package logic

import (
	"context"

	authentity "spark-server/internal/module/auth/entity"
	userentity "spark-server/internal/module/user/entity"
	"spark-server/internal/pkg/errs"
	"spark-server/internal/pkg/i18n"
	"spark-server/internal/pkg/reqctx"
	"spark-server/internal/pkg/validate"
)

// Verifier checks email OTP and records the login device. The user module owns the implementation.
type Verifier interface {
	AuthenticateEmail(ctx context.Context, email, verifyCode string, device *userentity.LoginDevice) (*userentity.User, error)
}

// LoginInput is the HTTP/TCP-shared login body. Validation tags drive client-visible messages.
type LoginInput struct {
	Email      string `json:"email" validate:"required,email" label:"field.email" errmsg:"required:validate.login.email_required;email:validate.login.email_invalid"`
	VerifyCode string `json:"verify_code" validate:"required" label:"field.verify_code" errmsg:"required:validate.login.code_required"`
	DeviceID   uint64 `json:"device_id" validate:"required" label:"field.device_id" errmsg:"required:validate.login.device_required"`
	DeviceType string `json:"device_type" validate:"omitempty,oneof=ios android harmony windows macos web" label:"field.device_type" errmsg:"oneof:validate.login.device_type_invalid"`
	Platform   string `json:"platform" validate:"omitempty,oneof=ios android harmony windows macos web" label:"field.device_type" errmsg:"oneof:validate.login.device_type_invalid"`
	DeviceName string `json:"device_name" validate:"omitempty,max=128" label:"field.device_name"`
}

type RefreshInput struct {
	RefreshToken string `json:"refresh_token" validate:"required" label:"field.refresh_token" errmsg:"required:validate.login.refresh_required"`
}

// SessionKicker drops the IM connection for one device after HTTP logout.
type SessionKicker interface {
	KickDevice(userID int64, deviceID uint64)
}

// LoginService is the application login use-case. Handlers only bind and call this.
type LoginService struct {
	Issuer   Issuer
	Users    Verifier
	Sessions SessionKicker
}

func NewLoginService(issuer Issuer, users Verifier) *LoginService {
	return &LoginService{Issuer: issuer, Users: users}
}

func (s *LoginService) Login(ctx context.Context, in *LoginInput) (*authentity.IssuedToken, error) {
	if s == nil || s.Issuer == nil || s.Users == nil || in == nil {
		return nil, errs.ErrUnauthorized
	}
	if err := validate.StructLang(reqctx.Lang(ctx), in); err != nil {
		return nil, err
	}
	if !userentity.ValidDeviceType(loginDeviceType(in)) {
		return nil, errs.ErrInvalidArgument.WithMsg(i18n.T(reqctx.Lang(ctx), i18n.KeyLoginDeviceTypeRequired, nil))
	}
	u, err := s.Users.AuthenticateEmail(ctx, in.Email, in.VerifyCode, loginDevice(ctx, in))
	if err != nil {
		return nil, err
	}
	if u == nil || u.ID <= 0 {
		return nil, errs.ErrUnauthorized
	}
	tok, err := s.Issuer.Issue(ctx, u.ID, in.DeviceID)
	if err != nil {
		return nil, err
	}
	tok.SparkID = u.SparkID
	return tok, nil
}

func (s *LoginService) Refresh(ctx context.Context, in RefreshInput) (*authentity.IssuedToken, error) {
	if s == nil || s.Issuer == nil {
		return nil, errs.ErrUnauthorized
	}
	if err := validate.StructLang(reqctx.Lang(ctx), in); err != nil {
		return nil, err
	}
	return s.Issuer.Refresh(ctx, in.RefreshToken)
}

func (s *LoginService) Logout(ctx context.Context) error {
	if s == nil || s.Issuer == nil {
		return errs.ErrUnauthorized
	}
	rc := reqctx.From(ctx)
	if rc == nil || rc.UserID <= 0 || rc.DeviceID == 0 {
		return errs.ErrUnauthorized
	}
	if err := s.Issuer.Logout(ctx, rc.UserID, rc.DeviceID, rc.JTI, rc.TokenExpires); err != nil {
		return err
	}
	if s.Sessions != nil {
		s.Sessions.KickDevice(rc.UserID, rc.DeviceID)
	}
	return nil
}

func loginDeviceType(in *LoginInput) string {
	if in == nil {
		return ""
	}
	if t := userentity.NormalizeDeviceType(in.DeviceType); userentity.ValidDeviceType(t) {
		return t
	}
	return userentity.NormalizeDeviceType(in.Platform)
}

func loginDevice(ctx context.Context, in *LoginInput) *userentity.LoginDevice {
	if in == nil {
		return &userentity.LoginDevice{}
	}
	d := &userentity.LoginDevice{
		DeviceID:   in.DeviceID,
		DeviceType: loginDeviceType(in),
		Platform:   in.Platform,
		DeviceName: in.DeviceName,
		RealIP:     reqctx.RealIP(ctx),
		Language:   reqctx.Language(ctx),
	}
	if rc := reqctx.From(ctx); rc != nil {
		d.AppVersion = rc.AppVersion
	}
	return d
}