package handlers

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"testing"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/jackc/pgx/v5/pgxpool"

	"git.netcell-it.de/projekte/edgeguard-native/internal/database"
	oidcsvc "git.netcell-it.de/projekte/edgeguard-native/internal/services/oidc"
	"git.netcell-it.de/projekte/edgeguard-native/internal/services/session"
	usersvc "git.netcell-it.de/projekte/edgeguard-native/internal/services/users"
)

// mockAuth erfüllt oidcsvc.Authenticator und liefert vorgegebene Claims —
// kein echter IdP nötig.
type mockAuth struct {
	claims *oidcsvc.Claims
	err    error
}

func (m *mockAuth) AuthCodeURL(_ context.Context, _, state, _, _ string) (string, error) {
	return "https://idp.example/authorize?state=" + state, nil
}
func (m *mockAuth) Exchange(_ context.Context, _, _, _ string) (*oidcsvc.Claims, error) {
	return m.claims, m.err
}

func oidcTestSetup(t *testing.T) (*usersvc.Repo, *pgxpool.Pool, *session.Signer) {
	t.Helper()
	dsn := os.Getenv("EG_FWTEST_DSN")
	if dsn == "" {
		t.Skip("set EG_FWTEST_DSN to run the oidc handler test")
	}
	ctx := context.Background()
	// Retry: goose-Erst-Apply ist nicht concurrency-safe, wenn mehrere
	// guarded Test-Pakete dieselbe frische DB parallel migrieren.
	var mErr error
	for i := 0; i < 3; i++ {
		if mErr = database.Migrate(ctx, dsn); mErr == nil {
			break
		}
		time.Sleep(700 * time.Millisecond)
	}
	if mErr != nil {
		t.Fatalf("migrate: %v", mErr)
	}
	pool, err := database.Open(ctx, dsn)
	if err != nil {
		t.Fatalf("open: %v", err)
	}
	t.Cleanup(pool.Close)
	return usersvc.New(pool), pool, session.NewSigner([]byte("0123456789abcdef0123456789abcdef"), nil, 0)
}

func seedUser(t *testing.T, repo *usersvc.Repo, pool *pgxpool.Pool, email, role string, active bool) {
	t.Helper()
	ctx := context.Background()
	_, _ = pool.Exec(ctx, `DELETE FROM users WHERE email=$1`, email)
	if _, err := repo.Create(ctx, email, "Sup3rSecret-pw-123", role, active); err != nil {
		t.Fatalf("seed user: %v", err)
	}
}

func runCallback(t *testing.T, h *OIDCHandler, flow oidcFlow, queryState, code string) *httptest.ResponseRecorder {
	t.Helper()
	gin.SetMode(gin.TestMode)
	rec := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(rec)
	blob, _ := json.Marshal(flow)
	signed, err := h.Signer.SignBlob(blob, oidcFlowTTL)
	if err != nil {
		t.Fatal(err)
	}
	req := httptest.NewRequest(http.MethodGet,
		"/api/v1/auth/oidc/callback?state="+queryState+"&code="+code, nil)
	req.AddCookie(&http.Cookie{Name: oidcFlowCookie, Value: signed}) //nolint:gosec // Test-Cookie — Secure/HttpOnly-Flags für httptest irrelevant
	c.Request = req
	h.Callback(c)
	return rec
}

func sessionCookie(rec *httptest.ResponseRecorder) string {
	for _, ck := range rec.Result().Cookies() {
		if ck.Name == cookieName && ck.Value != "" && ck.MaxAge >= 0 {
			return ck.Value
		}
	}
	return ""
}

func TestCallback_KnownActiveUser_RoleFromDB(t *testing.T) {
	users, pool, signer := oidcTestSetup(t)
	seedUser(t, users, pool, "sso-viewer@test.local", "viewer", true)

	h := NewOIDCHandler(nil, &mockAuth{claims: &oidcsvc.Claims{
		Email: "sso-viewer@test.local", EmailVerified: true, Subject: "sub-1", Nonce: "N",
	}}, users, signer, nil)

	rec := runCallback(t, h, oidcFlow{State: "S", Verifier: "v", Nonce: "N"}, "S", "code")

	if loc := rec.Header().Get("Location"); loc != "/dashboard" {
		t.Fatalf("expected redirect to /dashboard, got %q (body proves failure path)", loc)
	}
	raw := sessionCookie(rec)
	if raw == "" {
		t.Fatal("expected a session cookie to be set")
	}
	tok, err := signer.Verify(raw)
	if err != nil {
		t.Fatalf("session token invalid: %v", err)
	}
	// Kernbeweis: Rolle kommt aus der DB-Row (viewer), nicht aus Claims.
	if tok.Role != "viewer" {
		t.Errorf("token role = %q, want viewer (role must come from DB)", tok.Role)
	}
	if tok.Actor != "sso-viewer@test.local" {
		t.Errorf("token actor = %q", tok.Actor)
	}
}

func TestCallback_UnknownEmail_Rejected(t *testing.T) {
	users, pool, signer := oidcTestSetup(t)
	_, _ = pool.Exec(context.Background(), `DELETE FROM users WHERE email=$1`, "ghost@test.local")

	h := NewOIDCHandler(nil, &mockAuth{claims: &oidcsvc.Claims{
		Email: "ghost@test.local", EmailVerified: true, Subject: "x", Nonce: "N",
	}}, users, signer, nil)

	rec := runCallback(t, h, oidcFlow{State: "S", Nonce: "N"}, "S", "code")
	if !strings.Contains(rec.Header().Get("Location"), "sso_error=no_account") {
		t.Fatalf("expected sso_error=no_account, got %q", rec.Header().Get("Location"))
	}
	if sessionCookie(rec) != "" {
		t.Fatal("no session cookie expected for unknown user")
	}
}

func TestCallback_InactiveUser_Rejected(t *testing.T) {
	users, pool, signer := oidcTestSetup(t)
	seedUser(t, users, pool, "sso-disabled@test.local", "admin", false)

	h := NewOIDCHandler(nil, &mockAuth{claims: &oidcsvc.Claims{
		Email: "sso-disabled@test.local", EmailVerified: true, Subject: "x", Nonce: "N",
	}}, users, signer, nil)

	rec := runCallback(t, h, oidcFlow{State: "S", Nonce: "N"}, "S", "code")
	if !strings.Contains(rec.Header().Get("Location"), "sso_error=disabled") {
		t.Fatalf("expected sso_error=disabled, got %q", rec.Header().Get("Location"))
	}
	if sessionCookie(rec) != "" {
		t.Fatal("no session cookie expected for inactive user")
	}
}

func TestCallback_EmailUnverified_Rejected(t *testing.T) {
	users, pool, signer := oidcTestSetup(t)
	seedUser(t, users, pool, "sso-unverified@test.local", "admin", true)

	h := NewOIDCHandler(nil, &mockAuth{claims: &oidcsvc.Claims{
		Email: "sso-unverified@test.local", EmailVerified: false, Subject: "x", Nonce: "N",
	}}, users, signer, nil)

	rec := runCallback(t, h, oidcFlow{State: "S", Nonce: "N"}, "S", "code")
	if !strings.Contains(rec.Header().Get("Location"), "sso_error=unverified") {
		t.Fatalf("expected sso_error=unverified, got %q", rec.Header().Get("Location"))
	}
	if sessionCookie(rec) != "" {
		t.Fatal("no session cookie expected for unverified email")
	}
}

func TestCallback_NonceMismatch_Rejected(t *testing.T) {
	users, pool, signer := oidcTestSetup(t)
	seedUser(t, users, pool, "sso-nonce@test.local", "admin", true)

	h := NewOIDCHandler(nil, &mockAuth{claims: &oidcsvc.Claims{
		Email: "sso-nonce@test.local", EmailVerified: true, Subject: "x", Nonce: "WRONG",
	}}, users, signer, nil)

	rec := runCallback(t, h, oidcFlow{State: "S", Nonce: "N"}, "S", "code")
	if !strings.Contains(rec.Header().Get("Location"), "sso_error=nonce") {
		t.Fatalf("expected sso_error=nonce, got %q", rec.Header().Get("Location"))
	}
}

func TestCallback_StateMismatch_Rejected(t *testing.T) {
	users, _, signer := oidcTestSetup(t)
	h := NewOIDCHandler(nil, &mockAuth{claims: &oidcsvc.Claims{}}, users, signer, nil)

	rec := runCallback(t, h, oidcFlow{State: "S", Nonce: "N"}, "WRONG", "code")
	if !strings.Contains(rec.Header().Get("Location"), "sso_error=state") {
		t.Fatalf("expected sso_error=state, got %q", rec.Header().Get("Location"))
	}
}