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

package app

import (
	"context"
	"encoding/json"
	"errors"
	"os"
	"testing"
	"time"

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

type consentFormRequest struct {
	ctx   context.Context
	form  interaction.Form
	reply chan internalUIResult
}
type consentTestForms struct{ requests chan consentFormRequest }

func (forms *consentTestForms) Open(context.Context, interaction.Form) (<-chan internalUIResult, error) {
	return nil, errors.New("ordinary form used for consent")
}
func (forms *consentTestForms) Notice(context.Context, tentaclewire.Presentation) {}
func (forms *consentTestForms) OpenLocal(ctx context.Context, form interaction.Form) (<-chan internalUIResult, error) {
	reply := make(chan internalUIResult, 1)
	forms.requests <- consentFormRequest{ctx, form, reply}
	output := make(chan internalUIResult, 1)
	go func() {
		select {
		case value := <-reply:
			output <- value
		case <-ctx.Done():
			output <- internalUIResult{Cancelled: true}
		}
	}()
	return output, nil
}

func consent_runtime_fixture(t *testing.T) (*tentacleRuntime, *tentacle.Session, *consentTestForms, *focusGate) {
	t.Helper()
	executable, err := os.Executable()
	if err != nil {
		t.Fatal(err)
	}
	manager, err := tentacle.NewManager(tentacle.DefaultLimits(), nil)
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() {
		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
		defer cancel()
		if err := manager.Shutdown(ctx); err != nil {
			t.Error(err)
		}
	})
	policy := tentacle.NewRemotePolicy()
	if err := manager.UseRemotePolicy(policy); err != nil {
		t.Fatal(err)
	}
	session, err := manager.Start(t.Context(), tentacle.Spec{ID: "consent-probe", Program: []string{executable, "-test.run=^TestRemoteManagementPeer$", "--", "remote-management-peer"}, SessionEvents: true, RemoteGrants: []string{"output-observe", "clipboard-exchange"}})
	if err != nil {
		t.Fatal(err)
	}
	select {
	case <-session.Ready():
	case <-time.After(5 * time.Second):
		t.Fatal("peer not ready")
	}
	if err := session.Activate(); err != nil {
		t.Fatal(err)
	}
	forms := &consentTestForms{requests: make(chan consentFormRequest, 1)}
	runtime := &tentacleRuntime{remotePolicy: policy, forms: forms, sessions: []*tentacle.Session{session}, interactionSlots: make(chan struct{}, 1)}
	return runtime, session, forms, &focusGate{remotePolicy: policy}
}

func TestRemoteConsentFormDefaultsAndRevocation(t *testing.T) {
	for _, action := range []string{"approve", "cancel", "empty", "lock", "handoff", "revoke", "disable"} {
		t.Run(action, func(t *testing.T) {
			runtime, session, forms, gate := consent_runtime_fixture(t)
			ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
			defer cancel()
			result := make(chan error, 1)
			go func() {
				_, err := runtime.authorize_remote(ctx, "consent-probe", "controlled", []string{"output-observe", "clipboard-exchange"})
				result <- err
			}()
			var request consentFormRequest
			select {
			case request = <-forms.requests:
			case <-ctx.Done():
				t.Fatal("no consent form")
			}
			if _, err := interaction.NewSession(request.form); err != nil {
				t.Fatal("invalid consent form", err)
			}
			if request.form.Elements[0].ID != "cancel" {
				t.Fatal("approval was default action")
			}
			for _, element := range request.form.Elements {
				if element.Checked {
					t.Fatal("permission preselected")
				}
			}
			reply := internalUIResult{Activated: "approve", Values: map[string]interaction.Value{"output-observe": {Checked: true}}}
			switch action {
			case "cancel":
				reply.Activated = "cancel"
			case "empty":
				reply.Values = nil
			case "lock":
				gate.SetLocked(true, nil, nil, nil, nil, &brailleWorker{})
				gate.SetLocked(false, nil, nil, nil, nil, &brailleWorker{})
			case "handoff":
				gate.SetSuspended(true)
				gate.SetSuspended(false)
			case "revoke":
				runtime.revokeManagedRemote("consent-probe")
			case "disable":
				session.Disable()
			}
			request.reply <- reply
			select {
			case err := <-result:
				if action == "approve" && err != nil {
					t.Fatal(err)
				}
				if action != "approve" && err == nil {
					t.Fatal("stale/denied consent issued action")
				}
			case <-ctx.Done():
				t.Fatal("consent worker did not finish")
			}
			if action != "approve" {
				return
			}
			pending, err := session.Invoke(ctx, "open", nil)
			if err != nil {
				t.Fatal(err)
			}
			var lease tentaclewire.RemoteLease
			select {
			case opened := <-pending:
				if opened.Err != nil || json.Unmarshal(opened.Value, &lease) != nil {
					t.Fatal("approved action failed", opened.Err)
				}
			case <-ctx.Done():
				t.Fatal("open timed out")
			}
			delivery, err := session.RemoteContext(lease, "output-observe")
			if err != nil {
				t.Fatal(err)
			}
			if _, err := session.RemoteContext(lease, "clipboard-exchange"); err == nil {
				t.Fatal("unchecked permission granted")
			}
			gate.SetSuspended(true)
			if delivery.Err() == nil {
				t.Fatal("handoff did not synchronously cancel delivery")
			}
			gate.SetSuspended(false)
			if _, err := session.RemoteContext(lease, "output-observe"); err == nil {
				t.Fatal("handoff resume revived access")
			}
		})
	}
}

func TestRemoteGrantedTentacleUsesLocalForms(t *testing.T) {
	runtime, session, forms, _ := consent_runtime_fixture(t)
	form := interaction.Form{Title: "Certificate review", Elements: []interaction.Element{{ID: "cancel", Label: "Cancel", Kind: interaction.Button}}}
	if _, err := runtime.open_tentacle_form(t.Context(), tentacleCommand{session: session}, form); err != nil {
		t.Fatal(err)
	}
	select {
	case <-forms.requests:
	default:
		t.Fatal("remote form used ordinary input")
	}
}

type ordinaryOnlyForms struct{ tentacleForms }

func TestRemoteConsentCannotFallBackToOrdinaryForms(t *testing.T) {
	runtime, session, _, _ := consent_runtime_fixture(t)
	runtime.forms = ordinaryOnlyForms{runtime.forms}
	if _, err := runtime.authorize_remote(t.Context(), "consent-probe", "controlled", []string{"output-observe"}); err == nil {
		t.Fatal("consent fell back to ordinary input")
	}
	if _, err := runtime.open_tentacle_form(t.Context(), tentacleCommand{session: session}, remote_consent_form("consent-probe", "controlled", []string{"output-observe"})); err == nil {
		t.Fatal("sensitive form fell back to ordinary input")
	}
}

func TestRemotePolicyAttachedToRuntimeManagers(t *testing.T) {
	runtime := &tentacleRuntime{remotePolicy: tentacle.NewRemotePolicy(), newManager: func() (*tentacle.Manager, error) { return tentacle.NewManager(tentacle.DefaultLimits(), nil) }}
	manager, err := runtime.makeManager()
	if err != nil {
		t.Fatal(err)
	}
	if err := manager.UseRemotePolicy(tentacle.NewRemotePolicy()); err == nil {
		t.Fatal("reader manager omitted policy")
	}
}

func TestRemoteOptionalGrantsRespectInstallationAndLocalSelection(t *testing.T) {
	runtime, session, forms, _ := consent_runtime_fixture(t)
	type result struct {
		action tentaclewire.SessionEvent
		err    error
	}
	completed := make(chan result, 1)
	go func() {
		action, err := runtime.authorize_remote_request(t.Context(), session, tentaclewire.RemoteRequest{Role: "controlled", Grants: []string{"output-observe"}, OptionalGrants: []string{"clipboard-exchange", "keyboard-inject", "braille-stream"}})
		completed <- result{action, err}
	}()
	request := next_remote_form(t, forms)
	offered := map[string]bool{}
	for _, element := range request.form.Elements {
		if element.Kind == interaction.CheckBox {
			offered[element.ID] = true
			if element.Checked {
				t.Fatal("grant preselected")
			}
		}
	}
	if !offered["output-observe"] || !offered["clipboard-exchange"] || offered["keyboard-inject"] || offered["braille-stream"] {
		t.Fatal("uninstalled access offered", offered)
	}
	request.reply <- internalUIResult{Activated: "approve", Values: map[string]interaction.Value{"output-observe": {Checked: true}, "keyboard-inject": {Checked: true}}}
	select {
	case value := <-completed:
		if value.err != nil || len(value.action.Grants) != 1 || value.action.Grants[0] != "output-observe" {
			t.Fatal("unselected or uninstalled grant authorized", value)
		}
	case <-time.After(time.Second):
		t.Fatal("approval did not finish")
	}
}