package main

import (
	"crypto/sha256"
	"net/url"
	"os"

	"github.com/goccy/go-yaml"
)

type listenerDef struct {
	protocol    string
	address     string
	acceptProxy bool
}

var listenerDefs []listenerDef

type credentials struct {
	username []byte
	password []byte
}

type pathDef struct {
	path        string
	targetURL   *url.URL
	credentials []credentials
}

var hostDefs map[string][]pathDef

func parseConfig(configFile string) {
	configData, err := os.ReadFile(configFile)
	if err != nil {
		panic(err)
	}

	var config struct {
		Listeners []struct {
			Protocol    string
			Address     string
			AcceptProxy bool
		}
		Hosts []struct {
			Host  string
			Paths []struct {
				Path        string
				Address     string
				Credentials []struct {
					Username string
					Password string
				}
			}
		}
	}

	err = yaml.Unmarshal(configData, &config)
	if err != nil {
		panic(err)
	}

	hostDefs = make(map[string][]pathDef, len(config.Hosts))
	for _, host := range config.Hosts {
		hostDef := make([]pathDef, len(host.Paths))
		hostDefs[host.Host] = hostDef
		for i, path := range host.Paths {
			targetURL, err := url.Parse(path.Address)
			if err != nil {
				panic(err)
			}

			var pdCredentials []credentials
			if path.Credentials != nil {
				pdCredentials = make([]credentials, len(path.Credentials))
				for j, cfgCredentials := range path.Credentials {
					hash := sha256.New()
					hash.Write([]byte(cfgCredentials.Username))
					usernameSum := hash.Sum(nil)

					hash = sha256.New()
					hash.Write([]byte(cfgCredentials.Password))
					passwordSum := hash.Sum(nil)

					pdCredentials[j] = credentials{
						username: usernameSum,
						password: passwordSum,
					}
				}
			}

			hostDef[i] = pathDef{
				path:        path.Path,
				targetURL:   targetURL,
				credentials: pdCredentials,
			}
		}
	}

	listenerDefs = make([]listenerDef, len(config.Listeners))
	for i, listener := range config.Listeners {
		listenerDef := listenerDef{
			protocol:    listener.Protocol,
			address:     listener.Address,
			acceptProxy: listener.AcceptProxy,
		}
		listenerDefs[i] = listenerDef
	}
}