package agent

import (
	"bufio"
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"strconv"
	"strings"
	"testing"
	"time"

	"github.com/fnproject/fn/api/datastore"
	"github.com/fnproject/fn/api/models"
	"github.com/fnproject/fn/api/mqs"
	"github.com/sirupsen/logrus"
)

func checkExpectedHeaders(t *testing.T, expectedHeaders http.Header, receivedHeaders http.Header) {

	checkMap := make([]string, 0, len(expectedHeaders))
	for k, _ := range expectedHeaders {
		checkMap = append(checkMap, k)
	}

	for k, vs := range receivedHeaders {
		for i, v := range expectedHeaders[k] {
			if i >= len(vs) || vs[i] != v {
				t.Fatal("header mismatch", k, vs)
			}
		}

		for i, _ := range checkMap {
			if checkMap[i] == k {
				checkMap = append(checkMap[:i], checkMap[i+1:]...)
				break
			}
		}
	}

	if len(checkMap) > 0 {
		t.Fatalf("expected headers not found=%v", checkMap)
	}
}

func TestCallConfigurationRequest(t *testing.T) {
	appName := "myapp"
	path := "/sleeper"
	image := "fnproject/sleeper"
	const timeout = 1
	const idleTimeout = 20
	const memory = 256
	typ := "sync"
	format := "default"

	cfg := models.Config{"APP_VAR": "FOO"}
	rCfg := models.Config{"ROUTE_VAR": "BAR"}

	ds := datastore.NewMockInit(
		[]*models.App{
			{Name: appName, Config: cfg},
		},
		[]*models.Route{
			{
				Config:      rCfg,
				Path:        path,
				AppName:     appName,
				Image:       image,
				Type:        typ,
				Format:      format,
				Timeout:     timeout,
				IdleTimeout: idleTimeout,
				Memory:      memory,
			},
		}, nil,
	)

	a := New(NewCachedDataAccess(NewDirectDataAccess(ds, ds, new(mqs.Mock))))
	defer a.Close()

	w := httptest.NewRecorder()

	method := "GET"
	url := "http://127.0.0.1:8080/r/" + appName + path
	payload := "payload"
	contentLength := strconv.Itoa(len(payload))
	req, err := http.NewRequest(method, url, strings.NewReader(payload))
	if err != nil {
		t.Fatal(err)
	}

	req.Header.Add("MYREALHEADER", "FOOLORD")
	req.Header.Add("MYREALHEADER", "FOOPEASANT")
	req.Header.Add("Content-Length", contentLength)
	req.Header.Add("FN_PATH", "thewrongroute") // ensures that this doesn't leak out, should be overwritten

	call, err := a.GetCall(
		WithWriter(w), // XXX (reed): order matters [for now]
		FromRequest(appName, path, req),
	)
	if err != nil {
		t.Fatal(err)
	}

	model := call.Model()

	// make sure the values are all set correctly
	if model.ID == "" {
		t.Fatal("model does not have id, GetCall should assign id")
	}
	if model.AppName != appName {
		t.Fatal("app name mismatch", model.AppName, appName)
	}
	if model.Path != path {
		t.Fatal("path mismatch", model.Path, path)
	}
	if model.Image != image {
		t.Fatal("image mismatch", model.Image, image)
	}
	if model.Type != "sync" {
		t.Fatal("route type mismatch", model.Type)
	}
	if model.Priority == nil {
		t.Fatal("GetCall should make priority non-nil so that async works because for whatever reason some clowns plumbed it all over the mqs even though the user can't specify it gg")
	}
	if model.Timeout != timeout {
		t.Fatal("timeout mismatch", model.Timeout, timeout)
	}
	if model.IdleTimeout != idleTimeout {
		t.Fatal("idle timeout mismatch", model.IdleTimeout, idleTimeout)
	}
	if time.Time(model.CreatedAt).IsZero() {
		t.Fatal("GetCall should stamp CreatedAt, got nil timestamp")
	}
	if model.URL != url {
		t.Fatal("url mismatch", model.URL, url)
	}
	if model.Method != method {
		t.Fatal("method mismatch", model.Method, method)
	}
	if model.Payload != "" { // NOTE: this is expected atm
		t.Fatal("GetCall FromRequest should not fill payload, got non-empty payload", model.Payload)
	}

	expectedConfig := map[string]string{
		"FN_FORMAT":   format,
		"FN_APP_NAME": appName,
		"FN_PATH":     path,
		"FN_MEMORY":   strconv.Itoa(memory),
		"FN_TYPE":     typ,
		"APP_VAR":     "FOO",
		"ROUTE_VAR":   "BAR",
	}

	for k, v := range expectedConfig {
		if v2 := model.Config[k]; v2 != v {
			t.Fatal("config mismatch", k, v, v2, model.Config)
		}
		delete(expectedConfig, k)
	}

	if len(expectedConfig) > 0 {
		t.Fatal("got extra vars in config set, add me to tests ;)", expectedConfig)
	}

	expectedHeaders := make(http.Header)
	expectedHeaders.Add("FN_CALL_ID", model.ID)
	expectedHeaders.Add("FN_METHOD", method)
	expectedHeaders.Add("FN_REQUEST_URL", url)

	expectedHeaders.Add("MYREALHEADER", "FOOLORD")
	expectedHeaders.Add("MYREALHEADER", "FOOPEASANT")
	expectedHeaders.Add("Content-Length", contentLength)

	checkExpectedHeaders(t, expectedHeaders, model.Headers)

	// TODO check response writer for route headers
}

func TestCallConfigurationModel(t *testing.T) {
	appName := "myapp"
	path := "/sleeper"
	image := "fnproject/sleeper"
	const timeout = 1
	const idleTimeout = 20
	const memory = 256
	CPUs := models.MilliCPUs(1000)
	method := "GET"
	url := "http://127.0.0.1:8080/r/" + appName + path
	payload := "payload"
	typ := "sync"
	format := "default"
	cfg := models.Config{
		"FN_FORMAT":   format,
		"FN_APP_NAME": appName,
		"FN_PATH":     path,
		"FN_MEMORY":   strconv.Itoa(memory),
		"FN_CPUS":     CPUs.String(),
		"FN_TYPE":     typ,
		"APP_VAR":     "FOO",
		"ROUTE_VAR":   "BAR",
	}

	cm := &models.Call{
		Config:      cfg,
		AppName:     appName,
		Path:        path,
		Image:       image,
		Type:        typ,
		Format:      format,
		Timeout:     timeout,
		IdleTimeout: idleTimeout,
		Memory:      memory,
		CPUs:        CPUs,
		Payload:     payload,
		URL:         url,
		Method:      method,
	}

	// FromModel doesn't need a datastore, for now...
	ds := datastore.NewMockInit(nil, nil, nil)

	a := New(NewCachedDataAccess(NewDirectDataAccess(ds, ds, new(mqs.Mock))))
	defer a.Close()

	callI, err := a.GetCall(FromModel(cm))
	if err != nil {
		t.Fatal(err)
	}

	req := callI.(*call).req

	var b bytes.Buffer
	io.Copy(&b, req.Body)

	if b.String() != payload {
		t.Fatal("expected payload to match, but it was a lie")
	}
}

func TestAsyncCallHeaders(t *testing.T) {
	appName := "myapp"
	path := "/sleeper"
	image := "fnproject/sleeper"
	const timeout = 1
	const idleTimeout = 20
	const memory = 256
	CPUs := models.MilliCPUs(200)
	method := "GET"
	url := "http://127.0.0.1:8080/r/" + appName + path
	payload := "payload"
	typ := "async"
	format := "http"
	contentType := "suberb_type"
	contentLength := strconv.FormatInt(int64(len(payload)), 10)
	config := map[string]string{
		"FN_FORMAT":   format,
		"FN_APP_NAME": appName,
		"FN_PATH":     path,
		"FN_MEMORY":   strconv.Itoa(memory),
		"FN_CPUS":     CPUs.String(),
		"FN_TYPE":     typ,
		"APP_VAR":     "FOO",
		"ROUTE_VAR":   "BAR",
		"DOUBLE_VAR":  "BIZ, BAZ",
	}
	headers := map[string][]string{
		// FromRequest would insert these from original HTTP request
		"Content-Type":   []string{contentType},
		"Content-Length": []string{contentLength},
	}

	cm := &models.Call{
		Config:      config,
		Headers:     headers,
		AppName:     appName,
		Path:        path,
		Image:       image,
		Type:        typ,
		Format:      format,
		Timeout:     timeout,
		IdleTimeout: idleTimeout,
		Memory:      memory,
		CPUs:        CPUs,
		Payload:     payload,
		URL:         url,
		Method:      method,
	}

	// FromModel doesn't need a datastore, for now...
	ds := datastore.NewMockInit(nil, nil, nil)

	a := New(NewCachedDataAccess(NewDirectDataAccess(ds, ds, new(mqs.Mock))))
	defer a.Close()

	callI, err := a.GetCall(FromModel(cm))
	if err != nil {
		t.Fatal(err)
	}

	// make sure headers seem reasonable
	req := callI.(*call).req

	// These should be here based on payload length and/or fn_header_* original headers
	expectedHeaders := make(http.Header)
	expectedHeaders.Set("Content-Type", contentType)
	expectedHeaders.Set("Content-Length", strconv.FormatInt(int64(len(payload)), 10))

	checkExpectedHeaders(t, expectedHeaders, req.Header)

	var b bytes.Buffer
	io.Copy(&b, req.Body)

	if b.String() != payload {
		t.Fatal("expected payload to match, but it was a lie")
	}
}

func TestLoggerIsStringerAndWorks(t *testing.T) {
	// TODO test limit writer, logrus writer, etc etc

	loggyloo := logrus.WithFields(logrus.Fields{"yodawg": true})
	logger := setupLogger(loggyloo)

	if _, ok := logger.(fmt.Stringer); !ok {
		// NOTE: if you are reading, maybe what you've done is ok, but be aware we were relying on this for optimization...
		t.Fatal("you turned the logger into something inefficient and possibly better all at the same time, how dare ye!")
	}

	str := "0 line\n1 line\n2 line\n\n4 line"
	logger.Write([]byte(str))

	strGot := logger.(fmt.Stringer).String()

	if strGot != str {
		t.Fatal("logs did not match expectations, like being an adult", strGot, str)
	}

	logger.Close() // idk maybe this would panic might as well call this

	// TODO we could check for the toilet to flush here to logrus
}

func TestSubmitError(t *testing.T) {
	appName := "myapp"
	path := "/error"
	image := "fnproject/error"
	const timeout = 10
	const idleTimeout = 20
	const memory = 256
	CPUs := models.MilliCPUs(200)
	method := "GET"
	url := "http://127.0.0.1:8080/r/" + appName + path
	payload := "payload"
	typ := "sync"
	format := "default"
	config := map[string]string{
		"FN_FORMAT":   format,
		"FN_APP_NAME": appName,
		"FN_PATH":     path,
		"FN_MEMORY":   strconv.Itoa(memory),
		"FN_CPUS":     CPUs.String(),
		"FN_TYPE":     typ,
		"APP_VAR":     "FOO",
		"ROUTE_VAR":   "BAR",
		"DOUBLE_VAR":  "BIZ, BAZ",
	}

	cm := &models.Call{
		Config:      config,
		AppName:     appName,
		Path:        path,
		Image:       image,
		Type:        typ,
		Format:      format,
		Timeout:     timeout,
		IdleTimeout: idleTimeout,
		Memory:      memory,
		CPUs:        CPUs,
		Payload:     payload,
		URL:         url,
		Method:      method,
	}

	// FromModel doesn't need a datastore, for now...
	ds := datastore.NewMockInit(nil, nil, nil)

	a := New(NewCachedDataAccess(NewDirectDataAccess(ds, ds, new(mqs.Mock))))
	defer a.Close()

	callI, err := a.GetCall(FromModel(cm))
	if err != nil {
		t.Fatal(err)
	}

	err = a.Submit(callI)
	if err == nil {
		t.Fatal("expected error but got none")
	}

	if cm.Status != "error" {
		t.Fatal("expected status to be set to 'error' but was", cm.Status)
	}

	if cm.Error == "" {
		t.Fatal("expected error string to be set on call")
	}
}

// this implements io.Reader, but importantly, is not a strings.Reader or
// a type of reader than NewRequest can identify to set the content length
// (important, for some tests)
type dummyReader struct {
	inner io.Reader
}

func (d *dummyReader) Read(b []byte) (int, error) {
	return d.inner.Read(b)
}

func TestHTTPWithoutContentLengthWorks(t *testing.T) {
	// TODO it may be a good idea to mock out the http server and use a real
	// response writer with sync, and also test that this works with async + log

	appName := "myapp"
	path := "/hello"
	url := "http://127.0.0.1:8080/r/" + appName + path

	// we need to load in app & route so that FromRequest works
	ds := datastore.NewMockInit(
		[]*models.App{
			{Name: appName},
		},
		[]*models.Route{
			{
				Path:        path,
				AppName:     appName,
				Image:       "fnproject/fn-test-utils",
				Type:        "sync",
				Format:      "http", // this _is_ the test
				Timeout:     5,
				IdleTimeout: 10,
				Memory:      128,
			},
		}, nil,
	)

	a := New(NewDirectDataAccess(ds, ds, new(mqs.Mock)))
	defer a.Close()

	bodOne := `{"echoContent":"yodawg"}`

	// get a req that uses the dummy reader, so that this can't determine
	// the size of the body and set content length (user requests may also
	// forget to do this, and we _should_ read it as chunked without issue).
	req, err := http.NewRequest("GET", url, &dummyReader{strings.NewReader(bodOne)})
	if err != nil {
		t.Fatal("unexpected error building request", err)
	}

	// grab a buffer so we can read what gets written to this guy
	var out bytes.Buffer
	callI, err := a.GetCall(FromRequest(appName, path, req), WithWriter(&out))
	if err != nil {
		t.Fatal(err)
	}

	err = a.Submit(callI)
	if err != nil {
		t.Error("submit should not error:", err)
	}

	// we're using http format so this will have written a whole http request
	res, err := http.ReadResponse(bufio.NewReader(&out), nil)
	if err != nil {
		t.Fatal(err)
	}
	defer res.Body.Close()

	// {"request":{"echoContent":"yodawg"}}
	var resp struct {
		R struct {
			Body string `json:"echoContent"`
		} `json:"request"`
	}

	json.NewDecoder(res.Body).Decode(&resp)

	if resp.R.Body != "yodawg" {
		t.Fatal(`didn't get a yodawg in the body, http protocol may be fudged up
			(to debug, recommend ensuring inside the function gets 'Transfer-Encoding: chunked' if
			no Content-Length is set. also make sure the body makes it (and the image hasn't changed)); GLHF, got:`, resp.R.Body)
	}
}