package main

import (
	"fmt"
	"io"
	"net/url"
	"strings"

	"github.com/spf13/cobra"

	"housecarl/internal/api"
	"housecarl/internal/model"
)

// ---- helpers shared by the object commands

// change sends a change and reports it.
func change(method, path string, body any) error {
	c, err := newClient()
	if err != nil {
		return err
	}
	var resp api.MutationResponse
	if err := c.Do(ctx(), method, path, nil, body, &resp); err != nil {
		return err
	}
	return report(&resp)
}

func objPath(kind, ref string) string { return "/" + kind + "/" + url.PathEscape(ref) }

func get[T any](path string, query url.Values) (T, error) {
	var out T
	c, err := newClient()
	if err != nil {
		return out, err
	}
	err = c.Get(ctx(), path, query, &out)
	return out, err
}

// counters returns the hit counters, or none when they can't be read
// (no log:read permission).
func counters() map[string]api.Counter {
	cs, err := get[api.Counters]("/counters", nil)
	if err != nil {
		return map[string]api.Counter{}
	}
	return cs.Counters
}

func hits(c map[string]api.Counter, marks ...string) string {
	var p uint64
	found := false
	for _, m := range marks {
		if x, ok := c[m]; ok {
			p += x.Packets
			found = true
		}
	}
	if !found {
		return "-"
	}
	return humanCount(p)
}

func humanCount(n uint64) string {
	switch {
	case n >= 10_000_000_000:
		return fmt.Sprintf("%dG", n/1_000_000_000)
	case n >= 10_000_000:
		return fmt.Sprintf("%dM", n/1_000_000)
	case n >= 10_000:
		return fmt.Sprintf("%dk", n/1_000)
	}
	return fmt.Sprint(n)
}

func list(vals []string) string { return orDash(strings.Join(vals, ", ")) }

// patch collects the flags given on an update command.
type patch map[string]any

func deleteCmd(kind, what string) *cobra.Command {
	var yes bool
	cmd := &cobra.Command{
		Use: "delete " + strings.ToUpper(what), Short: "Delete a " + what, Args: cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			if !confirm(fmt.Sprintf("Delete %s %s?", what, args[0]), yes) {
				return fmt.Errorf("not deleted")
			}
			return change("DELETE", objPath(kind, args[0]), nil)
		},
	}
	cmd.Flags().BoolVarP(&yes, "yes", "y", false, "don't ask")
	return cmd
}

func showCmd[T any](kind, what string, print func(w io.Writer, o T)) *cobra.Command {
	return &cobra.Command{
		Use: "show " + strings.ToUpper(what), Short: "Show a " + what, Args: cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			o, err := get[T](objPath(kind, args[0]), nil)
			if err != nil {
				return err
			}
			return output(o, func(w io.Writer) { print(w, o) })
		},
	}
}

// ---- zones

func zoneCmd() *cobra.Command {
	cmd := &cobra.Command{Use: "zone", Aliases: []string{"zones"}, Short: "Zones: groups of interfaces rules refer to"}
	cmd.AddCommand(&cobra.Command{
		Use: "list", Short: "List the zones", Args: cobra.NoArgs,
		RunE: func(cmd *cobra.Command, args []string) error {
			zs, err := get[[]model.Zone]("/zones", nil)
			if err != nil {
				return err
			}
			return output(zs, func(w io.Writer) {
				fmt.Fprintln(w, "NAME\tINTERFACES\tEXTERNAL\tCOMMENT")
				for _, z := range zs {
					fmt.Fprintf(w, "%s\t%s\t%s\t%s\n", z.Name, list(z.Interfaces), yesNo(z.External), z.Comment)
				}
			})
		},
	})
	cmd.AddCommand(showCmd("zones", "zone", func(w io.Writer, z model.Zone) {
		fmt.Fprintf(w, "Name:\t%s\nInterfaces:\t%s\nExternal:\t%s\n", z.Name, list(z.Interfaces), yesNo(z.External))
		if z.Comment != "" {
			fmt.Fprintf(w, "Comment:\t%s\n", z.Comment)
		}
	}))
	var ifaces []string
	var external bool
	var comment string
	add := &cobra.Command{
		Use: "add NAME --interface IFACE...", Short: "Add a zone", Args: cobra.ExactArgs(1),
		Long: `Adds a zone: interfaces rules can then name together. Wildcards match
many: --interface 'incusbr*'. --external marks a zone facing the internet:
antispoofing, MSS clamping and port forwards apply there.

  hc zone add wan --interface wan --external
  hc zone add lan --interface enp2s0`,
		RunE: func(cmd *cobra.Command, args []string) error {
			return change("POST", "/zones", model.Zone{Name: args[0], Interfaces: ifaces, External: external, Comment: comment})
		},
	}
	add.Flags().StringArrayVarP(&ifaces, "interface", "i", nil, "an interface (repeat; a trailing * matches many)")
	add.Flags().BoolVar(&external, "external", false, "the zone faces the internet")
	add.Flags().StringVar(&comment, "comment", "", "a comment")
	cmd.AddCommand(add)
	var addIf, removeIf []string
	var name string
	update := &cobra.Command{
		Use: "update ZONE", Short: "Change a zone", Args: cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			p := patch{}
			fl := cmd.Flags()
			if fl.Changed("interface") || len(addIf) > 0 || len(removeIf) > 0 {
				cur := ifaces
				if !fl.Changed("interface") {
					z, err := get[model.Zone](objPath("zones", args[0]), nil)
					if err != nil {
						return err
					}
					cur = z.Interfaces
				}
				p["interfaces"] = editList(cur, addIf, removeIf)
			}
			if fl.Changed("external") {
				p["external"] = external
			}
			if fl.Changed("comment") {
				p["comment"] = comment
			}
			if fl.Changed("name") {
				p["name"] = name
			}
			return change("PATCH", objPath("zones", args[0]), p)
		},
	}
	f := update.Flags()
	f.StringArrayVarP(&ifaces, "interface", "i", nil, "replace the interfaces (repeat)")
	f.StringArrayVar(&addIf, "add", nil, "add an interface")
	f.StringArrayVar(&removeIf, "remove", nil, "remove an interface")
	f.BoolVar(&external, "external", false, "the zone faces the internet (--external=false: it doesn't)")
	f.StringVar(&comment, "comment", "", "a comment")
	f.StringVar(&name, "name", "", "a new name")
	cmd.AddCommand(update)
	cmd.AddCommand(deleteCmd("zones", "zone"))
	return cmd
}

func editList(cur, add, remove []string) []string {
	out := []string{}
	drop := map[string]bool{}
	for _, r := range remove {
		drop[r] = true
	}
	for _, x := range cur {
		if !drop[x] {
			out = append(out, x)
		}
	}
	return append(out, add...)
}

func yesNo(b bool) string {
	if b {
		return "yes"
	}
	return "no"
}

// ---- sets

func setCmd() *cobra.Command {
	cmd := &cobra.Command{Use: "set", Aliases: []string{"sets"}, Short: "Address sets: named lists of IPv4 and IPv6 addresses"}
	cmd.AddCommand(&cobra.Command{
		Use: "list", Short: "List the sets", Args: cobra.NoArgs,
		RunE: func(cmd *cobra.Command, args []string) error {
			ss, err := get[[]model.AddressSet]("/sets", nil)
			if err != nil {
				return err
			}
			return output(ss, func(w io.Writer) {
				fmt.Fprintln(w, "NAME\tENTRIES\tCOMMENT")
				for _, s := range ss {
					entries := list(s.Entries)
					if s.Dynamic {
						entries = "dynamic"
						if s.Timeout > 0 {
							entries += ", timeout " + fmtSeconds(s.Timeout)
						}
					}
					fmt.Fprintf(w, "%s\t%s\t%s\n", s.Name, entries, s.Comment)
				}
			})
		},
	})
	cmd.AddCommand(showCmd("sets", "set", func(w io.Writer, s model.AddressSet) {
		fmt.Fprintf(w, "Name:\t%s\n", s.Name)
		if s.Dynamic {
			fmt.Fprintf(w, "Dynamic:\tyes (entries: hc set entries %s)\n", s.Name)
			if s.Timeout > 0 {
				fmt.Fprintf(w, "Timeout:\t%s\n", fmtSeconds(s.Timeout))
			}
		}
		for i, e := range s.Entries {
			label := ""
			if i == 0 {
				label = "Entries:"
			}
			fmt.Fprintf(w, "%s\t%s\n", label, e)
		}
		if s.Comment != "" {
			fmt.Fprintf(w, "Comment:\t%s\n", s.Comment)
		}
	}))
	var dynamic bool
	var timeout, comment string
	add := &cobra.Command{
		Use: "add NAME [ENTRY...]", Short: "Add a set", Args: cobra.MinimumNArgs(1),
		Long: `Adds a set of addresses, prefixes and ranges, IPv4 and IPv6 mixed:

  hc set add trusted 10.0.10.0/24 10.20.30.0/24 2a02:8013:7f3d:10::/64
  hc set add guests --dynamic --timeout 24h

A dynamic set takes entries at run time, each with its own timeout ('hc
set entries', or the API with a token for that set alone: a captive
portal's signed-in clients).`,
		RunE: func(cmd *cobra.Command, args []string) error {
			s := model.AddressSet{Name: args[0], Entries: args[1:], Dynamic: dynamic, Comment: comment}
			if timeout != "" {
				n, err := parseSeconds(timeout)
				if err != nil {
					return err
				}
				s.Timeout = n
			}
			return change("POST", "/sets", s)
		},
	}
	add.Flags().BoolVar(&dynamic, "dynamic", false, "entries are added at run time")
	add.Flags().StringVar(&timeout, "timeout", "", "a dynamic set's default entry lifetime (1h, 7d)")
	add.Flags().StringVar(&comment, "comment", "", "a comment")
	cmd.AddCommand(add)
	var addE, removeE, entries []string
	var name string
	update := &cobra.Command{
		Use: "update SET", Short: "Change a set", Args: cobra.ExactArgs(1),
		Long: `Changes a set: --add and --remove change entries, --entry replaces them all.

  hc set update trusted --add 10.65.65.0/24 --remove 10.1.1.0/24`,
		RunE: func(cmd *cobra.Command, args []string) error {
			p := patch{}
			fl := cmd.Flags()
			if fl.Changed("entry") || len(addE) > 0 || len(removeE) > 0 {
				cur := entries
				if !fl.Changed("entry") {
					s, err := get[model.AddressSet](objPath("sets", args[0]), nil)
					if err != nil {
						return err
					}
					cur = s.Entries
				}
				p["entries"] = editList(cur, addE, removeE)
			}
			if fl.Changed("timeout") {
				n, err := parseSeconds(timeout)
				if err != nil {
					return err
				}
				p["timeout"] = n
			}
			if fl.Changed("comment") {
				p["comment"] = comment
			}
			if fl.Changed("name") {
				p["name"] = name
			}
			return change("PATCH", objPath("sets", args[0]), p)
		},
	}
	f := update.Flags()
	f.StringArrayVar(&entries, "entry", nil, "replace the entries (repeat)")
	f.StringArrayVar(&addE, "add", nil, "add an entry")
	f.StringArrayVar(&removeE, "remove", nil, "remove an entry")
	f.StringVar(&timeout, "timeout", "", "a dynamic set's default entry lifetime")
	f.StringVar(&comment, "comment", "", "a comment")
	f.StringVar(&name, "name", "", "a new name")
	cmd.AddCommand(update)
	cmd.AddCommand(deleteCmd("sets", "set"))
	cmd.AddCommand(entriesCmd())
	return cmd
}

// entriesCmd manages a dynamic set's run-time entries.
func entriesCmd() *cobra.Command {
	cmd := &cobra.Command{Use: "entries SET", Short: "A dynamic set's entries: list, add, remove", Args: cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			es, err := get[[]api.Element](objPath("sets", args[0])+"/elements", nil)
			if err != nil {
				return err
			}
			return output(es, func(w io.Writer) {
				fmt.Fprintln(w, "ADDRESS\tEXPIRES IN")
				for _, e := range es {
					exp := "-"
					if e.Timeout > 0 {
						exp = fmtSeconds(e.Timeout)
					}
					fmt.Fprintf(w, "%s\t%s\n", e.Address, exp)
				}
			})
		}}
	var timeout string
	add := &cobra.Command{Use: "add SET ADDRESS", Short: "Add an entry to a dynamic set", Args: cobra.ExactArgs(2),
		RunE: func(cmd *cobra.Command, args []string) error {
			e := api.Element{Address: args[1]}
			if timeout != "" {
				n, err := parseSeconds(timeout)
				if err != nil {
					return err
				}
				e.Timeout = n
			}
			c, err := newClient()
			if err != nil {
				return err
			}
			return c.Do(ctx(), "POST", objPath("sets", args[0])+"/elements", nil, e, nil)
		}}
	add.Flags().StringVar(&timeout, "timeout", "", "how long it stays (1h; default: the set's)")
	cmd.AddCommand(add)
	cmd.AddCommand(&cobra.Command{Use: "remove SET ADDRESS", Short: "Remove an entry from a dynamic set", Args: cobra.ExactArgs(2),
		RunE: func(cmd *cobra.Command, args []string) error {
			c, err := newClient()
			if err != nil {
				return err
			}
			return c.Do(ctx(), "DELETE", objPath("sets", args[0])+"/elements/"+url.PathEscape(args[1]), nil, nil, nil)
		}})
	return cmd
}

// ---- services

func serviceCmd() *cobra.Command {
	cmd := &cobra.Command{Use: "service", Aliases: []string{"services"}, Short: "Services: named ports and ICMP types (many are built in)"}
	var own bool
	ls := &cobra.Command{
		Use: "list", Short: "List the services, built-in ones too", Args: cobra.NoArgs,
		RunE: func(cmd *cobra.Command, args []string) error {
			ss, err := get[[]model.Service]("/services", q("own", map[bool]string{true: "1"}[own]))
			if err != nil {
				return err
			}
			return output(ss, func(w io.Writer) {
				fmt.Fprintln(w, "NAME\tENTRIES\tSOURCE\tCOMMENT")
				for _, s := range ss {
					src := "yours"
					if s.Builtin {
						src = "built in"
					}
					fmt.Fprintf(w, "%s\t%s\t%s\t%s\n", s.Name, list(s.Entries), src, s.Comment)
				}
			})
		},
	}
	ls.Flags().BoolVar(&own, "own", false, "only yours")
	cmd.AddCommand(ls)
	cmd.AddCommand(showCmd("services", "service", func(w io.Writer, s model.Service) {
		fmt.Fprintf(w, "Name:\t%s\nEntries:\t%s\n", s.Name, list(s.Entries))
		if s.Builtin {
			fmt.Fprintln(w, "Source:\tbuilt in (add one of the same name to change it)")
		}
	}))
	var comment string
	add := &cobra.Command{
		Use: "add NAME ENTRY...", Short: "Add a service", Args: cobra.MinimumNArgs(2),
		Long: `Adds a service: ports of a protocol, and ICMP types.

  hc service add jellyfin tcp/8096 tcp/8920
  hc service add games udp/27015-27030 tcp/27015
  hc service add pmtu icmp/destination-unreachable icmpv6/packet-too-big`,
		RunE: func(cmd *cobra.Command, args []string) error {
			return change("POST", "/services", model.Service{Name: args[0], Entries: args[1:], Comment: comment})
		},
	}
	add.Flags().StringVar(&comment, "comment", "", "a comment")
	cmd.AddCommand(add)
	var addE, removeE []string
	update := &cobra.Command{
		Use: "update SERVICE", Short: "Change a service", Args: cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			p := patch{}
			if len(addE) > 0 || len(removeE) > 0 {
				s, err := get[model.Service](objPath("services", args[0]), nil)
				if err != nil {
					return err
				}
				p["entries"] = editList(s.Entries, addE, removeE)
			}
			if cmd.Flags().Changed("comment") {
				p["comment"] = comment
			}
			return change("PATCH", objPath("services", args[0]), p)
		},
	}
	update.Flags().StringArrayVar(&addE, "add", nil, "add an entry")
	update.Flags().StringArrayVar(&removeE, "remove", nil, "remove an entry")
	update.Flags().StringVar(&comment, "comment", "", "a comment")
	cmd.AddCommand(update)
	cmd.AddCommand(deleteCmd("services", "service"))
	return cmd
}