package config

import (
	"errors"
	"io"
	"os"
	"strings"

	"gopkg.in/yaml.v3"
)

// Config captures node-agent runtime configuration.
type Config struct {
	ListenAddr   string        `json:"listen_addr" yaml:"listen_addr"`
	LibvirtURI   string        `json:"libvirt_uri" yaml:"libvirt_uri"`
	LXCPath      string        `json:"lxc_path" yaml:"lxc_path"`
	PodmanSocket string        `json:"podman_socket" yaml:"podman_socket"`
	VMPath       string        `json:"vm_path" yaml:"vm_path"`
	CTPath       string        `json:"ct_path" yaml:"ct_path"`
	AuthToken    string        `json:"auth_token" yaml:"auth_token"`
	StoragePools []StoragePool `json:"storage_pools" yaml:"storage_pools"`
	Bridges      []Bridge      `json:"bridges" yaml:"bridges"`
}

type StoragePool struct {
	Name string `json:"name" yaml:"name"`
	Type string `json:"type" yaml:"type"`
	Path string `json:"path" yaml:"path"`
}

type Bridge struct {
	Name      string `json:"name" yaml:"name"`
	VlanAware bool   `json:"vlan_aware" yaml:"vlan_aware"`
	MTU       int    `json:"mtu" yaml:"mtu"`
}

// LoadOrExit loads YAML/JSON config and applies defaults. It panics on fatal errors
// to keep the agent simple for now.
func LoadOrExit(path string) Config {
	cfg := Config{
		ListenAddr: ":8000",
		LibvirtURI: "qemu:///system",
		LXCPath:    "/etc/jagacloud/lxc",
		VMPath:     "/etc/jagacloud/vm",
		CTPath:     "/etc/jagacloud/ct",
	}

	f, err := os.Open(path)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			// File missing is allowed; defaults stay in place.
			return cfg
		}
		panic(err)
	}
	defer f.Close()

	raw, err := io.ReadAll(f)
	if err != nil {
		panic(err)
	}
	if err := yaml.Unmarshal(raw, &cfg); err != nil {
		panic(err)
	}

	cfg.ListenAddr = strings.TrimSpace(cfg.ListenAddr)
	if cfg.ListenAddr == "" {
		cfg.ListenAddr = ":8000"
	}
	if cfg.LibvirtURI == "" {
		cfg.LibvirtURI = "qemu:///system"
	}
	if cfg.LXCPath == "" {
		cfg.LXCPath = "/etc/jagacloud/lxc"
	}
	if cfg.VMPath == "" {
		cfg.VMPath = "/etc/jagacloud/vm"
	}
	if cfg.CTPath == "" {
		cfg.CTPath = "/etc/jagacloud/ct"
	}

	return cfg
}