package agentruntime

import (
	"context"
	"errors"
	"reflect"
	"strings"
	"sync"
	"testing"
	"time"

	agentsessionstore "github.com/tutti-os/tutti/packages/agent/daemon/activity"
	activityshared "github.com/tutti-os/tutti/packages/agent/daemon/activity/events"
)

type canonicalSubmitSequenceAdapter struct {
	recordingStartAdapter
	release <-chan struct{}
	emitted chan struct{}
	once    sync.Once
}

func TestCanonicalSubmitFactRequiresCompleteIdentityAndOccurrence(t *testing.T) {
	for _, testCase := range []struct {
		name             string
		clientSubmitID   string
		occurredAtUnixMS int64
	}{
		{name: "identity_without_occurrence", clientSubmitID: "submit-1"},
		{name: "occurrence_without_identity", occurredAtUnixMS: 1_234},
	} {
		t.Run(testCase.name, func(t *testing.T) {
			if _, err := newCanonicalSubmitFact(testCase.clientSubmitID, testCase.occurredAtUnixMS); err == nil {
				t.Fatal("expected incomplete canonical submit fact to fail")
			}
		})
	}
}

func (a *canonicalSubmitSequenceAdapter) ExecAsync(
	ctx context.Context,
	session Session,
	content []PromptContentBlock,
	displayPrompt string,
	turnID string,
	emit EventSink,
	_ CommandSnapshotSink,
) error {
	select {
	case <-a.release:
	case <-ctx.Done():
		return ctx.Err()
	}
	explicitDisplayPrompt, visibleText := explicitAndVisiblePromptText(content, displayPrompt)
	if emit != nil {
		emit([]activityshared.Event{
			newUserPromptActivityEvent(
				ctx,
				session,
				content,
				explicitDisplayPrompt,
				visibleText,
				turnID,
				nil,
			),
		})
	}
	a.once.Do(func() { close(a.emitted) })
	return nil
}

func TestCanonicalSubmitSequenceIsStableAcrossRuntimeAndProvenanceOrder(t *testing.T) {
	for _, provenanceFirst := range []bool{false, true} {
		name := "runtime-first"
		if provenanceFirst {
			name = "provenance-first"
		}
		t.Run(name, func(t *testing.T) {
			release := make(chan struct{})
			adapter := &canonicalSubmitSequenceAdapter{
				recordingStartAdapter: recordingStartAdapter{provider: "canonical-submit-sequence"},
				release:               release,
				emitted:               make(chan struct{}),
			}
			reporter := &recordingReporter{}
			controller := NewController([]Adapter{adapter}, reporter)
			started, err := controller.Start(t.Context(), StartInput{
				RoomID:         "workspace-" + name,
				AgentSessionID: "session-" + name,
				Provider:       adapter.Provider(),
			})
			if err != nil {
				t.Fatal(err)
			}

			const occurredAtUnixMS = int64(1_234)
			const clientSubmitID = "submit-1"
			content := textPrompt("hello")
			execResult, err := controller.Exec(t.Context(), ExecInput{
				RoomID:                          started.Session.RoomID,
				AgentSessionID:                  started.Session.AgentSessionID,
				TurnID:                          "turn-1",
				ClientSubmitID:                  clientSubmitID,
				CanonicalSubmitOccurredAtUnixMS: occurredAtUnixMS,
				Content:                         content,
			})
			if err != nil {
				t.Fatal(err)
			}

			if !provenanceFirst {
				close(release)
				waitForCanonicalSubmitEmission(t, adapter.emitted)
				waitForCanonicalSubmitMessageReports(t, reporter, clientSubmitID, 1)
			}
			if err := controller.DurablyReportSubmitProvenance(t.Context(), SubmitProvenanceInput{
				RoomID:                          started.Session.RoomID,
				AgentSessionID:                  started.Session.AgentSessionID,
				TurnID:                          execResult.TurnID,
				ClientSubmitID:                  clientSubmitID,
				CanonicalSubmitOccurredAtUnixMS: occurredAtUnixMS,
				Content:                         content,
			}); err != nil {
				t.Fatal(err)
			}
			if provenanceFirst {
				close(release)
				waitForCanonicalSubmitEmission(t, adapter.emitted)
			}

			updates := waitForCanonicalSubmitMessageReports(t, reporter, clientSubmitID, 2)
			if !reflect.DeepEqual(updates[0], updates[1]) {
				t.Fatalf("canonical submit updates differ:\nfirst=%#v\nsecond=%#v", updates[0], updates[1])
			}
			if updates[0].Seq != uint64(occurredAtUnixMS) || updates[0].OccurredAtUnixMS != occurredAtUnixMS {
				t.Fatalf("canonical submit sequence = %d occurredAt=%d", updates[0].Seq, updates[0].OccurredAtUnixMS)
			}
			projected := agentsessionstore.SessionMessageUpdateFromActivityUpdate(updates[0])
			if projected.Payload["seq"] != uint64(occurredAtUnixMS) {
				t.Fatalf("canonical payload seq = %#v", projected.Payload["seq"])
			}
		})
	}
}

func waitForCanonicalSubmitEmission(t *testing.T, emitted <-chan struct{}) {
	t.Helper()
	select {
	case <-emitted:
	case <-time.After(10 * time.Second):
		t.Fatal("timed out waiting for canonical submit user message")
	}
}

func waitForCanonicalSubmitMessageReports(
	t *testing.T,
	reporter *recordingReporter,
	clientSubmitID string,
	count int,
) []agentsessionstore.WorkspaceAgentMessageUpdate {
	t.Helper()
	messageID := userPromptActivityMessageIDFromClientSubmitID(clientSubmitID)
	var matches []agentsessionstore.WorkspaceAgentMessageUpdate
	reporter.waitForReports(t, "canonical submit message reports", func(calls []reportCall) bool {
		matches = matches[:0]
		for _, call := range calls {
			for _, update := range call.report.MessageUpdates {
				if update.MessageID == messageID {
					matches = append(matches, update)
				}
			}
		}
		return len(matches) >= count
	})
	return append([]agentsessionstore.WorkspaceAgentMessageUpdate(nil), matches...)
}

type submittedTurnBarrierReporter struct {
	entered         chan struct{}
	release         chan struct{}
	err             error
	once            sync.Once
	input           agentsessionstore.ReportActivityInput
	provenanceCalls int
}

func (r *submittedTurnBarrierReporter) Report(ctx context.Context, input agentsessionstore.ReportActivityInput) error {
	r.input = input
	r.once.Do(func() { close(r.entered) })
	select {
	case <-r.release:
		return r.err
	case <-ctx.Done():
		return ctx.Err()
	}
}

func (r *submittedTurnBarrierReporter) ReportSubmitProvenance(ctx context.Context, report agentsessionstore.ReportActivityInput) error {
	r.provenanceCalls++
	return r.Report(ctx, report)
}

type executionSignalAdapter struct {
	recordingStartAdapter
	executed chan struct{}
	once     sync.Once
}

func (a *executionSignalAdapter) Exec(context.Context, Session, []PromptContentBlock, string, string, EventSink, CommandSnapshotSink) ([]activityshared.Event, error) {
	a.once.Do(func() { close(a.executed) })
	return nil, nil
}

func TestControllerExecWaitsForSubmittedTurnDurableReportBeforeProviderStart(t *testing.T) {
	t.Parallel()
	reporter := &submittedTurnBarrierReporter{entered: make(chan struct{}), release: make(chan struct{})}
	adapter := &executionSignalAdapter{
		recordingStartAdapter: recordingStartAdapter{provider: ProviderCodex},
		executed:              make(chan struct{}),
	}
	controller := NewController([]Adapter{adapter}, reporter)
	_, err := controller.Start(context.Background(), StartInput{
		RoomID: "room-1", AgentSessionID: "agent-session-1", Provider: ProviderCodex, Provisional: true,
	})
	if err != nil {
		t.Fatalf("Start() error = %v", err)
	}
	execDone := make(chan error, 1)
	go func() {
		_, execErr := controller.Exec(context.Background(), ExecInput{
			RoomID:                          "room-1",
			AgentSessionID:                  "agent-session-1",
			ClientSubmitID:                  "submit-1",
			CanonicalSubmitOccurredAtUnixMS: 1_234,
			Content:                         textPrompt("hello"),
		})
		execDone <- execErr
	}()
	select {
	case <-reporter.entered:
	case <-time.After(2 * time.Second):
		t.Fatal("timed out waiting for submitted-turn report")
	}
	select {
	case <-adapter.executed:
		t.Fatal("provider started before submitted Turn became durable")
	case err := <-execDone:
		t.Fatalf("Exec returned before submitted Turn became durable: %v", err)
	case <-time.After(50 * time.Millisecond):
	}
	close(reporter.release)
	select {
	case err := <-execDone:
		if err != nil {
			t.Fatalf("Exec() error = %v", err)
		}
	case <-time.After(2 * time.Second):
		t.Fatal("Exec did not return after durable report")
	}
	if len(reporter.input.MessageUpdates) != 1 ||
		reporter.input.MessageUpdates[0].MessageID != userPromptActivityMessageIDFromClientSubmitID("submit-1") ||
		reporter.input.MessageUpdates[0].Role != string(activityshared.MessageRoleUser) ||
		reporter.input.MessageUpdates[0].TurnID == "" {
		t.Fatalf("submitted report message updates = %#v", reporter.input.MessageUpdates)
	}
	if reporter.provenanceCalls != 1 {
		t.Fatalf("submit provenance calls = %d, want one atomic admission call", reporter.provenanceCalls)
	}
	select {
	case <-adapter.executed:
	case <-time.After(2 * time.Second):
		t.Fatal("provider did not start after durable report")
	}
}

func TestControllerExecRollsBackWhenSubmittedTurnDurableReportFails(t *testing.T) {
	t.Parallel()
	reporter := &submittedTurnBarrierReporter{
		entered: make(chan struct{}), release: make(chan struct{}), err: errors.New("sqlite unavailable"),
	}
	close(reporter.release)
	adapter := &executionSignalAdapter{
		recordingStartAdapter: recordingStartAdapter{provider: ProviderCodex},
		executed:              make(chan struct{}),
	}
	controller := NewController([]Adapter{adapter}, reporter)
	_, err := controller.Start(context.Background(), StartInput{
		RoomID: "room-1", AgentSessionID: "agent-session-1", Provider: ProviderCodex, Provisional: true,
	})
	if err != nil {
		t.Fatalf("Start() error = %v", err)
	}
	if _, err := controller.Exec(context.Background(), ExecInput{
		RoomID: "room-1", AgentSessionID: "agent-session-1", Content: textPrompt("hello"),
	}); err == nil || !strings.Contains(err.Error(), "persist submitted agent turn") {
		t.Fatalf("Exec() error = %v, want durable report failure", err)
	}
	select {
	case <-adapter.executed:
		t.Fatal("provider started after submitted Turn report failed")
	default:
	}
	if controller.HasActiveTurn("room-1", "agent-session-1") {
		t.Fatal("active Turn survived submitted report rollback")
	}
	stored, ok := controller.Session("room-1", "agent-session-1")
	if !ok || stored.Status != SessionStatusReady || stored.TurnLifecycle != nil {
		t.Fatalf("rolled-back session = %#v, ok=%v", stored, ok)
	}
	controller.mu.Lock()
	provisional := controller.provisionalSessions[sessionKey("room-1", "agent-session-1")]
	controller.mu.Unlock()
	if !provisional {
		t.Fatal("failed first Turn committed provisional session")
	}
}