package capture

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

	"github.com/mathiasbq/hyperguild/ingestion/internal/classification"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// --- fakes ---

type fakeBrain struct {
	writes  []Note
	updates []Note
	gets    []string
	failOn  func(Note) error // nil = always succeed
	hashSeq int
}

func (f *fakeBrain) ref(prefix string, n Note, superseded bool) Ref {
	f.hashSeq++
	path := "wiki/" + n.Wing + "/" + n.Hall + "/" + n.Filename + ".md"
	return Ref{ID: path, Path: path, ContentHash: prefix + string(rune('0'+f.hashSeq)), Superseded: superseded}
}

func (f *fakeBrain) Write(_ context.Context, n Note) (Ref, error) {
	if f.failOn != nil {
		if err := f.failOn(n); err != nil {
			return Ref{}, err
		}
	}
	f.writes = append(f.writes, n)
	return f.ref("w", n, false), nil
}

func (f *fakeBrain) Update(_ context.Context, slug string, n Note) (Ref, error) {
	if f.failOn != nil {
		if err := f.failOn(n); err != nil {
			return Ref{}, err
		}
	}
	n.Filename = slug
	f.updates = append(f.updates, n)
	return f.ref("u", n, true), nil
}

func (f *fakeBrain) Get(_ context.Context, id string) (StoredNote, error) {
	f.gets = append(f.gets, id)
	return StoredNote{ID: id, Path: id}, nil
}

type fakeTracker struct {
	created  []string
	closed   []int
	comments []int
	err      error
}

func (f *fakeTracker) CreateIssue(_ context.Context, repo, title, _ string) (IssueRef, error) {
	if f.err != nil {
		return IssueRef{}, f.err
	}
	f.created = append(f.created, repo+":"+title)
	return IssueRef{Repo: repo, Number: 100 + len(f.created), URL: "https://git/" + repo + "/issues/x"}, nil
}

func (f *fakeTracker) CloseIssue(_ context.Context, repo string, number int, _ string) (IssueRef, error) {
	if f.err != nil {
		return IssueRef{}, f.err
	}
	f.closed = append(f.closed, number)
	return IssueRef{Repo: repo, Number: number}, nil
}

func (f *fakeTracker) CommentIssue(_ context.Context, repo string, number int, _ string) (IssueRef, error) {
	if f.err != nil {
		return IssueRef{}, f.err
	}
	f.comments = append(f.comments, number)
	return IssueRef{Repo: repo, Number: number}, nil
}

type fakeSummary struct {
	paths   []string
	content []string
	err     error
}

func (f *fakeSummary) WriteFile(_ context.Context, _, path, content string) error {
	if f.err != nil {
		return f.err
	}
	f.paths = append(f.paths, path)
	f.content = append(f.content, content)
	return nil
}

// fakePolicy derives from an explicit map; default Internal so tests pin
// behaviour without depending on the real defaulting.
type fakePolicy struct{ tags map[string]classification.Level }

func (p fakePolicy) Derive(t classification.Target) classification.Level {
	if lvl, ok := p.tags[t.Name]; ok {
		return lvl
	}
	return classification.Internal
}

type fakeAudit struct {
	entries []AuditEntry
	err     error
}

func (f *fakeAudit) Record(_ context.Context, e AuditEntry) error {
	if f.err != nil {
		return f.err
	}
	f.entries = append(f.entries, e)
	return nil
}

// --- helpers ---

func newSvc(b BrainStore, tr IssueTracker, sw SummaryWriter, p ClassificationPolicy, a AuditSink) *Service {
	s := NewService(b, tr, sw, p, a)
	s.now = func() time.Time { return time.Date(2026, 6, 22, 12, 0, 0, 0, time.UTC) }
	return s
}

func baseCtx() CaptureContext {
	return CaptureContext{Harness: "claude-code", Actor: "mathias", Principal: "mathias", Classification: "internal"}
}

// --- scenarios ---

func TestCaptureHappyPath(t *testing.T) {
	b := &fakeBrain{}
	tr := &fakeTracker{}
	au := &fakeAudit{}
	svc := newSvc(b, tr, nil, fakePolicy{}, au)

	rec, err := svc.Capture(context.Background(), CaptureInput{
		Context: baseCtx(),
		Insights: []Insight{
			{Text: "a", Wing: "hyperguild", Hall: "decisions", SupersedeSlug: ""},
			{Text: "b", Wing: "hyperguild", Hall: "facts"},
		},
		Tickets: []Ticket{{Repo: "hyperguild", Action: "create", Title: "do x", Body: "y"}},
	})
	require.NoError(t, err)
	require.Len(t, rec.Insights, 2)
	for _, r := range rec.Insights {
		assert.True(t, r.OK)
		assert.NotEmpty(t, r.ContentHash, "read-after-write hash returned")
	}
	require.Len(t, rec.Tickets, 1)
	assert.True(t, rec.Tickets[0].OK)
	assert.Equal(t, 2, len(b.writes))
	assert.Empty(t, rec.Errors)
	// Audit emitted naming principal/harness + items that landed.
	require.Len(t, au.entries, 1)
	assert.Equal(t, "mathias", au.entries[0].Principal)
	assert.Equal(t, "claude-code", au.entries[0].Harness)
	assert.Len(t, au.entries[0].Items, 3)
}

func TestCaptureSupersedeNotDuplicate(t *testing.T) {
	b := &fakeBrain{}
	svc := newSvc(b, &fakeTracker{}, nil, fakePolicy{}, &fakeAudit{})

	rec, err := svc.Capture(context.Background(), CaptureInput{
		Context:  baseCtx(),
		Insights: []Insight{{Text: "revised", Wing: "hyperguild", Hall: "facts", SupersedeSlug: "prior-note"}},
	})
	require.NoError(t, err)
	assert.Empty(t, b.writes, "supersede must not create")
	require.Len(t, b.updates, 1)
	assert.Equal(t, "prior-note", b.updates[0].Filename)
	assert.True(t, rec.Insights[0].Superseded)
}

func TestCaptureValidationFailClosed(t *testing.T) {
	b := &fakeBrain{}
	tr := &fakeTracker{}
	au := &fakeAudit{}
	svc := newSvc(b, tr, nil, fakePolicy{}, au)

	_, err := svc.Capture(context.Background(), CaptureInput{
		Context: baseCtx(),
		Insights: []Insight{
			{Text: "ok", Wing: "hyperguild", Hall: "facts"},
			{Text: "bad", Wing: "hyperguild", Hall: "garbage-hall"}, // invalid hall
		},
		Tickets: []Ticket{{Repo: "hyperguild", Action: "create", Title: "t"}},
	})
	require.Error(t, err)
	// Nothing written anywhere.
	assert.Empty(t, b.writes)
	assert.Empty(t, b.updates)
	assert.Empty(t, tr.created)
	assert.Empty(t, au.entries)
}

func TestCaptureValidationRejectsBadTicket(t *testing.T) {
	svc := newSvc(&fakeBrain{}, &fakeTracker{}, nil, fakePolicy{}, &fakeAudit{})
	_, err := svc.Capture(context.Background(), CaptureInput{
		Context: baseCtx(),
		Tickets: []Ticket{{Repo: "hyperguild", Action: "frobnicate"}}, // bad action
	})
	require.Error(t, err)

	_, err = svc.Capture(context.Background(), CaptureInput{
		Context: baseCtx(),
		Tickets: []Ticket{{Repo: "hyperguild", Action: "close"}}, // close needs number
	})
	require.Error(t, err)
}

func TestCapturePartialFailureBestEffort(t *testing.T) {
	b := &fakeBrain{failOn: func(n Note) error {
		if strings.Contains(n.Content, "FAIL") {
			return errors.New("disk full")
		}
		return nil
	}}
	tr := &fakeTracker{}
	au := &fakeAudit{}
	svc := newSvc(b, tr, nil, fakePolicy{}, au)

	rec, err := svc.Capture(context.Background(), CaptureInput{
		Context: baseCtx(),
		Insights: []Insight{
			{Text: "good one", Wing: "hyperguild", Hall: "facts"},
			{Text: "FAIL here", Wing: "hyperguild", Hall: "facts"},
		},
		Tickets: []Ticket{{Repo: "hyperguild", Action: "create", Title: "t"}},
	})
	require.NoError(t, err, "partial failure is not a request-level error")
	assert.True(t, rec.Insights[0].OK)
	assert.False(t, rec.Insights[1].OK)
	assert.True(t, rec.Tickets[0].OK, "ticket still persisted; no rollback")
	require.Len(t, rec.Errors, 1)
	assert.Equal(t, "insight[1]", rec.Errors[0].Item)
	// Audit reflects exactly what landed: 1 insight + 1 ticket.
	require.Len(t, au.entries, 1)
	assert.Len(t, au.entries[0].Items, 2)
}

func TestCaptureDryRunWritesNothing(t *testing.T) {
	b := &fakeBrain{}
	tr := &fakeTracker{}
	au := &fakeAudit{}
	svc := newSvc(b, tr, nil, fakePolicy{}, au)

	rec, err := svc.Capture(context.Background(), CaptureInput{
		Context:  baseCtx(),
		DryRun:   true,
		Insights: []Insight{{Text: "a", Wing: "hyperguild", Hall: "facts"}},
		Tickets:  []Ticket{{Repo: "hyperguild", Action: "create", Title: "t"}},
	})
	require.NoError(t, err)
	assert.True(t, rec.DryRun)
	assert.Len(t, rec.Insights, 1)
	assert.True(t, rec.Insights[0].OK, "would-be receipt marks planned items ok")
	// Nothing written anywhere, including audit.
	assert.Empty(t, b.writes)
	assert.Empty(t, tr.created)
	assert.Empty(t, au.entries)
}

func TestCaptureStricterClassificationWins(t *testing.T) {
	// Caller declares internal; target wing tagged confidential → effective confidential + security event.
	b := &fakeBrain{}
	au := &fakeAudit{}
	pol := fakePolicy{tags: map[string]classification.Level{"client-seb": classification.Confidential}}
	svc := newSvc(b, &fakeTracker{}, nil, pol, au)

	ctx := baseCtx()
	ctx.Classification = "internal"
	rec, err := svc.Capture(context.Background(), CaptureInput{
		Context:  ctx,
		Insights: []Insight{{Text: "x", Wing: "client-seb", Hall: "facts"}},
	})
	require.NoError(t, err)
	assert.Equal(t, "confidential", rec.EffectiveClassification)
	require.Len(t, au.entries, 1)
	assert.NotEmpty(t, au.entries[0].SecurityEvents, "under-declaration logged as security event")
	assert.Equal(t, "confidential", au.entries[0].EffectiveClassification)
}

func TestCaptureCallerRaisingSensitivityHonoured(t *testing.T) {
	// Caller declares confidential; target internal → effective confidential, NOT a security event.
	au := &fakeAudit{}
	pol := fakePolicy{tags: map[string]classification.Level{"hyperguild": classification.Internal}}
	svc := newSvc(&fakeBrain{}, &fakeTracker{}, nil, pol, au)

	ctx := baseCtx()
	ctx.Classification = "confidential"
	rec, err := svc.Capture(context.Background(), CaptureInput{
		Context:  ctx,
		Insights: []Insight{{Text: "x", Wing: "hyperguild", Hall: "facts"}},
	})
	require.NoError(t, err)
	assert.Equal(t, "confidential", rec.EffectiveClassification)
	assert.Empty(t, au.entries[0].SecurityEvents, "raising sensitivity is honoured, not flagged")
}

func TestCaptureSummaryPathAndFidelity(t *testing.T) {
	sw := &fakeSummary{}
	svc := newSvc(&fakeBrain{}, &fakeTracker{}, sw, fakePolicy{}, &fakeAudit{})

	ctx := baseCtx()
	ctx.Fidelity = "transcript-parse"
	ctx.SessionRef = "abc123def456"
	rec, err := svc.Capture(context.Background(), CaptureInput{
		Context: ctx,
		Summary: &Summary{Title: "Session Wrap", Body: "did stuff", ReposTouched: []string{"hyperguild"}},
	})
	require.NoError(t, err)
	require.NotNil(t, rec.Summary)
	assert.True(t, rec.Summary.OK)
	require.Len(t, sw.paths, 1)
	assert.True(t, strings.HasPrefix(sw.paths[0], "summaries/claude-code/2026-06/"), "path: %s", sw.paths[0])
	assert.Contains(t, sw.paths[0], "session-wrap")
	assert.Contains(t, sw.content[0], "fidelity: transcript-parse", "fidelity stamped in frontmatter")
}

// --- I1 sovereignty gate (#53) ---

func TestCaptureRefusesConfidentialViaUSNexus(t *testing.T) {
	b := &fakeBrain{}
	tr := &fakeTracker{}
	au := &fakeAudit{}
	pol := fakePolicy{tags: map[string]classification.Level{"client-seb": classification.Confidential}}
	svc := newSvc(b, tr, nil, pol, au)

	ctx := baseCtx()
	ctx.Classification = "confidential"
	ctx.Origin = ZoneUSNexus
	_, err := svc.Capture(context.Background(), CaptureInput{
		Context:  ctx,
		Insights: []Insight{{Text: "x", Wing: "client-seb", Hall: "facts"}},
	})
	require.Error(t, err)
	assert.ErrorIs(t, err, ErrSovereigntyRefused)
	// Refused before any write.
	assert.Empty(t, b.writes)
	assert.Empty(t, tr.created)
	// Refusal is audited.
	require.Len(t, au.entries, 1)
	assert.Empty(t, au.entries[0].Items, "no items landed on refusal")
}

func TestCaptureAllowsConfidentialViaSovereign(t *testing.T) {
	b := &fakeBrain{}
	pol := fakePolicy{tags: map[string]classification.Level{"client-seb": classification.Confidential}}
	svc := newSvc(b, &fakeTracker{}, nil, pol, &fakeAudit{})

	ctx := baseCtx()
	ctx.Classification = "confidential"
	ctx.Origin = ZoneSovereign
	rec, err := svc.Capture(context.Background(), CaptureInput{
		Context:  ctx,
		Insights: []Insight{{Text: "x", Wing: "client-seb", Hall: "facts"}},
	})
	require.NoError(t, err)
	assert.True(t, rec.Insights[0].OK)
	assert.Len(t, b.writes, 1)
}

func TestCaptureAssertedLabelIgnoredAndLogged(t *testing.T) {
	// Caller asserts harness "sovereign-soil" but principal resolves to
	// us-nexus; confidential ⇒ refused, and the discrepancy is a security event.
	au := &fakeAudit{}
	pol := fakePolicy{tags: map[string]classification.Level{"client-seb": classification.Confidential}}
	svc := newSvc(&fakeBrain{}, &fakeTracker{}, nil, pol, au)

	ctx := baseCtx()
	ctx.Harness = "sovereign-soil" // asserted
	ctx.Origin = ZoneUSNexus       // server-derived
	ctx.Classification = "confidential"
	_, err := svc.Capture(context.Background(), CaptureInput{
		Context:  ctx,
		Insights: []Insight{{Text: "x", Wing: "client-seb", Hall: "facts"}},
	})
	require.ErrorIs(t, err, ErrSovereigntyRefused)
	require.Len(t, au.entries, 1)
	joined := strings.Join(au.entries[0].SecurityEvents, " | ")
	assert.Contains(t, joined, "asserted-vs-derived origin mismatch")
	assert.Contains(t, joined, "I1 refusal")
}

func TestCaptureInternalViaUSNexusAllowed(t *testing.T) {
	// us-nexus origin is fine for non-confidential data.
	b := &fakeBrain{}
	svc := newSvc(b, &fakeTracker{}, nil, fakePolicy{}, &fakeAudit{})
	ctx := baseCtx()
	ctx.Origin = ZoneUSNexus // internal classification, so gate doesn't fire
	rec, err := svc.Capture(context.Background(), CaptureInput{
		Context:  ctx,
		Insights: []Insight{{Text: "x", Wing: "hyperguild", Hall: "facts"}},
	})
	require.NoError(t, err)
	assert.True(t, rec.Insights[0].OK)
}