package business

import (
	"context"
	"time"

	"github.com/go-kratos/kratos/v3/errors"
	"kra/internal/biz/system"
)

var (
	ErrOtherSettingsScope  = errors.Forbidden("SW_OTHER_SETTINGS_SCOPE", "仅超级管理员可以查看和修改其他设置")
	ErrOtherSettingsInput  = errors.BadRequest("SW_OTHER_SETTINGS_INPUT", "达标金额须为不小于0的整数，判定窗口须为不小于1的整数，且不能超过安全整数范围")
	ErrOtherSettingsStored = errors.BadRequest("SW_OTHER_SETTINGS_STORED", "已保存的设置格式不正确，请恢复默认后重新保存")
)

const MaxSettingsInteger int64 = 9007199254740991

type OtherSettings struct {
	Amount, Days int64
	UpdatedAt    time.Time
}

func DefaultOtherSettings() OtherSettings { return OtherSettings{Amount: 3000, Days: 30} }

func ValidateOtherSettings(value OtherSettings) error {
	if value.Amount < 0 || value.Amount > MaxSettingsInteger || value.Days < 1 || value.Days > MaxSettingsInteger {
		return ErrOtherSettingsInput
	}
	return nil
}

type OtherSettingsRepo interface {
	Find(context.Context) (*OtherSettings, error)
	Save(context.Context, OtherSettings) (*OtherSettings, error)
}

type OtherSettingsUsecase struct {
	repo          OtherSettingsRepo
	effectiveness *EffectivenessUsecase
}

func NewOtherSettingsUsecase(repo OtherSettingsRepo, effectiveness *EffectivenessUsecase) *OtherSettingsUsecase {
	return &OtherSettingsUsecase{repo: repo, effectiveness: effectiveness}
}

func requireSettingsAdmin(ctx context.Context) error {
	actor, ok := system.ActorFromContext(ctx)
	if !ok || actor.UserID == 0 {
		return ErrUnauthenticated
	}
	if actor.AuthorityID != system.SuperAdminAuthorityID {
		return ErrOtherSettingsScope
	}
	return nil
}

func (uc *OtherSettingsUsecase) Get(ctx context.Context) (*OtherSettings, error) {
	if err := requireSettingsAdmin(ctx); err != nil {
		return nil, err
	}
	value, err := uc.repo.Find(ctx)
	if err != nil {
		return nil, err
	}
	if value == nil {
		defaults := DefaultOtherSettings()
		return &defaults, nil
	}
	return value, nil
}

func (uc *OtherSettingsUsecase) Save(ctx context.Context, value OtherSettings) (*OtherSettings, error) {
	if err := requireSettingsAdmin(ctx); err != nil {
		return nil, err
	}
	if err := ValidateOtherSettings(value); err != nil {
		return nil, err
	}
	if uc.effectiveness != nil {
		return uc.effectiveness.Reconfigure(ctx, value)
	}
	return uc.repo.Save(ctx, value)
}