package main

import (
	"bytes"
	"fmt"
	"net"
	"net/http"
	"strings"
)

func healthcheck(w http.ResponseWriter, r *http.Request) {
	w.Write([]byte("ok"))
}

func reloadRules(c *Config) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		err := c.LoadMappingFile("")
		if err != nil {
			e := fmt.Errorf("cannot reload rules: %+v", err)
			http.Error(w, e.Error(), http.StatusInternalServerError)
			return
		}
		w.Write([]byte("ok"))
	}
}

func serveRules(c *Config) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var nameOfPkg string
		if r.Method != http.MethodGet {
			http.Error(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusInternalServerError)
			return
		}

		// if go-get param is absent, return nothing
		if r.FormValue("go-get") != "1" {
			data, err := getDefaultHtml()
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
			w.Write(data)
			return
		}

		ipFragments := strings.Split(r.Host, ":")
		if len(ipFragments) > 1 {
			ipAddr := net.ParseIP(ipFragments[0])
			if ipAddr.IsLoopback() {
				nameOfPkg = ipAddr.String() + r.URL.Path
			}
		} else {
			nameOfPkg = r.Host + r.URL.Path
		}

		var found bool
		var vanityUrl, proto, repoUrl string
		for _, rule := range c.MappingRules.Mappings {
			if strings.HasPrefix(strings.ToLower(rule.VanityUrl+"/"), strings.Trim(strings.ToLower(nameOfPkg), " ")) {
				vanityUrl = rule.VanityUrl
				repoUrl = rule.RealUrl
				proto = rule.Protocol
				found = true
				break
			}
		}

		if !found {
			data, err := getDefaultHtml()
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
			w.Write(data)
			return
		}

		d := ImportRuleStruct{
			VanityUrl: vanityUrl,
			Proto:     proto,
			RepoUrl:   repoUrl,
		}
		tmpl, err := getServeHtml()
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		var buf bytes.Buffer
		err = tmpl.Execute(&buf, &d)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		w.Header().Set("Cache-Control", "public, max-age=500")
		w.Write(buf.Bytes())
	}
}