package user

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

	"git.golem15.com/golem15/sm-user-plugin/controllers"
	"git.golem15.com/golem15/sm-user-plugin/models"
	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/bouncer"
	"git.golem15.com/golem15/summercms/modules/lagoon"
	"git.golem15.com/golem15/summercms/modules/phrasebook"
	"git.golem15.com/golem15/summercms/modules/towel"
	"gorm.io/gorm"
)

const (
	lastMethodBlockedEN = "This is the only remaining way to sign in. Link another method before disconnecting this one."
	lastMethodBlockedPL = "To jedyna droga logowania na to konto. Najpierw podłącz inną, zanim odetniesz tę."
	winter404Body       = `<!DOCTYPE html>
<html lang="pl">
    <head>
        <meta charset="utf-8">
        <title>Nie znaleziono strony</title>
        <link href="http://127.0.0.1:8423/modules/system/assets/css/styles.css" rel="stylesheet">
    </head>
    <body>
        <div class="container">
            <h1><i class="icon-chain-broken warning"></i> Nie znaleziono strony</h1>
            <p class="lead">Żądana strona nie została znaleziona.</p>
        </div>
    </body>
</html>`
)

func TestOAuthIdentitiesIndexEmptyList(t *testing.T) {
	app, db := sessionApp(t, "0s")
	user := insertUser(t, db, "oauth-empty@example.test", "correct-horse")
	req := httptest.NewRequest(http.MethodGet, "/_fonoteka/api/v1/oauth-identities", nil)
	req = req.WithContext(bouncer.WithUser(req.Context(), &bouncer.Principal{ID: user.ID}))
	rec := httptest.NewRecorder()
	controllers.OAuthIdentitiesIndex(app).ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("status %d body %s", rec.Code, rec.Body.String())
	}
	if rec.Body.String() != `{"data":[]}` {
		t.Fatalf("body = %s", rec.Body.String())
	}
	var body map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
		t.Fatal(err)
	}
	if len(body) != 1 {
		t.Fatalf("top-level keys = %#v", body)
	}
	if cc := rec.Header().Get("Cache-Control"); !strings.Contains(cc, "no-cache") {
		t.Fatalf("Cache-Control = %q", cc)
	}
}

func TestOAuthIdentitiesDestroyNoContentKeepsSibling(t *testing.T) {
	app, db := sessionApp(t, "0s")
	user := insertUser(t, db, "oauth-unlink@example.test", "correct-horse")
	for _, row := range []models.OAuthIdentity{
		{UserID: user.ID, Provider: "facebook", ProviderID: "fb-alice"},
		{UserID: user.ID, Provider: "google", ProviderID: "goog-alice"},
	} {
		if err := db.Create(&row).Error; err != nil {
			t.Fatal(err)
		}
	}
	req := httptest.NewRequest(http.MethodDelete, "/_fonoteka/api/v1/oauth-identities/facebook", nil)
	req.SetPathValue("provider", "facebook")
	req = req.WithContext(bouncer.WithUser(req.Context(), &bouncer.Principal{ID: user.ID}))
	rec := httptest.NewRecorder()
	controllers.OAuthIdentitiesDestroy(app, controllers.OAuthIdentitiesOptions{
		WriteNotFound: func(http.ResponseWriter, *http.Request) {
			t.Fatal("WriteNotFound called")
		},
	}).ServeHTTP(rec, req)
	if rec.Code != http.StatusNoContent {
		t.Fatalf("status %d body %s", rec.Code, rec.Body.String())
	}
	if rec.Body.Len() != 0 {
		t.Fatalf("body = %q", rec.Body.String())
	}
	var leftover []models.OAuthIdentity
	if err := db.Where("user_id = ?", user.ID).Order("provider").Find(&leftover).Error; err != nil {
		t.Fatal(err)
	}
	if len(leftover) != 1 || leftover[0].Provider != "google" {
		t.Fatalf("remaining = %#v", leftover)
	}
}

func TestOAuthIdentitiesDestroyLastMethodBlockedENAndPL(t *testing.T) {
	app, db := sessionApp(t, "0s")
	activateOAuthIdentitiesLang(t, app)
	for _, tc := range []struct {
		locale, email, want string
	}{
		{"en", "oauth-last-en@example.test", lastMethodBlockedEN},
		{"pl", "oauth-last-pl@example.test", lastMethodBlockedPL},
	} {
		t.Run(tc.locale, func(t *testing.T) {
			user := insertUser(t, db, tc.email, "correct-horse")
			seedOAuthIdentity(t, db, user.ID, "facebook", "fb-only-"+tc.locale)
			rec := destroyOAuthIdentity(t, app, user.ID, "facebook", tc.locale, winter404OrFatal(t))
			if rec.Code != http.StatusConflict {
				t.Fatalf("status %d body %s", rec.Code, rec.Body.String())
			}
			var body map[string]any
			if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
				t.Fatal(err)
			}
			if body["error"] != tc.want {
				t.Fatalf("golem15.user::lang.oauth.last_method_blocked %s = %#v", tc.locale, body["error"])
			}
			if remaining := countOAuthIdentities(t, db, user.ID); remaining != 1 {
				t.Fatalf("row still present = %d", remaining)
			}
		})
	}
}

func TestOAuthIdentitiesDestroyLastMethodBlockedWithPassword(t *testing.T) {
	app, db := sessionApp(t, "0s")
	activateOAuthIdentitiesLang(t, app)
	user := insertUser(t, db, "oauth-last-password@example.test", "correct-horse")
	if err := db.Model(user).Update("has_self_set_password", true).Error; err != nil {
		t.Fatal(err)
	}
	seedOAuthIdentity(t, db, user.ID, "google", "g-only")
	rec := destroyOAuthIdentity(t, app, user.ID, "google", "en", winter404OrFatal(t))
	if rec.Code != http.StatusConflict {
		t.Fatalf("status %d body %s", rec.Code, rec.Body.String())
	}
	var body map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
		t.Fatal(err)
	}
	if body["error"] != lastMethodBlockedEN {
		t.Fatalf("last_method_blocked with password = %#v", body["error"])
	}
	if remaining := countOAuthIdentities(t, db, user.ID); remaining != 1 {
		t.Fatalf("row still present = %d", remaining)
	}
}

func TestOAuthIdentitiesDestroyWinter404BodiesAreByteIdentical(t *testing.T) {
	app, db := sessionApp(t, "0s")
	owner := insertUser(t, db, "oauth-404-owner@example.test", "correct-horse")
	stranger := insertUser(t, db, "oauth-404-stranger@example.test", "correct-horse")
	seedOAuthIdentity(t, db, owner.ID, "google", "g-owner")
	seedOAuthIdentity(t, db, stranger.ID, "facebook", "fb-stranger")

	foreign := destroyOAuthIdentity(t, app, stranger.ID, "google", "en", writeWinter404)
	missing := destroyOAuthIdentity(t, app, stranger.ID, "github", "en", writeWinter404)
	unknown := destroyOAuthIdentity(t, app, stranger.ID, "linkedin", "en", writeWinter404)
	for name, rec := range map[string]*httptest.ResponseRecorder{
		"foreign": foreign, "missing": missing, "unknown": unknown,
	} {
		if rec.Code != http.StatusNotFound {
			t.Fatalf("%s status %d body %s", name, rec.Code, rec.Body.String())
		}
		if rec.Header().Get("Content-Type") != "text/html; charset=UTF-8" {
			t.Fatalf("%s Content-Type = %q", name, rec.Header().Get("Content-Type"))
		}
		if !bytes.Equal(rec.Body.Bytes(), []byte(winter404Body)) {
			t.Fatalf("%s body = %q", name, rec.Body.String())
		}
	}
	if !bytes.Equal(foreign.Body.Bytes(), missing.Body.Bytes()) || !bytes.Equal(missing.Body.Bytes(), unknown.Body.Bytes()) {
		t.Fatalf("404 bodies differ")
	}
	if remaining := countOAuthIdentities(t, db, owner.ID); remaining != 1 {
		t.Fatalf("owner google row = %d", remaining)
	}
}

func TestOAuthIdentitiesIndexDoesNotLeakEncryptedTokensOrProfileData(t *testing.T) {
	app, db := sessionApp(t, "0s")
	if err := lagoon.PublishEncryptionKeys(nil, bytes.Repeat([]byte("K"), 32), nil); err != nil {
		t.Fatal(err)
	}
	user := insertUser(t, db, "oauth-secret-leak@example.test", "correct-horse")
	const (
		plaintext = "secret-access-token-oauth-leak-probe"
		refresh   = "secret-refresh-token-oauth-leak-probe"
		marker    = "profile-distinctive-xyzzy-oauth"
	)
	now := time.Now().UTC()
	row := models.OAuthIdentity{
		UserID:       user.ID,
		Provider:     "google",
		ProviderID:   "g-secret-leak",
		AccessToken:  lagoon.NewEncrypted(plaintext),
		RefreshToken: lagoon.NewEncrypted(refresh),
		ProfileData: lagoon.Jsonable[map[string]any]{
			Data:  map[string]any{"email": "leak@example.test", "marker": marker},
			Valid: true,
		},
		LinkedAt: &now,
	}
	if err := db.Create(&row).Error; err != nil {
		t.Fatal(err)
	}
	req := httptest.NewRequest(http.MethodGet, "/_fonoteka/api/v1/oauth-identities", nil)
	req = req.WithContext(bouncer.WithUser(req.Context(), &bouncer.Principal{ID: user.ID}))
	rec := httptest.NewRecorder()
	controllers.OAuthIdentitiesIndex(app).ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("status %d body %s", rec.Code, rec.Body.String())
	}
	body := rec.Body.String()
	for _, needle := range []string{plaintext, refresh, marker, "access_token", "refresh_token", "profile_data", "[redacted]"} {
		if strings.Contains(body, needle) {
			t.Fatalf("GET list leaked %q: %s", needle, body)
		}
	}
	var parsed struct {
		Data []map[string]any `json:"data"`
	}
	if err := json.Unmarshal(rec.Body.Bytes(), &parsed); err != nil {
		t.Fatal(err)
	}
	if len(parsed.Data) != 1 {
		t.Fatalf("data = %#v", parsed.Data)
	}
	if len(parsed.Data[0]) != 2 {
		t.Fatalf("row keys = %#v, want provider and linked_at only", parsed.Data[0])
	}
	if parsed.Data[0]["provider"] != "google" {
		t.Fatalf("provider = %#v", parsed.Data[0]["provider"])
	}
	if _, ok := parsed.Data[0]["linked_at"]; !ok {
		t.Fatalf("linked_at missing: %#v", parsed.Data[0])
	}
}

func TestOAuthIdentitiesUnauthorizedOnGoogle(t *testing.T) {
	app, _ := sessionApp(t, "0s")
	getReq := httptest.NewRequest(http.MethodGet, "/_fonoteka/api/v1/oauth-identities", nil)
	getRec := httptest.NewRecorder()
	controllers.OAuthIdentitiesIndex(app).ServeHTTP(getRec, getReq)
	assertOAuthIdentityUnauthorized(t, "GET", getRec)

	delReq := httptest.NewRequest(http.MethodDelete, "/_fonoteka/api/v1/oauth-identities/google", nil)
	delReq.SetPathValue("provider", "google")
	delRec := httptest.NewRecorder()
	controllers.OAuthIdentitiesDestroy(app, controllers.OAuthIdentitiesOptions{
		WriteNotFound: func(http.ResponseWriter, *http.Request) {
			t.Fatal("unauthenticated /google must 401 before WriteNotFound")
		},
	}).ServeHTTP(delRec, delReq)
	assertOAuthIdentityUnauthorized(t, "DELETE /google", delRec)
}

func activateOAuthIdentitiesLang(t *testing.T, app *backpack.App) {
	t.Helper()
	if err := phrasebook.Activate(app, []*Plugin{{}}); err != nil {
		t.Fatal(err)
	}
}

func seedOAuthIdentity(t *testing.T, db *gorm.DB, userID uint, provider, providerID string) {
	t.Helper()
	now := time.Now().UTC()
	row := models.OAuthIdentity{
		UserID:     userID,
		Provider:   provider,
		ProviderID: providerID,
		LinkedAt:   &now,
	}
	if err := db.Create(&row).Error; err != nil {
		t.Fatal(err)
	}
}

func countOAuthIdentities(t *testing.T, db *gorm.DB, userID uint) int64 {
	t.Helper()
	var n int64
	if err := db.Model(&models.OAuthIdentity{}).Where("user_id = ?", userID).Count(&n).Error; err != nil {
		t.Fatal(err)
	}
	return n
}

func writeWinter404(w http.ResponseWriter, _ *http.Request) {
	w.Header().Set("Content-Type", "text/html; charset=UTF-8")
	w.Header().Set("Cache-Control", "no-cache, private")
	w.WriteHeader(http.StatusNotFound)
	_, _ = w.Write([]byte(winter404Body))
}

func winter404OrFatal(t *testing.T) func(http.ResponseWriter, *http.Request) {
	t.Helper()
	return func(http.ResponseWriter, *http.Request) {
		t.Fatal("WriteNotFound called")
	}
}

func destroyOAuthIdentity(t *testing.T, app *backpack.App, userID uint, provider, locale string, notFound func(http.ResponseWriter, *http.Request)) *httptest.ResponseRecorder {
	t.Helper()
	req := httptest.NewRequest(http.MethodDelete, "/_fonoteka/api/v1/oauth-identities/"+provider, nil)
	req.SetPathValue("provider", provider)
	ctx := bouncer.WithUser(req.Context(), &bouncer.Principal{ID: userID})
	if locale != "" {
		ctx = towel.WithLocale(ctx, locale)
	}
	req = req.WithContext(ctx)
	rec := httptest.NewRecorder()
	controllers.OAuthIdentitiesDestroy(app, controllers.OAuthIdentitiesOptions{
		WriteNotFound: notFound,
	}).ServeHTTP(rec, req)
	return rec
}

func assertOAuthIdentityUnauthorized(t *testing.T, name string, rec *httptest.ResponseRecorder) {
	t.Helper()
	if rec.Code != http.StatusUnauthorized {
		t.Fatalf("%s status %d body %s", name, rec.Code, rec.Body.String())
	}
	if rec.Body.String() != `{"error":true,"message":"Unauthorized"}` {
		t.Fatalf("%s body = %s", name, rec.Body.String())
	}
	if cc := rec.Header().Get("Cache-Control"); cc != "no-cache, private" {
		t.Fatalf("%s Cache-Control = %q", name, cc)
	}
}