"
	"sort"
	"strings"
	"text/template"
)

type (
	blogData struct {
		Date        string
		Title       string
		URL         string
		Text        string
		Attachments []string
	}
)

func generateBlog() {
	fmt.Println("Generating blog page...")
	blogDataSlice := generateBlogPage()
	fmt.Println("Generating blog posts...")
	generateBlogPosts(blogDataSlice)
}

func generateBlogPage() []blogData {
	// open blog dir
	blogDir, err := os.Open("blog")
	if err != nil {
		fmt.Printf("ERROR opening blog dir: %s\n", err)
	}
	// read blog dir list
	postDirList, err := blogDir.Readdirnames(0)
	if err != nil {
		fmt.Printf("ERROR reading blog list: %s\n", err)
	}

	// sort in reverse to show latest post first
	sort.Sort(sort.Reverse(sort.StringSlice(postDirList)))

	var blogDataSlice []blogData
	// separate date and title in struct
	for _, post := range postDirList {
		fmt.Println(post)
		blogDataSlice = append(blogDataSlice, blogData{
			Date:  post[:10],
			Title: post[11:],
			URL: "blog/" +
				strings.ToLower(strings.ReplaceAll(post, " ", "-")),
		})
	}

	// template
	tpl, err := template.ParseFiles("templates/blogposts.gotmpl")
	if err != nil {
		fmt.Printf("ERROR creating template: %s\n", err)
	}

	f, err := os.Create("html/blog.html")
	if err != nil {
		fmt.Printf("ERROR creating html: %s\n", err)
		panic(1)
	}

	err = tpl.ExecuteTemplate(f, "blogposts.gotmpl", blogDataSlice)
	if err != nil {
		fmt.Printf("ERROR executing template: %s\n", err)
	}

	return blogDataSlice
}

func generateBlogPosts(blogDataSlice []blogData) {
	for _, post := range blogDataSlice {
		content, err := os.ReadFile(
			"blog/" + post.Date + " " + post.Title + "/post.txt")
		if err != nil {
			fmt.Printf("ERROR reading post file: %s\n", err)
		}
		post.Text = string(content)
		post.Text = strings.ReplaceAll(post.Text, "\n", "<br>")

		tpl, err := template.ParseFiles("templates/blogpost.gotmpl")
		if err != nil {
			fmt.Printf("ERROR creating template: %s\n", err)
		}

		f, err := os.Create("html/" + post.URL + ".html")
		if err != nil {
			fmt.Printf("ERROR creating html: %s\n", err)
			panic(1)
		}

		err = tpl.ExecuteTemplate(f, "blogpost.gotmpl", post)
		if err != nil {
			fmt.Printf("ERROR executing template: %s\n", err)
		}
	}
}