package main

import (
	"bytes"
	"log"
	"net/http"
	"os"

	chromahtml "github.com/alecthomas/chroma/v2/formatters/html"
	"github.com/alecthomas/chroma/v2/styles"

	"ridgwaysystems.org/paste/internal/handler"
	"ridgwaysystems.org/paste/internal/paste"
)

func main() {
	port := getenv("PORT", "8081")
	dataDir := getenv("DATA_DIR", "data")

	// Generate syntax.css at startup (light + dark via media query)
	if err := generateSyntaxCSS("static/css/syntax.css"); err != nil {
		log.Printf("warning: could not generate syntax.css: %v", err)
	}

	store, err := paste.NewStore(dataDir)
	if err != nil {
		log.Fatal("paste store:", err)
	}

	h := handler.New(store)

	mux := http.NewServeMux()

	// Static files
	mux.Handle("GET /static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))

	// Public routes
	mux.HandleFunc("GET /{$}", h.List)
	mux.HandleFunc("GET /{id}", h.ViewPaste)
	mux.HandleFunc("GET /raw/{id}", h.RawPaste)

	// Paste creation (auth required)
	mux.HandleFunc("GET /new", h.RequireAuth(h.NewPasteForm))
	mux.HandleFunc("POST /new", h.RequireAuth(h.NewPastePost))

	// Admin
	mux.HandleFunc("GET /admin", h.RequireAuth(h.AdminDashboard))
	mux.HandleFunc("GET /admin/login", h.AdminLogin)
	mux.HandleFunc("POST /admin/login", h.AdminLoginPost)
	mux.HandleFunc("POST /admin/logout", h.RequireAuth(h.AdminLogout))
	mux.HandleFunc("POST /admin/delete/{id}", h.RequireAuth(h.DeletePaste))

	srv := handler.Chain(mux,
		handler.LoggingMiddleware,
		handler.SecurityHeadersMiddleware,
	)

	log.Printf("paste.ridgwaysystems.org starting on :%s (DEV=%s)", port, os.Getenv("DEV"))
	log.Fatal(http.ListenAndServe(":"+port, srv))
}

// generateSyntaxCSS writes a chroma CSS file with light and dark themes.
func generateSyntaxCSS(path string) error {
	formatter := chromahtml.New(chromahtml.WithClasses(true))

	var buf bytes.Buffer
	buf.WriteString("/* Auto-generated by chroma at server startup. Do not edit. */\n\n")
	if err := formatter.WriteCSS(&buf, styles.Get("github")); err != nil {
		return err
	}

	buf.WriteString("\n@media (prefers-color-scheme: dark) {\n")
	var dark bytes.Buffer
	if err := formatter.WriteCSS(&dark, styles.Get("github-dark")); err != nil {
		return err
	}
	buf.Write(dark.Bytes())
	buf.WriteString("}\n")

	return os.WriteFile(path, buf.Bytes(), 0644)
}

func getenv(key, def string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return def
}