package main

import (
	"fmt"
	"image"
	"image/color"
	"image/jpeg"
	"io"
	"net/http"
)

func main() {
	http.HandleFunc("/", getRoot)
	http.HandleFunc("/favicon.ico", getRoot)
	http.HandleFunc("/{videoId}", getYouTubeThumbnail)

	_ = http.ListenAndServe(":3333", nil)
}

func getYouTubeThumbnail(writer http.ResponseWriter, request *http.Request) {
	videoId := request.PathValue("videoId")

	resp, err := http.Get("https://img.youtube.com/vi/" + videoId + "/maxresdefault.jpg")

	if err != nil {
		fmt.Println(err.Error())
		return
	}

	if resp.StatusCode == 200 {
		body, _ := io.ReadAll(resp.Body)

		_, _ = io.WriteString(writer, string(body))
	} else if resp.StatusCode == 404 {
		mqResp, err := http.Get("https://img.youtube.com/vi/" + videoId + "/mqdefault.jpg")

		if err != nil {
			fmt.Println(err.Error())
			return
		}

		imageMq, _, err := image.Decode(mqResp.Body)

		if err != nil {
			fmt.Println(err.Error())
			return
		}

		fmt.Println(imageMq.Bounds().Max.X, imageMq.Bounds().Max.Y)

		hqResp, err := http.Get("https://img.youtube.com/vi/" + videoId + "/hqdefault.jpg")
		if err != nil {
			fmt.Println(err.Error())
			return
		}

		imageHq, _, err := image.Decode(hqResp.Body)

		if err != nil {
			fmt.Println(err.Error())
			return
		}

		imageMqBounds := imageMq.Bounds()
		imageHqBounds := imageHq.Bounds()

		if imageMqBounds.Max.X > imageMqBounds.Max.Y {
			fmt.Println("Youtube thumbnail horizontal")
			fmt.Println("Ideal size")
			fmt.Print(imageHq.Bounds().Max.X, ", ")
			idealHeight := imageMqBounds.Max.Y * 100 /
				(imageMqBounds.Max.X * 100 / imageHqBounds.Max.X)
			idealHeight -= 4
			fmt.Println(idealHeight)

			newImage := image.NewRGBA64(image.Rectangle{
				Min: image.Point{},
				Max: image.Point{
					X: imageHqBounds.Max.X, Y: idealHeight,
				},
			})

			for i := 0; i < idealHeight; i++ {
				for j := 0; j < imageHqBounds.Max.X; j++ {
					iHq := (imageHqBounds.Max.Y / 2) - (idealHeight / 2) + i
					r, g, b, a := imageHq.At(j, iHq).RGBA()
					newImage.SetRGBA64(j, i, color.RGBA64{
						R: uint16(r),
						G: uint16(g),
						B: uint16(b),
						A: uint16(a),
					})
				}
			}

			err := jpeg.Encode(writer, newImage, nil)
			if err != nil {
				return
			}
			return
		} else {
			fmt.Println("Youtube thumbnail vertical")
		}
	} else {
		_, _ = io.WriteString(writer, "Something went wrong")
	}
}

func getRoot(writer http.ResponseWriter, request *http.Request) {
	_, _ = io.WriteString(writer, "youtubethumbnails is a tool that allows you to get YouTube thumbnails. You can fetch thumbnails with the /{videoId} endpoint.")
}