// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Commercial
// SPDX-FileCopyrightText: 2025-2026 Christian Galo

package forms

import (
	"strings"
	"testing"
)

// The three modes and the rules the render decides (design D5, D8, D9,
// D11, D12). The markup itself is asserted where the parts execute
// (internal/server's render tests); these assert the view the parts are
// handed, which is where every decision is made.

func sided() FormSpec {
	return FormSpec{
		Name:       "test.sided",
		Kind:       KindCreate,
		Family:     Stacked,
		Method:     "POST",
		Path:       "/partials/test",
		EditMethod: "PUT",
		EditPath:   "/partials/test/{id}",
		Commit:     "Create",
		CommitEdit: "Save changes",
		WayOut:     LinkOut("Cancel", "/list"),
		Fields: []Field{
			{Name: "name", Label: "Name", Control: Text},
			// A record is created active, so Active is edit-only; the
			// why is this comment, not a string in the declaration.
			{Name: "is_active", Label: "Active", Control: Checkbox, Value: "true", Only: EditOnly},
			{Name: "seed", Label: "Seed", Control: Text, Optional: true,
				Only: CreateOnly, Notice: "Set now; this cannot be changed later."},
		},
	}
}

func fieldNames(v FormView) []string {
	out := make([]string, 0, len(v.Fields))
	for _, f := range v.Fields {
		out = append(out, f.Name)
	}
	return out
}

func TestRenderSidesCarryTheirOwnFields(t *testing.T) {
	create := Render(sided(), Binding{Mode: ModeUnbound, Side: CreateOnly})
	if got := strings.Join(fieldNames(create), ","); got != "name,seed" {
		t.Errorf("create side fields = %q", got)
	}
	edit := Render(sided(), Binding{Mode: ModeRecord, Side: EditOnly})
	if got := strings.Join(fieldNames(edit), ","); got != "name,is_active" {
		t.Errorf("edit side fields = %q", got)
	}
	// The declared reason documents the difference for the registry and
	// the reviewer; it is never copy, so no field renders it (maintainer,
	// 2026-09-03). Only a declared Notice reaches the page.
	for _, f := range edit.Fields {
		if f.Name == "is_active" && f.Notice != "" {
			t.Errorf("a one-sided field renders nothing unless it declares a notice, got %q", f.Notice)
		}
	}
	for _, f := range create.Fields {
		if f.Name == "seed" && f.Notice != "Set now; this cannot be changed later." {
			t.Errorf("a declared notice must render, got %q", f.Notice)
		}
	}
}

// The create page and the edit form are one declaration in two modes: the
// kind, the commit label, the route and the way out follow the side, and
// nothing else does (design D5; finding FA-19).
func TestRenderSideDecidesKindCommitRouteAndWayOut(t *testing.T) {
	create := Render(sided(), Binding{Mode: ModeUnbound, Side: CreateOnly})
	if create.Kind != KindCreate || create.Commit != "Create" || !create.WayOut.Shown() {
		t.Errorf("create side = %+v", create)
	}
	if !strings.Contains(string(create.HX), `hx-post="/partials/test"`) {
		t.Errorf("create side verb = %q", create.HX)
	}

	edit := Render(sided(), Binding{Mode: ModeRecord, Side: EditOnly, Action: "/partials/test/7"})
	if edit.Kind != KindEdit || edit.Commit != "Save changes" {
		t.Errorf("edit side = %+v", edit)
	}
	if edit.WayOut.Shown() {
		t.Error("an always-open edit form carries no way out")
	}
	if !strings.Contains(string(edit.HX), `hx-put="/partials/test/7"`) {
		t.Errorf("edit side verb = %q", edit.HX)
	}
}

// Every mutation form locks its commit and shows the request in flight
// (finding FA-20).
func TestRenderEveryMutationDisablesItsCommit(t *testing.T) {
	v := Render(sided(), Binding{Mode: ModeUnbound, Side: CreateOnly})
	for _, want := range []string{`hx-disable="find button[type=submit]"`, `hx-target="this"`, `hx-swap="outerHTML"`} {
		if !strings.Contains(string(v.HX), want) {
			t.Errorf("form attributes %q missing %q", v.HX, want)
		}
	}
}

func TestRenderIdsAreStable(t *testing.T) {
	v := Render(sided(), Binding{Mode: ModeUnbound, Side: CreateOnly})
	if v.ID != "form-test.sided" {
		t.Errorf("form id = %q", v.ID)
	}
	if v.Fields[0].WrapperID != "form-test.sided-name" {
		t.Errorf("wrapper id = %q", v.Fields[0].WrapperID)
	}
	if v.FormErrorID != "form-test.sided-error" {
		t.Errorf("form error id = %q", v.FormErrorID)
	}
}

// The hint survives the error, both carry ids the control names, and the
// first errored control takes focus (findings FA-48, FA-49; lesson L§41).
func TestRenderSubmissionWiresHintErrorAndFocus(t *testing.T) {
	spec := sided()
	spec.Fields[0].Hint = "As it appears on invoices."
	values := NewValues()
	values.Set("name", "typed")
	errs := NewErrors()
	errs.Field("name", "Enter a name.")

	v := Render(spec, Binding{Mode: ModeSubmission, Side: CreateOnly, Values: values, Errors: errs})
	f := v.Fields[0]
	if f.Value != "typed" {
		t.Errorf("the submitted value must be carried back, got %q", f.Value)
	}
	if f.Hint == "" || f.HintID == "" {
		t.Error("the hint must survive the error, with its id")
	}
	if f.ErrorID == "" || f.Error == "" {
		t.Error("the error must render with its id")
	}
	attrs := string(f.Attrs)
	if !strings.Contains(attrs, `aria-describedby="form-test.sided-name-hint form-test.sided-name-error"`) {
		t.Errorf("described-by wiring = %q", attrs)
	}
	if !strings.Contains(attrs, `aria-invalid="true"`) {
		t.Errorf("aria-invalid missing from %q", attrs)
	}
	if !strings.HasSuffix(attrs, "autofocus") {
		t.Errorf("the first errored control must take focus, got %q", attrs)
	}
	// Only the first errored control takes it.
	if strings.Count(attrs+string(v.Fields[1].Attrs), "autofocus") != 1 {
		t.Error("exactly one control carries autofocus")
	}
}

// An edit form never opens showing errors (lessons L§6, L§7).
func TestRenderRecordModeHasNoErrors(t *testing.T) {
	values := NewValues()
	values.Set("name", "Pro")
	v := Render(sided(), Binding{Mode: ModeRecord, Side: EditOnly, Values: values})
	for _, f := range v.Fields {
		if f.Invalid() {
			t.Errorf("field %q renders an error in record mode", f.Name)
		}
		if strings.Contains(string(f.Attrs), "autofocus") {
			t.Errorf("field %q takes focus in record mode", f.Name)
		}
	}
	if v.FormError != "" {
		t.Error("record mode renders no form-level error")
	}
}

// The constraint attributes come from the declaration and from nowhere
// else, so the browser's rule and the server's rule cannot differ (spec
// form-library "Constraint attributes derive from the declaration").
func TestRenderConstraintAttributesFollowTheDeclaration(t *testing.T) {
	spec := base()
	spec.Fields[0] = Field{
		Name: "code", Label: "Code", Control: Text, MaxLen: 8,
		Pattern: "^[a-z]+$", PatternHint: "Lowercase letters only.",
		Inputmode: "text", Autocomplete: "off",
	}
	v := Render(spec, Binding{Mode: ModeUnbound})
	attrs := string(v.Fields[0].Attrs)
	for _, want := range []string{`required`, `maxlength="8"`, `pattern="^[a-z]+$"`, `inputmode="text"`, `autocomplete="off"`} {
		if !strings.Contains(attrs, want) {
			t.Errorf("attributes %q missing %q", attrs, want)
		}
	}
}

// A currency amount's Step ("0.01") renders alongside Min so the browser's
// spinner and the server's cents-precision rule agree.
func TestRenderStepAttribute(t *testing.T) {
	spec := base()
	spec.Fields[0] = Field{Name: "amount", Label: "Amount", Control: Number, Min: "0.01", Step: "0.01"}
	v := Render(spec, Binding{Mode: ModeUnbound})
	attrs := string(v.Fields[0].Attrs)
	if !strings.Contains(attrs, `step="0.01"`) {
		t.Errorf("attributes %q missing step", attrs)
	}
}

// A select's requiredness is its option set: a "Choose a ..." placeholder
// is disabled, so the control is required; an enabled "None" makes the
// empty value a choice, so it is not (design D12).
func TestRenderSelectRequirednessFollowsItsOptions(t *testing.T) {
	spec := base()
	spec.Fields[0] = Field{Name: "kind", Label: "Kind", Control: Select, RuntimeOptions: true}

	needed := Render(spec, Binding{Mode: ModeUnbound, Options: map[string][]Option{
		"kind": {ChooseOption("a kind"), {Value: "a", Label: "A"}},
	}})
	if !strings.Contains(string(needed.Fields[0].Attrs), "required") {
		t.Errorf("a select that needs a choice is required, got %q", needed.Fields[0].Attrs)
	}
	if !needed.Fields[0].Options[0].Selected || !needed.Fields[0].Options[0].Disabled {
		t.Error("the placeholder opens disabled and selected")
	}

	optional := Render(spec, Binding{Mode: ModeUnbound, Options: map[string][]Option{
		"kind": {NoneOption(), {Value: "a", Label: "A"}},
	}})
	if strings.Contains(string(optional.Fields[0].Attrs), "required") {
		t.Errorf("an optional select is not required, got %q", optional.Fields[0].Attrs)
	}
}

// A radio group has no "choose nothing" member the way a Select's enabled
// empty option does, so its requiredness follows Optional directly, like
// every other control except Select (forms.go's Field.Optional doc).
func TestRenderRadioRequirednessFollowsOptional(t *testing.T) {
	spec := base()
	spec.Fields[0] = Field{Name: "disposition", Label: "Disposition", Control: Radio,
		Options: []Option{{Value: "a", Label: "A"}, {Value: "b", Label: "B"}}}
	required := Render(spec, Binding{Mode: ModeUnbound})
	if !strings.Contains(string(required.Fields[0].Attrs), "required") {
		t.Errorf("a required radio group carries required, got %q", required.Fields[0].Attrs)
	}

	spec.Fields[0].Optional = true
	optional := Render(spec, Binding{Mode: ModeUnbound})
	if strings.Contains(string(optional.Fields[0].Attrs), "required") {
		t.Errorf("an optional radio group is not required, got %q", optional.Fields[0].Attrs)
	}
}

// A checkbox reads its state back from the bound values, so a refusal
// cannot re-tick a box the operator cleared (finding FA-23).
func TestRenderCheckboxCarriesItsStateBack(t *testing.T) {
	spec := base()
	spec.Fields[0] = Field{Name: "public", Label: "Public", Control: Checkbox, Value: "public"}
	values := NewValues()
	values.SetBool(spec.Fields[0], false)
	v := Render(spec, Binding{Mode: ModeSubmission, Values: values, Errors: NewErrors()})
	if v.Fields[0].Checked {
		t.Error("an unticked checkbox must render unticked on the refusal")
	}
	values.SetBool(spec.Fields[0], true)
	v = Render(spec, Binding{Mode: ModeSubmission, Values: values, Errors: NewErrors()})
	if !v.Fields[0].Checked {
		t.Error("a ticked checkbox must render ticked on the refusal")
	}
}

// A dense form is one row of small controls with each field in its
// declared column (design D10).
func TestRenderDenseFamily(t *testing.T) {
	spec := base()
	spec.Family = Dense
	spec.Fields[0].Width = WidthNarrower
	spec.Fields[0].HideLabel = true
	v := Render(spec, Binding{Mode: ModeUnbound})
	if !v.Dense {
		t.Error("the view must report the dense family")
	}
	// A Text control's natural rung is a third; narrower steps it to a
	// quarter.
	if v.Fields[0].ColClass != "col-12 col-xl-3" || !v.Fields[0].Small || !v.Fields[0].LabelHidden {
		t.Errorf("dense field = %+v", v.Fields[0])
	}
}

// ColClass follows the resolved rung for every control the library renders
// in a dense row (design D3, D5): each control's natural rung with no
// declared Width, and the two declarations the codebase actually makes (a
// narrower select, a wider text).
func TestRenderDenseColClass(t *testing.T) {
	oneField := func(f Field) FormSpec {
		spec := denseBase()
		spec.Fields = []Field{f}
		return spec
	}
	for _, tc := range []struct {
		name  string
		field Field
		want  string
	}{
		{"number", Field{Name: "n", Label: "N", Control: Number}, "col-12 col-xl-2"},
		{"date", Field{Name: "d", Label: "D", Control: Date}, "col-12 col-xl-2"},
		{"date-time", Field{Name: "dt", Label: "DT", Control: DateTime}, "col-12 col-xl-3"},
		{"select", Field{Name: "s", Label: "S", Control: Select, Options: []Option{{Value: "a", Label: "A"}}}, "col-12 col-xl-4"},
		{"text", Field{Name: "t", Label: "T", Control: Text}, "col-12 col-xl-4"},
		{"textarea", Field{Name: "ta", Label: "TA", Control: Textarea}, "col-12"},
		{"checkbox", Field{Name: "c", Label: "C", Control: Checkbox, Value: "true"}, "col-12 col-xl-auto"},
		{"hidden", Field{Name: "h", Label: "H", Control: Hidden, Optional: true}, ""},
		{"narrower select", Field{Name: "s2", Label: "S2", Control: Select, Options: []Option{{Value: "a", Label: "A"}}, Width: WidthNarrower}, "col-12 col-xl-3"},
		{"wider text", Field{Name: "t2", Label: "T2", Control: Text, Width: WidthWider}, "col-12 col-xl-6"},
	} {
		t.Run(tc.name, func(t *testing.T) {
			v := Render(oneField(tc.field), Binding{Mode: ModeUnbound})
			if got := v.Fields[0].ColClass; got != tc.want {
				t.Errorf("ColClass = %q, want %q", got, tc.want)
			}
		})
	}
}

// The escape hatch renders in a stable order, because the capture utility
// compares pixels between runs.
func TestRenderEscapeHatchIsOrdered(t *testing.T) {
	spec := base()
	spec.Fields[0].Attrs = map[string]string{"hx-trigger": "input", "hx-get": "/check", "data-role": "x"}
	first := string(Render(spec, Binding{Mode: ModeUnbound}).Fields[0].Attrs)
	for i := 0; i < 20; i++ {
		if got := string(Render(spec, Binding{Mode: ModeUnbound}).Fields[0].Attrs); got != first {
			t.Fatalf("attribute order is not stable:\n%s\n%s", first, got)
		}
	}
	if !strings.Contains(first, `data-role="x" hx-get="/check" hx-trigger="input"`) {
		t.Errorf("attributes = %q", first)
	}
}

// A search form keeps a real method and action, which is the recorded
// no-JavaScript answer for list controls and the lookup.
func TestRenderSearchIsNative(t *testing.T) {
	spec := base()
	spec.Kind = KindSearch
	spec.Method = "GET"
	spec.Path = "/operator/lookup"
	v := Render(spec, Binding{Mode: ModeUnbound})
	if !v.Native || v.Method != "GET" || v.Action != "/operator/lookup" {
		t.Errorf("search form = %+v", v)
	}
	if strings.Contains(string(v.HX), "hx-disable") {
		t.Errorf("a search form locks nothing, got %q", v.HX)
	}
}

// Every form whose refusal is a 422 carries novalidate, so pressing the
// commit with an empty required field reaches the handler and the message
// a person reads is the server's (maintainer, 2026-09-03: pressing Save on
// a cleared name produced no feedback at all). The constraint attributes
// stay on the controls.
func TestRenderServerValidatedFormsCarryNoValidate(t *testing.T) {
	for _, kind := range []Kind{KindCreate, KindEdit, KindSubRecord, KindSettings, KindPreview} {
		spec := base()
		spec.Kind = kind
		if !Render(spec, Binding{Mode: ModeUnbound}).NoValidate {
			t.Errorf("a %s form must carry novalidate", kind)
		}
	}
	for _, kind := range []Kind{KindSearch, KindConfirm} {
		spec := base()
		spec.Kind = kind
		if kind == KindSearch {
			spec.Method = "GET"
		}
		if Render(spec, Binding{Mode: ModeUnbound}).NoValidate {
			t.Errorf("a %s form navigates or confirms; it keeps the browser's validation", kind)
		}
	}
	// The rule does not take the constraints off the control.
	spec := base()
	spec.Fields[0].MaxLen = 8
	attrs := string(Render(spec, Binding{Mode: ModeUnbound}).Fields[0].Attrs)
	if !strings.Contains(attrs, "required") || !strings.Contains(attrs, `maxlength="8"`) {
		t.Errorf("constraint attributes must survive novalidate, got %q", attrs)
	}
}

// The edit side's kind decides the attribute too, since one declaration
// filed as a create form renders both sides.
func TestRenderNoValidateOnBothSides(t *testing.T) {
	if !Render(sided(), Binding{Mode: ModeUnbound, Side: CreateOnly}).NoValidate {
		t.Error("the create side must carry novalidate")
	}
	if !Render(sided(), Binding{Mode: ModeRecord, Side: EditOnly}).NoValidate {
		t.Error("the edit side must carry novalidate")
	}
}

// showIfSpec is the field-set-depends-on-a-value shape entitlement-set rule
// authoring needs: a Hidden marker a handler sets from server-derived data,
// and a field that shows only for one of the marker's values (design D2,
// ShowIf).
func showIfSpec() FormSpec {
	return FormSpec{
		Name: "test.showif", Kind: KindSubRecord, Family: Dense,
		Method: "POST", Path: "/partials/test", Commit: "Add",
		Fields: []Field{
			{Name: "kind", Label: "Kind", Control: Hidden, Optional: true},
			{Name: "amount", Label: "Amount", Control: Number, Optional: true,
				ShowIf: ShowIf{Field: "kind", Equals: []string{"numeric"}}},
		},
	}
}

func TestRenderShowIfHidesAFieldByDefault(t *testing.T) {
	view := Render(showIfSpec(), Binding{Mode: ModeUnbound})
	if got := fieldNames(view); len(got) != 1 || got[0] != "kind" {
		t.Errorf("with no marker value set, only the marker field renders, got %v", got)
	}
}

func TestRenderShowIfRevealsAFieldWhenItsConditionMatches(t *testing.T) {
	values := NewValues()
	values.Set("kind", "numeric")
	view := Render(showIfSpec(), Binding{Mode: ModeRecord, Values: values})
	if got := fieldNames(view); len(got) != 2 || got[1] != "amount" {
		t.Errorf("with the marker set to a matching value, the dependent field renders, got %v", got)
	}
}

func TestRenderShowIfHidesAFieldWhenItsConditionDoesNotMatch(t *testing.T) {
	values := NewValues()
	values.Set("kind", "boolean")
	view := Render(showIfSpec(), Binding{Mode: ModeRecord, Values: values})
	if got := fieldNames(view); len(got) != 1 {
		t.Errorf("with the marker set to a non-matching value, the dependent field is absent, got %v", got)
	}
}

// A preview form's Discard returns to the specific record that produced
// it, which the declaration cannot name statically; Binding.WayOut
// overrides the declared way out for one render (a tier preview's ladder
// id, via forms.Discard).
func TestRenderBindingWayOutOverridesTheDeclaredOne(t *testing.T) {
	spec := base()
	spec.WayOut = LinkOut("Cancel", "/list")
	discard := Discard("Discard", "/records/42")
	view := Render(spec, Binding{Mode: ModeUnbound, WayOut: &discard})
	if view.WayOut.Kind != WayOutDiscard || view.WayOut.URL != "/records/42" {
		t.Errorf("Binding.WayOut must override the declared way out, got %+v", view.WayOut)
	}
}

func TestRenderBindingWayOutNilKeepsTheDeclaredOne(t *testing.T) {
	spec := base()
	spec.WayOut = LinkOut("Cancel", "/list")
	view := Render(spec, Binding{Mode: ModeUnbound})
	if view.WayOut.Kind != WayOutLink || view.WayOut.URL != "/list" {
		t.Errorf("a nil Binding.WayOut must not disturb the declared one, got %+v", view.WayOut)
	}
}

// The Rows family (design D1's "Rows family contract"; spec form-library "A
// batch form renders the caller's rows and one tray", "A binding names the
// control that takes focus"). The markup is asserted where the parts
// execute; these assert the view the parts are handed, which is where the
// hidden page state, the tray's shape and the one autofocus are decided.

func batchSpec() FormSpec {
	return FormSpec{
		Name:         "test.batch",
		Kind:         KindBatch,
		Family:       Rows,
		Method:       "POST",
		Path:         "/partials/test/rules",
		CommitAction: "/partials/test/rules/apply",
		Commit:       "Apply changes",
		WayOut:       WayOut{Label: "Discard all"},
		Target:       "#test-rules",
		Fields: []Field{
			{Name: "resource_key", Label: "Resource", Control: Select, Options: []Option{
				ChooseOption("a resource"), {Value: "seats", Label: "Seats"}, {Value: "sites", Label: "Sites"},
			}},
			{Name: "kind", Label: "Kind", Control: Hidden},
			{Name: "limit", Label: "Limit", Control: Number, Min: "0",
				ShowIf: ShowIf{Field: "kind", Equals: []string{"numeric"}}},
			{Name: "policy", Label: "Reduction policy", Control: Select, Placement: PlaceDelta, Options: []Option{
				{Value: "clamp", Label: "Clamp"}, {Value: "force_reduce", Label: "Force reduce"},
			}},
			{Name: "note", Label: "Note", Control: Textarea, Optional: true, Placement: PlaceTray},
		},
	}
}

// rowValues builds one record's values the way a handler binds them.
func rowValues(pairs ...string) Values {
	v := NewValues()
	for i := 0; i+1 < len(pairs); i += 2 {
		v.Set(pairs[i], pairs[i+1])
	}
	return v
}

// hidden returns the value of one hidden input, and whether it was written.
func hidden(v FormView, name string) (string, bool) {
	for _, h := range v.Hiddens {
		if h.Name == name {
			return h.Value, true
		}
	}
	return "", false
}

func stagedBinding() Binding {
	return Binding{
		Rows: map[string]RowBinding{
			"rule-12": {Values: rowValues("resource_key", "seats", "kind", "numeric", "limit", "5"), Errors: NewErrors()},
		},
		Staged: []StagedDelta{{
			Verb:   "edit",
			Key:    "rule-9",
			Values: rowValues("resource_key", "sites", "kind", "numeric", "limit", "3", "policy", "force_reduce"),
			Line:   "Sites: 1 becomes 3.",
		}},
	}
}

// Every action posts the whole form, so the whole page state rides with it:
// which editors are open, and every delta of the batch (design D2, D3).
func TestRenderRowsWritesTheWholePageStateAsHiddenInputs(t *testing.T) {
	v := batchSpec().Bind(stagedBinding())
	if got, ok := hidden(v, "open"); !ok || got != "rule-12" {
		t.Errorf("open input = %q, %v", got, ok)
	}
	for name, want := range map[string]string{
		"staged.0.verb":         "edit",
		"staged.0.key":          "rule-9",
		"staged.0.resource_key": "sites",
		"staged.0.kind":         "numeric",
		"staged.0.limit":        "3",
	} {
		if got, ok := hidden(v, name); !ok || got != want {
			t.Errorf("hidden %s = %q, %v; want %q", name, got, ok, want)
		}
	}
	// The delta's own control carries its value, so a hidden input of the
	// same name would submit twice and the first would win.
	if got, ok := hidden(v, "staged.0.policy"); ok {
		t.Errorf("staged.0.policy rides as a hidden input (%q) as well as a control", got)
	}
	if len(v.Deltas) != 1 || len(v.Deltas[0].Fields) != 1 || v.Deltas[0].Fields[0].Name != "staged.0.policy" {
		t.Fatalf("delta fields = %+v", v.Deltas)
	}
	if v.Deltas[0].Fields[0].Value != "force_reduce" {
		t.Errorf("the delta's policy control = %q", v.Deltas[0].Fields[0].Value)
	}
	if v.Deltas[0].Line != "Sites: 1 becomes 3." {
		t.Errorf("delta line = %q", v.Deltas[0].Line)
	}
}

// A delta's own option set: a control whose choices depend on the record it
// changes offers them per delta, not per render (design D7).
func TestRenderRowsDeltaOptionsOverrideTheRendersOwn(t *testing.T) {
	b := stagedBinding()
	b.Staged[0].Values.Set("policy", "block")
	b.Staged[0].Options = map[string][]Option{"policy": {
		{Value: "clamp", Label: "Clamp"},
		{Value: "force_reduce", Label: "Force reduce"},
		{Value: "block", Label: "Block"},
	}}
	v := batchSpec().Bind(b)
	opts := v.Deltas[0].Fields[0].Options
	if len(opts) != 3 || !opts[2].Selected || opts[2].Value != "block" {
		t.Errorf("the delta's policy options = %+v", opts)
	}
}

// A row's own option set: a control whose choices depend on the record it
// edits offers them per row, not per render (design D7: the rule row's
// policy select offers a dormant stored value as its own option).
func TestRenderRowFieldRowOptionsOverrideTheRendersOwn(t *testing.T) {
	b := stagedBinding()
	rb := b.Rows["rule-12"]
	rb.Values.Set("resource_key", "pages")
	rb.Options = map[string][]Option{"resource_key": {
		{Value: "seats", Label: "Seats"}, {Value: "pages", Label: "Pages"},
	}}
	b.Rows["rule-12"] = rb
	v := batchSpec().Bind(b)
	opts := v.RowField("rule-12", "resource_key").Options
	if len(opts) != 2 || !opts[1].Selected || opts[1].Value != "pages" {
		t.Errorf("the row's resource options = %+v", opts)
	}
	// Another row without its own set keeps the declaration's.
	if other := v.RowField("rule-77", "resource_key").Options; len(other) != 3 {
		t.Errorf("a row without its own options keeps the declaration's, got %+v", other)
	}
}

func TestRenderRowsEmptyBatchRendersNoTray(t *testing.T) {
	v := batchSpec().Bind(Binding{})
	if v.Tray {
		t.Error("an empty batch renders a tray")
	}
	if len(v.Deltas) != 0 || len(v.Hiddens) != 0 {
		t.Errorf("an empty batch wrote %d deltas and %d hidden inputs", len(v.Deltas), len(v.Hiddens))
	}
	asked := batchSpec().Bind(Binding{Tray: true})
	if !asked.Tray {
		t.Error("the binding asked for the tray and none rendered")
	}
}

// The tray's commit and way out are the family's own posting controls, not
// a submit button: the commit has a path of its own and a target of its own
// (design D2).
func TestRenderRowsTrayCommitAndWayOut(t *testing.T) {
	b := stagedBinding()
	b.CommitTarget = "#operator-body"
	v := batchSpec().Bind(b)
	if v.Apply.Label != "Apply changes" || v.Apply.Act != "apply" {
		t.Errorf("apply = %+v", v.Apply)
	}
	if !strings.Contains(string(v.Apply.HX), `hx-post="/partials/test/rules/apply"`) {
		t.Errorf("apply posts to %q", v.Apply.HX)
	}
	if !strings.Contains(string(v.Apply.HX), `hx-target="#operator-body"`) {
		t.Errorf("apply targets %q", v.Apply.HX)
	}
	if !v.Apply.Indicator {
		t.Error("the commit carries no in-flight indicator")
	}
	if v.Discard.Label != "Discard all" || v.Discard.Act != "discard" {
		t.Errorf("discard = %+v", v.Discard)
	}
	if !strings.Contains(string(v.Discard.HX), `hx-post="/partials/test/rules"`) {
		t.Errorf("discard posts to %q", v.Discard.HX)
	}
	if v.Deltas[0].Undo.Label != "Undo" || v.Deltas[0].Undo.Key != "rule-9" {
		t.Errorf("undo = %+v", v.Deltas[0].Undo)
	}
	// The commit falls back to the form's own target when the binding names
	// none, so a declaration that renders in place needs to say nothing.
	plain := batchSpec().Bind(stagedBinding())
	if !strings.Contains(string(plain.Apply.HX), `hx-target="#test-rules"`) {
		t.Errorf("apply's default target = %q", plain.Apply.HX)
	}
}

// A row's control is the declaration's control: same label, same
// constraints, same markup, under a name and a wrapper id carrying its row
// (spec form-library "The body's controls are the declaration's").
func TestRenderRowFieldCarriesTheDeclarationAndTheRow(t *testing.T) {
	v := batchSpec().Bind(stagedBinding())
	fv := v.RowField("rule-12", "limit")
	if fv.Name != "rows.rule-12.limit" {
		t.Errorf("name = %q", fv.Name)
	}
	if fv.WrapperID != "form-test.batch-limit-rule-12" {
		t.Errorf("wrapper id = %q", fv.WrapperID)
	}
	if fv.ControlID != fv.WrapperID+"-control" {
		t.Errorf("control id = %q", fv.ControlID)
	}
	if fv.Label != "Limit" || fv.Value != "5" {
		t.Errorf("label %q, value %q", fv.Label, fv.Value)
	}
	if !strings.Contains(string(fv.Attrs), `required`) || !strings.Contains(string(fv.Attrs), `min="0"`) {
		t.Errorf("attrs = %q", fv.Attrs)
	}
	if fv.LabelNarrowOnly {
		t.Error("the label hides itself with nothing asked for")
	}
	if got := v.RowField("rule-12", "limit", "label-hidden"); !got.LabelNarrowOnly {
		t.Error("the label-hidden option did not reach the view")
	}
	// A second row's control is the same control under its own ids, so two
	// open editors carry no duplicate id between them.
	other := v.RowField("rule-77", "limit")
	if other.WrapperID == fv.WrapperID {
		t.Errorf("two rows share the wrapper id %q", other.WrapperID)
	}
	if other.Value != "" {
		t.Errorf("a row with no binding carried the value %q", other.Value)
	}
}

// The dense option lays a row's field out as a dense row's column, for a
// body's own dense row beside its table (the add form); its error keeps
// its wiring and renders under the control as everywhere (design D16).
// Without the option a row's field renders as a cell's: no column.
func TestRenderRowFieldDenseOption(t *testing.T) {
	b := stagedBinding()
	errs := NewErrors()
	errs.Field("limit", "Enter a limit.")
	b.Rows["rule-12"] = RowBinding{Values: b.Rows["rule-12"].Values, Errors: errs}
	v := batchSpec().Bind(b)

	if cell := v.RowField("rule-12", "limit"); cell.ColClass != "" {
		t.Errorf("a cell's field carries the column class %q", cell.ColClass)
	}
	dense := v.RowField("rule-12", "limit", "dense")
	if dense.ColClass != "col-12 col-xl-2" {
		t.Errorf("a number's dense column = %q", dense.ColClass)
	}
	if dense.Error != "Enter a limit." || dense.ErrorID != "form-test.batch-limit-rule-12-error" {
		t.Errorf("the dense field keeps its error wiring: %q, %q", dense.Error, dense.ErrorID)
	}
	if got := v.RowField("rule-12", "resource_key", "dense", "label-hidden"); got.ColClass != "col-12 col-xl-4" || !got.LabelNarrowOnly {
		t.Errorf("both options together: col class %q, label narrow-only %v", got.ColClass, got.LabelNarrowOnly)
	}
}

// Every posting control of the form posts the whole form, names the act and
// the row it was pressed on, and swaps the form's own region back.
func TestRenderRowActionPostsTheWholeForm(t *testing.T) {
	v := batchSpec().Bind(stagedBinding())
	act := v.RowAction("edit", "rule-12", "Edit", "secondary")
	hx := string(act.HX)
	for _, want := range []string{
		`hx-post="/partials/test/rules"`,
		`hx-vals='{"act":"edit","key":"rule-12"}'`,
		`hx-include="closest form"`,
		`hx-target="#test-rules"`,
		`hx-swap="outerHTML"`,
	} {
		if !strings.Contains(hx, want) {
			t.Errorf("row action attributes %q lack %q", hx, want)
		}
	}
	if act.Classes != "btn btn-sm btn-outline-secondary ms-1" {
		t.Errorf("secondary classes = %q", act.Classes)
	}
	if got := v.RowAction("stage", "rule-12", "Stage change", "primary").Classes; got != "btn btn-sm btn-primary ms-1" {
		t.Errorf("primary classes = %q", got)
	}
	if got := v.RowAction("remove", "rule-12", "Remove", "danger").Classes; got != "btn btn-sm btn-outline-danger ms-1" {
		t.Errorf("danger classes = %q", got)
	}
}

// A successful render focuses what the binding names, and nothing else
// (spec form-library "A successful render focuses the named control").
func TestRenderRowsAutofocusFollowsTheBinding(t *testing.T) {
	b := stagedBinding()
	b.Autofocus = Focus{Field: "limit", Instance: "rule-12"}
	v := batchSpec().Bind(b)
	if !strings.Contains(string(v.RowField("rule-12", "limit").Attrs), "autofocus") {
		t.Error("the named control carries no autofocus")
	}
	if strings.Contains(string(v.RowField("rule-12", "resource_key").Attrs), "autofocus") {
		t.Error("a control the binding did not name carries autofocus")
	}
	if v.TrayFocus {
		t.Error("the tray took focus the binding gave to a control")
	}
	for _, f := range v.Fields {
		if strings.Contains(string(f.Attrs), "autofocus") {
			t.Errorf("the tray field %q carries autofocus", f.Name)
		}
	}
}

func TestRenderRowsAutofocusTrayHeading(t *testing.T) {
	b := stagedBinding()
	b.Autofocus = Focus{Tray: true}
	v := batchSpec().Bind(b)
	if !v.TrayFocus {
		t.Error("the tray heading did not take focus")
	}
	if strings.Contains(string(v.RowField("rule-12", "limit").Attrs), "autofocus") {
		t.Error("a control took focus the binding gave to the tray")
	}
	// Nothing staged and no tray: there is nothing to focus.
	empty := batchSpec().Bind(Binding{Autofocus: Focus{Tray: true}})
	if empty.TrayFocus {
		t.Error("a tray that does not render took focus")
	}
}

// A refusal focuses the first invalid control and ignores what the binding
// asked for (spec form-library "A refusal overrides the binding").
func TestRenderRowsRefusalOverridesTheBinding(t *testing.T) {
	b := stagedBinding()
	b.Autofocus = Focus{Tray: true}
	errs := NewErrors()
	errs.Field("limit", "Limit must be 0 or more.")
	b.Rows["rule-12"] = RowBinding{Values: b.Rows["rule-12"].Values, Errors: errs}
	v := batchSpec().Bind(b)
	if v.TrayFocus {
		t.Error("the tray took focus on a refusal")
	}
	fv := v.RowField("rule-12", "limit")
	if !strings.Contains(string(fv.Attrs), "autofocus") {
		t.Errorf("the invalid control carries no autofocus: %q", fv.Attrs)
	}
	if fv.Error == "" || !strings.Contains(string(fv.Attrs), `aria-invalid="true"`) {
		t.Errorf("the invalid control is not marked invalid: %+v", fv)
	}
	if !v.HasErrors() {
		t.Error("a refused row does not report errors")
	}
}

// A delta's refusal renders on its own line with the batch intact
// (design D3).
func TestRenderRowsDeltaRefusalKeepsTheBatch(t *testing.T) {
	b := stagedBinding()
	b.Staged[0].Error = "That rule is no longer active."
	v := batchSpec().Bind(b)
	if v.Deltas[0].Error != "That rule is no longer active." || v.Deltas[0].ErrorID == "" {
		t.Errorf("delta = %+v", v.Deltas[0])
	}
	if _, ok := hidden(v, "staged.0.key"); !ok {
		t.Error("a refused delta dropped out of the hidden batch")
	}
	if !v.HasErrors() {
		t.Error("a refused delta does not report errors")
	}
}

// The Rows family's own binding on any other family is a programming
// error, refused the first time the page renders (spec form-library "A body
// belongs to a batch form only").
func TestRenderRefusesRowsBindingOutsideTheFamily(t *testing.T) {
	for name, b := range map[string]Binding{
		"body":   {Body: "<table></table>"},
		"staged": {Staged: []StagedDelta{{Verb: "edit", Key: "x"}}},
		"rows":   {Rows: map[string]RowBinding{"x": {}}},
	} {
		func() {
			defer func() {
				r := recover()
				if r == nil {
					t.Errorf("%s: a stacked form rendered the rows family's binding", name)
					return
				}
				msg, _ := r.(string)
				if !strings.Contains(msg, "test.sided") || !strings.Contains(msg, "rows family") {
					t.Errorf("%s: refusal %q names neither the form nor the family", name, msg)
				}
			}()
			Render(sided(), b)
		}()
	}
}

// The body is the caller's, set on the view because the fragment that
// produces it calls RowField on that same view.
func TestRenderRowsBodyIsTheCallers(t *testing.T) {
	v := batchSpec().Bind(Binding{Body: "<table id=\"bound\"></table>"})
	if v.Body != `<table id="bound"></table>` {
		t.Errorf("body from the binding = %q", v.Body)
	}
	v.Body = "<table id=\"set\"></table>"
	if v.Body != `<table id="set"></table>` {
		t.Errorf("body set after Bind = %q", v.Body)
	}
	// Fields is what the library itself renders, which here is the tray's
	// own field and neither a row's nor a delta's.
	if len(v.Fields) != 1 || v.Fields[0].Name != "note" {
		t.Errorf("library-rendered fields = %v", fieldNames(v))
	}
}

func TestBindIsRender(t *testing.T) {
	b := Binding{Mode: ModeUnbound, Side: CreateOnly}
	if got, want := sided().Bind(b).ID, Render(sided(), b).ID; got != want {
		t.Errorf("Bind = %q, Render = %q", got, want)
	}
}

// Every posting control of a batch form is a <button>, so the library's
// default target, "this", would resolve to the button that was pressed
// rather than to the form. A declaration that names no target still swaps
// its whole form back (design D2).
func TestRenderRowActionsTargetTheFormWhenNoneIsNamed(t *testing.T) {
	spec := batchSpec()
	spec.Target = ""
	v := spec.Bind(Binding{Instance: "set-4", Staged: stagedBinding().Staged})
	want := `hx-target="#` + v.ID + `"`
	if v.ID != "form-test.batch-set-4" {
		t.Fatalf("form id = %q", v.ID)
	}
	for name, hx := range map[string]string{
		"edit":    string(v.RowAction("edit", "rule-12", "Edit", "secondary").HX),
		"undo":    string(v.Deltas[0].Undo.HX),
		"apply":   string(v.Apply.HX),
		"discard": string(v.Discard.HX),
	} {
		if strings.Contains(hx, `hx-target="this"`) || !strings.Contains(hx, want) {
			t.Errorf("%s targets %q, want %q", name, hx, want)
		}
	}
}

// The commit is the one control a double press could apply twice, and the
// form tag's own hx-disable names a submit button this family has none of.
func TestRenderRowsCommitDisablesItself(t *testing.T) {
	v := batchSpec().Bind(stagedBinding())
	if !strings.Contains(string(v.Apply.HX), `hx-disable="this"`) {
		t.Errorf("the commit does not disable itself: %q", v.Apply.HX)
	}
	for name, hx := range map[string]string{
		"undo":    string(v.Deltas[0].Undo.HX),
		"discard": string(v.Discard.HX),
		"edit":    string(v.RowAction("edit", "rule-12", "Edit", "secondary").HX),
	} {
		if strings.Contains(hx, "hx-disable") {
			t.Errorf("%s disables itself: %q", name, hx)
		}
	}
}

// A row's own Edit can take focus, so a Cancel returns focus to the button
// the person pressed rather than dropping it at the top of the swapped
// region (design D9).
func TestRenderRowsAutofocusNamesARowAction(t *testing.T) {
	b := stagedBinding()
	b.Autofocus = Focus{Act: "edit", Key: "rule-12"}
	v := batchSpec().Bind(b)
	if !strings.Contains(string(v.RowAction("edit", "rule-12", "Edit", "secondary").HX), "autofocus") {
		t.Error("the named row action carries no autofocus")
	}
	for name, hx := range map[string]string{
		"another row's Edit":    string(v.RowAction("edit", "rule-77", "Edit", "secondary").HX),
		"the same row's Remove": string(v.RowAction("remove", "rule-12", "Remove", "danger").HX),
		"undo":                  string(v.Deltas[0].Undo.HX),
		"apply":                 string(v.Apply.HX),
		"discard":               string(v.Discard.HX),
	} {
		if strings.Contains(hx, "autofocus") {
			t.Errorf("%s carries autofocus", name)
		}
	}
	if strings.Contains(string(v.RowField("rule-12", "limit").Attrs), "autofocus") {
		t.Error("a control took the focus a row action was given")
	}
	if v.TrayFocus {
		t.Error("the tray took the focus a row action was given")
	}
	// A refusal still wins: the first invalid control takes focus and the
	// binding's name is ignored, whatever kind of thing it named.
	errs := NewErrors()
	errs.Field("limit", "Limit must be 0 or more.")
	b.Rows["rule-12"] = RowBinding{Values: b.Rows["rule-12"].Values, Errors: errs}
	refused := batchSpec().Bind(b)
	if strings.Contains(string(refused.RowAction("edit", "rule-12", "Edit", "secondary").HX), "autofocus") {
		t.Error("a row action took focus on a refusal")
	}
	if !strings.Contains(string(refused.RowField("rule-12", "limit").Attrs), "autofocus") {
		t.Error("the invalid control did not take focus on a refusal")
	}
}

// A row checkbox hides its own label the same way every other row control
// does: visually, from lg up, where the column header labels it (D11).
func TestRenderRowCheckboxHonoursTheLabelHiddenOption(t *testing.T) {
	spec := batchSpec()
	spec.Fields = append(spec.Fields, Field{Name: "granted", Label: "Granted", Control: Checkbox})
	v := spec.Bind(stagedBinding())
	if !v.RowField("rule-12", "granted", "label-hidden").LabelNarrowOnly {
		t.Error("a checkbox row ignored the label-hidden option")
	}
	if v.RowField("rule-12", "granted").LabelNarrowOnly {
		t.Error("a checkbox row hid its label with nothing asked for")
	}
}

// The commit alone may swap differently: its target is often a container
// the page keeps, whose response is that container's contents rather than a
// wrapper, so replacing the element itself would leave the next request
// with nothing to swap into.
func TestRenderRowsCommitSwapIsTheBindingsAlone(t *testing.T) {
	b := stagedBinding()
	b.CommitTarget = "#operator-body"
	b.CommitSwap = "innerHTML"
	v := batchSpec().Bind(b)
	if !strings.Contains(string(v.Apply.HX), `hx-swap="innerHTML"`) {
		t.Errorf("apply swaps %q", v.Apply.HX)
	}
	for name, hx := range map[string]string{
		"undo":    string(v.Deltas[0].Undo.HX),
		"discard": string(v.Discard.HX),
		"edit":    string(v.RowAction("edit", "rule-12", "Edit", "secondary").HX),
	} {
		if !strings.Contains(hx, `hx-swap="outerHTML"`) {
			t.Errorf("%s swaps %q", name, hx)
		}
	}
	if plain := batchSpec().Bind(stagedBinding()); !strings.Contains(string(plain.Apply.HX), `hx-swap="outerHTML"`) {
		t.Errorf("apply's default swap = %q", plain.Apply.HX)
	}
}