package pipeline

import (
	"context"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"textmachine/backend/internal/chunk"
	"textmachine/backend/internal/obs"
	"textmachine/backend/internal/store"
)

// rebill_test.go: the consent-to-a-re-payment gate (D20.2-Q2, rebill.go). The load-bearing property is
// NEGATIVE — that a run which would re-pay for already-billed work stops BEFORE any reservation — so
// every scenario asserts the money state (committed unchanged, reserved 0), the provider-call count and
// the durable rows, not just the error string.

// driftPipelineVersion bumps the prompt_version of EVERY stage in the fixture pipeline, so BOTH wave
// snapshots move — the "the whole book would be re-paid" case the threshold exists for.
func driftPipelineVersion(t *testing.T, bookPath string) {
	t.Helper()
	path := filepath.Join(filepath.Dir(bookPath), "pipeline.yaml")
	raw, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	changed := strings.ReplaceAll(string(raw), "prompt_version: v-test", "prompt_version: v-test-drift")
	if changed == string(raw) {
		t.Fatal("setup: prompt_version token not found in the fixture pipeline")
	}
	writeFile(t, path, changed)
}

// chunksOf is the book's current chunk manifest — the "which positions still exist" input the
// projection needs so an orphaned row is not billed to the operator's consent.
func chunksOf(t *testing.T, r *Runner) []chunk.Chunk {
	t.Helper()
	chunks, err := r.bookChunks()
	if err != nil {
		t.Fatal(err)
	}
	return chunks
}

// moneyState is the book's ledger + durable resume state, for before/after comparison across a refusal.
type moneyState struct {
	committed, reserved float64
	draftSnap, editSnap string
	calls               int
}

func readMoneyState(t *testing.T, r *Runner, rec *reqRec) moneyState {
	t.Helper()
	committed, reserved, err := r.Store.SpentUSD("test-book")
	if err != nil {
		t.Fatal(err)
	}
	m := moneyState{committed: committed, reserved: reserved, calls: rec.count()}
	if cs, err := r.Store.GetChunkStatus("test-book", 1, 0, "draft"); err == nil && cs != nil {
		m.draftSnap = cs.SnapshotID
	}
	if cs, err := r.Store.GetChunkStatus("test-book", 1, 0, "edit"); err == nil && cs != nil {
		m.editSnap = cs.SnapshotID
	}
	return m
}

// TestRebillConsentRefusesOverThresholdBeforeAnyMoney is the pack's headline invariant: --resnapshot
// alone no longer re-buys a book silently. The run stops with the SUM and the unit count, having
// reserved nothing, called nothing and rewritten no durable row.
func TestRebillConsentRefusesOverThresholdBeforeAnyMoney(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, draftEdit)
	defer srv.Close()
	bookPath := setupProject(t, srv.URL)
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r1 := newRunner(t, bookPath)
	if _, err := r1.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	before := readMoneyState(t, r1, rec)
	r1.Close()
	if before.committed <= 0 || before.calls != 2 {
		t.Fatalf("setup: run 1 must bill 2 calls, got committed=%v calls=%d", before.committed, before.calls)
	}

	driftPipelineVersion(t, bookPath)

	r2 := newRunner(t, bookPath)
	defer r2.Close()
	r2.Resnapshot = true // permission to RE-PIN — deliberately not consent to the AMOUNT
	_, err := r2.TranslateBook(ctx)
	if err == nil {
		t.Fatal("a re-payment over the consent threshold must refuse, not proceed on --resnapshot alone")
	}
	msg := err.Error()
	for _, want := range []string{"RE-PAY", "chunk×stage unit(s)", "--accept-rebill", "consent threshold"} {
		if !strings.Contains(msg, want) {
			t.Errorf("the refusal must name %q so the operator sees what to do; got: %s", want, msg)
		}
	}
	// The projected sum itself must be IN the message (both rows of the fixture, 2×fakeCallUSD).
	if !strings.Contains(msg, "0.003640") {
		t.Errorf("the refusal must carry the projected amount (~$%.6f); got: %s", 2*fakeCallUSD, msg)
	}

	after := readMoneyState(t, r2, rec)
	if after.calls != before.calls {
		t.Errorf("a refused run must reach no provider: calls %d → %d", before.calls, after.calls)
	}
	if after.committed != before.committed || after.reserved != 0 {
		t.Errorf("a refused run must move no money: committed %v → %v, reserved=%v", before.committed, after.committed, after.reserved)
	}
	if after.draftSnap != before.draftSnap || after.editSnap != before.editSnap {
		t.Errorf("a refused run must not re-pin any durable row: draft %.12s → %.12s, edit %.12s → %.12s",
			before.draftSnap, after.draftSnap, before.editSnap, after.editSnap)
	}
}

// TestRebillConsentGivenProceeds is the positive half: with the consent the same run goes through and
// really does re-pay (so the gate is a gate, not a permanent stop).
func TestRebillConsentGivenProceeds(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, draftEdit)
	defer srv.Close()
	bookPath := setupProject(t, srv.URL)
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r1 := newRunner(t, bookPath)
	if _, err := r1.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	r1.Close()
	callsAfterRun1 := rec.count()

	driftPipelineVersion(t, bookPath)

	r2 := newRunner(t, bookPath)
	defer r2.Close()
	r2.Resnapshot = true
	r2.AcceptRebill = RebillConsent{Given: true}
	res, err := r2.TranslateBook(ctx)
	if err != nil {
		t.Fatalf("consent given → the run must proceed: %v", err)
	}
	if rec.count() <= callsAfterRun1 {
		t.Fatalf("the consented run must actually re-call the provider: calls=%d (after run1=%d)", rec.count(), callsAfterRun1)
	}
	if res.TotalUSD <= 0 {
		t.Fatal("the consented re-translation must be billed")
	}
}

// TestRebillConsentCapBelowProjectionRefuses pins the Р6 half that makes the consent CONCRETE: a named
// ceiling below the projection refuses, and the same ceiling above it proceeds. Without the cap branch
// `--accept-rebill=0.001` would be a blanket consent under a number.
func TestRebillConsentCapBelowProjectionRefuses(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, draftEdit)
	defer srv.Close()
	bookPath := setupProject(t, srv.URL)
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r1 := newRunner(t, bookPath)
	if _, err := r1.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	r1.Close()
	callsAfterRun1 := rec.count()

	driftPipelineVersion(t, bookPath)

	// Ceiling BELOW the projected $0.00364 → refuse.
	r2 := newRunner(t, bookPath)
	r2.Resnapshot = true
	r2.AcceptRebill = RebillConsent{Given: true, Capped: true, CapUSD: 0.001}
	_, err := r2.TranslateBook(ctx)
	r2.Close()
	if err == nil || !strings.Contains(err.Error(), "caps consent at") {
		t.Fatalf("a ceiling below the projection must refuse naming the cap, got: %v", err)
	}
	if rec.count() != callsAfterRun1 {
		t.Fatalf("a cap-refused run must reach no provider: calls=%d", rec.count())
	}

	// Ceiling ABOVE it → proceed.
	r3 := newRunner(t, bookPath)
	defer r3.Close()
	r3.Resnapshot = true
	r3.AcceptRebill = RebillConsent{Given: true, Capped: true, CapUSD: 0.01}
	if _, err := r3.TranslateBook(ctx); err != nil {
		t.Fatalf("a ceiling above the projection must proceed: %v", err)
	}
	if rec.count() <= callsAfterRun1 {
		t.Fatalf("the capped-but-sufficient consent must re-call the provider: calls=%d", rec.count())
	}
}

// TestRebillUnderThresholdProceedsUnasked pins the ratified "below the threshold — automatically"
// behaviour, through the book's own `rebill_consent_usd` override (a cent-scale append must not cost
// the operator a round-trip). It also pins the override itself, which is otherwise unreachable.
func TestRebillUnderThresholdProceedsUnasked(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, draftEdit)
	defer srv.Close()
	bookPath := setupProjectOpts(t, srv.URL, projectOpts{regenerate: 1, rebillConsentUSD: 1.0})
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r1 := newRunner(t, bookPath)
	if r1.Book.RebillConsentUSD != 1.0 {
		t.Fatalf("setup: the book override did not load, got %v", r1.Book.RebillConsentUSD)
	}
	if _, err := r1.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	r1.Close()
	callsAfterRun1 := rec.count()

	driftPipelineVersion(t, bookPath)

	r2 := newRunner(t, bookPath)
	defer r2.Close()
	r2.Resnapshot = true // NO --accept-rebill: the projection ($0.00364) is under the book's $1.00 threshold
	if _, err := r2.TranslateBook(ctx); err != nil {
		t.Fatalf("a re-payment under the threshold must proceed unasked: %v", err)
	}
	if rec.count() <= callsAfterRun1 {
		t.Fatalf("the under-threshold run must still do the work: calls=%d", rec.count())
	}
}

// TestRebillConsentThresholdFormula is the ratified arithmetic, in isolation: min($0.50, 5%×projected),
// the $0.50 FLOOR for a book with nothing processed yet (the 5% branch would be $0 and would demand
// consent for a cent), and the book override winning over both.
func TestRebillConsentThresholdFormula(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, draftEdit)
	defer srv.Close()
	r := newRunner(t, setupProject(t, srv.URL))
	defer r.Close()

	for _, tc := range []struct {
		name      string
		projected float64
		override  float64
		want      float64
	}{
		{"floor when nothing processed", 0, 0, 0.50},
		{"5% of a cheap book", 4.0, 0, 0.20},
		{"capped at $0.50 on an expensive book", 100.0, 0, 0.50},
		{"exactly at the $10 crossover", 10.0, 0, 0.50},
		{"book override wins", 100.0, 2.5, 2.5},
	} {
		r.Book.RebillConsentUSD = tc.override
		got, _ := r.rebillConsentThreshold(tc.projected)
		if got != tc.want {
			t.Errorf("%s: threshold(projected=%v, override=%v) = %v, want %v", tc.name, tc.projected, tc.override, got, tc.want)
		}
	}
}

// TestRebillProjectionIsPerWave pins the money keystone the wave split bought: a mined sign moves ONLY
// the edit-wave snapshot, so the projection must count ONE row (the edit), never the draft. A whole-
// pipeline comparison would report the paid draft wave as re-billed and ask the owner to consent to
// double the real amount — the "re-paid ONCE" invariant, seen from the consent side.
func TestRebillProjectionIsPerWave(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, draftEdit)
	defer srv.Close()
	src := "方源走进了魔法学院的图书馆。"
	seed := "terms:\n  - src: 魔法学院\n    dst: Академия магии\n    status: approved\n"
	bookPath := setupProjectOpts(t, srv.URL, projectOpts{source: src, glossarySeed: seed, regenerate: 0})
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r1 := newRunner(t, bookPath)
	if _, err := r1.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	editBefore, err := r1.Store.GetChunkStatus("test-book", 1, 0, "edit")
	if err != nil || editBefore == nil {
		t.Fatalf("setup: edit row after run 1: %v / %v", editBefore, err)
	}
	// Baseline, and the OTHER direction of the per-wave rule: with both waves resolved under their own
	// current snapshots nothing is superseded. Comparing an edit row against the draft wave's snapshot
	// (or vice versa) would report a re-bill on a book that has not drifted at all.
	statusesBefore, err := r1.Store.ChunkStatusesForBook("test-book")
	if err != nil {
		t.Fatal(err)
	}
	if proj, err := r1.projectRebill(statusesBefore, chunksOf(t, r1)); err != nil || proj.Rows != 0 {
		t.Fatalf("a freshly-run book projects no re-bill; each row must be judged against ITS OWN wave, got %+v (err=%v)", proj, err)
	}
	r1.Close()

	dir := filepath.Dir(bookPath)
	writeFile(t, filepath.Join(dir, "mined-delta.yaml"), "terms:\n  - src: 方源\n    dst: Фан Юань\n    status: approved\n")
	rawBook, err := os.ReadFile(bookPath)
	if err != nil {
		t.Fatal(err)
	}
	writeFile(t, bookPath, strings.Replace(string(rawBook), "pipeline: pipeline.yaml", "pipeline: pipeline.yaml\nmined_delta: mined-delta.yaml", 1))

	r2 := newRunner(t, bookPath)
	defer r2.Close()
	if err := r2.seedGlossary(ctx); err != nil { // materializes the banks the wave snapshots fold
		t.Fatal(err)
	}
	statuses, err := r2.Store.ChunkStatusesForBook("test-book")
	if err != nil {
		t.Fatal(err)
	}
	proj, err := r2.projectRebill(statuses, chunksOf(t, r2))
	if err != nil {
		t.Fatal(err)
	}
	if proj.Rows != 1 {
		t.Fatalf("a mined sign re-bills the EDIT wave only — projection must count 1 row, got %d ($%.6f)", proj.Rows, proj.USD)
	}
	if proj.USD != editBefore.CostUSD {
		t.Fatalf("the projected amount must be the edit row's stored cost $%.6f, got $%.6f", editBefore.CostUSD, proj.USD)
	}
}

// TestRebillProjectionExcludesSkippedAndUnchanged: a `skipped` row never reached a provider and cost
// nothing, so re-running it is NEW work, not a re-payment — counting it would inflate the number the
// operator consents to. And with no drift at all the projection is empty, so an ordinary $0 resume is
// never asked anything.
func TestRebillProjectionExcludesSkippedAndUnchanged(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, func(body string) (string, string) {
		if strings.Contains(body, "ОТКАЗ") && !isEditBody(body) {
			return "Извините, я не могу перевести это.", "stop"
		}
		return draftEdit(body)
	})
	defer srv.Close()
	bookPath := setupProjectOpts(t, srv.URL, projectOpts{source: "ОТКАЗ", regenerate: 0})
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r1 := newRunner(t, bookPath)
	if _, err := r1.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	statuses, err := r1.Store.ChunkStatusesForBook("test-book")
	if err != nil {
		t.Fatal(err)
	}
	var skipped int
	for _, cs := range statuses {
		if cs.Disposition == string(DispSkipped) {
			skipped++
		}
	}
	if skipped == 0 {
		t.Fatal("setup: the refusal fixture must leave a skipped edit row")
	}
	// No drift yet: nothing is superseded, so nothing is projected.
	if proj, err := r1.projectRebill(statuses, chunksOf(t, r1)); err != nil || proj.Rows != 0 || proj.USD != 0 {
		t.Fatalf("an undrifted book must project no re-bill, got %+v (err=%v)", proj, err)
	}
	r1.Close()

	driftPipelineVersion(t, bookPath)

	r2 := newRunner(t, bookPath)
	defer r2.Close()
	if err := r2.seedGlossary(ctx); err != nil {
		t.Fatal(err)
	}
	proj, err := r2.projectRebill(statuses, chunksOf(t, r2))
	if err != nil {
		t.Fatal(err)
	}
	if proj.Rows != 1 {
		t.Fatalf("only the BILLED draft row may be projected (the skipped edit costs nothing to redo), got %d rows", proj.Rows)
	}
	if proj.USD != fakeCallUSD {
		t.Fatalf("projected amount = the draft row's stored cost $%.6f, got $%.6f", fakeCallUSD, proj.USD)
	}
}

// TestRebillProjectionIgnoresRetiredStages: a row left behind by a stage the pipeline no longer runs
// can never be re-billed, because nothing will call it. Counting it would inflate the amount the
// operator is asked to consent to (and, on a book with a long stage history, arbitrarily so).
func TestRebillProjectionIgnoresRetiredStages(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, draftEdit)
	defer srv.Close()
	bookPath := setupProject(t, srv.URL)
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r := newRunner(t, bookPath)
	defer r.Close()
	if _, err := r.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	// A leftover row of a stage this pipeline does not have, under a snapshot that is nobody's current one.
	if err := r.Store.UpsertChunkStatus(store.ChunkStatus{
		BookID: "test-book", Chapter: 1, ChunkIdx: 0, Stage: "annotate",
		SnapshotID: strings.Repeat("a", 64), ContentHash: "x", Disposition: string(DispOK), CostUSD: 9.99,
	}); err != nil {
		t.Fatal(err)
	}
	statuses, err := r.Store.ChunkStatusesForBook("test-book")
	if err != nil {
		t.Fatal(err)
	}
	proj, err := r.projectRebill(statuses, chunksOf(t, r))
	if err != nil {
		t.Fatal(err)
	}
	if proj.Rows != 0 || proj.USD != 0 {
		t.Fatalf("a retired stage's row is not re-billable and must not be projected, got %+v", proj)
	}
}

// TestRebillProjectionIgnoresVanishedChunks: the other orphan class. If the source is shortened, the
// rows of the removed positions stay in the store but nothing will re-run them, so they must not be
// billed to the operator's consent. Over-asking is the safe direction, but a number that is asked for
// and then not spent is how such a number stops being read.
func TestRebillProjectionIgnoresVanishedChunks(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, draftEdit)
	defer srv.Close()
	bookPath := setupProjectOpts(t, srv.URL, projectOpts{source: "ГЛАВАПЕРВАЯ\fГЛАВАВТОРАЯ", regenerate: 0})
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r1 := newRunner(t, bookPath)
	if _, err := r1.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	statuses, err := r1.Store.ChunkStatusesForBook("test-book")
	if err != nil {
		t.Fatal(err)
	}
	if len(statuses) != 4 { // 2 chapters × (draft + edit)
		t.Fatalf("setup: want 4 stored rows over 2 chapters, got %d", len(statuses))
	}
	r1.Close()

	// Chapter 2 disappears from the source, and the config drifts so everything surviving is superseded.
	writeFile(t, filepath.Join(filepath.Dir(bookPath), "source.txt"), "ГЛАВАПЕРВАЯ")
	driftPipelineVersion(t, bookPath)

	r2 := newRunner(t, bookPath)
	defer r2.Close()
	if err := r2.seedGlossary(ctx); err != nil {
		t.Fatal(err)
	}
	proj, err := r2.projectRebill(statuses, chunksOf(t, r2))
	if err != nil {
		t.Fatal(err)
	}
	if proj.Rows != 2 {
		t.Fatalf("only the SURVIVING chapter's 2 rows are re-billable (chapter 2 is gone from the manifest), got %d rows / $%.6f", proj.Rows, proj.USD)
	}
}

// TestRebillConsentKeepsReadOnlyPathsAlive is the D20.4 $0 contract: a book whose next translate would
// be refused for want of consent must stay fully inspectable — status/report/export make no money
// decision, so the gate must not be anywhere near them.
func TestRebillConsentKeepsReadOnlyPathsAlive(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, draftEdit)
	defer srv.Close()
	bookPath := setupProject(t, srv.URL)
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r1 := newRunner(t, bookPath)
	if _, err := r1.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	r1.Close()

	driftPipelineVersion(t, bookPath)

	// The write path refuses…
	rw := newRunner(t, bookPath)
	rw.Resnapshot = true
	_, werr := rw.TranslateBook(ctx)
	rw.Close()
	if werr == nil {
		t.Fatal("setup: the write path must be refused for this to mean anything")
	}

	// …and every read-only surface still answers, at $0.
	ro, err := NewReadOnlyRunner(bookPath, obs.NewLogger())
	if err != nil {
		t.Fatalf("a book awaiting re-bill consent must still open read-only: %v", err)
	}
	defer ro.Close()
	callsBefore := rec.count()
	rep, err := ro.Status(ctx)
	if err != nil {
		t.Fatalf("status must stay alive: %v", err)
	}
	if !rep.ConfigDrift {
		t.Error("status should report the drift that the consent gate is refusing over")
	}
	if _, err := ro.Export(false); err != nil {
		t.Fatalf("export must stay alive: %v", err)
	}
	if _, err := ro.QualityReport(); err != nil {
		t.Fatalf("report must stay alive: %v", err)
	}
	if rec.count() != callsBefore {
		t.Fatalf("the read-only surfaces must stay $0: calls %d → %d", callsBefore, rec.count())
	}
}

// TestRedriveRefusesRebillBeforeDestructiveReset is the external-review 1c discipline applied to the new
// gate: a redrive that would re-pay over the threshold must refuse BEFORE ResetChunkStages, so the flag
// telemetry it was about to re-attack still exists afterwards. Moving the check below the reset loop
// leaves this test with a deleted row.
func TestRedriveRefusesRebillBeforeDestructiveReset(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, func(body string) (string, string) {
		if strings.Contains(body, "ОТКАЗ") && !isEditBody(body) {
			return "Извините, я не могу перевести это.", "stop"
		}
		return draftEdit(body)
	})
	defer srv.Close()
	bookPath := setupProjectOpts(t, srv.URL, projectOpts{source: "ОТКАЗ", regenerate: 0})
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r1 := newRunner(t, bookPath)
	if _, err := r1.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	r1.Close()
	callsAfterRun1 := rec.count()

	driftPipelineVersion(t, bookPath)

	r2 := newRunner(t, bookPath)
	defer r2.Close()
	r2.Resnapshot = true // skips the drift COMPARISON — but not the question of what the re-pin costs
	sum, res, err := r2.Redrive(ctx, RedriveSelector{Chapter: -1, ChunkIdx: -1})
	if err == nil {
		t.Fatal("redrive --resnapshot over the consent threshold must refuse")
	}
	if !strings.Contains(err.Error(), "--accept-rebill") {
		t.Errorf("the redrive refusal must name the flag; got: %v", err)
	}
	if res != nil || sum.ResetRun {
		t.Errorf("a consent-refused redrive must not re-run: res=%v resetRun=%v", res, sum.ResetRun)
	}
	if cs, _ := r2.Store.GetChunkStatus("test-book", 1, 0, "draft"); cs == nil || cs.Disposition != string(DispFlagged) {
		t.Fatalf("the flagged row must survive a consent-refused redrive (1c torn-state class), got: %+v", cs)
	}
	if rec.count() != callsAfterRun1 {
		t.Fatalf("a consent-refused redrive must reach no provider: calls=%d", rec.count())
	}
}

// TestRedriveDryRunNeedsNoConsent: --dry-run reports the plan and touches nothing, so it is $0 by
// construction and must never be gated on a spend consent.
func TestRedriveDryRunNeedsNoConsent(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, func(body string) (string, string) {
		if strings.Contains(body, "ОТКАЗ") && !isEditBody(body) {
			return "Извините, я не могу перевести это.", "stop"
		}
		return draftEdit(body)
	})
	defer srv.Close()
	bookPath := setupProjectOpts(t, srv.URL, projectOpts{source: "ОТКАЗ", regenerate: 0})
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r1 := newRunner(t, bookPath)
	if _, err := r1.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	r1.Close()

	driftPipelineVersion(t, bookPath)

	r2 := newRunner(t, bookPath)
	defer r2.Close()
	r2.Resnapshot = true
	sum, res, err := r2.Redrive(ctx, RedriveSelector{Chapter: -1, ChunkIdx: -1, DryRun: true})
	if err != nil {
		t.Fatalf("a dry-run redrive spends nothing and must not need consent: %v", err)
	}
	if res != nil || sum.ResetRun || len(sum.Targets) == 0 {
		t.Fatalf("dry-run must report a plan without running: %+v (res=%v)", sum, res)
	}
}

// TestProjectBookUSDExtrapolates pins the EXTRAPOLATION itself — the part a fully-processed fixture
// cannot see, because there processed == total and every wrong denominator gives the right answer. The
// threshold is 5% of this number, so an average taken over the wrong denominator would silently move
// the point at which the operator is asked for consent.
func TestProjectBookUSDExtrapolates(t *testing.T) {
	units := []editUnit{
		{Chapter: 1, FirstChunkIdx: 0, Members: []chunk.Chunk{{Chapter: 1, ChunkIdx: 0}}},
		{Chapter: 2, FirstChunkIdx: 0, Members: []chunk.Chunk{{Chapter: 2, ChunkIdx: 0}}},
		{Chapter: 3, FirstChunkIdx: 0, Members: []chunk.Chunk{{Chapter: 3, ChunkIdx: 0}}},
	}
	// Only chapter 1 has been attempted: draft + edit resolved ok at $1.00 each. Chapters 2-3 are pending.
	byChunk := map[chunkKey][]store.ChunkStatus{
		{chapter: 1, chunkIdx: 0}: {
			{Stage: "draft", Disposition: string(DispOK), CostUSD: 1.0},
			{Stage: "edit", Disposition: string(DispOK), CostUSD: 1.0},
		},
	}
	// $2.00 over 1 processed unit × 3 units in the book = $6.00.
	if got := projectBookUSD(units, byChunk, 1, 1); got != 6.0 {
		t.Fatalf("projected book cost = %v, want 6.0 ($2.00/processed unit × 3 units)", got)
	}
	// Nothing processed → no basis to extrapolate from → $0 (which is what makes the threshold fall back
	// to its $0.50 floor rather than to 5%×0 = $0).
	if got := projectBookUSD(units, map[chunkKey][]store.ChunkStatus{}, 1, 1); got != 0 {
		t.Fatalf("with nothing processed the projection is 0, got %v", got)
	}
}

// TestProjectBookUSDMatchesStatus locks the single-definition extraction: the threshold's base and the
// number `tmctl status` publishes are computed by the SAME function, so they cannot drift apart.
func TestProjectBookUSDMatchesStatus(t *testing.T) {
	rec := &reqRec{}
	srv := newJSONProvider(rec, draftEdit)
	defer srv.Close()
	bookPath := setupProject(t, srv.URL)
	ctx := obs.WithReqInfo(context.Background(), obs.ReqInfo{TraceID: obs.NewTraceID()})

	r := newRunner(t, bookPath)
	defer r.Close()
	if _, err := r.TranslateBook(ctx); err != nil {
		t.Fatal(err)
	}
	rep, err := r.Status(ctx)
	if err != nil {
		t.Fatal(err)
	}
	chunks, err := r.bookChunks()
	if err != nil {
		t.Fatal(err)
	}
	statuses, err := r.Store.ChunkStatusesForBook("test-book")
	if err != nil {
		t.Fatal(err)
	}
	byChunk := map[chunkKey][]store.ChunkStatus{}
	for _, cs := range statuses {
		byChunk[chunkKey{cs.Chapter, cs.ChunkIdx}] = append(byChunk[chunkKey{cs.Chapter, cs.ChunkIdx}], cs)
	}
	got := projectBookUSD(r.outputUnits(chunks), byChunk,
		len(r.waveStagesIndexed(waveDraft)), len(r.waveStagesIndexed(waveEdit)))
	if got != rep.ProjectedBookUSD {
		t.Fatalf("projectBookUSD = %v but status reports %v — the threshold base and the published projection diverged", got, rep.ProjectedBookUSD)
	}
	if got != 2*fakeCallUSD {
		t.Fatalf("the one-unit fixture projects its own cost: got %v, want %v", got, 2*fakeCallUSD)
	}
}