package app

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

	"github.com/go-sql-driver/mysql"
)

// This transactional fixture exercises the real HTTP handlers without needing
// production credentials. Unexpected SQL is an error, including session writes
// during administrator provisioning.
type provisionedUser struct {
	publicID, passwordHash, nickname, city, bio string
	phoneHash, phoneCipher                      []byte
	gender                                      int64
	privacy, notification                       bool
	audit                                       []byte
	sessions                                    int
}

type provisioningDB struct {
	t                 *testing.T
	user, pending     *provisionedUser
	allowed, inTx     bool
	failAt            string
	failure           error
	begins, rollbacks int
}

type provisioningConnector struct{ store *provisioningDB }

func (c provisioningConnector) Connect(context.Context) (driver.Conn, error) { return c.store, nil }
func (provisioningConnector) Driver() driver.Driver                          { return oauthTestDriver{} }
func (*provisioningDB) Prepare(string) (driver.Stmt, error) {
	return nil, fmt.Errorf("unexpected prepare")
}
func (*provisioningDB) Close() error { return nil }
func (s *provisioningDB) Begin() (driver.Tx, error) {
	s.begins++
	s.inTx = true
	s.pending = nil
	if s.user != nil {
		copy := *s.user
		s.pending = &copy
	}
	return s, nil
}
func (s *provisioningDB) BeginTx(context.Context, driver.TxOptions) (driver.Tx, error) {
	return s.Begin()
}
func (s *provisioningDB) Commit() error {
	s.user, s.pending, s.inTx = s.pending, nil, false
	return nil
}
func (s *provisioningDB) Rollback() error {
	s.pending, s.inTx = nil, false
	s.rollbacks++
	return nil
}

type provisioningInsertResult struct{}

func (provisioningInsertResult) LastInsertId() (int64, error) { return 42, nil }
func (provisioningInsertResult) RowsAffected() (int64, error) { return 1, nil }

func (s *provisioningDB) ExecContext(_ context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
	if s.failAt != "" && strings.Contains(query, s.failAt) {
		return nil, s.failure
	}
	if strings.Contains(query, "api_rate_limits") {
		return driver.RowsAffected(1), nil
	}
	if !s.inTx {
		s.t.Errorf("account mutation outside transaction: %s", query)
		return nil, fmt.Errorf("no transaction")
	}
	switch {
	case strings.HasPrefix(query, "INSERT INTO users "):
		if s.pending != nil && bytes.Equal(s.pending.phoneHash, args[1].Value.([]byte)) {
			return nil, &mysql.MySQLError{Number: 1062, Message: "Duplicate entry for key 'users.uk_users_phone_hash'"}
		}
		s.pending = &provisionedUser{publicID: args[0].Value.(string), phoneHash: args[1].Value.([]byte), phoneCipher: args[2].Value.([]byte), passwordHash: args[3].Value.(string)}
		return provisioningInsertResult{}, nil
	case strings.HasPrefix(query, "INSERT INTO user_profiles "):
		s.pending.nickname, s.pending.gender = args[1].Value.(string), args[2].Value.(int64)
		s.pending.city, s.pending.bio = args[3].Value.(string), args[4].Value.(string)
	case strings.HasPrefix(query, "INSERT INTO user_privacy_settings "):
		s.pending.privacy = true
	case strings.HasPrefix(query, "INSERT INTO user_notification_settings "):
		s.pending.notification = true
	case strings.HasPrefix(query, "INSERT INTO admin_audit_logs"):
		if args[0].Value != int64(7) || args[1].Value != int64(42) {
			s.t.Error("audit must identify both the administrator and created user")
		}
		s.pending.audit = args[2].Value.([]byte)
	case strings.HasPrefix(query, "INSERT INTO user_sessions "):
		s.pending.sessions++
	case strings.HasPrefix(query, "UPDATE user_sessions "), strings.HasPrefix(query, "INSERT INTO user_devices"), strings.HasPrefix(query, "UPDATE user_profiles SET last_active_at"):
	default:
		s.t.Errorf("unexpected exec: %s", query)
		return nil, fmt.Errorf("unexpected exec")
	}
	return driver.RowsAffected(1), nil
}

func (s *provisioningDB) QueryContext(_ context.Context, query string, args []driver.NamedValue) (driver.Rows, error) {
	switch {
	case strings.Contains(query, "SELECT status,token_version FROM admin_users"):
		return oauthRow(int64(1), int64(0)), nil
	case strings.Contains(query, "SELECT token_version FROM"):
		return oauthRow(int64(0)), nil
	case strings.Contains(query, "FROM admin_user_roles"):
		allowed := int64(0)
		if s.allowed && args[1].Value == "users:create" {
			allowed = 1
		}
		return oauthRow(allowed), nil
	case strings.Contains(query, "SELECT hits FROM api_rate_limits"):
		return oauthRow(int64(1)), nil
	case strings.HasPrefix(query, "SELECT u.id,u.password_hash,u.status,p.nickname"):
		if s.user == nil || !bytes.Equal(s.user.phoneHash, args[0].Value.([]byte)) {
			return &oauthTestRows{columns: []string{"id", "password_hash", "status", "nickname"}}, nil
		}
		return oauthRow(int64(42), s.user.passwordHash, int64(1), s.user.nickname), nil
	case strings.HasPrefix(query, "SELECT COUNT(*) FROM users u JOIN user_profiles"):
		return oauthRow(int64(1)), nil
	case strings.HasPrefix(query, "SELECT u.id,u.public_id,u.phone_cipher"):
		u := s.user
		return oauthRow(int64(42), u.publicID, u.phoneCipher, int64(1), int64(0), time.Now(), false, "", u.nickname, "", u.gender, u.city, int64(0), int64(0), nil, "UNVERIFIED", nil), nil
	default:
		s.t.Errorf("unexpected query: %s", query)
		return nil, fmt.Errorf("unexpected query")
	}
}

func provisioningApp(t *testing.T) (*App, *provisioningDB, http.HandlerFunc, string) {
	t.Helper()
	store := &provisioningDB{t: t, allowed: true}
	db := sql.OpenDB(provisioningConnector{store})
	t.Cleanup(func() { _ = db.Close() })
	a := &App{db: db, config: Config{JWTSecret: "test-provisioning-secret", Environment: "development"}}
	token, err := a.token(7, "admin", "tester", time.Hour)
	if err != nil {
		t.Fatal(err)
	}
	for _, route := range a.adminRoutes() {
		if route.Method == http.MethodPost && route.Path == "/admin/v1/users" {
			return a, store, route.Handler, token
		}
	}
	t.Fatal("admin create user route is not registered")
	return nil, nil, nil, ""
}

func provisionRequest(handler http.HandlerFunc, token string, payload any) *httptest.ResponseRecorder {
	body, _ := json.Marshal(payload)
	r := httptest.NewRequest(http.MethodPost, "/admin/v1/users", bytes.NewReader(body))
	if token != "" {
		r.Header.Set("Authorization", "Bearer "+token)
	}
	w := httptest.NewRecorder()
	handler(w, r)
	return w
}

func validProvisionPayload() map[string]any {
	return map[string]any{"phone": "13800138000", "password": "Password123!", "nickname": " 管理员创建用户 ", "gender": 1, "city": " 北京 ", "bio": " 简介 "}
}

func TestAdminCreateUserAndPasswordLogin(t *testing.T) {
	a, store, handler, token := provisioningApp(t)
	w := provisionRequest(handler, token, validProvisionPayload())
	if w.Code != http.StatusOK || store.user == nil {
		t.Fatalf("create failed: %d %s", w.Code, w.Body.String())
	}
	u := store.user
	if !u.privacy || !u.notification || len(u.audit) == 0 || u.sessions != 0 {
		t.Fatal("account must have default settings and an audit, but no login session")
	}
	if u.nickname != "管理员创建用户" || u.city != "北京" || u.bio != "简介" {
		t.Fatal("profile whitespace was not normalized")
	}
	if len(u.publicID) > 20 || !strings.HasPrefix(u.publicID, "XY") {
		t.Fatal("invalid public ID")
	}
	phone, err := a.decryptPhone(u.phoneCipher)
	if err != nil || phone != "13800138000" || bytes.Contains(u.phoneCipher, []byte(phone)) {
		t.Fatal("phone was not encrypted correctly")
	}
	if !checkPassword(u.passwordHash, "Password123!") || u.passwordHash == "Password123!" {
		t.Fatal("password must be bcrypt hashed")
	}
	for _, sensitive := range []string{"13800138000", "Password123!", "accessToken", "refreshToken"} {
		if strings.Contains(w.Body.String(), sensitive) || bytes.Contains(u.audit, []byte(sensitive)) {
			t.Fatalf("creation leaked %s", sensitive)
		}
	}
	list := httptest.NewRecorder()
	a.adminUsers(list, httptest.NewRequest(http.MethodGet, "/admin/v1/users?keyword="+u.publicID, nil))
	if list.Code != 200 || !strings.Contains(list.Body.String(), u.publicID) || !strings.Contains(list.Body.String(), `"phone":"138****8000"`) {
		t.Fatalf("new account missing from list: %s", list.Body.String())
	}
	wrong := provisionRequest(a.loginPassword, "", map[string]any{"phone": phone, "password": "wrong-password"})
	if wrong.Code != http.StatusUnauthorized || store.user.sessions != 0 {
		t.Fatal("incorrect initial password was accepted")
	}
	login := provisionRequest(a.loginPassword, "", map[string]any{"phone": phone, "password": "Password123!", "deviceId": "app-test"})
	var result struct {
		Data struct {
			AccessToken string `json:"accessToken"`
		} `json:"data"`
	}
	if login.Code != http.StatusOK || json.Unmarshal(login.Body.Bytes(), &result) != nil || store.user.sessions != 1 {
		t.Fatalf("password login failed: %d %s", login.Code, login.Body.String())
	}
	who, err := a.parseToken(result.Data.AccessToken)
	if err != nil || who.ID != 42 || who.Role != "user" {
		t.Fatal("login did not issue a valid user token")
	}
}

func TestAdminCreateUserPermissions(t *testing.T) {
	a, store, handler, token := provisioningApp(t)
	store.allowed = false
	if w := provisionRequest(handler, token, validProvisionPayload()); w.Code != http.StatusForbidden {
		t.Fatalf("missing create permission accepted: %d", w.Code)
	}
	if w := provisionRequest(handler, "", validProvisionPayload()); w.Code != http.StatusUnauthorized {
		t.Fatal("anonymous creation accepted")
	}
	userToken, _ := a.token(42, "user", "user", time.Hour)
	if w := provisionRequest(handler, userToken, validProvisionPayload()); w.Code != http.StatusUnauthorized {
		t.Fatal("client token accepted")
	}
	if store.begins != 0 {
		t.Fatal("unauthorized caller reached account creation")
	}
}

func TestAdminCreateUserValidation(t *testing.T) {
	cases := []struct {
		key   string
		value any
	}{
		{"phone", "12345678901"}, {"phone", ""}, {"password", ""},
		{"nickname", "   "}, {"nickname", strings.Repeat("名", 51)},
		{"gender", 3}, {"gender", -1}, {"gender", 1.5}, {"city", strings.Repeat("城", 51)}, {"bio", strings.Repeat("文", 501)},
		{"isTest", true}, {"status", 3}, {"vip", true},
	}
	for i, tc := range cases {
		t.Run(fmt.Sprintf("%s-%d", tc.key, i), func(t *testing.T) {
			_, store, handler, token := provisioningApp(t)
			payload := validProvisionPayload()
			payload[tc.key] = tc.value
			w := provisionRequest(handler, token, payload)
			if w.Code != http.StatusBadRequest || store.begins != 0 {
				t.Fatalf("invalid input accepted: %d %s", w.Code, w.Body.String())
			}
		})
	}
}

func TestAdminCreateUserDuplicatePhonePreservesAccount(t *testing.T) {
	_, store, handler, token := provisioningApp(t)
	if w := provisionRequest(handler, token, validProvisionPayload()); w.Code != http.StatusOK {
		t.Fatal(w.Body.String())
	}
	original := store.user
	payload := validProvisionPayload()
	payload["nickname"], payload["password"], payload["phone"] = "覆盖用户", "Different123", " 13800138000 "
	w := provisionRequest(handler, token, payload)
	if w.Code != http.StatusConflict || store.user != original || store.rollbacks != 1 {
		t.Fatalf("duplicate did not preserve original account: %d %s", w.Code, w.Body.String())
	}
}

// Admin-set passwords follow the same rule as self-service ones, and whatever
// passes it has to survive the round trip to a working login.
func TestAdminCreatedUserCanLoginWithVariedPasswords(t *testing.T) {
	for _, password := range []string{"letters8", "中文密码八个字符", "Str0ng!Passw0rd", strings.Repeat("长密码", 30)} {
		a, store, handler, token := provisioningApp(t)
		payload := validProvisionPayload()
		payload["password"] = password
		created := provisionRequest(handler, token, payload)
		if created.Code != http.StatusOK {
			t.Fatalf("password rejected: %d %s", created.Code, created.Body.String())
		}
		login := provisionRequest(a.loginPassword, "", map[string]any{"phone": payload["phone"], "password": password})
		if login.Code != http.StatusOK || store.user.sessions != 1 {
			t.Fatalf("new password cannot login: %d %s", login.Code, login.Body.String())
		}
	}
}

func TestAdminCreateUserRollsBackEveryFailedWrite(t *testing.T) {
	for _, table := range []string{"users", "user_profiles", "user_privacy_settings", "user_notification_settings", "admin_audit_logs"} {
		t.Run(table, func(t *testing.T) {
			_, store, handler, token := provisioningApp(t)
			store.failAt, store.failure = "INSERT INTO "+table, fmt.Errorf("database unavailable")
			w := provisionRequest(handler, token, validProvisionPayload())
			if w.Code != http.StatusInternalServerError || store.user != nil || store.rollbacks != 1 {
				t.Fatalf("failed %s write left partial account: %d %s", table, w.Code, w.Body.String())
			}
			if strings.Contains(w.Body.String(), "手机号已被使用") {
				t.Fatal("database error misreported as duplicate phone")
			}
		})
	}
}