package web

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

	"git.arnef.de/arnef/nidus/internal/config"
	"git.arnef.de/arnef/nidus/internal/db"
	"git.arnef.de/arnef/nidus/internal/store"
)

func newTestServer(t *testing.T) *Server {
	t.Helper()
	dir := t.TempDir()

	st, err := store.NewStore(filepath.Join(dir, "data"))
	if err != nil {
		t.Fatalf("NewStore: %v", err)
	}
	dbase, err := db.Open(filepath.Join(dir, "test.db"))
	if err != nil {
		t.Fatalf("db.Open: %v", err)
	}
	t.Cleanup(func() { dbase.Close() })

	cfg := &config.Config{}
	if err := dbase.CreateUser("alice", "password", "", ""); err != nil {
		t.Fatalf("CreateUser alice: %v", err)
	}
	if err := dbase.CreateUser("bob", "password", "", ""); err != nil {
		t.Fatalf("CreateUser bob: %v", err)
	}
	if err := dbase.CreateCalendar("alice", "work"); err != nil {
		t.Fatalf("CreateCalendar alice/work: %v", err)
	}
	if err := dbase.CreateAddressBook("alice", "contacts"); err != nil {
		t.Fatalf("CreateAddressBook alice/contacts: %v", err)
	}
	if err := dbase.CreateCalendar("bob", "personal"); err != nil {
		t.Fatalf("CreateCalendar bob/personal: %v", err)
	}
	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
	return NewServer(cfg, st, dbase, logger)
}

// loginAs performs a login request against handler and returns the
// resulting session cookie.
func loginAs(t *testing.T, handler http.Handler, username, password string) *http.Cookie {
	t.Helper()
	form := url.Values{"username": {username}, "password": {password}}
	req := httptest.NewRequest(http.MethodPost, "/login", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)

	if rr.Code != http.StatusSeeOther {
		t.Fatalf("login: expected 303, got %d: %s", rr.Code, rr.Body.String())
	}
	res := rr.Result()
	for _, c := range res.Cookies() {
		if c.Name == sessionCookieName {
			return c
		}
	}
	t.Fatal("login: no session cookie set")
	return nil
}

func TestLoginSuccessAndFailure(t *testing.T) {
	s := newTestServer(t)
	handler := s.Handler(emptyStaticFS{})

	cookie := loginAs(t, handler, "alice", "password")
	if cookie.Value == "" {
		t.Fatal("expected non-empty session token")
	}

	// Wrong password.
	form := url.Values{"username": {"alice"}, "password": {"wrong"}}
	req := httptest.NewRequest(http.MethodPost, "/login", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if rr.Code != http.StatusOK {
		t.Fatalf("expected 200 (re-rendered login form) on bad password, got %d", rr.Code)
	}
	if !strings.Contains(rr.Body.String(), "invalid username or password") {
		t.Fatalf("expected error message in body, got: %s", rr.Body.String())
	}
}

func TestDashboardRequiresLogin(t *testing.T) {
	s := newTestServer(t)
	handler := s.Handler(emptyStaticFS{})

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

	if rr.Code != http.StatusSeeOther {
		t.Fatalf("expected redirect to login, got %d", rr.Code)
	}
	if loc := rr.Result().Header.Get("Location"); loc != "/web/login" {
		t.Fatalf("expected redirect to /web/login, got %q", loc)
	}
}

func TestDashboardShowsOwnResources(t *testing.T) {
	s := newTestServer(t)
	handler := s.Handler(emptyStaticFS{})
	cookie := loginAs(t, handler, "alice", "password")

	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.AddCookie(cookie)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", rr.Code)
	}
	body := rr.Body.String()
	if !strings.Contains(body, "work") || !strings.Contains(body, "contacts") {
		t.Fatalf("expected dashboard to list alice's calendar/address book, got: %s", body)
	}
}

func TestShareUnshareCalendarFlow(t *testing.T) {
	s := newTestServer(t)
	handler := s.Handler(emptyStaticFS{})
	cookie := loginAs(t, handler, "alice", "password")

	// Share alice's "work" calendar with bob, write access.
	form := url.Values{"resource": {"work"}, "shared_with": {"bob"}, "permission": {"write"}}
	req := httptest.NewRequest(http.MethodPost, "/shares/calendar", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(cookie)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if rr.Code != http.StatusOK {
		t.Fatalf("share: expected 200, got %d: %s", rr.Code, rr.Body.String())
	}
	if !strings.Contains(rr.Body.String(), "bob") {
		t.Fatalf("expected updated card to mention bob, got: %s", rr.Body.String())
	}

	shares, err := s.dbase.SharesOfCalendar("alice", "work")
	if err != nil {
		t.Fatalf("SharesOfCalendar: %v", err)
	}
	if len(shares) != 1 || shares[0].SharedWith != "bob" {
		t.Fatalf("expected one share for bob, got %+v", shares)
	}

	// Unshare — htmx v2 sends DELETE params as a URL query string.
	req = httptest.NewRequest(http.MethodDelete, "/shares/calendar?resource=work&shared_with=bob", nil)
	req.AddCookie(cookie)
	rr = httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if rr.Code != http.StatusOK {
		t.Fatalf("unshare: expected 200, got %d: %s", rr.Code, rr.Body.String())
	}
	if !strings.Contains(rr.Body.String(), "Not shared with anyone") {
		t.Fatalf("expected card to show no shares, got: %s", rr.Body.String())
	}

	shares, err = s.dbase.SharesOfCalendar("alice", "work")
	if err != nil {
		t.Fatalf("SharesOfCalendar: %v", err)
	}
	if len(shares) != 0 {
		t.Fatalf("expected no shares after unshare, got %+v", shares)
	}
}

func TestCannotShareResourceNotOwned(t *testing.T) {
	s := newTestServer(t)
	handler := s.Handler(emptyStaticFS{})
	cookie := loginAs(t, handler, "alice", "password")

	// alice doesn't own "personal" (that's bob's calendar).
	form := url.Values{"resource": {"personal"}, "shared_with": {"bob"}, "permission": {"write"}}
	req := httptest.NewRequest(http.MethodPost, "/shares/calendar", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(cookie)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)

	if rr.Code != http.StatusNotFound {
		t.Fatalf("expected 404 for unowned resource, got %d", rr.Code)
	}
}

func TestLogoutClearsSession(t *testing.T) {
	s := newTestServer(t)
	handler := s.Handler(emptyStaticFS{})
	cookie := loginAs(t, handler, "alice", "password")

	req := httptest.NewRequest(http.MethodGet, "/logout", nil)
	req.AddCookie(cookie)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if rr.Code != http.StatusSeeOther {
		t.Fatalf("expected redirect on logout, got %d", rr.Code)
	}

	// Session should no longer be valid.
	if _, err := s.dbase.SessionUser(cookie.Value); err == nil {
		t.Fatal("expected session to be deleted after logout")
	}
}

// emptyStaticFS is a no-op http.FileSystem for tests that don't exercise
// static asset serving.
type emptyStaticFS struct{}

func (emptyStaticFS) Open(name string) (http.File, error) {
	return nil, os.ErrNotExist
}

func TestAccountRequiresLogin(t *testing.T) {
	s := newTestServer(t)
	handler := s.Handler(emptyStaticFS{})

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

	if rr.Code != http.StatusSeeOther {
		t.Fatalf("expected redirect to login, got %d", rr.Code)
	}
}

func TestAccountShowsOwnProfile(t *testing.T) {
	s := newTestServer(t)
	handler := s.Handler(emptyStaticFS{})
	cookie := loginAs(t, handler, "alice", "password")

	req := httptest.NewRequest(http.MethodGet, "/account", nil)
	req.AddCookie(cookie)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", rr.Code)
	}
	if !strings.Contains(rr.Body.String(), "alice") {
		t.Fatalf("expected account page to show username, got: %s", rr.Body.String())
	}
}

func TestAccountUpdateProfile(t *testing.T) {
	s := newTestServer(t)
	handler := s.Handler(emptyStaticFS{})
	cookie := loginAs(t, handler, "alice", "password")

	form := url.Values{"display_name": {"Alice Example"}, "email": {"alice@example.com"}}
	req := httptest.NewRequest(http.MethodPost, "/account/profile", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(cookie)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", rr.Code)
	}
	if !strings.Contains(rr.Body.String(), "Profile updated.") {
		t.Fatalf("expected success message, got: %s", rr.Body.String())
	}

	u, err := s.dbase.GetUser("alice")
	if err != nil {
		t.Fatalf("GetUser: %v", err)
	}
	if u.DisplayName != "Alice Example" || u.Email != "alice@example.com" {
		t.Fatalf("expected profile to be persisted, got %+v", u)
	}
}

func TestAccountChangePassword(t *testing.T) {
	s := newTestServer(t)
	handler := s.Handler(emptyStaticFS{})
	cookie := loginAs(t, handler, "alice", "password")

	// Wrong current password is rejected.
	form := url.Values{"current_password": {"wrong"}, "new_password": {"newpassword123"}, "confirm_password": {"newpassword123"}}
	req := httptest.NewRequest(http.MethodPost, "/account/password", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(cookie)
	rr := httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if !strings.Contains(rr.Body.String(), "current password is incorrect") {
		t.Fatalf("expected error for wrong current password, got: %s", rr.Body.String())
	}
	if s.dbase.VerifyPassword("alice", "newpassword123") {
		t.Fatal("password should not have changed")
	}

	// Correct current password succeeds.
	form = url.Values{"current_password": {"password"}, "new_password": {"newpassword123"}, "confirm_password": {"newpassword123"}}
	req = httptest.NewRequest(http.MethodPost, "/account/password", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(cookie)
	rr = httptest.NewRecorder()
	handler.ServeHTTP(rr, req)
	if !strings.Contains(rr.Body.String(), "Password changed.") {
		t.Fatalf("expected success message, got: %s", rr.Body.String())
	}
	if !s.dbase.VerifyPassword("alice", "newpassword123") {
		t.Fatal("expected password to have changed")
	}
}