85 lines
2.8 KiB
Go
85 lines
2.8 KiB
Go
package wmo
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import (
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"context"
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"go.mongodb.org/mongo-driver/bson"
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"go.mongodb.org/mongo-driver/mongo"
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ct "gogs.mikescher.com/BlackForestBytes/goext/cursortoken"
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"gogs.mikescher.com/BlackForestBytes/goext/exerr"
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"gogs.mikescher.com/BlackForestBytes/goext/langext"
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pag "gogs.mikescher.com/BlackForestBytes/goext/pagination"
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)
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func (c *Coll[TData]) Paginate(ctx context.Context, filter pag.Filter, page int, limit *int) ([]TData, pag.Pagination, error) {
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type totalCountResult struct {
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Count int `bson:"count"`
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}
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if page < 0 {
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page = 1
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}
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pipelineSort := mongo.Pipeline{}
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pipelineFilter := mongo.Pipeline{}
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pf1 := "_id"
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pd1 := ct.SortASC
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if filter != nil {
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pipelineFilter = filter.FilterQuery()
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pf1, pd1 = filter.Pagination()
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}
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if pd1 == ct.SortASC {
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pipelineSort = append(pipelineSort, bson.D{{Key: "$sort", Value: bson.D{{Key: pf1, Value: +1}}}})
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} else if pd1 == ct.SortDESC {
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pipelineSort = append(pipelineSort, bson.D{{Key: "$sort", Value: bson.D{{Key: pf1, Value: -1}}}})
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}
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pipelinePaginate := mongo.Pipeline{}
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pipelinePaginate = append(pipelinePaginate, bson.D{{Key: "$skip", Value: page - 1}})
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if limit != nil {
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pipelinePaginate = append(pipelinePaginate, bson.D{{Key: "$limit", Value: *limit}})
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}
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pipelineCount := mongo.Pipeline{}
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pipelinePaginate = append(pipelinePaginate, bson.D{{Key: "$count", Value: "count"}})
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pipelineList := langext.ArrConcat(mongo.Pipeline{}, pipelineFilter, pipelinePaginate)
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pipelineTotalCount := langext.ArrConcat(mongo.Pipeline{}, pipelineFilter, pipelineCount)
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cursorList, err := c.coll.Aggregate(ctx, pipelineList)
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if err != nil {
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return nil, pag.Pagination{}, exerr.Wrap(err, "mongo-aggregation failed").Any("pipeline", pipelineList).Str("collection", c.Name()).Build()
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}
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entities, err := c.decodeAll(ctx, cursorList)
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if err != nil {
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return nil, pag.Pagination{}, exerr.Wrap(err, "failed to all-decode entities").Build()
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}
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cursorTotalCount, err := c.coll.Aggregate(ctx, pipelineTotalCount)
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if err != nil {
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return nil, pag.Pagination{}, exerr.Wrap(err, "mongo-aggregation failed").Any("pipeline", pipelineTotalCount).Str("collection", c.Name()).Build()
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}
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var tcRes totalCountResult
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if cursorTotalCount.Next(ctx) {
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err = cursorTotalCount.Decode(&tcRes)
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if err != nil {
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return nil, pag.Pagination{}, exerr.Wrap(err, "failed to decode mongo-aggregation $count result").Any("pipeline", pipelineTotalCount).Str("collection", c.Name()).Build()
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}
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} else {
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tcRes.Count = 0 // no entries in DB
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}
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paginationObj := pag.Pagination{
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Page: page,
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Limit: langext.Coalesce(limit, tcRes.Count),
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TotalPages: pag.CalcPaginationTotalPages(tcRes.Count, langext.Coalesce(limit, tcRes.Count)),
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TotalItems: tcRes.Count,
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CurrentPageCount: len(entities),
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}
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return entities, paginationObj, nil
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}
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