// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

package app

import (
	"context"
	"encoding/json"
	"errors"
	"log/slog"
	"path/filepath"
	"strconv"
	"strings"
	"testing"
	"time"

	"git.stormux.org/storm/cthulhu/internal/tentacle"
	"git.stormux.org/storm/cthulhu/internal/tentaclewire"
)

func keyboard_attach_runtime(policy *tentacle.RemotePolicy, helper string) *tentacleRuntime {
	return &tentacleRuntime{logger: slog.New(slog.DiscardHandler), remotePolicy: policy, remoteInputHelper: helper,
		output: &tentacleOutput{gate: &focusGate{}}, announcements: make(chan string, 1)}
}

func keyboard_attach_key(t *testing.T, session *tentacle.Session, lease tentaclewire.RemoteLease, sequence uint64, name string, pressed bool) error {
	t.Helper()
	ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
	defer cancel()
	request := tentaclewire.RemoteKeyRequest{RemoteOperation: tentaclewire.RemoteOperation{Lease: lease.Lease, Epoch: lease.Epoch, Sequence: sequence}, Key: tentaclewire.RemoteKey{Name: name, Pressed: pressed}}
	data, _ := json.Marshal(map[string]any{"Method": "remote.key", "Params": request})
	pending, err := session.Invoke(ctx, "rpc", data)
	if err != nil {
		t.Fatal(err)
	}
	select {
	case result := <-pending:
		return result.Err
	case <-ctx.Done():
		t.Fatal("keyboard peer call timed out")
		return nil
	}
}

func keyboard_attach_open(t *testing.T, session *tentacle.Session) tentaclewire.RemoteLease {
	t.Helper()
	approval, err := session.BeginRemoteApproval("controlled", []string{"keyboard-inject"})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := session.AuthorizeRemoteWithApproval(approval, "controlled", []string{"keyboard-inject"}); err != nil {
		t.Fatal(err)
	}
	var lease tentaclewire.RemoteLease
	if json.Unmarshal(keyboard_owner_invoke(t, session, "open", nil), &lease) != nil || lease.Epoch == 0 {
		t.Fatal("keyboard peer failed to open lease")
	}
	return lease
}

func TestRemoteKeyboardProductionAttachDeliversAndRetires(t *testing.T) {
	policy := tentacle.NewRemotePolicy()
	program, log := keyboard_owner_helper(t)
	session := keyboard_owner_session(t, policy, []string{"keyboard-inject", "output-observe"})
	runtime := keyboard_attach_runtime(policy, program)
	ctx, cancel := context.WithCancel(t.Context())
	done := runtime.start_remote_keyboard(ctx, session)
	t.Cleanup(func() {
		cancel()
		select {
		case <-done:
		case <-time.After(6 * time.Second):
			t.Error("production keyboard owner did not join")
		}
	})
	lease := keyboard_attach_open(t, session)
	if err := keyboard_attach_key(t, session, lease, 1, "a", true); err != nil {
		t.Fatal(err)
	}
	if err := keyboard_attach_key(t, session, lease, 2, "a", false); err != nil {
		t.Fatal(err)
	}
	f := &keyboardOwnerFixture{log: log}
	prefix := strconv.FormatUint(lease.Epoch, 10) + " "
	f.wait(t, func() bool { return strings.Contains(f.effects(), prefix+"a false\n") })
	// Lock/handoff policy revokes the lease and releases the helper.
	policy.SetAvailable(false)
	f.wait(t, func() bool { return strings.Contains(f.effects(), prefix+"cleanup\n") })
	policy.SetAvailable(true)
	if runtime.remote_input_supervisor() != runtime.remoteInput || runtime.remoteInput == nil {
		t.Fatal("supervisor was not retained for the reader lifetime")
	}
}

func TestRemoteKeyboardProductionAttachRechecksReaderUI(t *testing.T) {
	policy := tentacle.NewRemotePolicy()
	program, log := keyboard_owner_helper(t)
	session := keyboard_owner_session(t, policy, []string{"keyboard-inject"})
	runtime := keyboard_attach_runtime(policy, program)
	runtime.output.gate.suspended.Store(true) // XTerm handoff.
	ctx, cancel := context.WithCancel(t.Context())
	done := runtime.start_remote_keyboard(ctx, session)
	defer func() { cancel(); <-done }()
	lease := keyboard_attach_open(t, session)
	_ = keyboard_attach_key(t, session, lease, 1, "a", true)
	deadline := time.Now().Add(5 * time.Second)
	for {
		if _, err := session.RemoteContext(lease, "keyboard-inject"); err != nil {
			break
		}
		if time.Now().After(deadline) {
			t.Fatal("suspended reader kept keyboard consent")
		}
		time.Sleep(2 * time.Millisecond)
	}
	f := &keyboardOwnerFixture{log: log}
	if strings.Contains(f.effects(), "a true") || strings.Contains(f.effects(), "starting") {
		t.Fatal("suspended reader delivered a remote key", f.effects())
	}
}

func TestRemoteKeyboardProductionAttachRequiresGrantAndHelper(t *testing.T) {
	policy := tentacle.NewRemotePolicy()
	program, _ := keyboard_owner_helper(t)
	for name, test := range map[string]struct {
		grants []string
		helper string
	}{
		"no grant":       {[]string{"output-observe"}, program},
		"missing helper": {[]string{"keyboard-inject"}, filepath.Join(t.TempDir(), "absent")},
	} {
		t.Run(name, func(t *testing.T) {
			session := keyboard_owner_session(t, policy, test.grants)
			runtime := keyboard_attach_runtime(policy, test.helper)
			done := runtime.start_remote_keyboard(t.Context(), session)
			select {
			case <-done:
			case <-time.After(time.Second):
				t.Fatal("unavailable keyboard owner did not finish immediately")
			}
			if name == "missing helper" {
				lease := keyboard_attach_open(t, session)
				err := keyboard_attach_key(t, session, lease, 1, "a", true)
				if err == nil || errors.Is(err, context.DeadlineExceeded) {
					t.Fatalf("missing helper accepted a key: %v", err)
				}
			}
		})
	}
}