package main

import (
	"embed"
	"encoding/json"
	"flag"
	"fmt"
	"io/fs"
	"net/http"
	"runtime/debug"
)

//go:embed dist/*
var embeddedFiles embed.FS

var buildInfoJSON []byte

func main() {
	port := flag.Int("port", 8000, "Port to listen on")
	flag.Parse()

	frontend, err := fs.Sub(embeddedFiles, "dist")
	if err != nil {
		panic(err)
	}
	http.Handle("GET /", http.FileServer(http.FS(frontend)))

	initializeBuildInfoJSON()
	http.HandleFunc("GET /api/v1/version", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write(buildInfoJSON)
	})

	fmt.Printf("Serving on :%v\n", *port)
	panic(http.ListenAndServe(fmt.Sprintf(":%v", *port), nil))
}

func initializeBuildInfoJSON() {
	rawBuildInfo, _ := debug.ReadBuildInfo()
	var revision, time string
	var dirty bool
	for _, buildSetting := range rawBuildInfo.Settings {
		if buildSetting.Key == "vcs.revision" {
			revision = buildSetting.Value
		} else if buildSetting.Key == "vcs.time" {
			time = buildSetting.Value
		} else if buildSetting.Key == "vcs.modified" {
			dirty = buildSetting.Value == "true"
		}
	}
	buildInfo := map[string]interface{}{
		"GitRev":       revision,
		"GitDirty":     dirty,
		"GitTime":      time,
		"GoVersion":    rawBuildInfo.GoVersion,
		"AllBuildInfo": rawBuildInfo.String(),
	}

	var err error
	buildInfoJSON, err = json.Marshal(buildInfo)
	if err != nil {
		panic(err)
	}
}