package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"
	"time"

	"atp.pics/internal/fetch"
	"atp.pics/internal/handler"
	"atp.pics/internal/resolve"

	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/service/s3"
)

type responseRecorder struct {
	http.ResponseWriter
	status int
}

func (r *responseRecorder) WriteHeader(status int) {
	r.status = status
	r.ResponseWriter.WriteHeader(status)
}

func logMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		rec := &responseRecorder{ResponseWriter: w, status: http.StatusOK}
		next.ServeHTTP(rec, r)
		log.Printf("%s %s %d %dms", r.Method, r.URL.Path, rec.status, time.Since(start).Milliseconds())
	})
}

func main() {
	bucket := requireEnv("BUCKET_NAME")
	publicHost := envOr("BUCKET_PUBLIC_HOST", "")
	addr := envOr("LISTEN_ADDR", ":8080")

	ctx := context.Background()
	cfg, err := config.LoadDefaultConfig(ctx)
	if err != nil {
		log.Fatalf("loading AWS config: %v", err)
	}

	s3Client := s3.NewFromConfig(cfg)
	store := fetch.New(s3Client, bucket, publicHost)
	resolver := resolve.New()

	mux := http.NewServeMux()
	handler.New(resolver, store).Register(mux)

	log.Printf("atp.pics listening on %s", addr)
	if err := http.ListenAndServe(addr, logMiddleware(mux)); err != nil {
		log.Fatalf("server error: %v", err)
	}
}

func requireEnv(key string) string {
	v := os.Getenv(key)
	if v == "" {
		fmt.Fprintf(os.Stderr, "required environment variable %s is not set\n", key)
		os.Exit(1)
	}
	return v
}

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