//go:build integration

package integration_test

import (
	"bytes"
	"context"
	"encoding/json"
	"io"
	"log/slog"
	"net/http"
	"net/http/cookiejar"
	"net/http/httptest"
	"net/url"
	"strings"
	"testing"
	"time"

	"github.com/google/uuid"

	"github.com/alchemistkay/guestguard/internal/api"
	"github.com/alchemistkay/guestguard/internal/storage"
)

const authTestPassword = "correct-horse-battery-staple"

// recordingEmailSender captures the most recent verification / reset link so
// tests can finish the signup flow without a real inbox.
type recordingEmailSender struct {
	verifyLink string
	resetLink  string
}

func (s *recordingEmailSender) SendVerification(_ context.Context, _, _, link string) error {
	s.verifyLink = link
	return nil
}

func (s *recordingEmailSender) SendPasswordReset(_ context.Context, _, _, link string) error {
	s.resetLink = link
	return nil
}

func TestAuthFlow(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping integration test in -short mode")
	}

	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Minute)
	t.Cleanup(cancel)

	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
	dsn := startPostgres(t, ctx)

	db, err := storage.NewDB(ctx, dsn)
	must(t, err, "connect db")
	t.Cleanup(db.Close)
	must(t, db.Migrate(ctx), "migrate")

	emails := &recordingEmailSender{}

	apiSrv, err := api.NewServer(api.ServerDeps{
		Logger:               logger,
		DB:                   db,
		TokenTTL:             24 * time.Hour,
		JWTSecret:            "test-secret-must-be-at-least-32-bytes-long-xx",
		JWTIssuer:            "guestguard-test",
		AccessTokenTTL:       5 * time.Minute,
		RefreshTokenTTL:      24 * time.Hour,
		EmailVerificationTTL: 1 * time.Hour,
		PasswordResetTTL:     1 * time.Hour,
		PublicBaseURL:        "http://localhost",
		EmailSender:          emails,
	})
	must(t, err, "build api server")
	srv := httptest.NewServer(apiSrv.Handler())
	t.Cleanup(srv.Close)

	jar, _ := cookiejar.New(nil)
	client := &http.Client{Jar: jar}

	email := uniqueEmail(t)

	t.Run("signup", func(t *testing.T) {
		resp := post(t, client, srv.URL+"/auth/signup", map[string]string{
			"email":    email,
			"name":     "Auth Test",
			"password": authTestPassword,
		})
		if resp.StatusCode != http.StatusCreated {
			t.Fatalf("signup status: %d", resp.StatusCode)
		}
		resp.Body.Close()
		if emails.verifyLink == "" {
			t.Fatal("verification email not captured")
		}
	})

	t.Run("login before verify is forbidden", func(t *testing.T) {
		resp := post(t, client, srv.URL+"/auth/login", map[string]string{
			"email":    email,
			"password": authTestPassword,
		})
		defer resp.Body.Close()
		if resp.StatusCode != http.StatusForbidden {
			body, _ := io.ReadAll(resp.Body)
			t.Fatalf("expected 403, got %d: %s", resp.StatusCode, body)
		}
	})

	t.Run("verify email", func(t *testing.T) {
		token := tokenFromQuery(t, emails.verifyLink, "token")
		resp := post(t, client, srv.URL+"/auth/verify-email", map[string]string{"token": token})
		defer resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			body, _ := io.ReadAll(resp.Body)
			t.Fatalf("verify status: %d %s", resp.StatusCode, body)
		}
	})

	t.Run("verify token replay rejected", func(t *testing.T) {
		token := tokenFromQuery(t, emails.verifyLink, "token")
		resp := post(t, client, srv.URL+"/auth/verify-email", map[string]string{"token": token})
		resp.Body.Close()
		if resp.StatusCode != http.StatusBadRequest {
			t.Fatalf("replay should be 400, got %d", resp.StatusCode)
		}
	})

	var firstAccess string
	t.Run("login returns access + refresh cookie", func(t *testing.T) {
		resp := post(t, client, srv.URL+"/auth/login", map[string]string{
			"email":    email,
			"password": authTestPassword,
		})
		defer resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			body, _ := io.ReadAll(resp.Body)
			t.Fatalf("login status: %d %s", resp.StatusCode, body)
		}
		var body struct {
			AccessToken string `json:"access_token"`
		}
		must(t, json.NewDecoder(resp.Body).Decode(&body), "decode login")
		if body.AccessToken == "" {
			t.Fatal("missing access token")
		}
		firstAccess = body.AccessToken
		assertRefreshCookieSet(t, srv.URL, jar)
	})

	t.Run("access token authorises /me", func(t *testing.T) {
		req, _ := http.NewRequest(http.MethodGet, srv.URL+"/me", nil)
		req.Header.Set("Authorization", "Bearer "+firstAccess)
		resp, err := client.Do(req)
		must(t, err, "GET /me")
		defer resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			body, _ := io.ReadAll(resp.Body)
			t.Fatalf("/me status: %d %s", resp.StatusCode, body)
		}
	})

	t.Run("refresh rotates tokens", func(t *testing.T) {
		oldCookie := refreshCookieValue(t, srv.URL, jar)

		resp := post(t, client, srv.URL+"/auth/refresh", nil)
		defer resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			body, _ := io.ReadAll(resp.Body)
			t.Fatalf("refresh status: %d %s", resp.StatusCode, body)
		}
		var body struct {
			AccessToken string `json:"access_token"`
		}
		must(t, json.NewDecoder(resp.Body).Decode(&body), "decode refresh")
		if body.AccessToken == "" {
			t.Fatal("missing new access token")
		}
		newCookie := refreshCookieValue(t, srv.URL, jar)
		if newCookie == oldCookie {
			t.Fatal("refresh did not rotate cookie")
		}

		// Replay of the old refresh token must be rejected and revoke the family.
		jar2, _ := cookiejar.New(nil)
		client2 := &http.Client{Jar: jar2}
		setRefreshCookie(t, srv.URL, jar2, oldCookie)
		replay := post(t, client2, srv.URL+"/auth/refresh", nil)
		replay.Body.Close()
		if replay.StatusCode != http.StatusUnauthorized {
			t.Fatalf("old refresh replay should be 401, got %d", replay.StatusCode)
		}

		// And the family should be revoked: even the new (just-rotated) cookie
		// no longer works.
		familyReplay := post(t, client, srv.URL+"/auth/refresh", nil)
		familyReplay.Body.Close()
		if familyReplay.StatusCode != http.StatusUnauthorized {
			t.Fatalf("family-revoked refresh should be 401, got %d", familyReplay.StatusCode)
		}
	})

	// After family revocation, log back in to keep going.
	resp := post(t, client, srv.URL+"/auth/login", map[string]string{
		"email":    email,
		"password": authTestPassword,
	})
	resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("second login: %d", resp.StatusCode)
	}

	t.Run("forgot-password emits link without leaking existence", func(t *testing.T) {
		// Unknown email — still 202, no link sent.
		emails.resetLink = ""
		unknown := post(t, client, srv.URL+"/auth/forgot-password", map[string]string{
			"email": "nobody-" + uuid.NewString() + "@guestguard.test",
		})
		unknown.Body.Close()
		if unknown.StatusCode != http.StatusAccepted {
			t.Fatalf("unknown forgot-password: %d", unknown.StatusCode)
		}
		if emails.resetLink != "" {
			t.Fatal("reset link sent for unknown email")
		}

		known := post(t, client, srv.URL+"/auth/forgot-password", map[string]string{
			"email": email,
		})
		known.Body.Close()
		if known.StatusCode != http.StatusAccepted {
			t.Fatalf("known forgot-password: %d", known.StatusCode)
		}
		if emails.resetLink == "" {
			t.Fatal("reset link not captured")
		}
	})

	t.Run("reset password invalidates sessions", func(t *testing.T) {
		token := tokenFromPath(t, emails.resetLink, "/reset-password/")
		newPw := "new-correct-horse-battery-staple"
		resp := post(t, client, srv.URL+"/auth/reset-password", map[string]string{
			"token":        token,
			"new_password": newPw,
		})
		resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			t.Fatalf("reset status: %d", resp.StatusCode)
		}

		// Old password fails.
		bad := post(t, client, srv.URL+"/auth/login", map[string]string{
			"email":    email,
			"password": authTestPassword,
		})
		bad.Body.Close()
		if bad.StatusCode != http.StatusUnauthorized {
			t.Fatalf("old password should 401, got %d", bad.StatusCode)
		}

		// Existing refresh cookie should no longer work.
		refresh := post(t, client, srv.URL+"/auth/refresh", nil)
		refresh.Body.Close()
		if refresh.StatusCode != http.StatusUnauthorized {
			t.Fatalf("refresh after reset should 401, got %d", refresh.StatusCode)
		}

		// New password works.
		ok := post(t, client, srv.URL+"/auth/login", map[string]string{
			"email":    email,
			"password": newPw,
		})
		ok.Body.Close()
		if ok.StatusCode != http.StatusOK {
			t.Fatalf("new password login: %d", ok.StatusCode)
		}
	})

	t.Run("logout revokes refresh", func(t *testing.T) {
		resp := post(t, client, srv.URL+"/auth/logout", nil)
		resp.Body.Close()
		if resp.StatusCode != http.StatusNoContent {
			t.Fatalf("logout status: %d", resp.StatusCode)
		}
		refresh := post(t, client, srv.URL+"/auth/refresh", nil)
		refresh.Body.Close()
		if refresh.StatusCode != http.StatusUnauthorized {
			t.Fatalf("refresh after logout should 401, got %d", refresh.StatusCode)
		}
	})

	t.Run("requireAuth rejects invalid bearer", func(t *testing.T) {
		req, _ := http.NewRequest(http.MethodGet, srv.URL+"/me", nil)
		req.Header.Set("Authorization", "Bearer not-a-real-jwt")
		resp, err := client.Do(req)
		must(t, err, "GET /me bad token")
		resp.Body.Close()
		if resp.StatusCode != http.StatusUnauthorized {
			t.Fatalf("bad bearer should 401, got %d", resp.StatusCode)
		}
	})
}

// --- helpers ---

func uniqueEmail(t *testing.T) string {
	t.Helper()
	return "auth-" + uuid.NewString() + "@guestguard.test"
}

func post(t *testing.T, client *http.Client, url string, body any) *http.Response {
	t.Helper()
	var r io.Reader
	if body != nil {
		b, err := json.Marshal(body)
		must(t, err, "marshal post body")
		r = bytes.NewReader(b)
	}
	req, err := http.NewRequest(http.MethodPost, url, r)
	must(t, err, "build post request")
	if body != nil {
		req.Header.Set("Content-Type", "application/json")
	}
	resp, err := client.Do(req)
	must(t, err, "do post "+url)
	return resp
}

func tokenFromQuery(t *testing.T, link, key string) string {
	t.Helper()
	idx := strings.Index(link, key+"=")
	if idx < 0 {
		t.Fatalf("link missing %s: %s", key, link)
	}
	return link[idx+len(key)+1:]
}

func tokenFromPath(t *testing.T, link, prefix string) string {
	t.Helper()
	idx := strings.LastIndex(link, prefix)
	if idx < 0 {
		t.Fatalf("link missing prefix %s: %s", prefix, link)
	}
	return link[idx+len(prefix):]
}

func assertRefreshCookieSet(t *testing.T, baseURL string, jar http.CookieJar) {
	t.Helper()
	if refreshCookieValue(t, baseURL, jar) == "" {
		t.Fatal("refresh cookie not set")
	}
}

func refreshCookieValue(t *testing.T, baseURL string, jar http.CookieJar) string {
	t.Helper()
	// jar.Cookies needs a URL whose path matches the cookie's Path (/auth).
	u := baseURL + "/auth/refresh"
	parsed, err := url.Parse(u)
	must(t, err, "parse url")
	for _, c := range jar.Cookies(parsed) {
		if c.Name == "gg_refresh" {
			return c.Value
		}
	}
	return ""
}

func setRefreshCookie(t *testing.T, baseURL string, jar http.CookieJar, value string) {
	t.Helper()
	parsed, err := url.Parse(baseURL + "/auth/refresh")
	must(t, err, "parse url")
	jar.SetCookies(parsed, []*http.Cookie{{
		Name:  "gg_refresh",
		Value: value,
		Path:  "/auth",
	}})
}