package server

import (
	"bytes"
	"context"
	"errors"
	"html/template"
	"io"
	"io/fs"
	"log/slog"
	"regexp"
	"strconv"
	"strings"
	"testing"

	"git.coopcloud.tech/wiki-cafe/member-console/internal/billing"
	"git.coopcloud.tech/wiki-cafe/member-console/internal/config"
	"git.coopcloud.tech/wiki-cafe/member-console/internal/embeds"
	"git.coopcloud.tech/wiki-cafe/member-console/internal/entitlements"
	"git.coopcloud.tech/wiki-cafe/member-console/internal/identity"
	"git.coopcloud.tech/wiki-cafe/member-console/internal/organization"
	"git.coopcloud.tech/wiki-cafe/member-console/internal/web"
)

// Render coverage for the operator landing surface's overview regions ("At a
// glance" + "System"). Template-level only: it executes operator.html against
// hand-built OperatorPageData, so it needs no database and runs in every
// environment. The loader that fills that data (loadOverview) is exercised
// separately by the pure-function tests at the bottom of this file.

// overviewTemplate parses the operator template set the same way
// NewOperatorPartialsHandler does — partials first, then the shell — so this
// test fails on the same parse errors production would hit.
func overviewTemplate(t *testing.T) *template.Template {
	t.Helper()
	sub, err := fs.Sub(embeds.Templates, "templates")
	if err != nil {
		t.Fatalf("fs.Sub: %v", err)
	}
	partialsSub, err := fs.Sub(embeds.Templates, "templates/partials")
	if err != nil {
		t.Fatalf("fs.Sub partials: %v", err)
	}
	tmpl := template.New("operator").Funcs(template.FuncMap{
		"renderBody":      func(string, any) (template.HTML, error) { return "", nil },
		"routeURL":        web.RouteURL,
		"fieldErr":        func(_, _, _, _ string, _, _ any) string { return "" },
		"stripeEntityURL": func(string, string) string { return "" },
		"deploymentName":  config.DeploymentName,
	})
	if tmpl, err = tmpl.ParseFS(partialsSub, "operator_*.html"); err != nil {
		t.Fatalf("ParseFS partials: %v", err)
	}
	if tmpl, err = tmpl.ParseFS(sub, "operator.html"); err != nil {
		t.Fatalf("ParseFS operator.html: %v", err)
	}
	return tmpl
}

func renderOperator(t *testing.T, data OperatorPageData) string {
	t.Helper()
	var buf bytes.Buffer
	if err := overviewTemplate(t).ExecuteTemplate(&buf, "operator.html", data); err != nil {
		t.Fatalf("ExecuteTemplate: %v", err)
	}
	return buf.String()
}

// landingRegion slices the rendered document down to the landing surface
// itself. The navbar, sidebar, toast container and confirmation modal are
// outside <main> (or outside #operator-body) and carry their own markup —
// including an <h5> in the modal — so assertions about this page's structure
// must not see them.
func landingRegion(t *testing.T, out string) string {
	t.Helper()
	const openTag = `<div id="operator-body">`
	start := strings.Index(out, openTag)
	if start < 0 {
		t.Fatalf("rendered output has no #operator-body region")
	}
	end := strings.Index(out, "</main>")
	if end < start {
		t.Fatalf("rendered output has no </main> after #operator-body")
	}
	return out[start+len(openTag) : end]
}

// populatedOverview is a representative landing payload: every tile
// available, a mix of healthy and unhealthy integrations, and a draining
// queue.
func populatedOverview() OperatorPageData {
	return OperatorPageData{
		CSRFToken:  "csrf",
		IAPosition: "runtime:landing",
		Overview: OverviewData{
			Stats: []OverviewStat{
				{Label: "People", Value: "1,204", Caption: "212 joined in the last 30 days", Available: true},
				{Label: "Team organizations", Value: "38", Caption: "Personal orgs excluded", Href: "/operator/organizations", Available: true},
				{Label: "Monthly recurring", Value: "$2,295.00", Caption: "205 active subscriptions; 9 trialing", Href: "/operator/billing/subscriptions", Available: true},
				{Label: "Open invoices", Value: "3", Caption: "$372.00 outstanding; issued and awaiting payment", Href: "/operator/billing/invoices", Available: true},
				{Label: "Delivering grants", Value: "7", Caption: "Plus 80 signup defaults", Href: "/operator/grants", Available: true},
			},
			Providers: []OverviewProvider{
				{Slug: "alpha", DisplayName: "Alpha", Kind: "provisioning", Status: "active", SurfacePath: "/operator/alpha-sites", Healthy: true, Configured: true},
				{Slug: "beta", DisplayName: "Beta", Kind: "billing", Status: "disabled", MissingKeysText: "beta-api-key"},
			},
			Queue: OverviewQueue{Pending: 4, Retrying: 1, Available: true},
		},
		Activity: []ActivityEvent{{
			EventType: "grant_issued",
			Timestamp: "Jan 2, 2026 3:04 PM",
			OrgID:     "org-1",
			OrgName:   "Example Org",
			Summary:   "Issued Example Plan (promo)",
			LinkPath:  "/operator/organizations/org-1",
		}},
	}
}

func TestOperatorOverviewRendersStatTiles(t *testing.T) {
	out := landingRegion(t, renderOperator(t, populatedOverview()))

	for _, want := range []string{
		"At a glance",
		"People",
		"1,204",                          // grouped value, formatted in Go
		"Team organizations",             // deliberately created orgs, not personal ones
		`href="/operator/organizations"`, // tile drills into its section
		"Monthly recurring",              // commitment as money, not a bare count
		"$2,295.00",                      // largest-currency-bucket value
		`href="/operator/billing/subscriptions"`,
		"Delivering grants",       // operator-issued grants; defaults ride the caption
		"Plus 80 signup defaults", // composition caption
		`href="/operator/grants"`,
		"Open invoices",                     // receivables tile
		`href="/operator/billing/invoices"`, // drills into the invoices page
		"$372.00 outstanding",               // caption leads with the balance
	} {
		if !strings.Contains(out, want) {
			t.Errorf("landing surface missing %q", want)
		}
	}

	// A tile with no Href must not render as a link — there is no persons
	// browse route, so the People tile is static by design.
	if strings.Contains(out, `href=""`) {
		t.Errorf("hrefless stat tile rendered an empty link target")
	}
}

// An unavailable count must render an em dash. Rendering 0 would be an
// actively misleading answer to "how many organizations are there".
func TestOperatorOverviewUnavailableStatIsNotZero(t *testing.T) {
	data := OperatorPageData{
		CSRFToken: "csrf",
		Overview: OverviewData{Stats: []OverviewStat{
			{Label: "Organizations", Caption: "Active organizations", Href: "/operator/organizations", Available: false},
		}},
	}
	out := landingRegion(t, renderOperator(t, data))

	if !strings.Contains(out, "&mdash;") {
		t.Errorf("unavailable stat did not render an em dash")
	}
	if !strings.Contains(out, "Count unavailable") {
		t.Errorf("unavailable stat did not explain itself")
	}
	// The tile still renders its label and link; only the number is withheld.
	if !strings.Contains(out, "Organizations") {
		t.Errorf("unavailable stat dropped its label")
	}
	if regexp.MustCompile(`display-6[^>]*>\s*0\s*<`).MatchString(out) {
		t.Errorf("unavailable stat rendered a zero value")
	}
}

func TestOperatorOverviewSystemPanel(t *testing.T) {
	out := landingRegion(t, renderOperator(t, populatedOverview()))

	for _, want := range []string{
		"System",
		"Integrations",
		"Alpha",
		`href="/operator/alpha-sites"`,       // provider with a surface links to it
		"provisioning",                       // provider kind is shown
		`<span class="badge text-bg-success`, // healthy provider
		"Beta",
		`<span class="badge text-bg-warning`, // unhealthy provider
		"Not configured",                     // Beta's configuration-readiness signal
		"Delivery queue",
		"Stripe", // outbox coverage caption names what it tracks
		"Pending",
		"Retrying",
		"Dead-letter",
		"draining normally",
	} {
		if !strings.Contains(out, want) {
			t.Errorf("system panel missing %q", want)
		}
	}
	// A provider without a surface path must not become a dead link.
	if strings.Contains(out, `href="">Beta</a>`) {
		t.Errorf("surfaceless provider rendered an empty link")
	}
	// Alpha is fully configured; only Beta's row should carry the
	// not-configured marker (ux-honest-surfaces: the signal is a negative
	// marker, never a redundant positive claim).
	if n := strings.Count(out, "Not configured"); n != 1 {
		t.Errorf("system panel shows %d \"Not configured\" markers, want exactly 1 (Beta only)", n)
	}
	// The registry-status badge must not read as a live health/connectivity
	// claim (integration-settings spec: "cannot read as a health check").
	if strings.Contains(out, "read live") || strings.Contains(out, "Connected") || strings.Contains(out, "connected to") {
		t.Errorf("system panel implies a live health/connectivity check")
	}
}

// Dead-lettered outbox work is the one queue bucket nothing will clear on its
// own, so it must be called out rather than shown as another neutral number.
func TestOperatorOverviewDeadLetterRaisesAlarm(t *testing.T) {
	data := populatedOverview()
	data.Overview.Queue = OverviewQueue{Pending: 2, Retrying: 0, DeadLetter: 3, Available: true}
	out := landingRegion(t, renderOperator(t, data))

	if !strings.Contains(out, "text-danger") {
		t.Errorf("dead-lettered work did not render with alarm styling")
	}
	if !strings.Contains(out, "exhausted its retries") {
		t.Errorf("dead-letter state did not explain what an operator must do")
	}
	if strings.Contains(out, "draining normally") {
		t.Errorf("dead-lettered queue still claimed to be draining normally")
	}
}

// The landing surface is the first thing a fresh deployment shows, so every
// region needs a legible empty state rather than a blank panel.
func TestOperatorOverviewEmptyStates(t *testing.T) {
	out := landingRegion(t, renderOperator(t, OperatorPageData{CSRFToken: "csrf"}))

	for _, want := range []string{
		"Counts are unavailable.",
		"No activity recorded yet.",
		"No integrations registered.",
		"Queue health is unavailable.",
	} {
		if !strings.Contains(out, want) {
			t.Errorf("empty landing surface missing %q", want)
		}
	}
	// The lookup affordance is the one thing that must work on an empty
	// deployment, so it renders regardless.
	if !strings.Contains(out, "Find a person or organization") {
		t.Errorf("empty landing surface dropped the lookup affordance")
	}
}

// The landing surface is the page screenshotted for the project README, so
// its document outline has to be defensible: exactly one H1, no skipped
// levels. The older operator pages run H1 straight to H6; that pattern must
// not spread here.
func TestOperatorOverviewHeadingHierarchy(t *testing.T) {
	out := landingRegion(t, renderOperator(t, populatedOverview()))

	matches := regexp.MustCompile(`(?i)<h([1-6])[\s>]`).FindAllStringSubmatch(out, -1)
	if len(matches) == 0 {
		t.Fatalf("landing surface rendered no headings at all")
	}

	levels := make([]int, 0, len(matches))
	for _, m := range matches {
		n, err := strconv.Atoi(m[1])
		if err != nil {
			t.Fatalf("unparsable heading level %q", m[1])
		}
		levels = append(levels, n)
	}

	if levels[0] != 1 {
		t.Errorf("first heading is h%d, want h1", levels[0])
	}
	h1Count := 0
	for _, l := range levels {
		if l == 1 {
			h1Count++
		}
	}
	if h1Count != 1 {
		t.Errorf("found %d h1 elements, want exactly 1", h1Count)
	}
	for i := 1; i < len(levels); i++ {
		if levels[i] > levels[i-1]+1 {
			t.Errorf("heading level skips from h%d to h%d at position %d (levels: %v)",
				levels[i-1], levels[i], i, levels)
		}
	}
	// Guard the specific regression: no h4/h5/h6 on this surface at all.
	for _, l := range levels {
		if l > 3 {
			t.Errorf("landing surface uses h%d; the overview outline stops at h3 (levels: %v)", l, levels)
		}
	}
}

// Strict CSP: nothing on this surface may rely on an inline script, an inline
// event handler, or a style attribute.
func TestOperatorOverviewIsCSPClean(t *testing.T) {
	out := landingRegion(t, renderOperator(t, populatedOverview()))

	if regexp.MustCompile(`(?i)<script(\s[^>]*)?>[^<]`).MatchString(out) {
		t.Errorf("landing surface contains an inline <script> body")
	}
	if m := regexp.MustCompile(`(?i)\son(click|load|change|submit|input|focus|error)\s*=`).FindString(out); m != "" {
		t.Errorf("landing surface contains an inline event handler: %q", strings.TrimSpace(m))
	}
	if regexp.MustCompile(`(?i)\sstyle\s*=\s*"`).MatchString(out) {
		t.Errorf("landing surface contains an inline style attribute")
	}
}

// Brand neutrality: this is general-purpose OSS and the operator surface is
// the page a stranger evaluating the project sees first.
func TestOperatorShellIsBrandNeutral(t *testing.T) {
	out := renderOperator(t, populatedOverview())
	for _, forbidden := range []string{"Wiki Cafe", "wiki.cafe", "WikiCafe"} {
		if strings.Contains(out, forbidden) {
			t.Errorf("operator shell names a specific deployment: %q", forbidden)
		}
	}
	if !strings.Contains(out, "<title>Operator overview - Member Console</title>") {
		t.Errorf("operator shell lost its brand-neutral title")
	}
}

func TestFormatCount(t *testing.T) {
	cases := []struct {
		in   int64
		want string
	}{
		{0, "0"},
		{7, "7"},
		{999, "999"},
		{1000, "1,000"},
		{1204, "1,204"},
		{12480, "12,480"},
		{999999, "999,999"},
		{1000000, "1,000,000"},
		{-4200, "-4,200"},
	}
	for _, tc := range cases {
		if got := formatCount(tc.in); got != tc.want {
			t.Errorf("formatCount(%d) = %q, want %q", tc.in, got, tc.want)
		}
	}
}

// The "Delivering grants" caption states its composition (signup defaults
// vs deliberate grants) without echoing the headline, which the
// grant-backed provision count equals by construction.
func TestDeliveringGrantsCaptionStatesComposition(t *testing.T) {
	cases := []struct {
		name     string
		defaults int64
		err      error
		want     string
	}{
		{"plural", 2589, nil, "Plus 2,589 signup defaults"},
		{"singular", 1, nil, "Plus 1 signup default"},
		{"unavailable", 0, errors.New("boom"), "Signup defaults excluded"},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			got := deliveringGrantsCaption(tc.defaults, tc.err)
			if got != tc.want {
				t.Errorf("deliveringGrantsCaption(%d, %v) = %q, want %q", tc.defaults, tc.err, got, tc.want)
			}
		})
	}
}

// Money never crosses currencies on this surface: largest bucket wins the
// headline, the caption acknowledges the rest, and formatting matches the
// member-facing price renderer.
func TestMoneyStatPicksLargestBucket(t *testing.T) {
	stat := newMoneyStat("Monthly recurring", nil, []moneyBucket{
		{currency: "eur", cents: 4200},
		{currency: "usd", cents: 229500},
	}, "caption", "/operator/billing/subscriptions")
	if !stat.Available || stat.Value != "$2,295.00" {
		t.Errorf("money stat = %+v, want available $2,295.00 (largest bucket)", stat)
	}

	empty := newMoneyStat("Monthly recurring", nil, nil, "caption", "")
	if !empty.Available || empty.Value != "0" {
		t.Errorf("no-subscriptions money stat = %+v, want available bare 0", empty)
	}

	failed := newMoneyStat("Monthly recurring", errors.New("boom"), nil, "caption", "")
	if failed.Available || failed.Value != "" {
		t.Errorf("failed money stat = %+v, want unavailable with no value", failed)
	}
}

func TestRecurringCaption(t *testing.T) {
	if got, want := recurringCaption(205, 9, nil, 1),
		"205 active subscriptions; 9 trialing"; got != want {
		t.Errorf("recurringCaption = %q, want %q", got, want)
	}
	if got, want := recurringCaption(205, 0, nil, 3),
		"205 active subscriptions; plus 2 more currencies"; got != want {
		t.Errorf("multi-currency recurringCaption = %q, want %q", got, want)
	}
	if got, want := recurringCaption(0, 0, errors.New("boom"), 0),
		"Active subscriptions"; got != want {
		t.Errorf("failed recurringCaption = %q, want %q", got, want)
	}
}

func TestOpenInvoicesCaption(t *testing.T) {
	if got, want := openInvoicesCaption([]moneyBucket{{currency: "usd", cents: 37200}}, nil),
		"$372.00 outstanding; issued and awaiting payment"; got != want {
		t.Errorf("openInvoicesCaption = %q, want %q", got, want)
	}
	if got, want := openInvoicesCaption(nil, nil),
		"Issued and awaiting payment; drafts and settled invoices excluded"; got != want {
		t.Errorf("empty openInvoicesCaption = %q, want %q", got, want)
	}
}

func TestPeopleCaption(t *testing.T) {
	if got, want := peopleCaption(212, nil), "212 joined in the last 30 days"; got != want {
		t.Errorf("peopleCaption = %q, want %q", got, want)
	}
	if got := peopleCaption(0, errors.New("boom")); !strings.Contains(got, "search above") {
		t.Errorf("failed peopleCaption = %q, want the lookup fallback", got)
	}
}

// The headline row is reserved for core capability state
// (operator-overview-polish D5): pinning loadOverview's labels and order
// keeps a feature tile — the removed domain-claims one, or a future
// equivalent — from slipping back in without failing here. The fakes embed
// their Querier interfaces, so loadOverview calling any count not stubbed
// below panics, which doubles as a check on what the loader is allowed to
// read.
type overviewBillingQ struct{ billing.Querier }

func (overviewBillingQ) CountLiveSubscriptionsByStatus(context.Context) (billing.CountLiveSubscriptionsByStatusRow, error) {
	return billing.CountLiveSubscriptionsByStatusRow{ActiveCount: 205, TrialingCount: 9}, nil
}
func (overviewBillingQ) SumMonthlyRecurringByCurrency(context.Context) ([]billing.SumMonthlyRecurringByCurrencyRow, error) {
	return []billing.SumMonthlyRecurringByCurrencyRow{{Currency: "usd", MonthlyCents: 229500}}, nil
}
func (overviewBillingQ) CountOpenInvoices(context.Context) (int64, error) { return 3, nil }
func (overviewBillingQ) SumOpenInvoiceBalanceByCurrency(context.Context) ([]billing.SumOpenInvoiceBalanceByCurrencyRow, error) {
	return []billing.SumOpenInvoiceBalanceByCurrencyRow{{Currency: "usd", OutstandingCents: 37200}}, nil
}
func (overviewBillingQ) CountPublishedProducts(context.Context) (int64, error) { return 5, nil }

type overviewIdentityQ struct{ identity.Querier }

func (overviewIdentityQ) CountActivePersons(context.Context) (int64, error) { return 1204, nil }
func (overviewIdentityQ) CountPersonsJoinedLast30Days(context.Context) (int64, error) {
	return 212, nil
}

type overviewOrgQ struct{ organization.Querier }

func (overviewOrgQ) CountTeamOrganizations(context.Context) (int64, error) { return 38, nil }

type overviewEntitlementsQ struct{ entitlements.Querier }

func (overviewEntitlementsQ) CountDeliveringOperatorGrants(context.Context) (int64, error) {
	return 7, nil
}
func (overviewEntitlementsQ) CountDeliveringDefaultGrants(context.Context) (int64, error) {
	return 80, nil
}

func TestLoadOverviewTileSet(t *testing.T) {
	h := &OperatorHandler{
		Logger:        slog.New(slog.NewTextHandler(io.Discard, nil)),
		BillingQ:      overviewBillingQ{},
		EntitlementsQ: overviewEntitlementsQ{},
		OrgQ:          overviewOrgQ{},
		IdentityQ:     overviewIdentityQ{},
	}
	stats := h.loadOverview(context.Background()).Stats

	got := make([]string, len(stats))
	for i, s := range stats {
		got[i] = s.Label
	}
	want := []string{"People", "Team organizations", "Monthly recurring", "Open invoices", "Delivering grants", "Catalog products"}
	if len(got) != len(want) {
		t.Fatalf("tile labels = %v, want %v", got, want)
	}
	for i := range want {
		if got[i] != want[i] {
			t.Errorf("tile %d = %q, want %q (full set %v)", i, got[i], want[i], got)
		}
	}
	if mrr := stats[2]; mrr.Value != "$2,295.00" || mrr.Href != "/operator/billing/subscriptions" ||
		mrr.Caption != "205 active subscriptions; 9 trialing" {
		t.Errorf("Monthly recurring tile = %+v, want $2,295.00 with the active/trialing caption", mrr)
	}
	if inv := stats[3]; inv.Value != "3" || inv.Caption != "$372.00 outstanding; issued and awaiting payment" {
		t.Errorf("Open invoices tile = %+v, want count 3 with the outstanding caption", inv)
	}
	if ppl := stats[0]; ppl.Caption != "212 joined in the last 30 days" {
		t.Errorf("People tile caption = %q, want the 30-day trend", ppl.Caption)
	}
	if g := stats[4]; g.Value != "7" || g.Caption != "Plus 80 signup defaults" {
		t.Errorf("Delivering grants tile = %+v, want operator-issued count 7 with defaults in the caption", g)
	}
	// House style for this row: captions use no em dashes (the unavailable
	// value marker is separate, spec-mandated semantics).
	for _, s := range stats {
		if strings.Contains(s.Caption, "—") {
			t.Errorf("tile %q caption %q contains an em dash", s.Label, s.Caption)
		}
	}
}

// The console's card idiom is a plain bordered card. The landing surface
// shipped with a bespoke elevation/hover treatment and lost it in
// operator-overview-polish; this pins the whole rendered shell, hero
// included, so it cannot come back silently.
func TestOperatorOverviewUsesPlainCardIdiom(t *testing.T) {
	out := renderOperator(t, populatedOverview())
	for _, forbidden := range []string{"shadow-sm", "stat-tile"} {
		if strings.Contains(out, forbidden) {
			t.Errorf("landing surface carries bespoke card styling %q", forbidden)
		}
	}
}

func TestOverviewQueueNeedsAttention(t *testing.T) {
	if (OverviewQueue{Pending: 99, Retrying: 12, Available: true}).NeedsAttention() {
		t.Errorf("pending and retrying work must not raise an alarm on its own")
	}
	if !(OverviewQueue{DeadLetter: 1, Available: true}).NeedsAttention() {
		t.Errorf("dead-lettered work must raise an alarm")
	}
}

func TestNewOverviewStatWithholdsValueOnError(t *testing.T) {
	ok := newOverviewStat("Organizations", nil, 42, "caption", "/operator/organizations")
	if !ok.Available || ok.Value != "42" {
		t.Errorf("successful stat = %+v, want available with value 42", ok)
	}
	bad := newOverviewStat("Organizations", errors.New("boom"), 42, "caption", "/operator/organizations")
	if bad.Available {
		t.Errorf("failed stat reported itself available")
	}
	if bad.Value != "" {
		t.Errorf("failed stat carried a value %q; the template must have nothing to print", bad.Value)
	}
}