package main

import (
	"context"
	"fmt"
	"io"
	"log"
	"net/http"
	"strings"
	"time"

	s3 "github.com/minio/minio-go/v7"
)

func proxyHandler(w http.ResponseWriter, r *http.Request) {
	key := r.URL.Query().Get("key")

	if key == "" {
		http.Error(w, "Missing key param", http.StatusBadRequest)
		return
	}
	if !strings.HasPrefix(key, s3Prefix+"/") && !strings.HasPrefix(key, "docs/") {
		http.Error(w, "Forbidden", http.StatusForbidden)
		return
	}

	ctx, cancel := context.WithTimeout(r.Context(), 60*time.Second)
	defer cancel()

	obj, err := s3Client.GetObject(ctx, bucketName, key, s3.GetObjectOptions{})
	if err != nil {
		log.Printf("Error getting object %s/%s: %v", bucketName, key, err)
		http.Error(w, "File not found", http.StatusNotFound)
		return
	}
	defer obj.Close()

	stat, err := obj.Stat()
	if err != nil {
		log.Printf("Error stating object %s/%s: %v", bucketName, key, err)
		http.Error(w, "File not found or not accessible", http.StatusNotFound)
		return
	}

	w.Header().Set("Content-Length", fmt.Sprintf("%d", stat.Size))
	w.Header().Set("Content-Type", "application/octet-stream")
	w.Header().Set("Last-Modified", stat.LastModified.Format(http.TimeFormat))

	written, err := io.Copy(w, obj)
	if err != nil {
		log.Printf("Error streaming object: %v (sent %d/%d bytes)", err, written, stat.Size)
	} else {
		log.Printf("Proxy: sent %d bytes for %s", written, key)
	}
}