package main

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"log"
	"net/http"
	"os/exec"
	"time"
)

func compressRAMHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Только POST метод", http.StatusMethodNotAllowed)
		return
	}

	w.Header().Set("Content-Type", "video/mp4")
	w.Header().Set("Transfer-Encoding", "chunked")

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

	args := []string{
		"-y",
		"-analyzeduration", "10M",
		"-probesize", "10M",
		"-i", "pipe:0",
		"-c:v", "libx264",
		"-preset", "veryfast",
		"-crf", "28",
		"-threads", "4",
		"-movflags", "frag_keyframe+empty_moov",
		"-f", "mp4",
		"pipe:1",
	}

	cmd := exec.CommandContext(ctx, "ffmpeg", args...)

	cmd.Stdin = r.Body

	// Буфер для сбора ошибок FFmpeg
	var stderrBuf bytes.Buffer
	cmd.Stderr = &stderrBuf

	stdoutPipe, err := cmd.StdoutPipe()
	if err != nil {
		http.Error(w, fmt.Sprintf("Ошибка pipe stdout: %v", err), http.StatusInternalServerError)
		return
	}

	if err := cmd.Start(); err != nil {
		http.Error(w, fmt.Sprintf("Ошибка запуска FFmpeg: %v", err), http.StatusInternalServerError)
		return
	}

	_, _ = io.Copy(w, stdoutPipe)

	if waitErr := cmd.Wait(); waitErr != nil {
		log.Printf("FFmpeg завершился с ошибкой (%v):\n%s", waitErr, stderrBuf.String())
	}
}

func main() {
	http.HandleFunc("/compress", compressRAMHandler)

	log.Println("RAM Converter запущен на :1554...")
	log.Fatal(http.ListenAndServe("127.0.0.1:1554", nil))
}