package httpapi

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"ipecho/internal/clientip"
)

func TestIPEndpointReturnsPlainTextClientIP(t *testing.T) {
	handler := New(clientip.Resolver{})
	req := httptest.NewRequest(http.MethodGet, "/ip", nil)
	req.RemoteAddr = "198.51.100.20:54123"
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("got status %d, want %d", rec.Code, http.StatusOK)
	}

	if got, want := rec.Body.String(), "198.51.100.20\n"; got != want {
		t.Fatalf("got body %q, want %q", got, want)
	}

	if got := rec.Header().Get("Content-Type"); !strings.HasPrefix(got, "text/plain") {
		t.Fatalf("got content-type %q, want text/plain", got)
	}
}

func TestRootReturnsPlainTextClientIPForCLIRequests(t *testing.T) {
	handler := New(clientip.Resolver{})
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.RemoteAddr = "198.51.100.20:54123"
	req.Header.Set("Accept", "*/*")
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("got status %d, want %d", rec.Code, http.StatusOK)
	}

	if got, want := rec.Body.String(), "198.51.100.20\n"; got != want {
		t.Fatalf("got body %q, want %q", got, want)
	}

	if got := rec.Header().Get("Content-Type"); !strings.HasPrefix(got, "text/plain") {
		t.Fatalf("got content-type %q, want text/plain", got)
	}
}

func TestRootReturnsHTMLForBrowserRequests(t *testing.T) {
	handler := New(clientip.Resolver{})
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.RemoteAddr = "198.51.100.20:54123"
	req.Header.Set("Accept", "text/html,application/xhtml+xml")
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("got status %d, want %d", rec.Code, http.StatusOK)
	}

	if got := rec.Header().Get("Content-Type"); !strings.HasPrefix(got, "text/html") {
		t.Fatalf("got content-type %q, want text/html", got)
	}

	body := rec.Body.String()
	for _, want := range []string{"IP Echo", "198.51.100.20", "Copy IP", "/json"} {
		if !strings.Contains(body, want) {
			t.Fatalf("body does not contain %q", want)
		}
	}
}

func TestJSONEndpointReturnsRequestMetadata(t *testing.T) {
	handler := New(clientip.Resolver{TrustProxyHeaders: true})
	req := httptest.NewRequest(http.MethodGet, "/json", nil)
	req.RemoteAddr = "198.51.100.20:54123"
	req.Header.Set("User-Agent", "ipecho-test")
	req.Header.Set("X-Forwarded-For", "203.0.113.10")
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("got status %d, want %d", rec.Code, http.StatusOK)
	}

	var got ClientInfo
	if err := json.Unmarshal(rec.Body.Bytes(), &got); err != nil {
		t.Fatalf("decode response: %v", err)
	}

	if got.IP != "203.0.113.10" {
		t.Fatalf("got ip %q, want %q", got.IP, "203.0.113.10")
	}

	if got.UserAgent != "ipecho-test" {
		t.Fatalf("got user agent %q, want %q", got.UserAgent, "ipecho-test")
	}
}

func TestHeadersEndpointIncludesHostAndHeaders(t *testing.T) {
	handler := New(clientip.Resolver{})
	req := httptest.NewRequest(http.MethodGet, "/headers", nil)
	req.Host = "example.test"
	req.Header.Set("User-Agent", "ipecho-test")
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)

	body := rec.Body.String()
	for _, want := range []string{"Host: example.test", "User-Agent: ipecho-test"} {
		if !strings.Contains(body, want) {
			t.Fatalf("body %q does not contain %q", body, want)
		}
	}
}

func TestFaviconEndpointReturnsIconWithoutHTMLLink(t *testing.T) {
	handler := New(clientip.Resolver{})
	req := httptest.NewRequest(http.MethodGet, "/favicon.ico", nil)
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("got status %d, want %d", rec.Code, http.StatusOK)
	}

	if got := rec.Header().Get("Content-Type"); got != "image/x-icon" {
		t.Fatalf("got content-type %q, want image/x-icon", got)
	}

	if rec.Body.Len() == 0 {
		t.Fatal("favicon response is empty")
	}
}

func TestSecurityHeadersAreApplied(t *testing.T) {
	handler := New(clientip.Resolver{})
	req := httptest.NewRequest(http.MethodGet, "/healthz", nil)
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)

	for _, header := range []string{
		"X-Content-Type-Options",
		"X-Frame-Options",
		"Referrer-Policy",
		"Content-Security-Policy",
	} {
		if rec.Header().Get(header) == "" {
			t.Fatalf("missing %s header", header)
		}
	}
}

func TestUnknownEndpointReturnsNotFound(t *testing.T) {
	handler := New(clientip.Resolver{})
	req := httptest.NewRequest(http.MethodGet, "/missing", nil)
	rec := httptest.NewRecorder()

	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusNotFound {
		t.Fatalf("got status %d, want %d", rec.Code, http.StatusNotFound)
	}
}