package medias

import (
	"context"
	"database/sql"

	"backend/database/models/qvyun/public/model"
	"backend/database/models/qvyun/public/table"

	. "github.com/go-jet/jet/v2/postgres"
	"github.com/pkg/errors"
	"github.com/samber/lo"
	"github.com/sirupsen/logrus"
)

// @provider:except
type Service struct {
	db  *sql.DB
	log *logrus.Entry `inject:"false"`
}

func (svc *Service) Prepare() error {
	svc.log = logrus.WithField("module", "medias.service")
	return nil
}

// GetByID
func (svc *Service) GetByID(ctx context.Context, id, userId int64) (*ListItem, error) {
	log := svc.log.WithField("method", "GetByID")

	tbl := table.Medias
	stmt := tbl.SELECT(tbl.AllColumns).WHERE(tbl.ID.EQ(Int(id)))
	log.Debug(stmt.Sql())

	var media ListItem
	if err := stmt.QueryContext(ctx, svc.db, &media); err != nil {
		return nil, errors.Wrap(err, "query media by id")
	}

	tblResource := table.MediaResources
	stmtResource := tblResource.
		SELECT(
			tblResource.MediaID,
			tblResource.Type,
			tblResource.Size,
		).
		WHERE(tblResource.MediaID.EQ(Int(id)))
	log.Debug(stmtResource.DebugSql())

	var resources []model.MediaResources
	if err := stmt.QueryContext(ctx, svc.db, &resources); err != nil {
		return nil, errors.Wrap(err, "query media resources")
	}

	if len(resources) == 0 {
		return &media, nil
	}

	media.MediaResources = resources

	var err error
	media.Bought, err = svc.HasUserBought(ctx, media.TenantID, userId, media.ID)
	if err != nil {
		return nil, errors.Wrap(err, "check user bought")
	}

	return &media, nil
}

// Decorate List Resources
func (svc *Service) DecorateListResources(ctx context.Context, tenantId, userId int64, items []ListItem) ([]ListItem, error) {
	log := svc.log.WithField("method", "DecorateListResources")

	mediaIDs := make([]int64, len(items))
	for i, item := range items {
		mediaIDs[i] = item.ID
	}

	tbl := table.MediaResources
	stmt := tbl.
		SELECT(
			tbl.MediaID,
			tbl.Type,
			tbl.Size,
		).
		WHERE(tbl.MediaID.IN(lo.Map(mediaIDs, func(item int64, _ int) Expression {
			return Int(item)
		})...))
	log.Debug(stmt.DebugSql())

	var resources []model.MediaResources
	if err := stmt.QueryContext(ctx, svc.db, &resources); err != nil {
		return nil, errors.Wrap(err, "query media resources")
	}

	if len(resources) == 0 {
		return nil, nil
	}

	// group resources by media id
	resourcesMap := make(map[int64][]model.MediaResources)
	for _, resource := range resources {
		if _, ok := resourcesMap[resource.MediaID]; !ok {
			resourcesMap[resource.MediaID] = make([]model.MediaResources, 0)
		}
		resourcesMap[resource.MediaID] = append(resourcesMap[resource.MediaID], resource)
	}

	//  set resources to items
	for i, item := range items {
		if resources, ok := resourcesMap[item.ID]; ok {
			items[i].MediaResources = resources
		}
	}

	return items, nil
}

// List
func (svc *Service) List(ctx context.Context, tenantId, userId int64, filter *ListFilter) ([]ListItem, error) {
	log := svc.log.WithField("method", "List")

	boughtIDs, err := svc.GetUserBoughtMedias(ctx, tenantId, userId)
	if err != nil {
		return nil, errors.Wrap(err, "get user bought medias")
	}

	tbl := table.Medias
	stmt := tbl.
		SELECT(tbl.AllColumns).
		WHERE(tbl.TenantID.EQ(Int(tenantId))).
		ORDER_BY(tbl.ID.DESC())

	if filter.Title != nil && *filter.Title != "" {
		stmt = stmt.WHERE(tbl.Title.LIKE(String("%" + *filter.Title + "%")))
	}

	if filter.Bought != nil && *filter.Bought {
		if len(boughtIDs) > 0 {
			stmt = stmt.
				WHERE(tbl.ID.IN(lo.Map(boughtIDs, func(item int64, _ int) Expression {
					return Int(item)
				})...))
		}
	} else {
		stmt = stmt.WHERE(tbl.Publish.EQ(Bool(true)))
	}

	if filter.OffsetID > 0 {
		if filter.Action == 0 {
			stmt = stmt.WHERE(tbl.ID.GT(Int(filter.OffsetID)))
		}

		if filter.Action == 1 {
			stmt = stmt.WHERE(tbl.ID.LT(Int(filter.OffsetID)))
			stmt = stmt.LIMIT(10)
		}
	} else {
		stmt = stmt.LIMIT(10)
	}
	log.Debug(stmt.DebugSql())

	var dest []ListItem
	if err := stmt.QueryContext(ctx, svc.db, &dest); err != nil {
		return nil, errors.Wrap(err, "query medias")
	}

	items := lo.Map(dest, func(item ListItem, _ int) ListItem {
		if lo.Contains(boughtIDs, item.ID) {
			item.Bought = true
		}
		return item
	})

	return items, nil
}

// GetUserBoughtMedias
func (svc *Service) GetUserBoughtMedias(ctx context.Context, tenant int64, userID int64) ([]int64, error) {
	log := svc.log.WithField("method", "GetUserBoughtMedias")

	tbl := table.UserMedias
	stmt := tbl.
		SELECT(tbl.MediaID).
		WHERE(
			tbl.TenantID.EQ(Int(tenant)).AND(
				tbl.UserID.EQ(Int(userID)),
			),
		)
	log.Debug(stmt.Sql())

	var mediaIDs []int64
	if err := stmt.QueryContext(ctx, svc.db, &mediaIDs); err != nil {
		return nil, errors.Wrap(err, "query user bought medias")
	}

	return mediaIDs, nil
}

// HasUserBought
func (svc *Service) HasUserBought(ctx context.Context, tenantId, userId, mediaId int64) (bool, error) {
	log := svc.log.WithField("method", "HasUserBought")

	tbl := table.UserMedias
	stmt := tbl.
		SELECT(tbl.MediaID).
		WHERE(
			tbl.TenantID.EQ(Int(tenantId)).AND(
				tbl.UserID.EQ(Int(userId)).AND(
					tbl.MediaID.EQ(Int(mediaId)),
				),
			),
		)
	log.Debug(stmt.DebugSql())

	var mediaID int64
	if err := stmt.QueryContext(ctx, svc.db, &mediaID); err != nil {
		return false, errors.Wrap(err, "query user bought media")
	}

	return mediaID > 0, nil
}