// SPDX-License-Identifier: AGPL-3.0-or-later

package middleware

import (
	"net"
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestRealIPFromTrustedProxy(t *testing.T) {
	_, tailscale, _ := net.ParseCIDR("100.64.0.0/10")
	trusted := []*net.IPNet{tailscale}

	handler := RealIP(trusted)(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		ip := RealIPFromContext(r.Context())
		w.Write([]byte(ip))
	}))

	// Request from trusted proxy with X-Forwarded-For.
	req := httptest.NewRequest("GET", "/", nil)
	req.RemoteAddr = "100.64.1.1:12345"
	req.Header.Set("X-Forwarded-For", "203.0.113.50, 100.64.1.1")
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)

	if rr.Body.String() != "203.0.113.50" {
		t.Errorf("real IP = %q, want %q", rr.Body.String(), "203.0.113.50")
	}
}

func TestRealIPFromUntrustedProxy(t *testing.T) {
	_, localhost, _ := net.ParseCIDR("127.0.0.1/32")
	trusted := []*net.IPNet{localhost}

	handler := RealIP(trusted)(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		ip := RealIPFromContext(r.Context())
		w.Write([]byte(ip))
	}))

	// Request from untrusted IP — X-Forwarded-For should be ignored.
	req := httptest.NewRequest("GET", "/", nil)
	req.RemoteAddr = "192.168.1.100:12345"
	req.Header.Set("X-Forwarded-For", "spoofed-ip")
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)

	if rr.Body.String() != "192.168.1.100" {
		t.Errorf("real IP = %q, want %q (should ignore XFF from untrusted)", rr.Body.String(), "192.168.1.100")
	}
}

func TestBasePathStripping(t *testing.T) {
	handler := BasePath("/faves")(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte(r.URL.Path))
	}))

	tests := []struct {
		path string
		want string
	}{
		{"/faves/", "/"},
		{"/faves/login", "/login"},
		{"/faves/u/test", "/u/test"},
		{"/other", "/other"}, // No prefix match — passed through unchanged.
	}

	for _, tt := range tests {
		req := httptest.NewRequest("GET", tt.path, nil)
		rr := httptest.NewRecorder()
		handler.ServeHTTP(rr, req)
		if rr.Body.String() != tt.want {
			t.Errorf("BasePath(%q) = %q, want %q", tt.path, rr.Body.String(), tt.want)
		}
	}
}

func TestBasePathEmpty(t *testing.T) {
	// Empty base path should be a no-op.
	inner := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte(r.URL.Path))
	})
	handler := BasePath("")(inner)

	req := httptest.NewRequest("GET", "/login", nil)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if rr.Body.String() != "/login" {
		t.Errorf("empty base path: got %q, want /login", rr.Body.String())
	}
}

func TestRateLimiter(t *testing.T) {
	rl := NewRateLimiter(3)
	handler := rl.Limit(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))

	for i := 0; i < 3; i++ {
		req := httptest.NewRequest("POST", "/login", nil)
		// RealIP middleware hasn't run, so RealIPFromContext returns "".
		// The rate limiter falls back to RemoteAddr.
		req.RemoteAddr = "192.168.1.1:1234"
		rr := httptest.NewRecorder()
		handler.ServeHTTP(rr, req)
		if rr.Code != http.StatusOK {
			t.Errorf("request %d: got %d, want 200", i+1, rr.Code)
		}
	}

	// 4th request should be rate-limited.
	req := httptest.NewRequest("POST", "/login", nil)
	req.RemoteAddr = "192.168.1.1:1234"
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if rr.Code != http.StatusTooManyRequests {
		t.Errorf("rate-limited request: got %d, want 429", rr.Code)
	}

	// Different IP should not be rate-limited.
	req = httptest.NewRequest("POST", "/login", nil)
	req.RemoteAddr = "10.0.0.1:1234"
	rr = httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if rr.Code != http.StatusOK {
		t.Errorf("different IP: got %d, want 200", rr.Code)
	}
}

func TestRecovery(t *testing.T) {
	handler := Recovery(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		panic("test panic")
	}))

	req := httptest.NewRequest("GET", "/", nil)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)

	if rr.Code != http.StatusInternalServerError {
		t.Errorf("panic recovery: got %d, want 500", rr.Code)
	}
}

func TestSecurityHeaders(t *testing.T) {
	handler := SecurityHeaders(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))

	req := httptest.NewRequest("GET", "/", nil)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)

	headers := map[string]string{
		"X-Content-Type-Options": "nosniff",
		"X-Frame-Options":       "DENY",
		"Referrer-Policy":       "strict-origin-when-cross-origin",
	}
	for key, want := range headers {
		got := rr.Header().Get(key)
		if got != want {
			t.Errorf("%s = %q, want %q", key, got, want)
		}
	}

	csp := rr.Header().Get("Content-Security-Policy")
	if csp == "" {
		t.Error("Content-Security-Policy header missing")
	}
}

func TestRequireLoginRedirects(t *testing.T) {
	handler := RequireLogin("/faves")(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))

	// No user in context — should redirect.
	req := httptest.NewRequest("GET", "/settings", nil)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)

	if rr.Code != http.StatusSeeOther {
		t.Errorf("no user: got %d, want 303", rr.Code)
	}
	loc := rr.Header().Get("Location")
	if loc != "/faves/login" {
		t.Errorf("redirect location = %q, want /faves/login", loc)
	}
}

func TestMustResetPasswordGuard(t *testing.T) {
	handler := MustResetPasswordGuard("")(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))

	// No user — should pass through.
	req := httptest.NewRequest("GET", "/faves", nil)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if rr.Code != http.StatusOK {
		t.Errorf("no user: got %d, want 200", rr.Code)
	}

	// Static paths should always pass through even with must-reset user.
	req = httptest.NewRequest("GET", "/static/css/style.css", nil)
	rr = httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if rr.Code != http.StatusOK {
		t.Errorf("static path: got %d, want 200", rr.Code)
	}
}