package micro

import (
	"github.com/micro/go-micro/client"
	"github.com/micro/go-micro/metadata"

	"golang.org/x/net/context"
)

type clientWrapper struct {
	client.Client
	headers metadata.Metadata
}

func (c *clientWrapper) setHeaders(ctx context.Context) context.Context {
	md := make(metadata.Metadata)

	if mda, ok := metadata.FromContext(ctx); ok {
		// make copy of metadata
		for k, v := range mda {
			md[k] = v
		}
	}

	for k, v := range c.headers {
		if _, ok := md[k]; !ok {
			md[k] = v
		}
	}

	return metadata.NewContext(ctx, md)
}

func (c *clientWrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
	ctx = c.setHeaders(ctx)
	return c.Client.Call(ctx, req, rsp, opts...)
}

func (c *clientWrapper) Stream(ctx context.Context, req client.Request, opts ...client.CallOption) (client.Streamer, error) {
	ctx = c.setHeaders(ctx)
	return c.Client.Stream(ctx, req, opts...)
}

func (c *clientWrapper) Publish(ctx context.Context, p client.Publication, opts ...client.PublishOption) error {
	ctx = c.setHeaders(ctx)
	return c.Client.Publish(ctx, p, opts...)
}