package auth

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"net/url"
	"testing"
)

// newTestOIDCVerifier spins up a fake OIDC discovery endpoint (just enough
// for oidc.NewProvider's discovery GET to succeed) and returns a real
// oidcVerifier backed by it, for tests that exercise EndSessionURL without
// a live Keycloak.
func newTestOIDCVerifier(t *testing.T) Verifier {
	t.Helper()
	var issuerURL string
	mux := http.NewServeMux()
	mux.HandleFunc("/.well-known/openid-configuration", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		fmt.Fprintf(w, `{
			"issuer": %[1]q,
			"authorization_endpoint": "%[1]s/auth",
			"token_endpoint": "%[1]s/token",
			"end_session_endpoint": "%[1]s/logout",
			"jwks_uri": "%[1]s/certs"
		}`, issuerURL)
	})
	mux.HandleFunc("/certs", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		fmt.Fprint(w, `{"keys":[]}`)
	})
	srv := httptest.NewServer(mux)
	t.Cleanup(srv.Close)
	issuerURL = srv.URL

	verifier, err := NewOIDCVerifier(context.Background(), OIDCConfig{
		IssuerURL: issuerURL, ClientID: "geniusrun", ClientSecret: "secret", RedirectURL: issuerURL + "/callback",
	})
	if err != nil {
		t.Fatalf("NewOIDCVerifier: %v", err)
	}
	return verifier
}

func TestEndSessionURL_IncludesIDTokenHintWhenProvided(t *testing.T) {
	verifier := newTestOIDCVerifier(t)

	got := verifier.EndSessionURL("https://app.example.com/", "raw-id-token-jwt")
	u, err := url.Parse(got)
	if err != nil {
		t.Fatalf("parse EndSessionURL result %q: %v", got, err)
	}
	q := u.Query()
	if q.Get("id_token_hint") != "raw-id-token-jwt" {
		t.Errorf("id_token_hint = %q, want %q", q.Get("id_token_hint"), "raw-id-token-jwt")
	}
	if q.Get("client_id") != "geniusrun" {
		t.Errorf("client_id = %q, want geniusrun", q.Get("client_id"))
	}
	if q.Get("post_logout_redirect_uri") != "https://app.example.com/" {
		t.Errorf("post_logout_redirect_uri = %q, want https://app.example.com/", q.Get("post_logout_redirect_uri"))
	}
}

func TestEndSessionURL_OmitsIDTokenHintWhenEmpty(t *testing.T) {
	verifier := newTestOIDCVerifier(t)

	got := verifier.EndSessionURL("https://app.example.com/", "")
	u, err := url.Parse(got)
	if err != nil {
		t.Fatalf("parse EndSessionURL result %q: %v", got, err)
	}
	if u.Query().Has("id_token_hint") {
		t.Errorf("expected no id_token_hint param when idTokenHint is empty, got %q", got)
	}
}

func TestIDTokenClaims_HasRole(t *testing.T) {
	cases := []struct {
		name string
		json string
		role string
		want bool
	}{
		{"role present among others", `{"realm_access":{"roles":["geniusrun-user","other"]}}`, "geniusrun-user", true},
		{"role absent", `{"realm_access":{"roles":["other"]}}`, "geniusrun-user", false},
		{"realm_access missing entirely", `{}`, "geniusrun-user", false},
		{"roles array empty", `{"realm_access":{"roles":[]}}`, "geniusrun-user", false},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			var c idTokenClaims
			if err := json.Unmarshal([]byte(tc.json), &c); err != nil {
				t.Fatalf("unmarshal: %v", err)
			}
			if got := c.hasRole(tc.role); got != tc.want {
				t.Errorf("hasRole(%q) = %v, want %v", tc.role, got, tc.want)
			}
		})
	}
}