package task

import (
	"context"
	"crypto/md5"
	"fmt"
	"io"
	"log/slog"
	"net/http"
	"os"
	"slices"
	"time"

	"git.lastassault.de/speatzle/morffix/types"
)

func downloadFile(ctx context.Context, l *slog.Logger, address string, path string, t *types.Task) error {
	l.InfoContext(ctx, "Starting File Download", "task_id", t.ID, "file_id", t.FileID, "path", path, "md5", t.FileMD5)

	out, err := os.Create(path)
	if err != nil {
		return fmt.Errorf("Creating File: %w", err)
	}
	defer out.Close()

	req, err := http.NewRequest(http.MethodGet, fmt.Sprintf("%v/files/%v", address, t.FileID), nil)
	if err != nil {
		return fmt.Errorf("New Request: %w", err)
	}

	req.Close = true

	var client = &http.Client{
		Transport: &http.Transport{},
	}
	resp, err := client.Do(req)
	if err != nil {
		return fmt.Errorf("Getting File: %w", err)
	}

	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("Got HTTP Status Code: %v", resp.StatusCode)
	}

	req.Close = true

	// TODO Log at interval logs read

	// Calculate hash and write file at the same time
	hash := md5.New()
	tr := io.TeeReader(resp.Body, hash)

	cr := &countReader{Reader: tr}

	stopProgress := make(chan bool, 1)

	go func() {
		tik := time.NewTicker(time.Second)

		lastCount := 0

		for {
			select {
			case <-tik.C:
				speed := cr.n - lastCount
				l.InfoContext(ctx, "Download Progress", "bytes", cr.n, "lastCount", lastCount, "length", resp.ContentLength, "speed", speed)
				lastCount = cr.n
			case <-stopProgress:
				tik.Stop()
			}

		}
	}()

	defer func() {
		stopProgress <- true
	}()

	defer resp.Body.Close()
	n, err := io.Copy(out, cr)
	if err != nil {
		return fmt.Errorf("Reading File: %w", err)
	}

	md5 := hash.Sum(nil)

	l.InfoContext(ctx, "Downloaded File", "bytes", n, "md5", md5)

	if slices.Compare[[]byte](md5, t.FileMD5) != 0 {
		return fmt.Errorf("Downloaded File does not match md5")
	}

	return nil
}