package setup

import (
	"fmt"
	"strconv"
	"strings"

	"charm.land/huh/v2"

	"git.zb-server.de/Sebi/ssh-netbox-wrapper/internal/config"
)

// configureHosts edits a copy of the static hosts; the caller decides whether to keep it.
func configureHosts(hosts []config.StaticHost) ([]config.StaticHost, error) {
	hosts = append([]config.StaticHost(nil), hosts...)
	for {
		action := "done"
		var options []huh.Option[string]
		for i, host := range hosts {
			index := strconv.Itoa(i)
			options = append(options,
				huh.NewOption("Edit "+host.Name+" ("+host.Address+")", "edit:"+index),
				huh.NewOption("SSH options for "+host.Name, "ssh:"+index),
				huh.NewOption("Remove "+host.Name, "remove:"+index))
		}
		options = append(options, huh.NewOption("Add host", "add"), huh.NewOption("Back", "done"))
		err := huh.NewForm(huh.NewGroup(huh.NewSelect[string]().
			Title("Static hosts").
			Description("Hosts that are not in NetBox. They are found before NetBox and work offline.").
			Options(options...).
			Value(&action))).Run()
		if err != nil {
			return nil, err
		}
		if action == "done" {
			return hosts, nil
		}
		if action == "add" {
			host, err := editHost(config.StaticHost{}, hosts, -1)
			if err != nil {
				return nil, err
			}
			hosts = append(hosts, host)
			continue
		}
		verb, index, _ := strings.Cut(action, ":")
		i, _ := strconv.Atoi(index)
		switch verb {
		case "edit":
			host, err := editHost(hosts[i], hosts, i)
			if err != nil {
				return nil, err
			}
			hosts[i] = host
		case "ssh":
			options, err := editSSHOptions("SSH options for "+hosts[i].Name, hosts[i].SSH)
			if err != nil {
				return nil, err
			}
			hosts[i].SSH = options
		case "remove":
			remove := false
			if err := huh.NewConfirm().Title("Remove " + hosts[i].Name + "?").Value(&remove).Run(); err != nil {
				return nil, err
			}
			if remove {
				hosts = append(hosts[:i], hosts[i+1:]...)
			}
		}
	}
}

func editHost(host config.StaticHost, hosts []config.StaticHost, index int) (config.StaticHost, error) {
	name, address, user := host.Name, host.Address, host.User
	port := ""
	if host.Port > 0 {
		port = strconv.Itoa(host.Port)
	}
	tags := strings.Join(host.Tags, ", ")
	candidate := func() config.StaticHost {
		out := host
		out.Name = strings.TrimSpace(name)
		out.Address = strings.TrimSpace(address)
		out.User = strings.TrimSpace(user)
		out.Port, _ = strconv.Atoi(strings.TrimSpace(port))
		out.Tags = splitList(tags)
		return out
	}
	// huh validates the typed value before storing it, so each validator
	// checks the host with its own field taken from the argument.
	validate := func(set func(*config.StaticHost, string)) func(string) error {
		return func(value string) error {
			h := candidate()
			set(&h, strings.TrimSpace(value))
			return validateHostIn(h, hosts, index)
		}
	}

	err := huh.NewForm(huh.NewGroup(
		huh.NewInput().Title("Name").Description("What you type: netssh NAME. Letters, digits, dots, hyphens.").Value(&name).
			Validate(validate(func(h *config.StaticHost, v string) { h.Name = v })),
		huh.NewInput().Title("Address").Description("IP address or DNS name to connect to.").Value(&address).
			Validate(validate(func(h *config.StaticHost, v string) {
				h.Address = v
				if v == "" {
					h.Address = "-" // required: reported as invalid address
				}
			})),
		huh.NewInput().Title("User").Description("Leave empty for ssh.default_user.").Value(&user).
			Validate(validate(func(h *config.StaticHost, v string) { h.User = v })),
		huh.NewInput().Title("Port").Description("Leave empty for ssh.default_port or 22.").Value(&port).Validate(func(s string) error {
			if s = strings.TrimSpace(s); s == "" {
				return nil
			}
			if n, err := strconv.Atoi(s); err != nil || n < 1 || n > 65535 {
				return fmt.Errorf("must be a port number between 1 and 65535")
			}
			return nil
		}),
		huh.NewInput().Title("Tags").Description("Comma-separated, for ssh.rules match: {tag: …}.").Value(&tags),
	).Title("Static host")).Run()
	if err != nil {
		return host, err
	}
	return candidate(), nil
}

// validateHostIn checks host as entry index of hosts (-1 for a new host).
func validateHostIn(host config.StaticHost, hosts []config.StaticHost, index int) error {
	others := make([]config.StaticHost, 0, len(hosts)+1)
	for i, other := range hosts {
		if i != index {
			others = append(others, other)
		}
	}
	if host.Address == "" {
		host.Address = "placeholder" // reported once the address field is filled
	}
	return (&config.Config{Hosts: append(others, host)}).ValidateHosts()
}