package api_test

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

	"github.com/go-chi/chi/v5"
	"github.com/owncord/server/api"
	"github.com/owncord/server/auth"
	"github.com/owncord/server/db"
	"github.com/owncord/server/service"
)

// buildProfileRouter returns a chi router with profile routes mounted.
func buildProfileRouter(database *db.DB) http.Handler {
	r := chi.NewRouter()
	limiter := auth.NewRateLimiter()
	svc := service.New(database, limiter)
	api.MountProfileRoutes(r, database, svc, nil, limiter, nil, nil)
	return r
}

// profileCreateToken creates a user and session, returning the raw token.
func profileCreateToken(t *testing.T, database *db.DB, username string, roleID int) string {
	t.Helper()
	uid, err := database.CreateUser(context.Background(), username, mustHash(t), roleID)
	if err != nil {
		t.Fatalf("CreateUser(%s): %v", username, err)
	}
	token, err := auth.GenerateToken()
	if err != nil {
		t.Fatalf("GenerateToken: %v", err)
	}
	expiresAt := time.Now().Add(24 * time.Hour).UTC().Format("2006-01-02T15:04:05Z")
	_, err = database.ExecContext(context.Background(),
		"INSERT INTO sessions (user_id, token, device, ip_address, expires_at) VALUES (?, ?, ?, ?, ?)",
		uid, auth.HashToken(token), "TestAgent", "127.0.0.1", expiresAt,
	)
	if err != nil {
		t.Fatalf("insert session: %v", err)
	}
	return token
}

// mustHash returns a bcrypt hash of a standard test password.
func mustHash(t *testing.T) string {
	t.Helper()
	h, err := auth.HashPassword("securePass1")
	if err != nil {
		t.Fatalf("HashPassword: %v", err)
	}
	return h
}

// patchJSON sends a PATCH request with JSON body and auth token.
func patchJSON(t *testing.T, router http.Handler, path, token string, body any) *httptest.ResponseRecorder {
	t.Helper()
	raw, _ := json.Marshal(body)
	req := httptest.NewRequest(http.MethodPatch, path, bytes.NewReader(raw))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+token)
	req.RemoteAddr = "127.0.0.1:9999"
	rr := httptest.NewRecorder()
	router.ServeHTTP(rr, req)
	return rr
}

// putJSON sends a PUT request with JSON body and auth token.
func putJSON(t *testing.T, router http.Handler, path, token string, body any) *httptest.ResponseRecorder {
	t.Helper()
	raw, _ := json.Marshal(body)
	req := httptest.NewRequest(http.MethodPut, path, bytes.NewReader(raw))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+token)
	req.RemoteAddr = "127.0.0.1:9999"
	rr := httptest.NewRecorder()
	router.ServeHTTP(rr, req)
	return rr
}

// profileDelete sends a DELETE request with an auth token (no body).
func profileDelete(t *testing.T, router http.Handler, path, token string) *httptest.ResponseRecorder {
	t.Helper()
	req := httptest.NewRequest(http.MethodDelete, path, nil)
	req.Header.Set("Authorization", "Bearer "+token)
	req.RemoteAddr = "127.0.0.1:9999"
	rr := httptest.NewRecorder()
	router.ServeHTTP(rr, req)
	return rr
}

// ─── PATCH /api/v1/users/me ──────────────────────────────────────────────────

func TestUpdateProfile_Success(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "patchuser", 4)

	rr := patchJSON(t, router, "/api/v1/users/me", token, map[string]string{
		"username": "newname",
		"avatar":   "https://example.com/av.png",
	})

	if rr.Code != http.StatusOK {
		t.Errorf("status = %d, want 200; body = %s", rr.Code, rr.Body.String())
	}

	var resp map[string]any
	_ = json.NewDecoder(rr.Body).Decode(&resp)
	if resp["username"] != "newname" {
		t.Errorf("username = %v, want 'newname'", resp["username"])
	}
}

func TestUpdateProfile_EmptyUsername(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "emptyuser", 4)

	rr := patchJSON(t, router, "/api/v1/users/me", token, map[string]string{
		"username": "",
	})

	if rr.Code != http.StatusBadRequest {
		t.Errorf("status = %d, want 400; body = %s", rr.Code, rr.Body.String())
	}
}

func TestUpdateProfile_UsernameTaken(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	profileCreateToken(t, database, "takenname", 4)
	token := profileCreateToken(t, database, "wannatake", 4)

	rr := patchJSON(t, router, "/api/v1/users/me", token, map[string]string{
		"username": "takenname",
	})

	if rr.Code != http.StatusConflict {
		t.Errorf("status = %d, want 409; body = %s", rr.Code, rr.Body.String())
	}
}

func TestUpdateProfile_Unauthorized(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)

	rr := patchJSON(t, router, "/api/v1/users/me", "badtoken", map[string]string{
		"username": "hacker",
	})

	if rr.Code != http.StatusUnauthorized {
		t.Errorf("status = %d, want 401", rr.Code)
	}
}

// ─── PUT /api/v1/users/me/password ──────────────────────────────────────────

func TestChangePassword_Success(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "pwuser", 4)

	rr := putJSON(t, router, "/api/v1/users/me/password", token, map[string]string{
		"old_password": "securePass1",
		"new_password": "newSecure2",
	})

	if rr.Code != http.StatusNoContent {
		t.Errorf("status = %d, want 204; body = %s", rr.Code, rr.Body.String())
	}
}

// BUG-108: Password change must revoke other sessions.
func TestChangePassword_RevokesOtherSessions(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)

	// Create user with two sessions.
	token1 := profileCreateToken(t, database, "pw-revoke", 4)
	user, _ := database.GetUserByUsername(context.Background(), "pw-revoke")

	// Create a second session for the same user.
	token2, _ := auth.GenerateToken()
	expiresAt := time.Now().Add(24 * time.Hour).UTC().Format("2006-01-02T15:04:05Z")
	_, _ = database.ExecContext(context.Background(),
		"INSERT INTO sessions (user_id, token, device, ip_address, expires_at) VALUES (?, ?, ?, ?, ?)",
		user.ID, auth.HashToken(token2), "OtherDevice", "10.0.0.1", expiresAt,
	)

	// Change password using token1.
	rr := putJSON(t, router, "/api/v1/users/me/password", token1, map[string]string{
		"old_password": "securePass1",
		"new_password": "newSecure2",
	})
	if rr.Code != http.StatusNoContent {
		t.Fatalf("status = %d, want 204; body = %s", rr.Code, rr.Body.String())
	}

	// token1 (current session) should still work.
	sess1, _ := database.GetSessionByTokenHash(context.Background(), auth.HashToken(token1))
	if sess1 == nil {
		t.Error("current session should survive password change")
	}

	// token2 (other session) should be revoked.
	sess2, _ := database.GetSessionByTokenHash(context.Background(), auth.HashToken(token2))
	if sess2 != nil {
		t.Error("other session should be revoked after password change")
	}
}

func TestChangePassword_WrongOldPassword(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "wrongpw", 4)

	rr := putJSON(t, router, "/api/v1/users/me/password", token, map[string]string{
		"old_password": "wrongPassword1",
		"new_password": "newSecure2",
	})

	if rr.Code != http.StatusForbidden {
		t.Errorf("status = %d, want 403; body = %s", rr.Code, rr.Body.String())
	}
}

func TestChangePassword_WeakNewPassword(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "weakpw", 4)

	rr := putJSON(t, router, "/api/v1/users/me/password", token, map[string]string{
		"old_password": "securePass1",
		"new_password": "short",
	})

	if rr.Code != http.StatusBadRequest {
		t.Errorf("status = %d, want 400; body = %s", rr.Code, rr.Body.String())
	}
}

func TestChangePassword_SamePassword(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "samepw", 4)

	rr := putJSON(t, router, "/api/v1/users/me/password", token, map[string]string{
		"old_password": "securePass1",
		"new_password": "securePass1",
	})

	if rr.Code != http.StatusBadRequest {
		t.Errorf("status = %d, want 400; body = %s", rr.Code, rr.Body.String())
	}
}

// ─── GET /api/v1/users/me/sessions ──────────────────────────────────────────

func TestListSessions_Success(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "sessuser", 4)

	rr := getWithToken(t, router, "/api/v1/users/me/sessions", token)

	if rr.Code != http.StatusOK {
		t.Errorf("status = %d, want 200; body = %s", rr.Code, rr.Body.String())
	}

	var resp struct {
		Sessions []map[string]any `json:"sessions"`
	}
	if err := json.NewDecoder(rr.Body).Decode(&resp); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if len(resp.Sessions) == 0 {
		t.Error("expected at least 1 session (the current one)")
	}

	// Verify is_current flag is present.
	found := false
	for _, s := range resp.Sessions {
		if isCurrent, ok := s["is_current"]; ok && isCurrent == true {
			found = true
		}
	}
	if !found {
		t.Error("no session has is_current=true")
	}
}

func TestListSessions_Unauthorized(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)

	rr := getWithToken(t, router, "/api/v1/users/me/sessions", "badtoken")

	if rr.Code != http.StatusUnauthorized {
		t.Errorf("status = %d, want 401", rr.Code)
	}
}

// ─── DELETE /api/v1/users/me/sessions/:id ───────────────────────────────────

func TestRevokeSession_Success(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "revoke", 4)

	// Create a second session to revoke.
	user, _ := database.GetUserByUsername(context.Background(), "revoke")
	secondSessID, _ := database.CreateSession(context.Background(), user.ID, auth.HashToken("second-tok"), "Firefox", "1.2.3.4")

	rr := profileDelete(t, router, fmt.Sprintf("/api/v1/users/me/sessions/%d", secondSessID), token)

	if rr.Code != http.StatusNoContent {
		t.Errorf("status = %d, want 204; body = %s", rr.Code, rr.Body.String())
	}
}

func TestRevokeSession_NotFound(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "revokenf", 4)

	rr := profileDelete(t, router, "/api/v1/users/me/sessions/99999", token)

	if rr.Code != http.StatusNotFound {
		t.Errorf("status = %d, want 404; body = %s", rr.Code, rr.Body.String())
	}
}

func TestRevokeSession_OtherUsersSession(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "revokeother", 4)

	// Create another user with a session.
	otherUID, _ := database.CreateUser(context.Background(), "victim", mustHash(t), 4)
	otherSessID, _ := database.CreateSession(context.Background(), otherUID, auth.HashToken("victim-tok"), "Safari", "9.8.7.6")

	rr := profileDelete(t, router, fmt.Sprintf("/api/v1/users/me/sessions/%d", otherSessID), token)

	if rr.Code != http.StatusNotFound {
		t.Errorf("status = %d, want 404 (should not reveal other user's session); body = %s", rr.Code, rr.Body.String())
	}
}

func TestRevokeSession_CurrentSession(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "revokeself", 4)

	// Find the current session ID.
	user, _ := database.GetUserByUsername(context.Background(), "revokeself")
	sessions, _ := database.ListUserSessions(context.Background(), user.ID)
	if len(sessions) == 0 {
		t.Fatal("expected at least 1 session")
	}

	rr := profileDelete(t, router, fmt.Sprintf("/api/v1/users/me/sessions/%d", sessions[0].ID), token)

	// Revoking own session is allowed.
	if rr.Code != http.StatusNoContent {
		t.Errorf("status = %d, want 204; body = %s", rr.Code, rr.Body.String())
	}
}

// ─── PATCH /api/v1/users/me — identity_public_key (F3 voice E2EE TOFU) ───────

func TestUpdateProfile_PublishIdentityKey(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "idkeyuser", 4)

	key := "BPZ8bfkPz8B64iDeNtItYkEy0123456789abcdef+/=="
	rr := patchJSON(t, router, "/api/v1/users/me", token, map[string]string{
		"username":            "idkeyuser",
		"identity_public_key": key,
	})
	if rr.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body = %s", rr.Code, rr.Body.String())
	}

	u, err := database.GetUserByUsername(context.Background(), "idkeyuser")
	if err != nil || u == nil {
		t.Fatalf("GetUserByUsername: %v", err)
	}
	if u.IdentityPublicKey == nil || *u.IdentityPublicKey != key {
		t.Errorf("IdentityPublicKey = %v, want %q", u.IdentityPublicKey, key)
	}
}

func TestUpdateProfile_IdentityKeyOmitted_Unchanged(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "idkeykeep", 4)

	key := "a2VlcHRoaXNrZXk="
	u, err := database.GetUserByUsername(context.Background(), "idkeykeep")
	if err != nil || u == nil {
		t.Fatalf("GetUserByUsername: %v", err)
	}
	if err := database.UpdateUserIdentityKey(context.Background(), u.ID, &key); err != nil {
		t.Fatalf("UpdateUserIdentityKey: %v", err)
	}

	// PATCH without identity_public_key must not clear the stored key.
	rr := patchJSON(t, router, "/api/v1/users/me", token, map[string]string{
		"username": "idkeykeep",
	})
	if rr.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body = %s", rr.Code, rr.Body.String())
	}
	after, err := database.GetUserByID(context.Background(), u.ID)
	if err != nil || after == nil {
		t.Fatalf("GetUserByID: %v", err)
	}
	if after.IdentityPublicKey == nil || *after.IdentityPublicKey != key {
		t.Errorf("IdentityPublicKey = %v, want %q (unchanged)", after.IdentityPublicKey, key)
	}
}

func TestUpdateProfile_IdentityKeyInvalid(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)

	cases := []struct {
		name string
		key  string
	}{
		{"not base64", "!!!not-base64!!!"},
		{"url-safe alphabet", "abc-_def"},
		{"too large", strings.Repeat("A", 132)},
		{"empty", ""},
	}
	for i, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			token := profileCreateToken(t, database, fmt.Sprintf("idkeybad%d", i), 4)
			rr := patchJSON(t, router, "/api/v1/users/me", token, map[string]string{
				"username":            fmt.Sprintf("idkeybad%d", i),
				"identity_public_key": tc.key,
			})
			if rr.Code != http.StatusBadRequest {
				t.Errorf("status = %d, want 400; body = %s", rr.Code, rr.Body.String())
			}
		})
	}
}

// ─── GET /api/v1/users/me/sessions with an API-token principal ────────────────

func TestListSessions_APITokenPrincipal(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)

	// One login session exists, but the caller authenticates with an API
	// token (nil SessionKey). The sibling DELETE works for this principal;
	// the list must too, with no session marked current.
	_ = profileCreateToken(t, database, "apisessions", 4)
	user, _ := database.GetUserByUsername(context.Background(), "apisessions")
	if user == nil {
		t.Fatal("user not found")
	}
	apiTok, err := auth.GenerateToken()
	if err != nil {
		t.Fatalf("GenerateToken: %v", err)
	}
	if _, err := database.CreateAPIToken(context.Background(), user.ID, auth.HashToken(apiTok), "ci", nil); err != nil {
		t.Fatalf("CreateAPIToken: %v", err)
	}

	req := httptest.NewRequest(http.MethodGet, "/api/v1/users/me/sessions", nil)
	req.Header.Set("Authorization", "Bearer "+apiTok)
	req.RemoteAddr = "127.0.0.1:9999"
	rr := httptest.NewRecorder()
	router.ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("sessions list via API token: status = %d, want 200; body = %s", rr.Code, rr.Body.String())
	}
	var resp struct {
		Sessions []struct {
			ID        int64 `json:"id"`
			IsCurrent bool  `json:"is_current"`
		} `json:"sessions"`
	}
	_ = json.NewDecoder(rr.Body).Decode(&resp)
	if len(resp.Sessions) != 1 {
		t.Fatalf("sessions = %d, want 1", len(resp.Sessions))
	}
	if resp.Sessions[0].IsCurrent {
		t.Error("API-token principal must not mark any session as current")
	}
}

// ─── Rate-limit bucket isolation ─────────────────────────────────────────────

func TestRateLimit_ProfileUpdatesDoNotConsumePasswordBudget(t *testing.T) {
	database := newAuthTestDB(t)
	router := buildProfileRouter(database)
	token := profileCreateToken(t, database, "bucketuser", 4)

	// Five profile PATCHes (limit 10/min). If the password endpoint shared
	// the same bare-IP bucket, its 5/min budget would now read as exhausted
	// with zero password attempts made.
	for i := range 5 {
		rr := patchJSON(t, router, "/api/v1/users/me", token, map[string]string{
			"username": "bucketuser",
		})
		if rr.Code == http.StatusTooManyRequests {
			t.Fatalf("profile PATCH %d unexpectedly rate limited", i)
		}
	}

	raw, _ := json.Marshal(map[string]string{
		"old_password": "wrong-on-purpose",
		"new_password": "NewSecurePass1!",
	})
	req := httptest.NewRequest(http.MethodPut, "/api/v1/users/me/password", bytes.NewReader(raw))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+token)
	req.RemoteAddr = "127.0.0.1:9999"
	rr := httptest.NewRecorder()
	router.ServeHTTP(rr, req)

	if rr.Code == http.StatusTooManyRequests {
		t.Fatal("password change 429'd with zero password attempts made — unrelated endpoints share one rate-limit bucket")
	}
}
