package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"

	"github.com/DATA-DOG/godog"
	"github.com/DATA-DOG/godog/gherkin"
)

type apiFeature struct {
	resp *httptest.ResponseRecorder
}

func (a *apiFeature) resetResponse(interface{}) {
	a.resp = httptest.NewRecorder()
}

func (a *apiFeature) iSendrequestTo(method, endpoint string) (err error) {
	req, err := http.NewRequest(method, endpoint, nil)
	if err != nil {
		return
	}

	// handle panic
	defer func() {
		switch t := recover().(type) {
		case string:
			err = fmt.Errorf(t)
		case error:
			err = t
		}
	}()

	switch endpoint {
	case "/version":
		getVersion(a.resp, req)
	default:
		err = fmt.Errorf("unknown endpoint: %s", endpoint)
	}
	return
}

func (a *apiFeature) theResponseCodeShouldBe(code int) error {
	if code != a.resp.Code {
		return fmt.Errorf("expected response code to be: %d, but actual is: %d", code, a.resp.Code)
	}
	return nil
}

func (a *apiFeature) theResponseShouldMatchJSON(body *gherkin.DocString) (err error) {
	var expected, actual []byte
	var exp, act interface{}

	// re-encode expected response
	if err = json.Unmarshal([]byte(body.Content), &exp); err != nil {
		return
	}
	if expected, err = json.MarshalIndent(exp, "", "  "); err != nil {
		return
	}

	// re-encode actual response too
	if err = json.Unmarshal(a.resp.Body.Bytes(), &act); err != nil {
		return
	}
	if actual, err = json.MarshalIndent(act, "", "  "); err != nil {
		return
	}

	// the matching may be adapted per different requirements.
	if len(actual) != len(expected) {
		return fmt.Errorf(
			"expected json length: %d does not match actual: %d:\n%s",
			len(expected),
			len(actual),
			string(actual),
		)
	}

	for i, b := range actual {
		if b != expected[i] {
			return fmt.Errorf(
				"expected JSON does not match actual, showing up to last matched character:\n%s",
				string(actual[:i+1]),
			)
		}
	}
	return
}

func FeatureContext(s *godog.Suite) {
	api := &apiFeature{}

	s.BeforeScenario(api.resetResponse)

	s.Step(`^I send "(GET|POST|PUT|DELETE)" request to "([^"]*)"$`, api.iSendrequestTo)
	s.Step(`^the response code should be (\d+)$`, api.theResponseCodeShouldBe)
	s.Step(`^the response should match json:$`, api.theResponseShouldMatchJSON)
}