clipper/backend/server/handlers.go

package server

import (
	"encoding/json"
	"log"
	"net/http"
	"strconv"

	"git.netflux.io/rob/clipper/media"
	"git.netflux.io/rob/clipper/youtube"
	youtubev2 "github.com/kkdai/youtube/v2"
	"github.com/labstack/echo/v4"
)

// getMediaSet is a handler that responds with a MediaSet.
func getMediaSet(c echo.Context) error {
	videoID := c.Param("id")
	mediaSet := media.NewMediaSet(videoID)

	if mediaSet.Exists() {
		if err := mediaSet.Load(); err != nil {
			log.Printf("error loading MediaSet: %v", err)
			return echo.NewHTTPError(http.StatusInternalServerError, "could not fetch media set")
		}
		return c.JSON(http.StatusOK, mediaSet)
	}

	var youtubeClient youtubev2.Client
	downloader := youtube.NewDownloader(&youtubeClient)
	mediaSet, err := downloader.Download(c.Request().Context(), videoID)
	if err != nil {
		log.Printf("error downloading MediaSet: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError, "could not fetch media set")
	}
	return c.JSON(http.StatusOK, mediaSet)
}

// getThumbnails is a handler that responds with a MediaSet thumbnail grid.
func getThumbnails(c echo.Context) error {
	videoID := c.Param("id")
	mediaSet := media.NewMediaSet(videoID)
	if err := mediaSet.Load(); err != nil {
		log.Printf("error loading MediaSet: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError, "could not load media set")
	}

	return c.File(mediaSet.ThumbnailPath())
}

// getVideo is a handler that responds with the video file for a MediaSet
func getVideo(c echo.Context) error {
	videoID := c.Param("id")
	mediaSet := media.NewMediaSet(videoID)
	if err := mediaSet.Load(); err != nil {
		log.Printf("error loading MediaSet: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError, "could not load media set")
	}

	return c.File(mediaSet.VideoPath())
}

// getPeaks is a handler that returns a two-dimensional array of peaks, with
// the number of bins matching the provided parameter.
func getPeaks(c echo.Context) error {
	videoID := c.Param("id")

	start, err := strconv.ParseInt(c.QueryParam("start"), 0, 64)
	if err != nil {
		return echo.NewHTTPError(http.StatusBadRequest, "invalid start parameter provided")
	}

	end, err := strconv.ParseInt(c.QueryParam("end"), 0, 64)
	if err != nil {
		return echo.NewHTTPError(http.StatusBadRequest, "invalid end parameter provided")
	}

	numBins, err := strconv.Atoi(c.QueryParam("bins"))
	if err != nil {
		return echo.NewHTTPError(http.StatusBadRequest, "invalid bins parameter provided")
	}

	mediaSet := media.NewMediaSet(videoID)
	if err = mediaSet.Load(); err != nil {
		log.Printf("error loading MediaSet: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError, "could not load media set")
	}

	peaks, err := mediaSet.Peaks(start, end, numBins)
	if err != nil {
		log.Printf("error generating peaks: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError, "could not generate peaks")
	}

	return json.NewEncoder(c.Response()).Encode(peaks)
}