package httpapi

import (
	"context"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"cloudipvalidator/internal/config"
	"cloudipvalidator/internal/db"
	"cloudipvalidator/internal/openstack"
	"cloudipvalidator/internal/orchestrator"
)

const (
	testAdminToken = "admin-token-for-tests"
	testAgentToken = "agent-token-for-tests"
)

func newAuthTestServer(t *testing.T, admin, agent string) (*Server, *httptest.Server) {
	t.Helper()
	ctx := context.Background()
	d, err := db.Open(ctx, filepath.Join(t.TempDir(), "test.db"))
	if err != nil {
		t.Fatalf("open db: %v", err)
	}
	t.Cleanup(func() { d.Close() })
	cfg := &config.ControlAPI{
		Orchestrator: config.OrchestratorConfig{
			PollIntervalSeconds: 1, SelfCheckTimeoutSeconds: 10, MaxSelfCheckRetries: 3,
			CheckingWindowSeconds: 120, MaxRetries: 3, LeaseTTLSeconds: 180, HeartbeatTimeoutSeconds: 30,
		},
		Inbound: config.InboundConfig{Ports: []int{22}, ICMP: true},
	}
	if err := d.BootstrapFromConfig(ctx, cfg); err != nil {
		t.Fatalf("bootstrap: %v", err)
	}
	log := slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{Level: slog.LevelError}))
	orch := orchestrator.New(d, openstack.NewMockClient(), cfg, log)
	t.Cleanup(func() { orch.CancelScan() })
	srv := New(d, orch, log).WithAuth(admin, agent)
	ts := httptest.NewServer(srv.Handler())
	t.Cleanup(ts.Close)
	return srv, ts
}

// concretePath fills the {wildcards} of a ServeMux pattern with dummy values.
func concretePath(pattern string) (method, path string) {
	method, path, _ = strings.Cut(pattern, " ")
	var b strings.Builder
	for {
		i := strings.IndexByte(path, '{')
		if i < 0 {
			b.WriteString(path)
			break
		}
		j := strings.IndexByte(path, '}')
		b.WriteString(path[:i])
		b.WriteString("1")
		path = path[j+1:]
	}
	return method, b.String()
}

func callWithToken(t *testing.T, ts *httptest.Server, pattern, token string) *http.Response {
	t.Helper()
	method, path := concretePath(pattern)
	req, err := http.NewRequest(method, ts.URL+path, strings.NewReader("{}"))
	if err != nil {
		t.Fatalf("new request: %v", err)
	}
	req.Header.Set("Content-Type", "application/json")
	if token != "" {
		req.Header.Set("Authorization", "Bearer "+token)
	}
	resp, err := ts.Client().Do(req)
	if err != nil {
		t.Fatalf("%s: %v", pattern, err)
	}
	resp.Body.Close()
	return resp
}

func TestRouteTableIsClassified(t *testing.T) {
	srv, _ := newAuthTestServer(t, "", "")
	counts := map[string]int{}
	for _, rt := range srv.Routes() {
		counts[rt.Access]++
		if rt.Access == "invalid" {
			t.Fatalf("route %q has no valid access level", rt.Pattern)
		}
		if strings.Contains(rt.Pattern, "/api/v1/admin/") && rt.Access != "admin" {
			t.Fatalf("admin route %q is %s, want admin", rt.Pattern, rt.Access)
		}
	}
	if counts["admin"] != 34 || counts["agent"] != 5 || counts["open"] != 8 {
		t.Fatalf("access counts = %v, want admin=34 agent=5 open=8", counts)
	}
}

func TestAuthMatrixOverRouteTable(t *testing.T) {
	srv, ts := newAuthTestServer(t, testAdminToken, testAgentToken)
	for _, rt := range srv.Routes() {
		rt := rt
		t.Run(rt.Pattern, func(t *testing.T) {
			tokens := []struct {
				name, token string
				allowed     bool
			}{
				{"none", "", rt.Access == "open"},
				{"wrong", "definitely-wrong", rt.Access == "open"},
				{"admin token", testAdminToken, rt.Access == "open" || rt.Access == "admin"},
				{"agent token", testAgentToken, rt.Access == "open" || rt.Access == "agent"},
			}
			for _, tc := range tokens {
				resp := callWithToken(t, ts, rt.Pattern, tc.token)
				if tc.allowed && resp.StatusCode == http.StatusUnauthorized {
					t.Fatalf("%s: got 401, want request to pass auth", tc.name)
				}
				if !tc.allowed {
					if resp.StatusCode != http.StatusUnauthorized {
						t.Fatalf("%s: status=%d, want 401", tc.name, resp.StatusCode)
					}
					if resp.Header.Get("WWW-Authenticate") != "Bearer" {
						t.Fatalf("%s: missing WWW-Authenticate: Bearer", tc.name)
					}
				}
			}
		})
	}
}

func TestEmptyTokensLeaveEverythingOpen(t *testing.T) {
	srv, ts := newAuthTestServer(t, "", "")
	for _, rt := range srv.Routes() {
		if resp := callWithToken(t, ts, rt.Pattern, ""); resp.StatusCode == http.StatusUnauthorized {
			t.Fatalf("%s: got 401 with no tokens configured", rt.Pattern)
		}
	}
}

func TestOnlyConfiguredLevelIsEnforced(t *testing.T) {
	_, ts := newAuthTestServer(t, testAdminToken, "")
	if resp := callWithToken(t, ts, "GET /api/v1/admin/status", ""); resp.StatusCode != http.StatusUnauthorized {
		t.Fatalf("admin without token: status=%d, want 401", resp.StatusCode)
	}
	if resp := callWithToken(t, ts, "POST /api/v1/agents/{id}/results", ""); resp.StatusCode == http.StatusUnauthorized {
		t.Fatalf("agent route must stay open while agent token is unset")
	}
}

func TestHealthzAlwaysOpenAndBearerParsing(t *testing.T) {
	_, ts := newAuthTestServer(t, testAdminToken, testAgentToken)
	if resp := callWithToken(t, ts, "GET /healthz", ""); resp.StatusCode != http.StatusOK {
		t.Fatalf("healthz: status=%d, want 200", resp.StatusCode)
	}
	// Raw token without the Bearer scheme must not authenticate.
	req, _ := http.NewRequest(http.MethodGet, ts.URL+"/api/v1/admin/status", nil)
	req.Header.Set("Authorization", testAdminToken)
	resp, err := ts.Client().Do(req)
	if err != nil {
		t.Fatalf("request: %v", err)
	}
	resp.Body.Close()
	if resp.StatusCode != http.StatusUnauthorized {
		t.Fatalf("scheme-less token: status=%d, want 401", resp.StatusCode)
	}
	// Lowercase scheme is accepted (RFC 7235: case-insensitive).
	req, _ = http.NewRequest(http.MethodGet, ts.URL+"/api/v1/admin/status", nil)
	req.Header.Set("Authorization", "bearer "+testAdminToken)
	resp, err = ts.Client().Do(req)
	if err != nil {
		t.Fatalf("request: %v", err)
	}
	resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("lowercase bearer: status=%d, want 200", resp.StatusCode)
	}
}