package handlers

import (
	"errors"
	"platform/pkg/u"
	"platform/web/auth"
	"platform/web/core"
	g "platform/web/globals"
	m "platform/web/models"
	q "platform/web/queries"
	s "platform/web/services"
	"time"

	"github.com/gofiber/fiber/v2"
	"gorm.io/gen"
	"gorm.io/gen/field"
	"gorm.io/gorm"
)

// PageCouponUser 分页查询当前用户已发放优惠券
func PageCouponUser(c *fiber.Ctx) error {
	authCtx, err := auth.GetAuthCtx(c).PermitUser()
	if err != nil {
		return err
	}

	var req PageCouponUserReq
	if err := g.Validator.ParseBody(c, &req); err != nil {
		return err
	}

	conds := couponUserPageConditions(req.CouponUserPageFilter)
	conds = append(conds, q.CouponUser.UserID.Eq(authCtx.User.ID))

	list, total, err := q.CouponUser.
		Joins(q.CouponUser.Coupon).
		Select(couponUserSelect(false)...).
		Where(conds...).
		Order(q.CouponUser.CreatedAt.Desc()).
		FindByPage(req.GetOffset(), req.GetLimit())
	if err != nil {
		return core.NewBizErr("获取数据失败", err)
	}

	return c.JSON(core.PageResp{
		List:  list,
		Total: int(total),
		Page:  req.GetPage(),
		Size:  req.GetSize(),
	})
}

type PageCouponUserReq struct {
	core.PageReq
	CouponUserPageFilter
}

// GetCouponUser 获取当前用户已发放优惠券详情
func GetCouponUser(c *fiber.Ctx) error {
	authCtx, err := auth.GetAuthCtx(c).PermitUser()
	if err != nil {
		return err
	}

	var req core.IdReq
	if err := g.Validator.ParseBody(c, &req); err != nil {
		return err
	}

	item, err := q.CouponUser.
		Joins(q.CouponUser.Coupon).
		Select(couponUserSelect(false)...).
		Where(
			q.CouponUser.ID.Eq(req.Id),
			q.CouponUser.UserID.Eq(authCtx.User.ID),
		).
		Take()
	if errors.Is(err, gorm.ErrRecordNotFound) {
		return core.NewBizErr("已发放优惠券不存在")
	}
	if err != nil {
		return core.NewBizErr("获取数据失败", err)
	}

	return c.JSON(item)
}

// PageCouponUserByAdmin 分页查询全部已发放优惠券
func PageCouponUserByAdmin(c *fiber.Ctx) error {
	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserRead)
	if err != nil {
		return err
	}

	var req PageCouponUserByAdminReq
	if err := g.Validator.ParseBody(c, &req); err != nil {
		return err
	}

	conds := couponUserPageConditions(req.CouponUserPageFilter)
	if req.UserID != nil {
		conds = append(conds, q.CouponUser.UserID.Eq(*req.UserID))
	}
	if req.UserPhone != nil {
		conds = append(conds, q.User.As("User").Phone.Eq(*req.UserPhone))
	}

	list, total, err := q.CouponUser.
		Joins(q.CouponUser.Coupon, q.CouponUser.User).
		Select(couponUserSelect(true)...).
		Where(conds...).
		Order(q.CouponUser.CreatedAt.Desc()).
		FindByPage(req.GetOffset(), req.GetLimit())
	if err != nil {
		return core.NewBizErr("获取数据失败", err)
	}

	return c.JSON(core.PageResp{
		List:  list,
		Total: int(total),
		Page:  req.GetPage(),
		Size:  req.GetSize(),
	})
}

type PageCouponUserByAdminReq struct {
	core.PageReq
	CouponUserPageFilter
	UserID    *int32  `json:"user_id,omitempty"`
	UserPhone *string `json:"user_phone,omitempty"`
}

// PageCouponUserOfUserByAdmin 分页查询指定用户已发放优惠券
func PageCouponUserOfUserByAdmin(c *fiber.Ctx) error {
	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserReadOfUser)
	if err != nil {
		return err
	}

	var req PageCouponUserOfUserByAdminReq
	if err := g.Validator.ParseBody(c, &req); err != nil {
		return err
	}

	conds := couponUserPageConditions(req.CouponUserPageFilter)
	conds = append(conds, q.CouponUser.UserID.Eq(req.UserID))

	list, total, err := q.CouponUser.
		Joins(q.CouponUser.Coupon, q.CouponUser.User).
		Select(couponUserSelect(true)...).
		Where(conds...).
		Order(q.CouponUser.CreatedAt.Desc()).
		FindByPage(req.GetOffset(), req.GetLimit())
	if err != nil {
		return core.NewBizErr("获取数据失败", err)
	}

	return c.JSON(core.PageResp{
		List:  list,
		Total: int(total),
		Page:  req.GetPage(),
		Size:  req.GetSize(),
	})
}

type PageCouponUserOfUserByAdminReq struct {
	core.PageReq
	CouponUserPageFilter
	UserID int32 `json:"user_id" validate:"required"`
}

// GetCouponUserByAdmin 获取已发放优惠券详情
func GetCouponUserByAdmin(c *fiber.Ctx) error {
	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserRead)
	if err != nil {
		return err
	}

	var req core.IdReq
	if err := g.Validator.ParseBody(c, &req); err != nil {
		return err
	}

	item, err := q.CouponUser.
		Joins(q.CouponUser.Coupon, q.CouponUser.User).
		Select(couponUserSelect(true)...).
		Where(q.CouponUser.ID.Eq(req.Id)).
		Take()
	if errors.Is(err, gorm.ErrRecordNotFound) {
		return core.NewBizErr("已发放优惠券不存在")
	}
	if err != nil {
		return core.NewBizErr("获取数据失败", err)
	}

	return c.JSON(item)
}

func CreateCouponUserByAdmin(c *fiber.Ctx) error {
	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserWrite)
	if err != nil {
		return err
	}

	var req s.CreateCouponUserData
	if err := g.Validator.ParseBody(c, &req); err != nil {
		return err
	}

	if err := s.CouponUser.Create(req); err != nil {
		return err
	}

	return nil
}

func UpdateCouponUserByAdmin(c *fiber.Ctx) error {
	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserWrite)
	if err != nil {
		return err
	}

	var req s.UpdateCouponUserData
	if err := g.Validator.ParseBody(c, &req); err != nil {
		return err
	}

	if err := s.CouponUser.Update(req); err != nil {
		return err
	}

	return nil
}

func DeleteCouponUserByAdmin(c *fiber.Ctx) error {
	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserWrite)
	if err != nil {
		return err
	}

	var req core.IdReq
	if err := g.Validator.ParseBody(c, &req); err != nil {
		return err
	}

	if err := s.CouponUser.Delete(req.Id); err != nil {
		return err
	}

	return nil
}

type CouponUserPageFilter struct {
	CouponID       *int32              `json:"coupon_id,omitempty"`
	CouponName     *string             `json:"coupon_name,omitempty"`
	Status         *m.CouponUserStatus `json:"status,omitempty"`
	Expired        *bool               `json:"expired,omitempty"`
	CreatedAtStart *time.Time          `json:"created_at_start,omitempty"`
	CreatedAtEnd   *time.Time          `json:"created_at_end,omitempty"`
	ExpireAtStart  *time.Time          `json:"expire_at_start,omitempty"`
	ExpireAtEnd    *time.Time          `json:"expire_at_end,omitempty"`
	UsedAtStart    *time.Time          `json:"used_at_start,omitempty"`
	UsedAtEnd      *time.Time          `json:"used_at_end,omitempty"`
}

func couponUserPageConditions(req CouponUserPageFilter) []gen.Condition {
	conds := make([]gen.Condition, 0)
	if req.CouponID != nil {
		conds = append(conds, q.CouponUser.CouponID.Eq(*req.CouponID))
	}
	if req.CouponName != nil {
		conds = append(conds, q.Coupon.As("Coupon").Name.Like("%"+*req.CouponName+"%"))
	}
	if req.Status != nil {
		conds = append(conds, q.CouponUser.Status.Eq(int(*req.Status)))
	}
	if req.Expired != nil {
		if *req.Expired {
			conds = append(conds, q.CouponUser.ExpireAt.IsNotNull(), q.CouponUser.ExpireAt.Lte(time.Now()))
		} else {
			conds = append(conds, q.CouponUser.Where(q.CouponUser.ExpireAt.IsNull()).Or(q.CouponUser.ExpireAt.Gt(time.Now())))
		}
	}
	if req.CreatedAtStart != nil {
		conds = append(conds, q.CouponUser.CreatedAt.Gte(u.DateHead(*req.CreatedAtStart)))
	}
	if req.CreatedAtEnd != nil {
		conds = append(conds, q.CouponUser.CreatedAt.Lte(u.DateTail(*req.CreatedAtEnd)))
	}
	if req.ExpireAtStart != nil {
		conds = append(conds, q.CouponUser.ExpireAt.Gte(u.DateHead(*req.ExpireAtStart)))
	}
	if req.ExpireAtEnd != nil {
		conds = append(conds, q.CouponUser.ExpireAt.Lte(u.DateTail(*req.ExpireAtEnd)))
	}
	if req.UsedAtStart != nil {
		conds = append(conds, q.CouponUser.UsedAt.Gte(u.DateHead(*req.UsedAtStart)))
	}
	if req.UsedAtEnd != nil {
		conds = append(conds, q.CouponUser.UsedAt.Lte(u.DateTail(*req.UsedAtEnd)))
	}
	return conds
}

func couponUserSelect(includeUser bool) []field.Expr {
	cols := []field.Expr{
		q.CouponUser.ALL,
		q.Coupon.As("Coupon").ID.As("Coupon__id"),
		q.Coupon.As("Coupon").Name.As("Coupon__name"),
		q.Coupon.As("Coupon").Amount.As("Coupon__amount"),
		q.Coupon.As("Coupon").MinAmount.As("Coupon__min_amount"),
		q.Coupon.As("Coupon").Count_.As("Coupon__count"),
		q.Coupon.As("Coupon").Status.As("Coupon__status"),
		q.Coupon.As("Coupon").ExpireType.As("Coupon__expire_type"),
		q.Coupon.As("Coupon").ExpireAt.As("Coupon__expire_at"),
		q.Coupon.As("Coupon").ExpireIn.As("Coupon__expire_in"),
		q.Coupon.As("Coupon").CreatedAt.As("Coupon__created_at"),
		q.Coupon.As("Coupon").UpdatedAt.As("Coupon__updated_at"),
	}

	if includeUser {
		cols = append(cols,
			q.User.As("User").ID.As("User__id"),
			q.User.As("User").Phone.As("User__phone"),
			q.User.As("User").Name.As("User__name"),
		)
	}

	return cols
}