package main

import (
	"compress/gzip"
	"embed"
	"io"
	"log"
	"net/http"
	"strings"

	"github.com/joho/godotenv"

	"sprintpadawan/api"
	"sprintpadawan/lib"
)

type gzipResponseWriter struct {
	io.Writer
	http.ResponseWriter
}

func (w gzipResponseWriter) Write(b []byte) (int, error) {
	return w.Writer.Write(b)
}

func gzipMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
			next.ServeHTTP(w, r)
			return
		}

		w.Header().Set("Content-Encoding", "gzip")
		w.Header().Set("Vary", "Accept-Encoding")

		gz := gzip.NewWriter(w)
		defer gz.Close()

		gzw := gzipResponseWriter{Writer: gz, ResponseWriter: w}
		next.ServeHTTP(gzw, r)
	})
}

func cacheMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Cache-Control", "public, max-age=31536000")
		next.ServeHTTP(w, r)
	})
}

//go:embed static templates
var embeddedFiles embed.FS

func main() {
	// load .env file if it exists
	_ = godotenv.Load()

	lib.InitDB()
	api.InitTemplates(embeddedFiles)

	mux := http.NewServeMux()

	// serve static assets
	staticHandler := http.FileServer(http.FS(embeddedFiles))
	mux.Handle("/static/", cacheMiddleware(gzipMiddleware(staticHandler)))

	api.SetupRoutes(mux)

	addr := ":8080"
	log.Printf("Starting SprintPadawan server on http://localhost%s", addr)
	if err := http.ListenAndServe(addr, mux); err != nil {
		log.Fatalf("server error: %v", err)
	}
}