package cabana_test

import (
	"context"
	"encoding/json"
	"errors"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"

	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/bouncer"
	"git.golem15.com/golem15/summercms/modules/cabana"
	"git.golem15.com/golem15/summercms/modules/compass"
	"git.golem15.com/golem15/summercms/modules/pact"
	"git.golem15.com/golem15/summercms/modules/party"
	"git.golem15.com/golem15/summercms/modules/surf"
)

// journalShaped is a plugin route shaped like a WinterCMS-style API that
// resolves its admin inside the handler (no route guard): it answers the
// principal cabana.ResolveBackend gives it.
type journalShaped struct{ app *backpack.App }

func (journalShaped) ID() string                   { return "acme.posts" }
func (journalShaped) Requires() []string           { return nil }
func (journalShaped) Register(*backpack.App) error { return nil }
func (journalShaped) Boot(*backpack.App) error     { return nil }
func (p journalShaped) Routes(r pact.Router) error {
	r.Get("/acme/posts", func(w http.ResponseWriter, req *http.Request) {
		req, principal, err := cabana.ResolveBackend(p.app, req, "acme.posts")
		if err != nil {
			w.WriteHeader(http.StatusUnauthorized)
			return
		}
		user, _ := bouncer.User(req.Context())
		_ = json.NewEncoder(w).Encode(map[string]any{"principal": principal.ID, "stored": user.ID})
	})
	return nil
}

func markerApp(t *testing.T) *backpack.App {
	t.Helper()
	dir := t.TempDir()
	if err := os.WriteFile(filepath.Join(dir, "http.yaml"), []byte("body_limits:\n  default_bytes: 1048576\n  upload_bytes: 1048576\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	cfg, err := compass.Open(compass.Options{Dir: dir, Environ: []string{"SUMMER_ENV=development"}})
	if err != nil {
		t.Fatal(err)
	}
	return backpack.New(cfg)
}

// TestDispatchMarker (phase 19.7 D-17, the cabana side): ResolveBackend
// answers a backend marker's principal and refuses a frontend one; a
// plugin route that resolves its admin inside the handler sees the
// dispatched principal through surf's compiled chain; and (Postgres) the
// assembled admin API honours a marker only in-process: the same request
// sent over HTTP, with any dispatch-looking header or cookie, is 401.
func TestDispatchMarker(t *testing.T) {
	marker := func(r *http.Request, p *bouncer.Principal) *http.Request {
		return r.WithContext(bouncer.WithDispatch(r.Context(), &bouncer.Dispatch{Guards: []string{"backend"}, Principal: p}))
	}

	t.Run("ResolveBackend backend and frontend markers", func(t *testing.T) {
		app := backpack.New(nil)
		_, p, err := cabana.ResolveBackend(app, marker(httptest.NewRequest(http.MethodGet, "/x", nil), &bouncer.Principal{ID: 42, Backend: true}))
		if err != nil || p.ID != 42 {
			t.Fatalf("backend marker = %+v, %v", p, err)
		}
		if _, _, err := cabana.ResolveBackend(app, marker(httptest.NewRequest(http.MethodGet, "/x", nil), &bouncer.Principal{ID: 7})); !errors.Is(err, cabana.ErrUnauthenticated) {
			t.Fatalf("frontend marker: err = %v", err)
		}
		other := httptest.NewRequest(http.MethodGet, "/x", nil)
		other = other.WithContext(bouncer.WithDispatch(other.Context(), &bouncer.Dispatch{Guards: []string{"api_token"}, Principal: &bouncer.Principal{ID: 42, Backend: true}}))
		if _, _, err := cabana.ResolveBackend(app, other); !errors.Is(err, cabana.ErrUnauthenticated) {
			t.Fatalf("marker for another guard: err = %v", err)
		}
	})

	t.Run("plugin route resolving inside its handler", func(t *testing.T) {
		app := markerApp(t)
		router, err := surf.BuildRouter(app, []party.Plugin{journalShaped{app: app}})
		if err != nil {
			t.Fatal(err)
		}
		h, ok := router.Handler(http.MethodGet, "/acme/posts")
		if !ok {
			t.Fatal("no compiled handler for GET /acme/posts")
		}
		rec := httptest.NewRecorder()
		h.ServeHTTP(rec, marker(httptest.NewRequest(http.MethodGet, "/acme/posts", nil), &bouncer.Principal{ID: 42, Backend: true}))
		var got map[string]any
		_ = json.Unmarshal(rec.Body.Bytes(), &got)
		if rec.Code != http.StatusOK || got["principal"] != 42.0 || got["stored"] != 42.0 {
			t.Fatalf("dispatched = %d %s", rec.Code, rec.Body.String())
		}
		rec = httptest.NewRecorder()
		h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/acme/posts", nil))
		if rec.Code != http.StatusUnauthorized {
			t.Fatalf("without the marker = %d", rec.Code)
		}
	})

	// The Postgres part runs on a Docker host (the gate's docker stage);
	// under -short it is not created, so no subtest is reported as skipped.
	if testing.Short() {
		return
	}
	t.Run("admin API honours a marker only in-process", func(t *testing.T) {
		env := newScreensEnv(t)
		admin, _ := env.admin(t, env.unique("marker"), false, `{}`)
		principal, err := cabana.BackendPrincipal(context.Background(), env.app, admin.ID)
		if err != nil || principal == nil || !principal.Backend {
			t.Fatalf("BackendPrincipal = %+v, %v", principal, err)
		}

		// In-process: the marker carries the admin through the backend guard.
		req, err := env.request(http.MethodGet, "/auth/me", "", nil)
		if err != nil {
			t.Fatal(err)
		}
		rec := httptest.NewRecorder()
		env.h.ServeHTTP(rec, marker(req, principal))
		if rec.Code != http.StatusOK {
			t.Fatalf("in-process marker = %d %s", rec.Code, rec.Body.String())
		}
		var me struct {
			Data struct {
				ID uint `json:"id"`
			} `json:"data"`
		}
		if err := json.Unmarshal(rec.Body.Bytes(), &me); err != nil || me.Data.ID != admin.ID {
			t.Fatalf("/auth/me answered %s", rec.Body.String())
		}

		// Over HTTP the marker never arrives: the client's context is not
		// the server's, and no header, cookie or query string stands in.
		srv := httptest.NewServer(env.h)
		defer srv.Close()
		out, err := http.NewRequestWithContext(bouncer.WithDispatch(context.Background(), &bouncer.Dispatch{Guards: []string{"backend"}, Principal: principal}),
			http.MethodGet, srv.URL+adminAPI("/auth/me")+"?dispatch=backend", nil)
		if err != nil {
			t.Fatal(err)
		}
		out.Header.Set("X-Summer-Dispatch", "backend")
		out.Header.Set("Authorization", "Dispatch backend")
		out.AddCookie(&http.Cookie{Name: "summer_dispatch", Value: "backend"})
		res, err := http.DefaultClient.Do(out)
		if err != nil {
			t.Fatal(err)
		}
		_ = res.Body.Close()
		if res.StatusCode != http.StatusUnauthorized {
			t.Fatalf("over HTTP = %d, want 401", res.StatusCode)
		}

		// A frontend marker is not an admin, in-process either.
		req, _ = env.request(http.MethodGet, "/auth/me", "", nil)
		rec = httptest.NewRecorder()
		env.h.ServeHTTP(rec, marker(req, &bouncer.Principal{ID: admin.ID}))
		if rec.Code == http.StatusOK {
			t.Fatalf("frontend marker reached /auth/me: %s", rec.Body.String())
		}
	})
}