package apm

import (
	"context"
	"errors"
	"github.com/SkyAPM/go2sky"
	"github.com/SkyAPM/go2sky/propagation"
	"github.com/gin-gonic/gin"
	"net/http"
)

func (client *Client) initHttp(config HttpConfig) {
	if config.extractor == nil {
		client.httpExtractor = HttpExtractor
	} else {
		client.httpExtractor = config.extractor
	}
	if config.injector == nil {
		client.httpInjector = HttpInjector
	} else {
		client.httpInjector = config.injector
	}
}

func (client *Client) InjectHttpMiddleware(engine *gin.Engine) {
	if engine == nil {
		panic(errors.New("engine can not be empty"))
	}

	if client.isEnable() {
		engine.Use(HttpTraceMiddleware(engine, client.tracer))
	}
}

func (client *Client) CreateHttpExitSpan(ctx context.Context, req *http.Request, host, path string) go2sky.Span {
	span := client.CreateExitSpan(ctx, path, host, client.httpInjector(req))
	span.Tag(go2sky.TagHTTPMethod, req.Method)
	span.Tag(go2sky.TagURL, host+path)
	return span
}

func (client *Client) CreateHttpExitSpanWithInjector(ctx context.Context, method, host, path string,
	injector propagation.Injector) go2sky.Span {
	span := client.CreateExitSpan(ctx, path, host, injector)
	span.Tag(go2sky.TagHTTPMethod, method)
	span.Tag(go2sky.TagURL, host+path)
	return span
}

func (client *Client) CreateHttpExitSpanWithUrl(ctx context.Context, req *http.Request, url string) go2sky.Span {
	if !client.isEnable() || client.isNoTraceContext(ctx) {
		return nSpan
	}
	_, host, path := ParseURL(url)
	span := client.CreateExitSpan(ctx, path, host, client.httpInjector(req))
	span.Tag(go2sky.TagHTTPMethod, req.Method)
	span.Tag(go2sky.TagURL, host+path)
	return span
}

func (client *Client) CreateHttpExitSpanWithUrlAndInjector(ctx context.Context, method string, url string,
	injector propagation.Injector) go2sky.Span {
	if !client.isEnable() || client.isNoTraceContext(ctx) {
		return nSpan
	}
	_, host, path := ParseURL(url)
	span := client.CreateExitSpan(ctx, path, host, injector)
	span.Tag(go2sky.TagHTTPMethod, method)
	span.Tag(go2sky.TagURL, host+path)
	return span
}

func (client *Client) TraceContextFromGin(c *gin.Context) context.Context {
	if !client.isEnable() || c == nil || c.Request.Context() == nil {
		return context.Background()
	}

	res := c.Request.Context().Value(ctxKeyInstance)
	if res == nil {
		return context.Background()
	}

	resCtx, ok := res.(context.Context)
	if !ok {
		return context.Background()
	}
	return resCtx
}