package main

import (
	"flag"
	"fmt"
	"html/template"
	"os"
	"path/filepath"
	"sort"
	"strings"
)

type IndexData struct {
	Dir      string
	Files    []FileEntry
	RootURL  string
}

type FileEntry struct {
	Name string
	URL  string
}

func generateIndex(dir string, rootURL string) error {
	entries, err := os.ReadDir(dir)
	if err != nil {
		return fmt.Errorf("failed to read directory: %w", err)
	}

	// Normalize root URL (remove trailing slash)
	rootURL = strings.TrimSuffix(rootURL, "/")

	var fileNames []string
	for _, entry := range entries {
		name := entry.Name()
		// Skip the index.html itself and hidden files
		if name != "index.html" && !filepath.HasPrefix(name, ".") {
			fileNames = append(fileNames, name)
		}
	}
	sort.Strings(fileNames)

	// Build file entries with absolute URLs
	var files []FileEntry
	dirName := filepath.Base(dir)
	for _, name := range fileNames {
		// URL encode the filename for the path
		url := fmt.Sprintf("%s/%s/%s", rootURL, dirName, name)
		files = append(files, FileEntry{
			Name: name,
			URL:  url,
		})
	}

	templatePath := "build/index.html.tmpl"
	tmpl, err := template.ParseFiles(templatePath)
	if err != nil {
		return fmt.Errorf("failed to parse template: %w", err)
	}

	indexPath := filepath.Join(dir, "index.html")
	f, err := os.Create(indexPath)
	if err != nil {
		return fmt.Errorf("failed to create index.html: %w", err)
	}
	defer f.Close()

	data := IndexData{
		Dir:     dirName,
		Files:   files,
		RootURL: rootURL,
	}

	if err := tmpl.Execute(f, data); err != nil {
		return fmt.Errorf("failed to execute template: %w", err)
	}

	fmt.Printf("Generated index.html in %s\n", dir)
	return nil
}

func main() {
	rootURL := flag.String("root", "https://ss-6r6jq.ondigitalocean.app", "Root domain URL for absolute links")
	flag.Parse()

	dirs := flag.Args()
	if len(dirs) == 0 {
		fmt.Println("Usage: generate-index [-root <url>] <directory> [<directory>...]")
		fmt.Println("  -root string")
		fmt.Println("        Root domain URL for absolute links (default \"https://ss-6r6jq.ondigitalocean.app\")")
		os.Exit(1)
	}

	for _, dir := range dirs {
		if err := generateIndex(dir, *rootURL); err != nil {
			fmt.Fprintf(os.Stderr, "Error processing %s: %v\n", dir, err)
			os.Exit(1)
		}
	}
}