package httpserver_test

import (
	"net/http"
	"net/url"
	"testing"
)

// GET /api/v1/owliver/suggestions.
//
// The ranking itself is tested in internal/owliver, against no database and no
// server. What is tested here is only what the HTTP boundary adds: the session
// requirement, the query-string contract, the response envelope, and the fact
// that the role deciding which readings exist is the session's rather than
// anything the caller can set.

const suggestPath = "/api/v1/owliver/suggestions"

// suggestURL builds the endpoint's address, escaping as a browser would.
func suggestURL(page, query string) string {
	v := url.Values{}
	if page != "" {
		v.Set("page", page)
	}
	if query != "" {
		v.Set("query", query)
	}
	return suggestPath + "?" + v.Encode()
}

// suggestions reads the list out of the data envelope, failing the test if the
// response is not shaped as the contract says.
func suggestions(t *testing.T, r response) []map[string]any {
	t.Helper()
	if r.code != http.StatusOK {
		t.Fatalf("status %d, body %v", r.code, r.body)
	}
	data, ok := r.body["data"].(map[string]any)
	if !ok {
		t.Fatalf("data is not an object: %v", r.body)
	}
	raw, ok := data["suggestions"].([]any)
	if !ok {
		// json null decodes to nil, and an absent key to nothing at all. Both
		// break a client that iterates the list without checking.
		t.Fatalf("suggestions is not an array (got %#v)", data["suggestions"])
	}
	out := make([]map[string]any, len(raw))
	for i, item := range raw {
		entry, ok := item.(map[string]any)
		if !ok {
			t.Fatalf("suggestion %d is not an object: %#v", i, item)
		}
		out[i] = entry
	}
	return out
}

/* ── Authentication ─────────────────────────────────────────────────────── */

// The endpoint is not on the public allowlist. Which readings exist depends on
// who is asking, so an anonymous suggestion has no meaning.
func TestOwliverSuggestionsRequireASession(t *testing.T) {
	a := newAPI(t)

	got := a.doAnon("GET", suggestURL("positions", "pipeline"), nil)
	if got.code != http.StatusUnauthorized {
		t.Fatalf("status %d, want 401", got.code)
	}
	if code := got.codeOrEmpty(); code != "unauthorized" {
		t.Fatalf("error code %q, want unauthorized", code)
	}
	// A refusal must not describe the catalogue it refused to rank.
	if _, present := got.body["data"]; present {
		t.Fatalf("an unauthenticated refusal carried data: %v", got.body)
	}
}

/* ── The query string ───────────────────────────────────────────────────── */

func TestOwliverSuggestionsValidation(t *testing.T) {
	a := newAPI(t)

	cases := []struct {
		name string
		path string
		want int
	}{
		{"no page", suggestPath, http.StatusBadRequest},
		{"blank page", suggestPath + "?page=%20", http.StatusBadRequest},
		{"unknown page", suggestURL("nowhere", "pipeline"), http.StatusBadRequest},
		{"a route, not a surface", suggestURL("/admin/positions", "pipeline"), http.StatusBadRequest},
		{"unknown parameter", suggestURL("positions", "pipeline") + "&role=admin", http.StatusBadRequest},

		// A query is optional: with nothing typed there is nothing to rank, and
		// that is an empty list rather than a refusal.
		{"no query", suggestURL("positions", ""), http.StatusOK},
		{"page alias", suggestURL("hired", "recent"), http.StatusOK},
		{"page spelled loosely", suggestURL("Talent Pool", "availability"), http.StatusOK},
	}

	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			got := a.do("GET", c.path, nil)
			if got.code != c.want {
				t.Fatalf("status %d, want %d (body %v)", got.code, c.want, got.body)
			}
			if c.want == http.StatusBadRequest && got.codeOrEmpty() != "invalid_query" {
				t.Fatalf("error code %q, want invalid_query", got.codeOrEmpty())
			}
		})
	}
}

// The mux answers anything but GET, so the endpoint cannot be reached with a
// body that might carry a page, a role or an identity.
func TestOwliverSuggestionsAreReadOnly(t *testing.T) {
	a := newAPI(t)
	for _, method := range []string{"POST", "PATCH", "DELETE", "PUT"} {
		got := a.do(method, suggestURL("positions", "pipeline"), map[string]any{"page": "positions"})
		if got.code != http.StatusMethodNotAllowed {
			t.Errorf("%s: status %d, want 405", method, got.code)
		}
	}
}

/* ── The response ───────────────────────────────────────────────────────── */

func TestOwliverSuggestionsResponseShape(t *testing.T) {
	a := newAPI(t) // the seeded user is an admin

	got := suggestions(t, a.do("GET", suggestURL("positions", "pipeline"), nil))
	if len(got) == 0 {
		t.Fatal("pipeline on positions returned nothing")
	}
	if len(got) > 3 {
		t.Fatalf("%d suggestions, the cap is 3", len(got))
	}

	seenIntent, seenText := map[string]bool{}, map[string]bool{}
	for i, s := range got {
		text, _ := s["text"].(string)
		intent, _ := s["intent"].(string)
		if text == "" || intent == "" {
			t.Fatalf("suggestion %d is incomplete: %v", i, s)
		}
		if seenIntent[intent] {
			t.Fatalf("duplicate intent %q", intent)
		}
		if seenText[text] {
			t.Fatalf("duplicate text %q", text)
		}
		seenIntent[intent], seenText[text] = true, true

		// Nothing internal may ride along: no terms, no resource names, no
		// scores, no page keys.
		for key := range s {
			switch key {
			case "text", "intent", "capability":
			default:
				t.Fatalf("suggestion %d exposes %q: %v", i, key, s)
			}
		}
	}
}

// Asking for a rendering names it in the answer — and only where the reading
// can actually be drawn that way.
func TestOwliverSuggestionsCarryARequestedShape(t *testing.T) {
	a := newAPI(t)

	got := suggestions(t, a.do("GET", suggestURL("positions", "show hiring activity as a flow"), nil))
	if len(got) != 1 {
		t.Fatalf("got %d suggestions, want 1: %v", len(got), got)
	}
	if got[0]["intent"] != "hiring-operations" || got[0]["capability"] != "flow" {
		t.Fatalf("got %v", got[0])
	}

	// With no shape asked for, the field is absent rather than empty.
	plain := suggestions(t, a.do("GET", suggestURL("positions", "draft"), nil))
	if len(plain) == 0 {
		t.Fatal("draft on positions returned nothing")
	}
	if _, present := plain[0]["capability"]; present {
		t.Fatalf("capability was sent for an unshaped query: %v", plain[0])
	}
}

// No match is an empty array, not an error and not null.
func TestOwliverSuggestionsEmptyResults(t *testing.T) {
	a := newAPI(t)

	for _, c := range []struct{ name, query string }{
		{"nothing typed", ""},
		{"one character", "p"},
		{"irrelevant", "sourdough starter recipe"},
	} {
		t.Run(c.name, func(t *testing.T) {
			if got := suggestions(t, a.do("GET", suggestURL("positions", c.query), nil)); len(got) != 0 {
				t.Fatalf("got %v, want none", got)
			}
		})
	}

	// A real surface the catalogue holds no readings for is the same answer.
	if got := suggestions(t, a.do("GET", suggestURL("settings", "owliver"), nil)); len(got) != 0 {
		t.Fatalf("settings returned %v", got)
	}
}

// The page decides the answer, so the same word must not produce the same list
// everywhere.
func TestOwliverSuggestionsAreScopedToThePage(t *testing.T) {
	a := newAPI(t)

	read := func(page string) []string {
		out := []string{}
		for _, s := range suggestions(t, a.do("GET", suggestURL(page, "pipeline"), nil)) {
			out = append(out, s["intent"].(string))
		}
		return out
	}

	positions, candidates := read("positions"), read("candidates")
	if len(positions) == 0 || len(candidates) == 0 {
		t.Fatalf("positions=%v candidates=%v", positions, candidates)
	}
	if len(positions) == len(candidates) {
		same := true
		for i := range positions {
			if positions[i] != candidates[i] {
				same = false
				break
			}
		}
		if same {
			t.Fatalf("both pages answered pipeline with %v", positions)
		}
	}
}

/* ── Authorization ──────────────────────────────────────────────────────── */

// Who is asking comes from the session, and it decides which readings exist.
//
// Talent may list job applications — but only their own, by a predicate in the
// repository — so the organization-wide readings the operator console offers
// are not theirs, and are absent rather than refused.
func TestOwliverSuggestionsFollowTheCallersRole(t *testing.T) {
	r := newRBAC(t)

	// A query each page can actually answer, so an empty list means the role
	// was filtered rather than that the words matched nothing.
	operatorPages := []struct{ page, query string }{
		{"control-center", "pipeline attention"},
		{"positions", "pipeline attention"},
		{"candidates", "candidate score"},
		{"hired-history", "recent hires outcomes"},
		{"talent-pool", "talent pool availability"},
		{"activity", "audit unusual activity"},
	}

	for _, c := range operatorPages {
		for _, act := range []actor{r.admin, r.empA} {
			got := suggestions(t, r.as(act, "GET", suggestURL(c.page, c.query), nil))
			if len(got) == 0 {
				t.Errorf("%s was offered nothing on %s for %q", act.name, c.page, c.query)
			}
		}

		if got := suggestions(t, r.as(r.talA, "GET", suggestURL(c.page, c.query), nil)); len(got) != 0 {
			t.Errorf("talent was offered %v on %s", got, c.page)
		}
	}

	// Still 200 with an empty list, never 403: refusing would tell a caller
	// which pages hold readings they cannot have.
	refused := r.as(r.talA, "GET", suggestURL("positions", "pipeline"), nil)
	if refused.code != http.StatusOK {
		t.Fatalf("talent got status %d, want 200 with an empty list", refused.code)
	}
}

// The role filter is not a blanket refusal for talent: what they may genuinely
// ask — about their own account — is still offered. Without this, the test
// above would pass with the permission check stubbed out to deny everything.
func TestOwliverSuggestionsStillServeTalentTheirOwnReadings(t *testing.T) {
	r := newRBAC(t)

	got := suggestions(t, r.as(r.talA, "GET", suggestURL("profile", "permission"), nil))
	if len(got) == 0 {
		t.Fatal("talent was offered nothing about their own account")
	}
	if got[0]["intent"] != "profile-permissions" {
		t.Fatalf("got %v", got[0])
	}
}

// A permission-sensitive reading: Hired History reads the staff table, which
// policy.go grants to operators only. Nothing about the request differs — only
// the session behind it.
func TestOwliverSuggestionsHideReadingsARoleCannotPerform(t *testing.T) {
	r := newRBAC(t)
	const path = suggestPath + "?page=hired-history&query=recent+hires"

	for _, act := range []actor{r.admin, r.empA} {
		if got := suggestions(t, r.as(act, "GET", path, nil)); len(got) == 0 {
			t.Errorf("%s was offered no hiring outcomes", act.name)
		}
	}
	if got := suggestions(t, r.as(r.talA, "GET", path, nil)); len(got) != 0 {
		t.Fatalf("talent was offered readings of the staff table: %v", got)
	}
}