package options

import (
	"encoding/json"
	"flag"
	"fmt"
	"os"

	"rgdd.se/silent-ct/internal/manager"
	"rgdd.se/silent-ct/pkg/monitor"
	"rgdd.se/silent-ct/pkg/server"
)

const usage = `Usage:

  silent-ct [Options]

Options:

  -h, --help:      Output usage message and exit
  -c, --config:    Path to a configuration file (Default: %s)
  -l, --listen:    Listen address to receive submission on (Default: %s)
  -s, --state:     Path to a directory where state is stored (Default: %s)

Example configuration file:

  {
    "monitor": [
      {
        "wildcard": "example.org",
        "excludes": [
          "test"
        ]
      }
    ],
    "nodes": [
      {
        "name": "node_a",
        "secret": "aaaa",
        "issues": [
          "example.org",
          "www.example.org"
        ]
      }
    ]
  }

`

// Options are command-line options the user can specify
type Options struct {
	ListenAddr string
	ConfigFile string
	StateDir   string
}

func New(cmd string, args []string) (opts Options, err error) {
	fs := flag.NewFlagSet(cmd, flag.ContinueOnError)
	fs.Usage = func() {
		fmt.Fprintf(os.Stderr, usage, server.DefaultConfigFile, server.DefaultAddress, manager.DefaultStateDir)
	}
	stringOpt(fs, &opts.ConfigFile, "config", "c", server.DefaultConfigFile)
	stringOpt(fs, &opts.ListenAddr, "listen", "l", server.DefaultAddress)
	stringOpt(fs, &opts.StateDir, "state", "s", manager.DefaultStateDir)
	if err = fs.Parse(args); err != nil {
		return opts, err
	}

	if opts.ConfigFile == "" {
		return opts, fmt.Errorf("-c, --config: must not be an empty string")
	}
	if opts.StateDir == "" {
		return opts, fmt.Errorf("-s, --state: must not be an empty string")
	}
	if opts.ListenAddr == "" {
		return opts, fmt.Errorf("-l, --listen: must not be an empty string")
	}
	return opts, err
}

func stringOpt(fs *flag.FlagSet, opt *string, short, long, value string) {
	fs.StringVar(opt, short, value, "")
	fs.StringVar(opt, long, value, "")
}

type Config struct {
	Monitor monitor.MatchWildcards `json:"monitor"`
	Nodes   server.Nodes           `json:"nodes"`
}

func (c *Config) FromFile(fileName string) error {
	b, err := os.ReadFile(fileName)
	if err != nil {
		return err
	}
	return json.Unmarshal(b, c)
}