package web_test

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

	"github.com/owen/vibedns/internal/api"
	"github.com/owen/vibedns/internal/app"
	"github.com/owen/vibedns/internal/auditlog"
	"github.com/owen/vibedns/internal/config"
	"github.com/owen/vibedns/internal/database"
	"github.com/owen/vibedns/internal/models"
	"github.com/owen/vibedns/internal/web"
)

const testPassword = "an-adequate-test-phrase"

// newTestServer builds the whole HTTP stack against a temporary database and
// seeds one of every object, so page rendering is exercised with real data
// rather than only against empty tables.
func newTestServer(t *testing.T) (http.Handler, *app.App) {
	t.Helper()
	ctx := context.Background()

	path := filepath.Join(t.TempDir(), "web.db")
	db, err := database.Open(path)
	if err != nil {
		t.Fatalf("open database: %v", err)
	}
	t.Cleanup(func() { db.Close() })
	if _, err := db.Migrate(ctx); err != nil {
		t.Fatalf("migrate: %v", err)
	}

	log := slog.New(slog.NewTextHandler(io.Discard, nil))
	boot := config.DefaultBootstrap()
	boot.DBPath = path

	a, err := app.New(ctx, boot, db, log)
	if err != nil {
		t.Fatalf("build app: %v", err)
	}
	if _, _, err := a.Auth.EnsureAdmin(ctx, "admin", testPassword); err != nil {
		t.Fatalf("create admin: %v", err)
	}

	actor := auditlog.Actor{Name: "test", Source: auditlog.SourceCLI}

	zone, err := a.CreateZone(ctx, actor, app.ZoneInput{Name: "example.com"})
	if err != nil {
		t.Fatalf("seed zone: %v", err)
	}
	for _, in := range []app.RecordInput{
		{Name: "@", Type: "A", Data: "192.0.2.10"},
		{Name: "www", Type: "CNAME", Data: "example.com."},
		{Name: "txt", Type: "TXT", Data: `"hello"`},
	} {
		if _, err := a.CreateRecord(ctx, actor, zone.ID, in); err != nil {
			t.Fatalf("seed record: %v", err)
		}
	}
	if _, err := a.CreateZone(ctx, actor, app.ZoneInput{CIDR: "192.168.1.0/24", Kind: "reverse4"}); err != nil {
		t.Fatalf("seed reverse zone: %v", err)
	}

	list, err := a.CreateDomainList(ctx, actor, app.ListInput{Kind: models.KindBlacklist, Name: "Seeded"})
	if err != nil {
		t.Fatalf("seed list: %v", err)
	}
	if _, err := a.ImportDomains(ctx, actor, list.ID, strings.NewReader("ads.example\n"), true); err != nil {
		t.Fatalf("seed domains: %v", err)
	}
	policy, err := a.CreatePolicy(ctx, actor, app.PolicyInput{
		Name: "Seeded Policy", BlockAction: "nxdomain", ListIDs: []int64{list.ID},
	})
	if err != nil {
		t.Fatalf("seed policy: %v", err)
	}
	if _, err := a.CreateNetwork(ctx, actor, app.NetworkInput{
		Name: "Seeded Net", CIDR: "100.64.30.0/24", PolicyIDs: []int64{policy.ID},
	}); err != nil {
		t.Fatalf("seed network: %v", err)
	}
	if _, err := a.CreateAPIToken(ctx, actor, "seeded-token", ""); err != nil {
		t.Fatalf("seed token: %v", err)
	}

	srv, err := web.New(web.Options{App: a, Log: log, API: api.New(a, log).Handler()})
	if err != nil {
		t.Fatalf("build web server: %v", err)
	}
	return srv.Handler(), a
}

func get(t *testing.T, h http.Handler, path string, auth bool) *httptest.ResponseRecorder {
	t.Helper()
	req := httptest.NewRequest(http.MethodGet, path, nil)
	if auth {
		req.SetBasicAuth("admin", testPassword)
	}
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	return rec
}

// TestEveryPageRenders walks every GET route in the interface. A template that
// indexes a value the handler forgot to supply fails here rather than as a 500
// the first time an operator opens that page.
func TestEveryPageRenders(t *testing.T) {
	h, _ := newTestServer(t)

	paths := []string{
		"/", "/dashboard",
		"/zones", "/zones/reverse", "/zones/new", "/zones/new?kind=reverse4",
		"/zones/1", "/zones/1/edit", "/zones/1?q=www&type=A&status=enabled",
		"/records", "/records?search=192.0.2&type=A",
		"/resolver", "/cache", "/cache?q=example",
		"/policies", "/policies/networks", "/policies/networks/new", "/policies/networks/1",
		"/policies/rules/new", "/policies/rules/1",
		"/policies/blacklists", "/policies/allowlists", "/policies/lists/1",
		"/policies/lists/1?q=ads",
		"/querylog", "/querylog?domain=example&blocked=blocked",
		"/audit", "/audit?q=zone",
		"/tools", "/account",
		"/settings", "/settings/dns", "/settings/resolver", "/settings/cache",
		"/settings/logging", "/settings/http", "/settings/database", "/settings/api",
	}

	for _, p := range paths {
		t.Run(p, func(t *testing.T) {
			rec := get(t, h, p, true)
			if rec.Code >= 500 {
				t.Fatalf("GET %s = %d\n%s", p, rec.Code, truncateBody(rec.Body.String()))
			}
			if rec.Code != http.StatusOK && rec.Code != http.StatusSeeOther &&
				rec.Code != http.StatusFound {
				t.Errorf("GET %s = %d, want 200 or a redirect", p, rec.Code)
			}
			// A rendered page must actually contain the layout, not a stub.
			if rec.Code == http.StatusOK && strings.Contains(rec.Header().Get("Content-Type"), "text/html") {
				body := rec.Body.String()
				if !strings.Contains(body, "</html>") {
					t.Errorf("GET %s produced a truncated page", p)
				}
			}
		})
	}
}

func truncateBody(s string) string {
	if len(s) > 800 {
		return s[:800] + "..."
	}
	return s
}

// TestPagesRequireAuthentication is the guard that every administrative route
// is actually protected.
func TestPagesRequireAuthentication(t *testing.T) {
	h, _ := newTestServer(t)

	protected := []string{
		"/", "/zones", "/records", "/resolver", "/cache", "/policies",
		"/policies/networks", "/policies/blacklists", "/querylog", "/audit",
		"/tools", "/account", "/settings/dns", "/settings/api",
		"/api/v1/zones", "/api/v1/settings", "/api/v1/stats",
	}
	for _, p := range protected {
		t.Run(p, func(t *testing.T) {
			if rec := get(t, h, p, false); rec.Code != http.StatusUnauthorized {
				t.Errorf("GET %s without credentials = %d, want 401", p, rec.Code)
			}
		})
	}
}

func TestPublicEndpoints(t *testing.T) {
	h, _ := newTestServer(t)

	t.Run("healthz", func(t *testing.T) {
		rec := get(t, h, "/healthz", false)
		if rec.Code != http.StatusOK {
			t.Errorf("status = %d, want 200", rec.Code)
		}
		if !strings.Contains(rec.Body.String(), "ok") {
			t.Errorf("body = %q", rec.Body.String())
		}
	})

	t.Run("readyz reports not ready without listeners", func(t *testing.T) {
		// The DNS listeners are not started in this test, so readiness must
		// report that rather than claiming everything is fine.
		rec := get(t, h, "/readyz", false)
		if rec.Code != http.StatusServiceUnavailable {
			t.Errorf("status = %d, want 503 when the DNS listeners are down", rec.Code)
		}
	})

	t.Run("static assets", func(t *testing.T) {
		for _, p := range []string{
			"/static/css/app.css", "/static/css/bootstrap.min.css",
			"/static/js/app.js", "/static/fonts/bootstrap-icons.woff2",
		} {
			rec := get(t, h, p, false)
			if rec.Code != http.StatusOK {
				t.Errorf("GET %s = %d, want 200", p, rec.Code)
			}
			if rec.Body.Len() == 0 {
				t.Errorf("GET %s returned an empty body", p)
			}
		}
	})

	t.Run("metrics requires auth by default", func(t *testing.T) {
		if rec := get(t, h, "/metrics", false); rec.Code != http.StatusUnauthorized {
			t.Errorf("status = %d, want 401: metrics must not be public by default", rec.Code)
		}
		rec := get(t, h, "/metrics", true)
		if rec.Code != http.StatusOK {
			t.Fatalf("authenticated status = %d, want 200", rec.Code)
		}
		for _, want := range []string{"vibedns_dns_queries_total", "vibedns_build_info", "vibedns_cache_entries"} {
			if !strings.Contains(rec.Body.String(), want) {
				t.Errorf("metrics output is missing %q", want)
			}
		}
	})
}

func TestSecurityHeaders(t *testing.T) {
	h, _ := newTestServer(t)
	rec := get(t, h, "/", true)

	want := map[string]string{
		"X-Content-Type-Options": "nosniff",
		"X-Frame-Options":        "DENY",
		"Referrer-Policy":        "same-origin",
	}
	for k, v := range want {
		if got := rec.Header().Get(k); got != v {
			t.Errorf("header %s = %q, want %q", k, got, v)
		}
	}

	csp := rec.Header().Get("Content-Security-Policy")
	if csp == "" {
		t.Fatal("no Content-Security-Policy header")
	}
	// The policy must not permit inline scripts: page data travels in data-
	// attributes precisely so it does not have to.
	if strings.Contains(csp, "script-src") && strings.Contains(csp, "'unsafe-inline' 'self'") {
		t.Error("the CSP allows inline scripts")
	}
	for _, want := range []string{"default-src 'self'", "frame-ancestors 'none'", "object-src 'none'"} {
		if !strings.Contains(csp, want) {
			t.Errorf("CSP is missing %q: %s", want, csp)
		}
	}
}

// TestStateChangingRequestNeedsCSRF confirms the protection is actually wired
// up, not merely present in the code.
func TestStateChangingRequestNeedsCSRF(t *testing.T) {
	h, _ := newTestServer(t)

	req := httptest.NewRequest(http.MethodPost, "/zones/1/delete", nil)
	req.SetBasicAuth("admin", testPassword)
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)

	if rec.Code != http.StatusForbidden {
		t.Errorf("POST without a CSRF token = %d, want 403", rec.Code)
	}
}

func TestAPIReturnsJSON(t *testing.T) {
	h, _ := newTestServer(t)

	rec := get(t, h, "/api/v1/zones", true)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200", rec.Code)
	}
	if ct := rec.Header().Get("Content-Type"); !strings.Contains(ct, "application/json") {
		t.Errorf("content type = %q, want JSON", ct)
	}
	if !strings.Contains(rec.Body.String(), "example.com.") {
		t.Errorf("the seeded zone is missing from the response: %s", truncateBody(rec.Body.String()))
	}

	// A missing object must be a JSON 404, not an HTML error page.
	rec = get(t, h, "/api/v1/zones/9999", true)
	if rec.Code != http.StatusNotFound {
		t.Errorf("missing zone status = %d, want 404", rec.Code)
	}
	if !strings.Contains(rec.Body.String(), `"code"`) {
		t.Errorf("error body is not the standard shape: %s", rec.Body.String())
	}
}

func TestAPITokenAuthentication(t *testing.T) {
	h, a := newTestServer(t)
	ctx := context.Background()

	tok, err := a.CreateAPIToken(ctx, auditlog.Actor{Name: "test"}, "auth-test", "")
	if err != nil {
		t.Fatalf("create token: %v", err)
	}
	if tok.Secret == "" {
		t.Fatal("no secret returned at creation")
	}

	req := httptest.NewRequest(http.MethodGet, "/api/v1/zones", nil)
	req.Header.Set("Authorization", "Bearer "+tok.Secret)
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Errorf("bearer token status = %d, want 200", rec.Code)
	}

	// A wrong token must be rejected.
	req = httptest.NewRequest(http.MethodGet, "/api/v1/zones", nil)
	req.Header.Set("Authorization", "Bearer vibedns_thisisnotarealtokenvalue")
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != http.StatusUnauthorized {
		t.Errorf("invalid token status = %d, want 401", rec.Code)
	}
}

// TestAPIWriteWithTokenSkipsCSRF: automation must be able to write without
// obtaining a CSRF token, since a bearer token cannot be replayed by a browser.
func TestAPIWriteWithTokenSkipsCSRF(t *testing.T) {
	h, a := newTestServer(t)
	ctx := context.Background()

	tok, err := a.CreateAPIToken(ctx, auditlog.Actor{Name: "test"}, "write-test", "")
	if err != nil {
		t.Fatalf("create token: %v", err)
	}

	body := strings.NewReader(`{"name":"api-created.example"}`)
	req := httptest.NewRequest(http.MethodPost, "/api/v1/zones", body)
	req.Header.Set("Authorization", "Bearer "+tok.Secret)
	req.Header.Set("Content-Type", "application/json")
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)

	if rec.Code != http.StatusCreated {
		t.Errorf("status = %d, want 201: %s", rec.Code, truncateBody(rec.Body.String()))
	}
}

func TestNotFoundPage(t *testing.T) {
	h, _ := newTestServer(t)
	rec := get(t, h, "/no/such/page", true)
	if rec.Code != http.StatusNotFound {
		t.Errorf("status = %d, want 404", rec.Code)
	}
}