package mdbc

import (
	"context"
	"gitter.top/common/goref"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo/options"
)

type deleteScope struct {
	scope  *scope
	mdbc   *mdbc
	ctx    context.Context
	opts   *options.DeleteOptions
	filter interface{}
	err    error
}

func (ds *deleteScope) SetContext(ctx context.Context) *deleteScope {
	ds.ctx = ctx
	return ds
}

func (ds *deleteScope) SetOptions(opts options.DeleteOptions) *deleteScope {
	ds.opts = &opts
	return ds
}

// SetID delete documents based on ID, has the highest priority.
func (ds *deleteScope) SetID(id ...any) *deleteScope {
	if len(id) == 0 {
		return ds
	}
	if len(id) == 1 {
		ds.filter = bson.M{
			"_id": id[0],
		}
	}
	if len(id) > 1 {
		ds.filter = bson.M{
			"_id": bson.M{"$in": id},
		}
	}
	return ds
}

// SetFilter delete documents based on filter condition, filter type only support map or struct
func (ds *deleteScope) SetFilter(filter interface{}) *deleteScope {
	if ds.filter != nil {
		return ds
	}

	if filter == nil {
		ds.filter = bson.M{}
		return ds
	}

	if goref.IsBaseStruct(filter) {
		ds.filter, ds.err = goref.StructToMap(filter, goref.WithOmitempty(true), goref.WithTag("bson"))
		return ds
	}

	if goref.IsBaseMap(filter) {
		ds.filter = filter
		return ds
	}

	return ds
}

func (ds *deleteScope) mergeOptins() {
	if ds.ctx == nil {
		ds.ctx = context.Background()
	}
	if ds.opts == nil {
		ds.opts = new(options.DeleteOptions)
	}
	if ds.filter == nil {
		ds.filter = bson.M{}
	}
}

func (ds *deleteScope) One() (int64, error) {
	ds.mergeOptins()
	if ds.err != nil {
		return 0, ds.err
	}
	result, err := ds.mdbc.database.Collection(ds.scope.tableName).DeleteOne(ds.ctx, ds.filter, ds.opts)
	if err != nil {
		return 0, err
	}
	return result.DeletedCount, nil
}

func (ds *deleteScope) Many() (int64, error) {
	ds.mergeOptins()
	if ds.err != nil {
		return 0, ds.err
	}
	result, err := ds.mdbc.database.Collection(ds.scope.tableName).DeleteMany(ds.ctx, ds.filter, ds.opts)
	if err != nil {
		return 0, err
	}
	return result.DeletedCount, nil
}