package manager

import (
	"context"
	"encoding/binary"
	"fmt"
	"io"
	"net"
	"path/filepath"
	"strings"
	"sync"
	"testing"
	"time"

	"git.veillax.com/Veillax/megalodon/internal/config"
)

// fakeArk is a minimal ARK RCON server whose player list the test controls.
type fakeArk struct {
	ln      net.Listener
	mu      sync.Mutex
	players []string // "Name, steamid" lines
	got     []string
}

func startFake(t *testing.T) *fakeArk {
	t.Helper()
	ln, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatal(err)
	}
	f := &fakeArk{ln: ln}
	t.Cleanup(func() { ln.Close() })
	go func() {
		for {
			c, err := ln.Accept()
			if err != nil {
				return
			}
			go f.handle(c)
		}
	}()
	return f
}

func rawPacket(w io.Writer, id, typ int32, body string) {
	buf := make([]byte, 12+len(body)+2)
	binary.LittleEndian.PutUint32(buf[0:], uint32(10+len(body)))
	binary.LittleEndian.PutUint32(buf[4:], uint32(id))
	binary.LittleEndian.PutUint32(buf[8:], uint32(typ))
	copy(buf[12:], body)
	w.Write(buf)
}

func rawRead(r io.Reader) (id, typ int32, body string, err error) {
	var h [4]byte
	if _, err = io.ReadFull(r, h[:]); err != nil {
		return
	}
	buf := make([]byte, binary.LittleEndian.Uint32(h[:]))
	if _, err = io.ReadFull(r, buf); err != nil {
		return
	}
	return int32(binary.LittleEndian.Uint32(buf)), int32(binary.LittleEndian.Uint32(buf[4:])), string(buf[8 : len(buf)-2]), nil
}

func (f *fakeArk) handle(c net.Conn) {
	defer c.Close()
	id, _, _, err := rawRead(c)
	if err != nil {
		return
	}
	rawPacket(c, id, 0, "")
	rawPacket(c, id, 2, "")
	for {
		id, _, cmd, err := rawRead(c)
		if err != nil {
			return
		}
		f.mu.Lock()
		f.got = append(f.got, cmd)
		reply := "ok"
		switch cmd {
		case "ListPlayers":
			reply = "No Players Connected"
			if len(f.players) > 0 {
				var lines []string
				for n, p := range f.players {
					lines = append(lines, fmt.Sprintf("%d. %s", n, p))
				}
				reply = strings.Join(lines, "\n") + "\n"
			}
		case "GetChat":
			reply = "Server received, But no response!!"
		}
		f.mu.Unlock()
		rawPacket(c, id, 0, reply)
	}
}

func (f *fakeArk) setPlayers(p ...string) { f.mu.Lock(); f.players = p; f.mu.Unlock() }

func (f *fakeArk) received(cmd string) int {
	f.mu.Lock()
	defer f.mu.Unlock()
	n := 0
	for _, c := range f.got {
		if c == cmd {
			n++
		}
	}
	return n
}

func (f *fakeArk) port() int { return f.ln.Addr().(*net.TCPAddr).Port }

func newTestManager(t *testing.T, f *fakeArk) *Manager {
	t.Helper()
	h, err := config.Load(filepath.Join(t.TempDir(), "megalodon.json"))
	if err != nil {
		t.Fatal(err)
	}
	err = h.Update(func(c *config.Config) error {
		c.DataDir = t.TempDir()
		c.PollSeconds = 1
		c.Servers = []config.Server{{ID: "island", Name: "The Island", Host: "127.0.0.1", RCONPort: f.port(), Password: "pw"}}
		return nil
	})
	if err != nil {
		t.Fatal(err)
	}
	m, err := New(h)
	if err != nil {
		t.Fatal(err)
	}
	ctx, cancel := context.WithCancel(context.Background())
	m.Start(ctx)
	t.Cleanup(func() { cancel(); m.Wait() })
	return m
}

func waitFor(t *testing.T, what string, ok func() bool) {
	t.Helper()
	deadline := time.Now().Add(8 * time.Second)
	for time.Now().Before(deadline) {
		if ok() {
			return
		}
		time.Sleep(50 * time.Millisecond)
	}
	t.Fatalf("timed out waiting for %s", what)
}

func hasEvent(m *Manager, typ, contains string) bool {
	for _, e := range m.hub.Recent(Filter{Types: []string{typ}}) {
		if strings.Contains(e.Message, contains) {
			return true
		}
	}
	return false
}

const (
	alex = "76561198000000001"
	bo   = "76561198000000002"
)

func TestJoinLeaveAndBanEnforcement(t *testing.T) {
	f := startFake(t)
	f.setPlayers("Alex, " + alex)
	m := newTestManager(t, f)

	waitFor(t, "server online", func() bool { return m.Views()[0].Online })
	if hasEvent(m, "join", "Alex") {
		t.Fatal("someone already online at startup should not raise a join event")
	}

	f.setPlayers("Alex, "+alex, "Bo, "+bo)
	waitFor(t, "join event", func() bool { return hasEvent(m, "join", "Bo joined") })
	if v := m.Views()[0]; len(v.Players) != 2 {
		t.Fatalf("expected two players, got %+v", v.Players)
	}

	f.setPlayers("Bo, " + bo)
	waitFor(t, "leave event", func() bool { return hasEvent(m, "leave", "Alex left") })

	// A ban is sent to the server, and enforced again when the player shows up.
	if _, err := m.Do("tester", Action{Name: "ban", SteamID: alex, Reason: "griefing", Minutes: 60}); err != nil {
		t.Fatal(err)
	}
	if f.received("BanPlayer "+alex) != 1 {
		t.Fatal("the ban was not sent")
	}
	f.setPlayers("Alex, "+alex, "Bo, "+bo)
	waitFor(t, "ban enforcement", func() bool { return f.received("BanPlayer "+alex) >= 2 })
	waitFor(t, "kick event", func() bool { return hasEvent(m, "kick", "Removed banned player Alex") })

	if _, err := m.Do("tester", Action{Name: "unban", SteamID: alex}); err != nil {
		t.Fatal(err)
	}
	if f.received("UnbanPlayer "+alex) != 1 || len(m.Bans()) != 0 {
		t.Fatal("the unban did not go through")
	}
}

func TestActionsBuildSafeCommands(t *testing.T) {
	f := startFake(t)
	m := newTestManager(t, f)
	waitFor(t, "server online", func() bool { return m.Views()[0].Online })

	res, err := m.Do("tester", Action{Name: "broadcast", Message: "hello\nDoExit"})
	if err != nil || len(res) != 1 || !res[0].OK {
		t.Fatalf("broadcast: %+v, %v", res, err)
	}
	if f.received("Broadcast hello DoExit") != 1 || f.received("DoExit") != 0 {
		t.Fatalf("commands received: %v", f.got)
	}
	res, _ = m.Do("tester", Action{Name: "kick", SteamID: "1; DoExit"})
	if res[0].OK || f.received("DoExit") != 0 {
		t.Fatal("an invalid Steam ID got through")
	}
	if _, err := m.Do("tester", Action{Name: "save", Servers: []string{"nope"}}); err == nil {
		t.Fatal("unknown server accepted")
	}
	if !hasEvent(m, "audit", "broadcast") {
		t.Fatal("the action was not audited")
	}
}

func TestRestartCountdownCanBeCancelled(t *testing.T) {
	f := startFake(t)
	m := newTestManager(t, f)
	waitFor(t, "server online", func() bool { return m.Views()[0].Online })

	if _, err := m.Do("tester", Action{Name: "restart", Minutes: 10, Reason: "updates"}); err != nil {
		t.Fatal(err)
	}
	if m.Views()[0].Restart == nil {
		t.Fatal("no restart shown")
	}
	waitFor(t, "first warning", func() bool { return f.received("Broadcast Server restarting in 10 minutes. updates") == 1 })
	if res, _ := m.Do("tester", Action{Name: "restart", Minutes: 5}); res[0].OK {
		t.Fatal("a second restart was accepted")
	}
	m.Do("tester", Action{Name: "cancel_restart"})
	if m.Views()[0].Restart != nil {
		t.Fatal("restart still shown after cancelling")
	}
	if f.received("DoExit") != 0 {
		t.Fatal("the server was stopped despite the cancel")
	}
}

func TestSchedule(t *testing.T) {
	m := &Manager{lastRun: map[string]time.Time{}, lastFire: map[string]string{}}
	now := time.Date(2026, 3, 2, 4, 0, 10, 0, time.Local) // a Monday
	every := config.Job{ID: "e", Every: "30m"}
	if m.due(every, now) {
		t.Fatal("an interval job must not fire the moment it is first seen")
	}
	if m.due(every, now.Add(29*time.Minute)) || !m.due(every, now.Add(31*time.Minute)) {
		t.Fatal("interval job timing is wrong")
	}
	daily := config.Job{ID: "d", At: []string{"04:00"}, Days: []string{"mon"}}
	if !m.due(daily, now) || m.due(daily, now.Add(5*time.Second)) {
		t.Fatal("a timed job should fire once in its minute")
	}
	if m.due(config.Job{ID: "t", At: []string{"04:00"}, Days: []string{"tue"}}, now) {
		t.Fatal("job fired on the wrong day")
	}
}

func TestNotificationFilter(t *testing.T) {
	join := Event{Type: "join", Server: "island"}
	chat := Event{Type: "chat", Server: "island"}
	if !wants(config.Notify{}, join) || wants(config.Notify{}, chat) {
		t.Fatal("default event set is wrong")
	}
	if !wants(config.Notify{Events: []string{"chat"}}, chat) || wants(config.Notify{Events: []string{"chat"}}, join) {
		t.Fatal("explicit event list ignored")
	}
	if wants(config.Notify{Servers: []string{"other"}}, join) || !wants(config.Notify{Servers: []string{"island"}}, join) {
		t.Fatal("server filter is wrong")
	}
}