package db

import (
	"context"
	"fmt"
	"testing"

	"bj_power_mes/ent"
	"bj_power_mes/ent/workpiece"
)

func TestNewDBWithParams(t *testing.T) {
	client, _, err := NewDBWithParams("postgres", "postgres", "127.0.0.1", 5432, "bj_power_mes", false)
	if err != nil {
		t.Errorf("NewDBWithParams() error = %v", err)
		return
	}

	defer client.Close()
	ctx := context.Background()
	slot, err := nextEmptyTempSlot(ctx, client)
	if err != nil {
		t.Errorf("nextEmptyTempSlot() error = %v", err)
		return
	}
	t.Logf("nextEmptyTempSlot() = %v", slot)

}

// tempSlotCapacity 暂存台槽位总数。
const tempSlotCapacity = 8

// nextEmptyTempSlot 通过数据库查询已占用的 tempSlot，找第一个空位（1-8）。
func nextEmptyTempSlot(ctx context.Context, entClient *ent.Client) (int, error) {
	occupied, err := entClient.Workpiece.Query().
		Where(workpiece.TempSlotNotNil()).
		Select(workpiece.FieldTempSlot).
		All(ctx)
	if err != nil {
		return 0, fmt.Errorf("查询暂存台占用失败: %w", err)
	}

	used := make(map[int]struct{}, len(occupied))
	for _, wp := range occupied {
		used[wp.TempSlot] = struct{}{}
	}

	for i := 1; i <= tempSlotCapacity; i++ {
		if _, ok := used[i]; !ok {
			return i, nil
		}
	}
	return 0, fmt.Errorf("暂存台无空位")
}