package main

import (
	"encoding/json"
	"io/ioutil"
	"net"
	"os"
)

func LoadConfig(path string) (*Configuration, error) {
	data, err := ioutil.ReadFile(path)
	if err != nil {
		return nil, err
	}

	var c Configuration
	if err := json.Unmarshal(data, &c); err != nil {
		return nil, err
	}

	bindAddress := os.Getenv("GOPHERHOLE_BIND_ADDRESS")
	if ip := net.ParseIP(bindAddress); ip != nil {
		c.BindAddress = ip
	} else {
		c.BindAddress = net.ParseIP("127.0.0.1")
	}

	return &c, nil
}

type Configuration struct {
	BindAddress net.IP
	UseHosts    bool                    `json:"useHosts"`
	Upstream    []string                `json:"upstreams"`
	Blocklists  []string                `json:"blocklists"`
	Records     map[string]ConfigRecord `json:"records"`
}

type ConfigRecord struct {
	Type   string
	Record string
}

func NewConfig() *Configuration {
	return &Configuration{
		BindAddress: net.IPv4(127, 0, 0, 1),
		Upstream:    []string{"1.1.1.1"},
		UseHosts:    true,
		Blocklists:  []string{"https://s3.amazonaws.com/lists.disconnect.me/simple_tracking.txt"},
		Records: map[string]ConfigRecord{
			"home.internal": ConfigRecord{
				Type:   "A",
				Record: "127.0.0.1",
			},
		},
	}
}