package main

import (
	"crypto/ecdsa"
	"crypto/x509"
	"encoding/json"
	"encoding/pem"
	"fmt"
	"os"
)

type Config struct {
	Host          string `json:"host"`
	Port          int    `json:"port"`
	MasterKeyPath string `json:"masterKeyPath"`
	DataDirectory string `json:"dataDirectory"`
}

// LoadConfig loads the configuration from the given path.
func LoadConfig(path string) (*Config, error) {
	var config Config
	configFile, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer configFile.Close()
	err = json.NewDecoder(configFile).Decode(&config)
	if err != nil {
		return nil, err
	}
	return &config, nil
}

func LoadMasterKey(path string) (*ecdsa.PrivateKey, error) {
	masterKeyFile, err := os.ReadFile(path)
	if err != nil {
		return nil, err
	}

	// The second argument is not an error.
	derEncoded, _ := pem.Decode(masterKeyFile)
	if derEncoded == nil {
		return nil, fmt.Errorf("failed to decode master key file")
	}

	masterKey, err := x509.ParseECPrivateKey(derEncoded.Bytes)
	if err != nil {
		return nil, err
	}

	return masterKey, nil
}