package main

import (
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"bookmarkmanager/backend/internal/store"
	"bookmarkmanager/backend/internal/token"
)

// registerReader creates an extra Reader the way a first login does and
// returns its id. The credential is derived the same way the owner's is, so it
// authenticates through the real router.
func registerReader(t *testing.T, s *store.Store, discordID string) int64 {
	t.Helper()
	id, err := s.EnsureReader(discordID, token.Hash(readerCredential(discordID)))
	if err != nil {
		t.Fatalf("register reader %q: %v", discordID, err)
	}
	return id
}

// credRequest builds a request authenticated as the Reader whose credential
// is passed.
func credRequest(method, target, cred string) *http.Request {
	req := httptest.NewRequest(method, target, nil)
	req.Header.Set("Authorization", "Bearer "+cred)
	return req
}

// readerCredential is the epoch-0 derived credential of an arbitrary Reader.
func readerCredential(discordID string) string {
	return token.Token([]byte(testTokenKey), discordID, 0)
}

// withBody attaches a request body, for PUTs that carry a JSON payload.
func withBody(req *http.Request, body string) *http.Request {
	req.Body = io.NopCloser(strings.NewReader(body))
	req.ContentLength = int64(len(body))
	return req
}

// A refused credential is refused however plausible it looks: only a hash the
// readers table holds authenticates anything.
func TestUnknownCredentialRejected(t *testing.T) {
	srv := newRouter(newTestStore(t), testConfig())

	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", readerCredential("never-registered")))
	if rr.Code != http.StatusUnauthorized {
		t.Fatalf("unregistered Reader's credential: status = %d, want 401", rr.Code)
	}

	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", ownerCredential()))
	if rr.Code != http.StatusOK {
		t.Fatalf("owner's derived credential: status = %d, want 200", rr.Code)
	}
}

// A Reader's credential authenticates exactly that Reader: rows written under
// one credential are invisible to the other, on the same key.
func TestPerReaderIsolation(t *testing.T) {
	s := newTestStore(t)
	registerReader(t, s, "other-reader")
	srv := newRouter(s, testConfig())

	ownerKey := "asura:solo"
	putBookmark(t, srv, ownerKey, store.Bookmark{
		Key: ownerKey, Site: "asura", SeriesID: "solo",
		Title: "Solo Leveling", UpdatedAt: 1,
	})

	// The other Reader's list is empty even though the owner holds the key.
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", readerCredential("other-reader")))
	if rr.Code != http.StatusOK {
		t.Fatalf("other reader list: status = %d, want 200", rr.Code)
	}
	var theirs []store.Bookmark
	if err := json.Unmarshal(rr.Body.Bytes(), &theirs); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if len(theirs) != 0 {
		t.Fatalf("other reader sees %d bookmarks, want 0 (owner's rows leaked)", len(theirs))
	}

	// The other Reader writes the same key; both rows coexist, each visible
	// only to its owner. The series title is shared (ADR-0003) — the
	// reader-owned fields are progress and updated_at.
	req := credRequest(http.MethodPut, "/bookmarks/"+ownerKey, readerCredential("other-reader"))
	req.Header.Set("Content-Type", "application/json")
	body := `{"key":"asura:solo","site":"asura","series_id":"solo","title":"Theirs","last_chapter_num":3}`
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, withBody(req, body))
	if rr.Code != http.StatusOK {
		t.Fatalf("other reader put: status = %d, want 200", rr.Code)
	}

	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", readerCredential("other-reader")))
	var theirs2 []store.Bookmark
	if err := json.Unmarshal(rr.Body.Bytes(), &theirs2); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if len(theirs2) != 1 || theirs2[0].LastChapterNum != 3 {
		t.Fatalf("other reader list = %+v, want their own row with their progress", theirs2)
	}

	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", ownerCredential()))
	var owners []store.Bookmark
	if err := json.Unmarshal(rr.Body.Bytes(), &owners); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if len(owners) != 1 || owners[0].Title != "Solo Leveling" || owners[0].LastChapterNum != 0 {
		t.Fatalf("owner list = %+v, want their own row at their own progress", owners)
	}

	// The mirror: the owner's write does not move the other Reader's progress
	// either. Without it, isolation is only asserted in one direction.
	req = credRequest(http.MethodPut, "/bookmarks/"+ownerKey, ownerCredential())
	req.Header.Set("Content-Type", "application/json")
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, withBody(req, `{"key":"asura:solo","site":"asura","series_id":"solo","title":"Solo Leveling","last_chapter_num":9}`))
	if rr.Code != http.StatusOK {
		t.Fatalf("owner put: status = %d, want 200", rr.Code)
	}
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", readerCredential("other-reader")))
	var theirs3 []store.Bookmark
	if err := json.Unmarshal(rr.Body.Bytes(), &theirs3); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if len(theirs3) != 1 || theirs3[0].LastChapterNum != 3 {
		t.Fatalf("other reader list = %+v, want progress 3 after the owner's write", theirs3)
	}

	// DELETE is scoped to its caller too, asserted in both directions: each
	// Reader's delete on the shared key takes only their own row.
	list := func(cred string) []store.Bookmark {
		t.Helper()
		rr := httptest.NewRecorder()
		srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", cred))
		var got []store.Bookmark
		if err := json.Unmarshal(rr.Body.Bytes(), &got); err != nil {
			t.Fatalf("decode: %v", err)
		}
		return got
	}
	del := func(cred string) {
		t.Helper()
		rr := httptest.NewRecorder()
		srv.ServeHTTP(rr, credRequest(http.MethodDelete, "/bookmarks/"+ownerKey, cred))
		if rr.Code != http.StatusNoContent {
			t.Fatalf("delete: status = %d, want 204", rr.Code)
		}
	}

	del(readerCredential("other-reader"))
	if got := list(ownerCredential()); len(got) != 1 {
		t.Fatalf("owner's row was deletable by the other Reader: %+v", got)
	}
	if got := list(readerCredential("other-reader")); len(got) != 0 {
		t.Fatalf("other Reader's own delete left %+v behind", got)
	}

	// The mirror: the other Reader takes the key again, the owner deletes
	// theirs, and the other's row is untouched.
	req = credRequest(http.MethodPut, "/bookmarks/"+ownerKey, readerCredential("other-reader"))
	req.Header.Set("Content-Type", "application/json")
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, withBody(req, body))
	if rr.Code != http.StatusOK {
		t.Fatalf("other reader re-put: status = %d, want 200", rr.Code)
	}
	del(ownerCredential())
	if got := list(readerCredential("other-reader")); len(got) != 1 {
		t.Fatalf("other Reader's row was deletable by the owner: %+v", got)
	}
	if got := list(ownerCredential()); len(got) != 0 {
		t.Fatalf("owner's own delete left %+v behind", got)
	}
}

// The install endpoints are session-gated and render the script directly
// with the Reader's credential inside: the credential never appears in the
// address bar, the page markup, or any Location header.
func TestInstallServesScriptWithCredential(t *testing.T) {
	cfg := testConfig()
	dir := t.TempDir()
	path := filepath.Join(dir, "manga-bookmark.user.js")
	novelPath := filepath.Join(dir, "novel-bookmark.user.js")
	for _, p := range []string{path, novelPath} {
		if err := os.WriteFile(p, []byte("const API_TOKEN = \"__API_TOKEN__\";\n"), 0o644); err != nil {
			t.Fatalf("write script: %v", err)
		}
	}
	cfg.UserscriptPath = path
	cfg.NovelUserscriptPath = novelPath
	srv, st := newWebTestServer(t, cfg)

	for _, script := range []string{"manga-bookmark.user.js", "novel-bookmark.user.js"} {
		rr := httptest.NewRecorder()
		srv.ServeHTTP(rr, httptest.NewRequest(http.MethodGet, "/install/"+script, nil))
		if rr.Code != http.StatusUnauthorized {
			t.Fatalf("%s without session: status = %d, want 401", script, rr.Code)
		}

		req := httptest.NewRequest(http.MethodGet, "/install/"+script, nil)
		req.AddCookie(sessionCookie(t, st))
		rr = httptest.NewRecorder()
		srv.ServeHTTP(rr, req)
		if rr.Code != http.StatusOK {
			t.Fatalf("%s with session: status = %d, want 200", script, rr.Code)
		}
		body := rr.Body.String()
		if strings.Contains(body, "__API_TOKEN__") {
			t.Fatalf("%s served with an unsubstituted placeholder", script)
		}
		// The credential rides inside the served script — nowhere visible in
		// the UI — and is the session holder's own.
		if !strings.Contains(body, `API_TOKEN = "`+ownerCredential()+`"`) {
			t.Fatalf("%s does not carry the owner's credential:\n%s", script, body)
		}
		if loc := rr.Header().Get("Location"); loc != "" {
			t.Fatalf("%s answered with a redirect, credential in Location %q", script, loc)
		}
		// The plain link must stay inline: Violentmonkey's updater polls the
		// /u/ path and an attachment disposition there would break updates.
		if cd := rr.Header().Get("Content-Disposition"); cd != "" {
			t.Fatalf("%s served as %q, want inline", script, cd)
		}

		// ?download=1 is the mobile path: Violentmonkey on Chromium ignores a
		// .user.js navigation, so the Reader saves the file and adds it by hand.
		req = httptest.NewRequest(http.MethodGet, "/install/"+script+"?download=1", nil)
		req.AddCookie(sessionCookie(t, st))
		rr = httptest.NewRecorder()
		srv.ServeHTTP(rr, req)
		if rr.Code != http.StatusOK {
			t.Fatalf("%s?download=1: status = %d, want 200", script, rr.Code)
		}
		if got, want := rr.Header().Get("Content-Disposition"), `attachment; filename="`+script+`"`; got != want {
			t.Fatalf("%s?download=1: Content-Disposition = %q, want %q", script, got, want)
		}
		if !strings.Contains(rr.Body.String(), `API_TOKEN = "`+ownerCredential()+`"`) {
			t.Fatalf("%s?download=1 does not carry the owner's credential", script)
		}
	}
}

// Rotation through the web UI invalidates the old credential immediately,
// mints one that authenticates the API and the script path, and warns that
// every device must reinstall.
func TestRotateCredentialViaWebUI(t *testing.T) {
	s, _ := newTestStoreURL(t)
	path := filepath.Join(t.TempDir(), "manga-bookmark.user.js")
	if err := os.WriteFile(path, []byte("const API_TOKEN = \"__API_TOKEN__\";\n"), 0o644); err != nil {
		t.Fatalf("write script: %v", err)
	}
	cfg := testConfig()
	cfg.UserscriptPath = path
	srv := newRouter(s, cfg)

	oldCred := ownerCredential()
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", oldCred))
	if rr.Code != http.StatusOK {
		t.Fatalf("old credential before rotation: status = %d, want 200", rr.Code)
	}

	req := httptest.NewRequest(http.MethodPost, "/rotate-token", nil)
	req.AddCookie(sessionCookie(t, s))
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, req)
	if rr.Code != http.StatusOK {
		t.Fatalf("rotate: status = %d, want 200", rr.Code)
	}
	if !strings.Contains(rr.Body.String(), "Credential rotated") {
		t.Fatalf("rotation response does not warn about reinstall:\n%s", rr.Body.String())
	}

	// The old credential is dead on the API and on the script path.
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", oldCred))
	if rr.Code != http.StatusUnauthorized {
		t.Fatalf("old credential after rotation: status = %d, want 401", rr.Code)
	}
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, httptest.NewRequest(http.MethodGet, "/u/"+oldCred+"/manga-bookmark.user.js", nil))
	if rr.Code != http.StatusNotFound {
		t.Fatalf("old credential script path after rotation: status = %d, want 404", rr.Code)
	}

	// The new credential authenticates the API and the script path, and is
	// substituted into the served script.
	newCred := token.Token([]byte(testTokenKey), testDiscordID, 1)
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", newCred))
	if rr.Code != http.StatusOK {
		t.Fatalf("new credential after rotation: status = %d, want 200", rr.Code)
	}
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, httptest.NewRequest(http.MethodGet, "/u/"+newCred+"/manga-bookmark.user.js", nil))
	if rr.Code != http.StatusOK {
		t.Fatalf("new credential script path: status = %d, want 200", rr.Code)
	}
	if got := rr.Body.String(); !strings.Contains(got, `API_TOKEN = "`+newCred+`"`) {
		t.Fatalf("served script does not carry the rotated credential:\n%s", got)
	}

	// The install link now renders the script with the new credential.
	req = httptest.NewRequest(http.MethodGet, "/install/manga-bookmark.user.js", nil)
	req.AddCookie(sessionCookie(t, s))
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, req)
	if rr.Code != http.StatusOK {
		t.Fatalf("install after rotation: status = %d, want 200", rr.Code)
	}
	if got := rr.Body.String(); !strings.Contains(got, `API_TOKEN = "`+newCred+`"`) {
		t.Fatalf("install after rotation does not carry the new credential:\n%s", got)
	}
}

// The app page offers the install links; the credential never appears in its
// markup.
func TestIndexShowsSetupPanelWithoutCredential(t *testing.T) {
	srv, st := newWebTestServer(t, testConfig())
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.AddCookie(sessionCookie(t, st))
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, req)

	body := rr.Body.String()
	for _, want := range []string{
		`href="/install/manga-bookmark.user.js"`,
		`href="/install/novel-bookmark.user.js"`,
		`href="/install/manga-bookmark.user.js?download=1"`,
		`href="/install/novel-bookmark.user.js?download=1"`,
		"Rotate credential",
	} {
		if !strings.Contains(body, want) {
			t.Errorf("app page lacks %q", want)
		}
	}
	if strings.Contains(body, ownerCredential()) {
		t.Fatal("app page leaks the credential")
	}
}