package channel

import (
	"fmt"
	"sync"

	pkgpay "lone-services/pkg/payment"
	"lone-services/pkg/payment/alipay"
	"lone-services/pkg/payment/bank"
	wxchannel "lone-services/pkg/payment/wechat"
	"lone-services/pkg/utils"
	"lone-services/services/payment/internal/config"
)

var (
	cacheMu sync.Mutex
	cache   = map[string]pkgpay.Channel{}
)

func Get(channelCode, clientCode string) (pkgpay.Channel, error) {
	if channelCode == utils.StringEmpty {
		return nil, pkgpay.ErrUnsupportedChannel
	}
	if clientCode == utils.StringEmpty {
		clientCode = pkgpay.ClientMiniProgram
	}

	cacheKey := channelCode + ":" + clientCode
	cacheMu.Lock()
	if ch, ok := cache[cacheKey]; ok {
		cacheMu.Unlock()
		return ch, nil
	}
	cacheMu.Unlock()

	ch, err := newChannel(channelCode, clientCode)
	if err != nil {
		return nil, err
	}

	cacheMu.Lock()
	cache[cacheKey] = ch
	cacheMu.Unlock()
	return ch, nil
}

func newChannel(channelCode, clientCode string) (pkgpay.Channel, error) {
	switch channelCode {
	case pkgpay.ChannelWechat:
		cfg, err := config.NewWechatPayConfig(clientCode)
		if err != nil {
			return nil, err
		}
		return wxchannel.NewChannel(cfg)
	case pkgpay.ChannelAlipay:
		return alipay.NewChannel(), nil
	case pkgpay.ChannelBank:
		return bank.NewChannel(), nil
	default:
		return nil, fmt.Errorf("%w: %s", pkgpay.ErrUnsupportedChannel, channelCode)
	}
}