package main

import (
  "fmt"
  "html/template"
  "io/ioutil"
  "os"
  "path/filepath"
  "strings"
  "time"

  "github.com/russross/blackfriday/v2"
)

// NavItem represents a link in the navigation menu
type NavItem struct {
  Title string
  URL   string
}

func main() {
  contentDir := "./content"
  outputDir := "./public"
  templateFile := "./templates/layout.html"

  tpl, err := parseTemplate(templateFile)
  if err != nil {
    fmt.Printf("Template parsing error: %v\n", err)
    return
  }

  files, err := readMarkdownFiles(contentDir)
  if err != nil {
    fmt.Printf("Failed to read content directory: %v\n", err)
    return
  }

  nav := buildNavigation(files)

  generatePages(files, contentDir, outputDir, tpl, nav)

  fmt.Println("✅ Site generation complete.")
}

func parseTemplate(templateFile string) (*template.Template, error) {
  return template.ParseFiles(templateFile)
}

func readMarkdownFiles(contentDir string) ([]os.FileInfo, error) {
  return ioutil.ReadDir(contentDir)
}

func buildNavigation(files []os.FileInfo) []NavItem {
  var nav []NavItem
  for _, file := range files {
    if filepath.Ext(file.Name()) == ".md" {
      title := strings.Title(strings.TrimSuffix(file.Name(), filepath.Ext(file.Name())))
      filename := strings.TrimSuffix(file.Name(), filepath.Ext(file.Name())) + ".html"
      nav = append(nav, NavItem{Title: title, URL: "/" + filename})
    }
  }
  return nav
}

func generatePages(files []os.FileInfo, contentDir, outputDir string, tpl *template.Template, nav []NavItem) {
  for _, file := range files {
    if filepath.Ext(file.Name()) == ".md" {
      mdPath := filepath.Join(contentDir, file.Name())
      mdContent, err := ioutil.ReadFile(mdPath)
      if err != nil {
        fmt.Printf("Failed to read %s: %v\n", file.Name(), err)
        continue
      }

      htmlContent := blackfriday.Run(mdContent)
      outFile := strings.TrimSuffix(file.Name(), filepath.Ext(file.Name())) + ".html"
      outPath := filepath.Join(outputDir, outFile)
      out, err := os.Create(outPath)
      if err != nil {
        fmt.Printf("Failed to create %s: %v\n", outPath, err)
        continue
      }

      data := map[string]interface{}{
        "Content": template.HTML(htmlContent),
        "Title":   strings.Title(strings.TrimSuffix(file.Name(), filepath.Ext(file.Name()))),
        "Nav":     nav,
        "Year":    time.Now().Year(),
      }

      err = tpl.Execute(out, data)
      if err != nil {
        fmt.Printf("Template execution failed for %s: %v\n", file.Name(), err)
        continue
      }

      fmt.Printf("Generated: %s\n", outPath)
    }
  }
}