package db

import (
	"encoding/json"
	"io"
	"os"

	"git.stinnesbeck.com/go/jynx/backend/common"
	"git.stinnesbeck.com/go/jynx/backend/hetzner"
)

func Read() ([]common.Server, error) {
	// open file for reading, create it when necessary
	f, err := os.OpenFile("db.json", os.O_RDONLY|os.O_CREATE, os.ModePerm)
	if err != nil {
		return nil, err
	}

	servers, err := hetzner.ListServers()
	if err != nil {
		return nil, err
	}

	// close file when we are done
	defer f.Close()

	// read file as byte array
	b, err := io.ReadAll(f)
	if err != nil {
		return nil, err
	}

	if len(b) == 0 {
		return nil, nil
	}

	// parse byte array to []common.Server
	var serversFromDB []common.Server
	if err := json.Unmarshal(b, &serversFromDB); err != nil {
		return nil, err
	}

	// merge servers from db and hcloud
	servers = append(servers, serversFromDB...)

	// return read in servers
	return servers, nil
}

func Save(servers []common.Server) error {
	// open file with provided flags, create it when necessary
	f, err := os.OpenFile("db.json", os.O_RDWR|os.O_CREATE|os.O_TRUNC, os.ModePerm)
	if err != nil {
		return err
	}

	// close file when we are done
	defer f.Close()

	// Marshal data as JSON and put into byte array
	b, err := json.MarshalIndent(servers, "", "  ")
	if err != nil {
		return err
	}

	// write byte array to file
	_, err = f.Write(b)

	return err
}