package jira

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/http/httptest"
	"net/url"
	"reflect"
	"testing"
	"time"
)

const (
	testJIRAInstanceURL = "https://issues.apache.org/jira/"
)

var (
	// testMux is the HTTP request multiplexer used with the test server.
	testMux *http.ServeMux

	// testClient is the JIRA client being tested.
	testClient *Client

	// testServer is a test HTTP server used to provide mock API responses.
	testServer *httptest.Server
)

type testValues map[string]string

// setup sets up a test HTTP server along with a jira.Client that is configured to talk to that test server.
// Tests should register handlers on mux which provide mock responses for the API method being tested.
func setup() {
	// Test server
	testMux = http.NewServeMux()
	testServer = httptest.NewServer(testMux)

	// jira client configured to use test server
	testClient, _ = NewClient(nil, testServer.URL)
}

// teardown closes the test HTTP server.
func teardown() {
	testServer.Close()
}

func TestNewClient_WrongUrl(t *testing.T) {
	c, err := NewClient(nil, "://issues.apache.org/jira/")

	if err == nil {
		t.Error("Expected an error. Got none")
	}
	if c != nil {
		t.Errorf("Expected no client. Got %+v", c)
	}
}

func TestNewClient_WithHttpClient(t *testing.T) {
	httpClient := http.DefaultClient
	httpClient.Timeout = 10 * time.Minute
	c, err := NewClient(httpClient, testJIRAInstanceURL)

	if err != nil {
		t.Errorf("Got an error: %s", err)
	}
	if c == nil {
		t.Error("Expected a client. Got none")
	}
	if !reflect.DeepEqual(c.client, httpClient) {
		t.Errorf("HTTP clients are not equal. Injected %+v, got %+v", httpClient, c.client)
	}
}

func TestNewClient_WithServices(t *testing.T) {
	c, err := NewClient(nil, testJIRAInstanceURL)

	if err != nil {
		t.Errorf("Got an error: %s", err)
	}
	if c.Authentication == nil {
		t.Error("No AuthenticationService provided")
	}
	if c.Issue == nil {
		t.Error("No IssueService provided")
	}
}

func TestCheckResponse_GoodResults(t *testing.T) {
	codes := []int{
		http.StatusOK, http.StatusPartialContent, 299,
	}

	for _, c := range codes {
		r := &http.Response{
			StatusCode: c,
		}
		if err := CheckResponse(r); err != nil {
			t.Errorf("CheckResponse throws an error: %s", err)
		}
	}
}

func TestNewRequest(t *testing.T) {
	c, err := NewClient(nil, testJIRAInstanceURL)
	if err != nil {
		t.Errorf("An error occured. Expected nil. Got %+v.", err)
	}

	inURL, outURL := "rest/api/2/issue/", testJIRAInstanceURL+"rest/api/2/issue/"
	inBody, outBody := &Issue{Key: "MESOS"}, `{"key":"MESOS"}`+"\n"
	req, _ := c.NewRequest("GET", inURL, inBody)

	// Test that relative URL was expanded
	if got, want := req.URL.String(), outURL; got != want {
		t.Errorf("NewRequest(%q) URL is %v, want %v", inURL, got, want)
	}

	// Test that body was JSON encoded
	body, _ := ioutil.ReadAll(req.Body)
	if got, want := string(body), outBody; got != want {
		t.Errorf("NewRequest(%q) Body is %v, want %v", inBody, got, want)
	}
}

func TestNewRequest_InvalidJSON(t *testing.T) {
	c, err := NewClient(nil, testJIRAInstanceURL)
	if err != nil {
		t.Errorf("An error occured. Expected nil. Got %+v.", err)
	}

	type T struct {
		A map[int]interface{}
	}
	_, err = c.NewRequest("GET", "/", &T{})

	if err == nil {
		t.Error("Expected error to be returned.")
	}
	if err, ok := err.(*json.UnsupportedTypeError); !ok {
		t.Errorf("Expected a JSON error; got %+v.", err)
	}
}

func testURLParseError(t *testing.T, err error) {
	if err == nil {
		t.Errorf("Expected error to be returned")
	}
	if err, ok := err.(*url.Error); !ok || err.Op != "parse" {
		t.Errorf("Expected URL parse error, got %+v", err)
	}
}

func TestNewRequest_BadURL(t *testing.T) {
	c, err := NewClient(nil, testJIRAInstanceURL)
	if err != nil {
		t.Errorf("An error occured. Expected nil. Got %+v.", err)
	}
	_, err = c.NewRequest("GET", ":", nil)
	testURLParseError(t, err)
}

// If a nil body is passed to gerrit.NewRequest, make sure that nil is also passed to http.NewRequest.
// In most cases, passing an io.Reader that returns no content is fine,
// since there is no difference between an HTTP request body that is an empty string versus one that is not set at all.
// However in certain cases, intermediate systems may treat these differently resulting in subtle errors.
func TestNewRequest_EmptyBody(t *testing.T) {
	c, err := NewClient(nil, testJIRAInstanceURL)
	if err != nil {
		t.Errorf("An error occured. Expected nil. Got %+v.", err)
	}
	req, err := c.NewRequest("GET", "/", nil)
	if err != nil {
		t.Fatalf("NewRequest returned unexpected error: %v", err)
	}
	if req.Body != nil {
		t.Fatalf("constructed request contains a non-nil Body")
	}
}

func TestDo(t *testing.T) {
	setup()
	defer teardown()

	type foo struct {
		A string
	}

	testMux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		if m := "GET"; m != r.Method {
			t.Errorf("Request method = %v, want %v", r.Method, m)
		}
		fmt.Fprint(w, `{"A":"a"}`)
	})

	req, _ := testClient.NewRequest("GET", "/", nil)
	body := new(foo)
	testClient.Do(req, body)

	want := &foo{"a"}
	if !reflect.DeepEqual(body, want) {
		t.Errorf("Response body = %v, want %v", body, want)
	}
}

func TestDo_HTTPError(t *testing.T) {
	setup()
	defer teardown()

	testMux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, "Bad Request", 400)
	})

	req, _ := testClient.NewRequest("GET", "/", nil)
	_, err := testClient.Do(req, nil)

	if err == nil {
		t.Error("Expected HTTP 400 error.")
	}
}

// Test handling of an error caused by the internal http client's Do() function.
// A redirect loop is pretty unlikely to occur within the Gerrit API, but does allow us to exercise the right code path.
func TestDo_RedirectLoop(t *testing.T) {
	setup()
	defer teardown()

	testMux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		http.Redirect(w, r, "/", http.StatusFound)
	})

	req, _ := testClient.NewRequest("GET", "/", nil)
	_, err := testClient.Do(req, nil)

	if err == nil {
		t.Error("Expected error to be returned.")
	}
	if err, ok := err.(*url.Error); !ok {
		t.Errorf("Expected a URL error; got %+v.", err)
	}
}