package service

import (
	"electricity_bill_calc/exceptions"
	"electricity_bill_calc/global"
	"electricity_bill_calc/model"
	"electricity_bill_calc/repository"
	"time"

	"xorm.io/builder"
	"xorm.io/xorm"
)

type _ChargeService struct{}

var ChargeService _ChargeService

func (c _ChargeService) CreateChargeRecord(charge *model.UserCharge, extendWithIgnoreSettle bool) error {
	tx := global.DBConn.NewSession()
	defer tx.Close()
	if err := tx.Begin(); err != nil {
		return err
	}
	_, err := tx.Insert(charge)
	if err != nil {
		tx.Rollback()
		return err
	}
	if extendWithIgnoreSettle {
		err := c.updateUserExpiration(tx, charge.UserId, charge.ChargeTo)
		if err != nil {
			return err
		}
	}
	err = tx.Commit()
	if err != nil {
		tx.Rollback()
		return err
	}
	return nil
}

func (c _ChargeService) SettleCharge(seq int64, uid string) error {
	var record *model.UserCharge
	has, err := global.DBConn.Where(builder.Eq{"seq": seq, "user_id": uid}).NoAutoCondition().Get(record)
	if err != nil {
		return nil
	}
	if !has {
		return exceptions.NewNotFoundError("未找到匹配指定条件的计费记录。")
	}
	tx := global.DBConn.NewSession()
	defer tx.Close()
	if err := tx.Begin(); err != nil {
		return err
	}
	currentTime := time.Now()
	_, err = tx.Table(new(model.UserCharge)).Where(builder.Eq{"seq": seq, "user_id": uid}).Cols("settled", "settled_at").Update(&model.UserCharge{Settled: true, SettledAt: &currentTime})
	if err != nil {
		tx.Rollback()
		return err
	}
	err = c.updateUserExpiration(tx, uid, record.ChargeTo)
	if err != nil {
		return err
	}
	err = tx.Commit()
	if err != nil {
		tx.Rollback()
		return err
	}
	return nil
}

func (c _ChargeService) RefundCharge(seq int64, uid string) error {
	tx := global.DBConn.NewSession()
	defer tx.Close()
	if err := tx.Begin(); err != nil {
		return err
	}
	currentTime := time.Now()
	rows, err := tx.Table(new(model.UserCharge)).Where(builder.Eq{"seq": seq, "user_id": uid}).Cols("refunded", "refunded_at").Update(&model.UserCharge{Refunded: true, RefundedAt: &currentTime})
	if err != nil {
		tx.Rollback()
		return err
	}
	if rows == 0 {
		tx.Rollback()
		return exceptions.NewNotFoundError("未找到匹配指定条件的计费记录。")
	}
	lastValidExpriation, err := repository.ChargeRepo.LastValidChargeTo(uid)
	if err != nil {
		tx.Rollback()
		return exceptions.NewNotFoundError("未找到最后合法的计费时间。")
	}
	err = c.updateUserExpiration(tx, uid, lastValidExpriation)
	if err != nil {
		return err
	}
	err = tx.Commit()
	if err != nil {
		tx.Rollback()
		return err
	}
	return nil
}

func (c _ChargeService) CancelCharge(seq int64, uid string) error {
	tx := global.DBConn.NewSession()
	defer tx.Close()
	if err := tx.Begin(); err != nil {
		return err
	}
	currentTime := time.Now()
	rows, err := tx.Table(new(model.UserCharge)).Where(builder.Eq{"seq": seq, "user_id": uid}).Cols("cancelled", "cancelled_at").Update(&model.UserCharge{Cancelled: true, CancelledAt: &currentTime})
	if err != nil {
		tx.Rollback()
		return err
	}
	if rows == 0 {
		tx.Rollback()
		return exceptions.NewNotFoundError("未找到匹配指定条件的计费记录。")
	}
	lastValidExpriation, err := repository.ChargeRepo.LastValidChargeTo(uid)
	if err != nil {
		tx.Rollback()
		return exceptions.NewNotFoundError("未找到最后合法的计费时间。")
	}
	err = c.updateUserExpiration(tx, uid, lastValidExpriation)
	if err != nil {
		return err
	}
	err = tx.Commit()
	if err != nil {
		tx.Rollback()
		return err
	}
	return nil
}

func (_ChargeService) updateUserExpiration(tx *xorm.Session, uid string, expiration time.Time) error {
	_, err := tx.ID(uid).Cols("service_expiration").Update(&model.UserDetail{ServiceExpiration: expiration})
	if err != nil {
		tx.Rollback()
	}
	return err
}