package api

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

	"git.velvettear.de/velvettear/loggo"
	"git.velvettear.de/velvettear/slideshow/internal"
	"git.velvettear.de/velvettear/slideshow/internal/config"
)

// start the web server
func Run() {
	address := config.ServerAddress + ":" + strconv.Itoa(config.ServerPort)
	loggo.Info("starting web server...", "address: "+address)
	registerHandlers()
	error := http.ListenAndServe(address, nil)
	if error != nil {
		loggo.Fatal("encountered an error starting the web server", "address: "+address, error.Error())
	}
}

// register the handlers
func registerHandlers() {
	http.HandleFunc("/", handleImageRequest)
}

// handle the request to '/image'
func handleImageRequest(writer http.ResponseWriter, request *http.Request) {
	if !internal.HasFoundImages() {
		writer.WriteHeader(404)
		return
	}
	name, data, error := internal.GetRandomImage()
	if error != nil {
		loggo.Error("encountered an error getting a random image", error.Error())
		writer.WriteHeader(501)
		writer.Write([]byte("encountered an internal server error (" + error.Error() + ")\n"))
		return
	}
	palette, error := internal.GetColorPalette(data)
	if error != nil {
		writer.WriteHeader(501)
		writer.Write([]byte("encountered an internal server error (" + error.Error() + ")\n"))
		return
	}
	bytes, error := json.Marshal(struct {
		Name    string
		Palette string
		Data    []byte
	}{
		name,
		palette,
		data,
	})
	if error != nil {
		loggo.Error("encountered an error marshalling the json response", error.Error())
		writer.WriteHeader(501)
		writer.Write([]byte("encountered an internal server error (" + error.Error() + ")\n"))
		return
	}
	writer.Write(bytes)
}