// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Commercial
// SPDX-FileCopyrightText: 2025-2026 Christian Galo

package tests

import (
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"github.com/spf13/viper"

	"git.coopcloud.tech/wiki-cafe/member-console/internal/middleware"
)

func servedCSP(t *testing.T) string {
	t.Helper()
	h := middleware.SecureHeaders()(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/", nil))
	csp := rec.Result().Header.Get("Content-Security-Policy")
	if csp == "" {
		t.Fatal("no Content-Security-Policy header was set")
	}
	return csp
}

// The policy must authorize only origins the application actually loads from.
// Front-end assets are vendored into internal/embeds/static/ and served from
// /static/, so no content delivery network belongs in script-src. A dead
// unpkg.com entry lived here until the 2026-09 security audit.
func TestCSPAllowsNoThirdPartyScriptOrigin(t *testing.T) {
	csp := servedCSP(t)

	var scriptSrc string
	for _, d := range strings.Split(csp, ";") {
		if d = strings.TrimSpace(d); strings.HasPrefix(d, "script-src") {
			scriptSrc = d
		}
	}
	if scriptSrc == "" {
		t.Fatalf("policy declares no script-src: %q", csp)
	}
	if scriptSrc != "script-src 'self'" {
		t.Errorf("script-src must be exactly \"script-src 'self'\", got %q", scriptSrc)
	}
	for _, banned := range []string{"unpkg.com", "cdn.", "https://", "http://", "*"} {
		if strings.Contains(scriptSrc, banned) {
			t.Errorf("script-src names a third-party or wildcard source %q: %q", banned, scriptSrc)
		}
	}
}

// Defence in depth around the same header set.
func TestSecurityHeadersPinTheObviousProtections(t *testing.T) {
	h := middleware.SecureHeaders()(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/", nil))
	res := rec.Result()

	for header, want := range map[string]string{
		"X-Content-Type-Options": "nosniff",
		"X-Frame-Options":        "DENY",
		"Referrer-Policy":        "no-referrer",
	} {
		if got := res.Header.Get(header); got != want {
			t.Errorf("%s = %q, want %q", header, got, want)
		}
	}
	if !strings.Contains(servedCSP(t), "frame-ancestors 'none'") {
		t.Error("policy must set frame-ancestors 'none'")
	}
}

// upgrade-insecure-requests follows base-url's scheme, not the env label
// (2026-09 security audit, finding 5): served over https it is on whatever
// the deployment calls itself; over plain http it would upgrade every
// subresource to a scheme nothing listens on, so it is off.
func TestCSPUpgradeDirectiveFollowsTheBaseURLScheme(t *testing.T) {
	t.Cleanup(viper.Reset)
	for _, tc := range []struct {
		baseURL string
		env     string
		want    bool
	}{
		{"https://console.example.coop", "staging", true},
		{"https://console.example.coop", "development", true},
		{"http://member-console.localhost:9431", "production", false},
	} {
		viper.Set("base-url", tc.baseURL)
		viper.Set("env", tc.env)
		got := strings.Contains(servedCSP(t), "upgrade-insecure-requests")
		if got != tc.want {
			t.Errorf("base-url %q env %q: upgrade-insecure-requests present = %v, want %v", tc.baseURL, tc.env, got, tc.want)
		}
	}
}

// Strict-Transport-Security is sent only where the console is served over
// https: RFC 6797 section 7.2 forbids it over non-secure transport. The value
// is a year with includeSubDomains; the one-hour value it replaced lapsed
// before most return visits, which re-opened the first plain-HTTP request
// HSTS exists to prevent.
func TestHSTSFollowsTheBaseURLSchemeWithAYearLongPolicy(t *testing.T) {
	t.Cleanup(viper.Reset)
	serve := func(baseURL string) string {
		viper.Set("base-url", baseURL)
		h := middleware.SecureHeaders()(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
		rec := httptest.NewRecorder()
		h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/", nil))
		return rec.Result().Header.Get("Strict-Transport-Security")
	}
	if got, want := serve("https://console.example.coop"), "max-age=31536000; includeSubDomains"; got != want {
		t.Errorf("over https: Strict-Transport-Security = %q, want %q", got, want)
	}
	if got := serve("http://member-console.localhost:9431"); got != "" {
		t.Errorf("over http: Strict-Transport-Security = %q, want none (RFC 6797 section 7.2)", got)
	}
}

// The size limit and the timeout answer for the handler (a 413, a 503), and
// the timeout handler discards whatever an inner middleware set. So the
// security headers must be applied outside both, which is the order the
// server's stack uses (2026-09 audit candidate "413 responses bypass the
// security-header middleware"). This pins that order's effect.
func TestSecurityHeadersReachRefusalsWrittenByOuterMiddleware(t *testing.T) {
	refused := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		t.Error("the handler must not run")
	})

	t.Run("413 from the body limit", func(t *testing.T) {
		h := middleware.SecureHeaders()(middleware.MaxBodySize(4)(refused))
		req := httptest.NewRequest(http.MethodPost, "/", strings.NewReader("too large"))
		req.ContentLength = 9
		rec := httptest.NewRecorder()
		h.ServeHTTP(rec, req)
		if rec.Code != http.StatusRequestEntityTooLarge {
			t.Fatalf("status = %d, want 413", rec.Code)
		}
		if got := rec.Header().Get("X-Content-Type-Options"); got != "nosniff" {
			t.Errorf("the 413 carries no security headers (X-Content-Type-Options = %q)", got)
		}
	})

	t.Run("503 from the timeout", func(t *testing.T) {
		slow := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			<-r.Context().Done()
		})
		h := middleware.SecureHeaders()(middleware.Timeout(10 * time.Millisecond)(slow))
		rec := httptest.NewRecorder()
		h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/", nil))
		if rec.Code != http.StatusServiceUnavailable {
			t.Fatalf("status = %d, want 503", rec.Code)
		}
		if got := rec.Header().Get("X-Content-Type-Options"); got != "nosniff" {
			t.Errorf("the 503 carries no security headers (X-Content-Type-Options = %q)", got)
		}
	})
}