// ingestion/internal/mcp/tools_notes_test.go
package mcp_test

import (
	"context"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/mathiasbq/hyperguild/ingestion/internal/audit"
	"github.com/mathiasbq/hyperguild/ingestion/internal/brainstore"
	"github.com/mathiasbq/hyperguild/ingestion/internal/capture"
	"github.com/mathiasbq/hyperguild/ingestion/internal/capturehttp"
	"github.com/mathiasbq/hyperguild/ingestion/internal/classification"
	"github.com/mathiasbq/hyperguild/ingestion/internal/mcp"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// ---- brain#4: brain_read / brain_edit through the JSON-RPC surface --------

func newBrainRepo(t *testing.T) string {
	t.Helper()
	dir := t.TempDir()
	require.NoError(t, os.MkdirAll(filepath.Join(dir, ".git"), 0o755))
	require.NoError(t, os.MkdirAll(filepath.Join(dir, "wiki/homelab/facts"), 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(dir, "wiki/homelab/facts/n.md"),
		[]byte("---\ntitle: 'n'\n---\n\nalpha\nbeta\n"), 0o644))
	require.NoError(t, os.WriteFile(filepath.Join(dir, "CLAUDE.md"), []byte("# rules\n"), 0o644))
	return dir
}

func call(t *testing.T, srv *mcp.Server, name string, args map[string]any) map[string]any {
	t.Helper()
	req := httptest.NewRequest(http.MethodPost, "/mcp", body(t, map[string]any{
		"jsonrpc": "2.0", "id": 1, "method": "tools/call",
		"params": map[string]any{"name": name, "arguments": args},
	}))
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, req)
	var resp map[string]any
	require.NoError(t, json.Unmarshal(rr.Body.Bytes(), &resp))
	return resp
}

func TestBrainReadAndEdit_RoundTripThroughJSONRPC(t *testing.T) {
	// The Go functions are tested in internal/notes; this pins the transport,
	// because a tool that works in-process and is unreachable over JSON-RPC
	// is indistinguishable from a working one in a unit test.
	dir := newBrainRepo(t)
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_read", map[string]any{"path": "wiki/homelab/facts/n.md"})
	require.NotContains(t, resp, "error", "%v", resp["error"])

	resp = call(t, srv, "brain_edit", map[string]any{
		"path": "wiki/homelab/facts/n.md", "old_str": "beta", "new_str": "BETA",
	})
	require.NotContains(t, resp, "error", "%v", resp["error"])

	got, err := os.ReadFile(filepath.Join(dir, "wiki/homelab/facts/n.md"))
	require.NoError(t, err)
	assert.Equal(t, "---\ntitle: 'n'\n---\n\nalpha\nBETA\n", string(got),
		"only the matched bytes may change")
}

func TestBrainEdit_EmptyOldStrErrorNamesRawArgumentBytes(t *testing.T) {
	// hyperguild#115: a session reported "old_str is empty" with an old_str
	// that, on their end, was never empty. The server-side path was
	// unreachable to reproduce (verified separately: a fresh brain_edit call
	// with real content round-trips cleanly), which points at something
	// between a specific client and this call losing the field. The fix this
	// issue actually asked for isn't a behavior change — old_str=="" must
	// still refuse — it's that the refusal should say how many raw argument
	// bytes it received, so "client sent empty" is distinguishable from
	// "server received empty after some hop lost it" without a second
	// session's worth of guessing.
	dir := newBrainRepo(t)
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_edit", map[string]any{
		"path": "wiki/homelab/facts/n.md", "old_str": "", "new_str": "BETA",
	})
	errMsg, ok := resp["error"].(map[string]any)["message"].(string)
	require.True(t, ok, "%v", resp)
	assert.Contains(t, errMsg, "old_str is empty")
	assert.Contains(t, errMsg, "raw arguments were", "%v", errMsg)
}

func TestBrainEdit_RejectsAnInvalidClaimEnvelopeWrittenViaStringReplace(t *testing.T) {
	// hyperguild#123: brain_write/brain_update both validate the claim
	// envelope (half_life/applies/claim_provenance) before writing —
	// brain_edit didn't, even though it's the one live, model-facing path
	// that can rewrite an existing envelope line directly via raw string
	// replace, no parsing involved. "same rules when a note changes as when
	// it's born" (hyperguild#111's own framing) applies here too.
	dir := newBrainRepo(t)
	note := filepath.Join(dir, "wiki/homelab/facts/n.md")
	require.NoError(t, os.WriteFile(note,
		[]byte("---\ntitle: 'n'\nhalf_life: durable\napplies: universal\nclaim_provenance: asserted\n---\n\nbody\n"), 0o644))
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_edit", map[string]any{
		"path": "wiki/homelab/facts/n.md", "old_str": "claim_provenance: asserted", "new_str": "claim_provenance: guessed",
	})
	require.Contains(t, resp, "error", "%v", resp)

	got, err := os.ReadFile(note)
	require.NoError(t, err)
	assert.Contains(t, string(got), "claim_provenance: asserted", "rejected edit must leave the note byte-identical")
}

func TestBrainEdit_RejectsAValueOnlyEditThatBreaksTheEnvelope(t *testing.T) {
	// Found in review: the original gate (touchesClaimEnvelope) checked
	// whether old_str/new_str mention the FIELD NAME — but a minimal diff
	// (the natural shape of any real edit, model-generated or human) can
	// target just the VALUE token and never mention the field name at all.
	// "asserted" -> "guessed" on a claim_provenance line walked straight
	// past the field-name substring check and wrote an invalid enum value
	// with no error — the exact bypass #123 was supposed to close, closed
	// in name only.
	dir := newBrainRepo(t)
	note := filepath.Join(dir, "wiki/homelab/facts/n.md")
	require.NoError(t, os.WriteFile(note,
		[]byte("---\ntitle: 'n'\nhalf_life: durable\napplies: universal\nclaim_provenance: asserted\n---\n\nbody\n"), 0o644))
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_edit", map[string]any{
		"path": "wiki/homelab/facts/n.md", "old_str": "asserted", "new_str": "guessed",
	})
	require.Contains(t, resp, "error", "%v", resp)

	got, err := os.ReadFile(note)
	require.NoError(t, err)
	assert.Contains(t, string(got), "claim_provenance: asserted", "rejected edit must leave the note byte-identical")
}

func TestBrainEdit_RejectsAnOldStrThatCrossesTheClosingFence(t *testing.T) {
	// Found in round-2 review: the position-based gate required old_str to
	// be fully CONTAINED in the extracted frontmatter block (which excludes
	// both "---" fence lines). An old_str disambiguated by extending past
	// the closing fence into the body — a natural choice, since notes.Edit
	// requires old_str to be unique in the file — fails that containment
	// test, so checkClaimEnvelope skips validation entirely while
	// notes.Edit still applies the replace verbatim. Same invalid-enum
	// outcome as the original two bypasses, reached a third way.
	dir := newBrainRepo(t)
	note := filepath.Join(dir, "wiki/homelab/facts/n.md")
	require.NoError(t, os.WriteFile(note,
		[]byte("---\ntitle: 'n'\nhalf_life: durable\napplies: universal\nclaim_provenance: asserted\n---\n\nbody\n"), 0o644))
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_edit", map[string]any{
		"path":    "wiki/homelab/facts/n.md",
		"old_str": "asserted\n---\n\nbody",
		"new_str": "guessed\n---\n\nbody",
	})
	require.Contains(t, resp, "error", "%v", resp)

	got, err := os.ReadFile(note)
	require.NoError(t, err)
	assert.Contains(t, string(got), "claim_provenance: asserted", "rejected edit must leave the note byte-identical")
}

func TestBrainEdit_RejectsAnEditThatRemovesTheClosingFence(t *testing.T) {
	// Found in round-3 review: checkClaimEnvelope always validates the
	// resulting frontmatter of `after` — but an edit whose new_str drops
	// the closing "---" degrades `after` to "unfenced" in the same call.
	// frontmatterBlock(after) then returns ok=false, frontmatterScalars
	// returns an empty map, and claim.ValidateEnvelope({}) is nil by
	// design (absent fields are valid) — so an invalid enum value lands on
	// disk with zero error, and the note is left permanently unfenced.
	// Structural fix: a note that had a valid fence before the edit must
	// still have one after, or the edit is rejected outright.
	dir := newBrainRepo(t)
	note := filepath.Join(dir, "wiki/homelab/facts/n.md")
	require.NoError(t, os.WriteFile(note,
		[]byte("---\ntitle: 'n'\nhalf_life: durable\napplies: universal\nclaim_provenance: asserted\n---\n\nbody\n"), 0o644))
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_edit", map[string]any{
		"path":    "wiki/homelab/facts/n.md",
		"old_str": "claim_provenance: asserted\n---\n",
		"new_str": "claim_provenance: not-a-real-value\n",
	})
	require.Contains(t, resp, "error", "%v", resp)

	got, err := os.ReadFile(note)
	require.NoError(t, err)
	assert.Contains(t, string(got), "claim_provenance: asserted\n---\n", "rejected edit must leave the note byte-identical, fence intact")
}

func TestBrainEdit_AllowsAValidClaimEnvelopeEdit(t *testing.T) {
	dir := newBrainRepo(t)
	note := filepath.Join(dir, "wiki/homelab/facts/n.md")
	require.NoError(t, os.WriteFile(note,
		[]byte("---\ntitle: 'n'\nhalf_life: durable\napplies: universal\nclaim_provenance: asserted\n---\n\nbody\n"), 0o644))
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_edit", map[string]any{
		"path": "wiki/homelab/facts/n.md", "old_str": "half_life: durable", "new_str": "half_life: seasonal",
	})
	require.NotContains(t, resp, "error", "%v", resp)

	got, err := os.ReadFile(note)
	require.NoError(t, err)
	assert.Contains(t, string(got), "half_life: seasonal")
}

func TestBrainEdit_UnrelatedEditsSkipTheEnvelopeCheckEntirely(t *testing.T) {
	// The gate only engages when old_str/new_str actually mention an
	// envelope field name — an ordinary body edit on a note that happens to
	// carry a valid envelope must not pay for (or be affected by) a check
	// that has nothing to do with it.
	dir := newBrainRepo(t)
	note := filepath.Join(dir, "wiki/homelab/facts/n.md")
	require.NoError(t, os.WriteFile(note,
		[]byte("---\ntitle: 'n'\nhalf_life: durable\napplies: universal\nclaim_provenance: asserted\n---\n\nold body\n"), 0o644))
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_edit", map[string]any{
		"path": "wiki/homelab/facts/n.md", "old_str": "old body", "new_str": "new body",
	})
	require.NotContains(t, resp, "error", "%v", resp)

	got, err := os.ReadFile(note)
	require.NoError(t, err)
	assert.Contains(t, string(got), "new body")
}

func TestBrainEditRoot_GovernanceFilesAreNeverEnvelopeChecked(t *testing.T) {
	// CLAUDE.md has no claim-envelope concept at all — the check must be
	// scoped to notes (ScopeNotes), never applied on the governance path.
	srv, _, _, _ := govServer(t)

	resp := authCall(t, srv, "Bearer "+capStaticTok, "brain_edit_root", map[string]any{
		"path": "CLAUDE.md", "old_str": "# rules", "new_str": "half_life: durable",
	})
	require.NotContains(t, resp, "error", "%v", resp)
}

func TestBrainEdit_RefusesGovernanceFilesFromTheModelFacingTool(t *testing.T) {
	dir := newBrainRepo(t)
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_edit", map[string]any{
		"path": "CLAUDE.md", "old_str": "# rules", "new_str": "# rewritten",
	})
	require.Contains(t, resp, "error", "brain_edit must not reach CLAUDE.md")

	got, err := os.ReadFile(filepath.Join(dir, "CLAUDE.md"))
	require.NoError(t, err)
	assert.Equal(t, "# rules\n", string(got))
}

func TestBrainEditRoot_RefusedWithoutTheLocalStaticPrincipal(t *testing.T) {
	// No principal in context is the model-facing case (and the default in
	// this test server): the privileged door must stay shut.
	dir := newBrainRepo(t)
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_edit_root", map[string]any{
		"path": "CLAUDE.md", "old_str": "# rules", "new_str": "# rewritten",
	})
	require.Contains(t, resp, "error")

	got, err := os.ReadFile(filepath.Join(dir, "CLAUDE.md"))
	require.NoError(t, err)
	assert.Equal(t, "# rules\n", string(got), "governance file must be untouched")
}

func TestBrainGet_CannotReachSessionTranscripts(t *testing.T) {
	// Pre-existing hole, not introduced here: api.ReadNote resolves any
	// brain-relative path and parseFrontmatter returns the WHOLE file as body
	// when there is no frontmatter fence. archive/ holds verbatim Claude
	// session transcripts (up to 500 KB) that BM25 never indexes, so they are
	// invisible to search and trivially readable by path — and CLAUDE.md
	// documents the layout.
	dir := newBrainRepo(t)
	require.NoError(t, os.MkdirAll(filepath.Join(dir, "archive/claude-sessions/koala"), 0o755))
	require.NoError(t, os.WriteFile(
		filepath.Join(dir, "archive/claude-sessions/koala/session-1.md"),
		[]byte("verbatim transcript with tool output\n"), 0o644))

	srv := mcp.NewServer(dir, nil, nil, nil)
	resp := call(t, srv, "brain_get", map[string]any{"path": "archive/claude-sessions/koala/session-1.md"})

	require.Contains(t, resp, "error", "brain_get must not read outside knowledge/ and wiki/")
	assert.NotContains(t, string(mustJSON(t, resp)), "verbatim transcript")
}

func TestBrainGet_StillReadsNotes(t *testing.T) {
	dir := newBrainRepo(t)
	srv := mcp.NewServer(dir, nil, nil, nil)

	resp := call(t, srv, "brain_get", map[string]any{"path": "wiki/homelab/facts/n.md"})
	assert.NotContains(t, resp, "error", "%v", resp["error"])
}

func mustJSON(t *testing.T, v any) []byte {
	t.Helper()
	b, err := json.Marshal(v)
	require.NoError(t, err)
	return b
}

// ---- hyperguild#97: a governance rewrite must be observed, not just gated ----

// govSink captures audit records. Governance edits are rare, so the whole
// history is kept and asserted on rather than sampled.
type govSink struct {
	entries  []capture.AuditEntry
	outcomes []capture.AuditOutcome
	recErr   error
}

func (s *govSink) Reserve(context.Context, classification.Level) (capture.AuditOutcome, error) {
	return capture.AuditCentral, nil
}

func (s *govSink) Record(_ context.Context, e capture.AuditEntry, o capture.AuditOutcome) error {
	s.entries = append(s.entries, e)
	s.outcomes = append(s.outcomes, o)
	return s.recErr
}

type govNotifier struct {
	msgs []string
	err  error
}

func (n *govNotifier) Notify(_ context.Context, msg string) error {
	n.msgs = append(n.msgs, msg)
	return n.err
}

// govServer wires capture (which is what re-derives the static principal) plus
// the #97 observer, and returns the brain dir so the test can read the file.
func govServer(t *testing.T) (*mcp.Server, string, *govSink, *govNotifier) {
	t.Helper()
	dir := newBrainRepo(t)
	cfg, err := classification.Load(dir)
	require.NoError(t, err)
	svc := capture.NewService(brainstore.New(dir), capFakeTracker{}, cfg, audit.NewSlogSink(nil))

	srv := mcp.NewServer(dir, nil, nil, nil)
	srv.WithCapture(svc, nil, capStaticTok, "local-cli", capturehttp.NewOriginResolver(nil))
	sink, notifier := &govSink{}, &govNotifier{}
	srv.WithGovernanceObserver(sink, notifier)
	return srv, dir, sink, notifier
}

// authCall is call() with an Authorization header, so the static principal is
// present and brain_edit_root's gate opens.
func authCall(t *testing.T, srv *mcp.Server, authz, name string, args map[string]any) map[string]any {
	t.Helper()
	req := httptest.NewRequest(http.MethodPost, "/mcp", body(t, map[string]any{
		"jsonrpc": "2.0", "id": 1, "method": "tools/call",
		"params": map[string]any{"name": name, "arguments": args},
	}))
	if authz != "" {
		req.Header.Set("Authorization", authz)
	}
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, req)
	var resp map[string]any
	require.NoError(t, json.Unmarshal(rr.Body.Bytes(), &resp))
	return resp
}

func sha256hex(s string) string {
	sum := sha256.Sum256([]byte(s))
	return hex.EncodeToString(sum[:])
}

func TestBrainEditRoot_RecordsAnAuditEntryNamingPrincipalPathAndBothHashes(t *testing.T) {
	// The gate proves a rewrite was ALLOWED. Only a record proves one HAPPENED
	// — and brain-sync will commit it within 15 minutes authored `brain-sync`,
	// so git history cannot tell it apart from routine note traffic.
	srv, dir, sink, _ := govServer(t)

	resp := authCall(t, srv, "Bearer "+capStaticTok, "brain_edit_root", map[string]any{
		"path": "CLAUDE.md", "old_str": "# rules", "new_str": "# rewritten",
	})
	require.NotContains(t, resp, "error", "%v", resp["error"])

	require.Len(t, sink.entries, 1, "exactly one audit record per governance rewrite")
	e := sink.entries[0]
	assert.Equal(t, "local-cli", e.Principal)
	assert.Contains(t, e.Items, "CLAUDE.md", "the record must name what was rewritten")

	joined := strings.Join(e.SecurityEvents, " ")
	assert.Contains(t, joined, sha256hex("# rules\n"), "before-hash must be recorded")
	assert.Contains(t, joined, sha256hex("# rewritten\n"), "after-hash must be recorded")
	assert.NotZero(t, e.Timestamp)

	got, err := os.ReadFile(filepath.Join(dir, "CLAUDE.md"))
	require.NoError(t, err)
	assert.Equal(t, "# rewritten\n", string(got))
}

func TestBrainEditRoot_NotifiesWithPathAndHashesButNeverContent(t *testing.T) {
	srv, _, _, notifier := govServer(t)

	resp := authCall(t, srv, "Bearer "+capStaticTok, "brain_edit_root", map[string]any{
		"path": "CLAUDE.md", "old_str": "# rules", "new_str": "# rewritten",
	})
	require.NotContains(t, resp, "error", "%v", resp["error"])

	require.Len(t, notifier.msgs, 1)
	msg := notifier.msgs[0]
	assert.Contains(t, msg, "CLAUDE.md")
	assert.Contains(t, msg, "local-cli")
	assert.Contains(t, msg, sha256hex("# rules\n"))
	assert.Contains(t, msg, sha256hex("# rewritten\n"))

	// The notification travels to a phone through a third-party topic. A hash
	// identifies a rewrite; the bytes would leak whatever was written.
	assert.NotContains(t, msg, "# rewritten", "no file content in the notification body")
	assert.NotContains(t, msg, "# rules")
}

func TestBrainEditRoot_RefusedProducesNoRecordNoNotificationNoWrite(t *testing.T) {
	srv, dir, sink, notifier := govServer(t)

	// No Authorization header → no static principal → the gate stays shut.
	resp := authCall(t, srv, "", "brain_edit_root", map[string]any{
		"path": "CLAUDE.md", "old_str": "# rules", "new_str": "# rewritten",
	})
	require.Contains(t, resp, "error")

	assert.Empty(t, sink.entries, "a refusal is not a rewrite — recording one would cry wolf")
	assert.Empty(t, notifier.msgs)
	got, err := os.ReadFile(filepath.Join(dir, "CLAUDE.md"))
	require.NoError(t, err)
	assert.Equal(t, "# rules\n", string(got))
}

func TestBrainEditRoot_FailedEditProducesNoRecordNoNotification(t *testing.T) {
	// Authorised but no match: the door opened and nothing went through it.
	srv, _, sink, notifier := govServer(t)

	resp := authCall(t, srv, "Bearer "+capStaticTok, "brain_edit_root", map[string]any{
		"path": "CLAUDE.md", "old_str": "absent-from-the-file", "new_str": "x",
	})
	require.Contains(t, resp, "error")

	assert.Empty(t, sink.entries)
	assert.Empty(t, notifier.msgs)
}

func TestBrainEdit_OnOrdinaryNotesIsNotAudited(t *testing.T) {
	// The decided asymmetry (#97): note edits are covered by git history, which
	// carries the same before/after bytes with a diff. Governance files get the
	// extra trail because they change what later agents obey, not because they
	// are harder to reconstruct.
	srv, _, sink, notifier := govServer(t)

	resp := authCall(t, srv, "Bearer "+capStaticTok, "brain_edit", map[string]any{
		"path": "wiki/homelab/facts/n.md", "old_str": "beta", "new_str": "BETA",
	})
	require.NotContains(t, resp, "error", "%v", resp["error"])

	assert.Empty(t, sink.entries, "note edits must not fill the governance audit trail")
	assert.Empty(t, notifier.msgs)
}