package mysql

import (
	"git.hexq.cn/tiglog/mydb"
	"git.hexq.cn/tiglog/mydb/internal/sqladapter"
	"git.hexq.cn/tiglog/mydb/internal/sqlbuilder"
)

type collectionAdapter struct {
}

func (*collectionAdapter) Insert(col sqladapter.Collection, item interface{}) (interface{}, error) {
	columnNames, columnValues, err := sqlbuilder.Map(item, nil)
	if err != nil {
		return nil, err
	}

	pKey, err := col.PrimaryKeys()
	if err != nil {
		return nil, err
	}

	q := col.SQL().InsertInto(col.Name()).
		Columns(columnNames...).
		Values(columnValues...)

	res, err := q.Exec()
	if err != nil {
		return nil, err
	}

	lastID, err := res.LastInsertId()
	if err == nil && len(pKey) <= 1 {
		return lastID, nil
	}

	keyMap := mydb.Cond{}
	for i := range columnNames {
		for j := 0; j < len(pKey); j++ {
			if pKey[j] == columnNames[i] {
				keyMap[pKey[j]] = columnValues[i]
			}
		}
	}

	// There was an auto column among primary keys, let's search for it.
	if lastID > 0 {
		for j := 0; j < len(pKey); j++ {
			if keyMap[pKey[j]] == nil {
				keyMap[pKey[j]] = lastID
			}
		}
	}

	return keyMap, nil
}