orm/repository.go

package orm

import (
	"fmt"
	"reflect"
	"strings"

	"git.giaever.org/bnb.hosting/orm/conn"
	"github.com/huandu/go-sqlbuilder"
	"github.com/jmoiron/sqlx"
)

type repository struct {
	dbc map[string]MappableInterface
}

var r *repository = nil

func Repository() *repository {
	if r == nil {
		r = &repository{
			make(map[string]MappableInterface),
		}
	}
	return r
}

func (r *repository) FetchFirst(db *conn.DB, i MappableInterface) (MappableInterface, error) {
	res, err := r.Fetch(db, i, 1)

	if len(res) == 1 {
		return res[0], err
	}

	return nil, err
}

func (r *repository) Fetch(db *conn.DB, i MappableInterface, offlim ...int) ([]MappableInterface, error) {
	tbl := ctx.getTbl(i)
	b := getSelectBuilder(tbl)._select(tbl)._where(tbl, i)

	if len(offlim) == 1 {
		b.Limit(offlim[0])
	} else if len(offlim) > 1 {
		b.Limit(offlim[1])
		b.Offset(offlim[0])
	}

	return r.query(db, tbl, b)
}

func (r *repository) FetchRelated(i MappableInterface, n string) (interface{}, error) {
	tbl := ctx.getTbl(i)

	for rtype, rels := range tbl.getRelations() {
		for _, rel := range rels {
			if rel.f.getFieldName() == n {
				switch rtype {
				case hasMany, belongsTo:
					b := getSelectBuilder(tbl)
					b._select(rel.table)
					b._join(tbl, rel)
					b._wherePrimaryOrElse(tbl, i)

					switch rel.f.MakeType().Kind() {
					case reflect.Map, reflect.Slice:
						// No limit?
					default:
						b.Limit(1)
					}

					res, err := r.query(i.GetDB(), rel.table, b)

					if err != nil {
						return nil, err
					}

					return r.mapScanResultToInterface(i, tbl, rel, res), nil

				case hasOne:
					b := getSelectBuilder(tbl)
					b._select(rel.table)
					b._join(tbl, rel, sqlbuilder.RightJoin)
					b._wherePrimaryOrElse(tbl, i)
					b.Limit(1)

					res, err := r.query(i.GetDB(), rel.table, b)

					if err != nil || len(res) == 0 {
						return nil, err
					}

					return res[0], nil
				}
			}
		}
	}

	return nil, nil
}

func (r *repository) mapScanResultToInterface(i MappableInterface, tbl *table, rel relation, res []MappableInterface) interface{} {
	m := rel.f.Make()

	switch m.Kind() {
	case reflect.Map:
		for midx, rel := range res {
			if val, err := tbl.CallMethod(i, "GetId"); err != nil {
				switch val[0].(type) {
				case int, uint, int8, uint8, int16, uint16, int32, uint32, int64, uint64:
					m.SetMapIndex(reflect.ValueOf(val[0].(uint64)), reflect.ValueOf(rel))
				}
			} else {
				m.SetMapIndex(reflect.ValueOf(uint64(midx)), reflect.ValueOf(rel))
			}
		}
	case reflect.Slice:
		for _, rel := range res {
			m = reflect.Append(m, reflect.ValueOf(rel))
		}
	default:
		if len(res) != 0 {
			m.Set(reflect.ValueOf(res[0]))
		}
	}

	return m.Interface()
}

func (r *repository) mapScan(i MappableInterface, rows *sqlx.Rows, tbl *table) (MappableInterface, error) {
	res := make(map[string]interface{})

	if err := rows.MapScan(res); err != nil {
		fmt.Println("Error:", err)
		return nil, err
	}

	for n, s := range res {
		if fn := tbl.hasColumn(n).getFieldName(); len(fn) != 0 {
			if _, err := tbl.CallMethod(i, "Set"+strings.Title(fn), s); err != nil {
				fmt.Println("ERROR", err)
				//return nil, err
			}
		} else {
			fmt.Println("MISSING FIELD NAME")
		}
	}

	if col := tbl.getPrimaryKey(); col != nil {
		if v, err := tbl.CallMethod(i, "Get"+strings.Title(col.getFieldName())); err == nil {
			idx := fmt.Sprintf("%s_%#v", tbl.getStructName(), v[0])
			if ni, ok := r.dbc[idx]; ok {
				return ni, nil
			} else {
				r.dbc[idx] = i
			}
		}
	}

	return i, nil
}

func (r *repository) query(db *conn.DB, tbl *table, sql sqlbuilder.Builder) ([]MappableInterface, error) {
	var ret []MappableInterface

	q, args := sql.Build()
	rows, err := db.Queryx(q, args...)

	for err != nil {
		return nil, err
	}

	//defer rows.Close()
	for rows.Next() {
		i, err := r.mapScan(tbl.Make(), rows, tbl)

		if err == nil {
			i.SetDB(db)
			ret = append(ret, i)
		} else {
			fmt.Println(err)
			return nil, err
		}
	}

	return ret, nil
}