package main

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

func portOf(t *testing.T, ts *httptest.Server) int {
	t.Helper()
	u, err := url.Parse(ts.URL)
	if err != nil {
		t.Fatalf("parse %s: %v", ts.URL, err)
	}
	p, err := strconv.Atoi(u.Port())
	if err != nil {
		t.Fatalf("port %s: %v", u.Port(), err)
	}
	return p
}

func TestIsDocumentNav(t *testing.T) {
	cases := []struct {
		name    string
		method  string
		headers map[string]string
		want    bool
	}{
		{"GET sec-fetch-dest document", "GET", map[string]string{"Sec-Fetch-Dest": "document"}, true},
		{"GET accept html (no sec-fetch)", "GET", map[string]string{"Accept": "text/html,application/xhtml+xml"}, true},
		{"GET xhr empty dest beats accept", "GET", map[string]string{"Sec-Fetch-Dest": "empty", "Accept": "text/html"}, false},
		{"GET json", "GET", map[string]string{"Accept": "application/json"}, false},
		{"POST html", "POST", map[string]string{"Accept": "text/html"}, false},
		{"GET no headers", "GET", map[string]string{}, false},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			r, _ := http.NewRequest(c.method, "/", nil)
			for k, v := range c.headers {
				r.Header.Set(k, v)
			}
			if got := isDocumentNav(r); got != c.want {
				t.Errorf("isDocumentNav = %v, want %v", got, c.want)
			}
		})
	}
}

func sessionServer(status int, body string) *httptest.Server {
	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/auth/session" {
			http.NotFound(w, r)
			return
		}
		w.WriteHeader(status)
		_, _ = w.Write([]byte(body))
	}))
}

func TestSessionValid(t *testing.T) {
	ck := &http.Cookie{Name: cookieName, Value: "x"}

	t.Run("authenticated true -> valid", func(t *testing.T) {
		ts := sessionServer(200, `{"authenticated":true}`)
		defer ts.Close()
		if !sessionValid(entry{Port: portOf(t, ts)}, ck) {
			t.Fatal("want valid (true) for authenticated:true")
		}
	})
	t.Run("authenticated false -> invalid", func(t *testing.T) {
		ts := sessionServer(200, `{"authenticated":false}`)
		defer ts.Close()
		if sessionValid(entry{Port: portOf(t, ts)}, ck) {
			t.Fatal("want invalid (false) for authenticated:false")
		}
	})
	t.Run("500 -> fail-open valid", func(t *testing.T) {
		ts := sessionServer(500, `boom`)
		defer ts.Close()
		if !sessionValid(entry{Port: portOf(t, ts)}, ck) {
			t.Fatal("want fail-open true on 500")
		}
	})
	t.Run("malformed json -> fail-open valid", func(t *testing.T) {
		ts := sessionServer(200, `not json`)
		defer ts.Close()
		if !sessionValid(entry{Port: portOf(t, ts)}, ck) {
			t.Fatal("want fail-open true on unparseable body")
		}
	})
	t.Run("unreachable -> fail-open valid", func(t *testing.T) {
		ts := sessionServer(200, `{"authenticated":false}`)
		p := portOf(t, ts)
		ts.Close() // nothing listening now
		if !sessionValid(entry{Port: p}, ck) {
			t.Fatal("want fail-open true on connection refused")
		}
	})
}

// fakeInstance serves the three endpoints the dispatcher touches: the session
// check, the bootstrap exchange, and a catch-all standing in for the proxied app.
func fakeInstance(authenticated bool, bootstrapCalled *bool) *httptest.Server {
	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/api/auth/session":
			if authenticated {
				_, _ = w.Write([]byte(`{"authenticated":true}`))
			} else {
				_, _ = w.Write([]byte(`{"authenticated":false}`))
			}
		case "/api/auth/bootstrap":
			if bootstrapCalled != nil {
				*bootstrapCalled = true
			}
			http.SetCookie(w, &http.Cookie{Name: cookieName, Value: "fresh", Path: "/"})
			_, _ = w.Write([]byte(`{"authenticated":true}`))
		default:
			_, _ = w.Write([]byte("APP"))
		}
	}))
}

func setTable(port int) {
	mu.Lock()
	table = map[string]entry{"vbarzin": {OsUser: "wizard", Port: port}}
	mu.Unlock()
}

func TestHandlerRepairsOnInvalidCookieDocNav(t *testing.T) {
	called := false
	ts := fakeInstance(false, &called)
	defer ts.Close()
	setTable(portOf(t, ts))

	orig := mintToken
	mintToken = func(string) ([]byte, error) { return []byte(`{"credential":"tok"}`), nil }
	defer func() { mintToken = orig }()

	r := httptest.NewRequest("GET", "/", nil)
	r.Header.Set("X-authentik-username", "vbarzin@gmail.com")
	r.Header.Set("Sec-Fetch-Dest", "document")
	r.AddCookie(&http.Cookie{Name: cookieName, Value: "stale"})
	w := httptest.NewRecorder()

	handler(w, r)

	if w.Code != http.StatusFound {
		t.Fatalf("stale cookie on doc-nav should re-pair (302), got %d body=%q", w.Code, w.Body.String())
	}
	if !called {
		t.Fatal("expected bootstrap to be called during re-pair")
	}
	cookies := w.Result().Cookies()
	if len(cookies) == 0 || cookies[0].Value != "fresh" {
		t.Fatalf("expected fresh t3_session relayed, got %+v", cookies)
	}
}

func TestHandlerProxiesOnValidCookie(t *testing.T) {
	ts := fakeInstance(true, nil)
	defer ts.Close()
	setTable(portOf(t, ts))

	r := httptest.NewRequest("GET", "/", nil)
	r.Header.Set("X-authentik-username", "vbarzin@gmail.com")
	r.Header.Set("Sec-Fetch-Dest", "document")
	r.AddCookie(&http.Cookie{Name: cookieName, Value: "good"})
	w := httptest.NewRecorder()

	handler(w, r)

	if w.Code != http.StatusOK || w.Body.String() != "APP" {
		t.Fatalf("valid cookie should proxy (200 APP), got %d %q", w.Code, w.Body.String())
	}
}

func TestHandlerProxiesXHREvenIfCookieInvalid(t *testing.T) {
	called := false
	ts := fakeInstance(false, &called) // session would say invalid, but XHR must NOT be re-paired
	defer ts.Close()
	setTable(portOf(t, ts))

	r := httptest.NewRequest("GET", "/api/threads", nil)
	r.Header.Set("X-authentik-username", "vbarzin@gmail.com")
	r.Header.Set("Sec-Fetch-Dest", "empty") // XHR/fetch, not a document nav
	r.AddCookie(&http.Cookie{Name: cookieName, Value: "stale"})
	w := httptest.NewRecorder()

	handler(w, r)

	if called {
		t.Fatal("must NOT re-pair (302) a non-document sub-request — would corrupt the SPA fetch contract")
	}
	if w.Code != http.StatusOK || w.Body.String() != "APP" {
		t.Fatalf("XHR should proxy through, got %d %q", w.Code, w.Body.String())
	}
}