package tests

import (
	"strings"
	"testing"

	"github.com/go-bdd/gobdd"
)

// world is the state one scenario accumulates as its steps run: the exchange
// the last step performed, and the upload slot it is working with.
//
// It is stored in the gobdd context behind worldKey and handed out as a
// pointer, because gobdd clones the context between the Background steps and
// the scenario steps — a value would leave the Background's work behind.
type world struct {
	client *client

	// discovery is the read side, set by the Background step that checks it is
	// up. Nil in scenarios that never mention the catalogue.
	discovery *client

	// last is the most recent exchange with the CMS. Every "Then the request
	// …" step reads it.
	last response

	// The upload slot handed out by POST /api/videos/presign, and whether the
	// file has been PUT to it.
	slot     presignBody
	slotType string
	slotFile string
	uploaded bool

	// sent is the last registration body posted to POST /api/videos, and video
	// is the record that came back from it.
	sent  registerRequest
	video videoBody

	// categoriesByName caches GET /api/categories so scenarios can name a
	// category instead of hard-coding the id the seed migration happened to
	// give it.
	categoriesByName map[string]int16

	// announcement is the message the catalogue topic carried for this
	// scenario's video, once a step has waited for it.
	announcement *catalogueAnnouncement

	// catalogued is the read side's own copy of the video, once a step has
	// waited for it to arrive.
	catalogued *catalogueVideoBody

	// searchTitle is the exact title the scenario's video was catalogued
	// under. Scenarios name a plain title like "Desert Falcons"; the step
	// registering it appends a nonce, because nothing cleans up between runs
	// and a title reused across runs would make a result count meaningless.
	searchTitle string

	// results is the last page the catalogue search answered with.
	results searchResultsBody

	// pageSeen accumulates the ids from every page a paging scenario has
	// walked, so it can assert the pages tile the results rather than
	// repeating or dropping one.
	pageSeen []string

	// cohort is the ids of the videos a scenario catalogued together under one
	// shared title, in the order they were created.
	cohort []string
}

type worldKey struct{}

func worldOf(t gobdd.StepTest, ctx gobdd.Context) *world {
	value, err := ctx.Get(worldKey{})
	if err != nil {
		t.Fatalf("no world in the scenario context: %s", err)
		return nil
	}

	w, ok := value.(*world)
	if !ok {
		t.Fatalf("the scenario context holds a %T, not a *world", value)
		return nil
	}

	return w
}

// categoryID resolves a category name to the id the API issues for it, so the
// feature file can say "documentary" instead of "1".
func (w *world) categoryID(t gobdd.StepTest, name string) int16 {
	if w.categoriesByName == nil {
		result, err := w.client.get("/api/categories")
		if err != nil {
			t.Fatalf("could not load the category list: %s", err)
			return 0
		}
		if result.status != 200 {
			t.Fatalf("could not load the category list: %s", result.summary())
			return 0
		}

		var body categoriesBody
		if err := result.json(&body); err != nil {
			t.Fatalf("could not decode the category list: %s", err)
			return 0
		}

		w.categoriesByName = make(map[string]int16, len(body.Categories))
		for _, c := range body.Categories {
			w.categoriesByName[c.Name] = c.ID
		}
	}

	id, ok := w.categoriesByName[name]
	if !ok {
		t.Fatalf("the CMS knows no category named %q; it offers %v", name, w.categoriesByName)
		return 0
	}

	return id
}

// categoryName resolves a category id back to its name, for asserting on a
// message that names categories rather than numbering them.
func (w *world) categoryName(t gobdd.StepTest, id int16) string {
	w.categoryID(t, "other") // ensures the list is loaded
	for name, known := range w.categoriesByName {
		if known == id {
			return name
		}
	}
	t.Fatalf("the CMS knows no category with id %d; it offers %v", id, w.categoriesByName)
	return ""
}

// categoryIDs turns a comma-separated list of category names into the ids the
// register endpoint expects. An empty list stays empty — that is a scenario in
// its own right.
func (w *world) categoryIDs(t gobdd.StepTest, names string) []int16 {
	ids := []int16{}
	for _, name := range strings.Split(names, ",") {
		name = strings.TrimSpace(name)
		if name == "" {
			continue
		}
		ids = append(ids, w.categoryID(t, name))
	}
	return ids
}

// TestVideoUpload runs features/*.feature against a live CMS.
//
// The suite is black-box on purpose: it speaks only HTTP, so the same
// scenarios run against the docker-compose stack and against a deployed
// environment. Point it somewhere else with CMS_BASE_URL.
func TestVideoUpload(t *testing.T) {
	c := newClient()

	// Skip rather than fail when nothing is serving: a bare `go test ./...`
	// in a fresh checkout should not go red because the stack is down.
	if _, err := c.get("/health"); err != nil {
		t.Skipf("no CMS at %s (%s) — start one with `docker compose up` from the repo root, "+
			"or set CMS_BASE_URL to point at a running instance", c.base, err)
	}

	suite := gobdd.NewSuite(t,
		gobdd.WithFeaturesPath("features/*.feature"),
		gobdd.WithBeforeScenario(func(ctx gobdd.Context) {
			ctx.Set(worldKey{}, &world{client: newClient()})
		}),
	)

	// Given — the stack is up, and steps that arrange state a later When acts on.
	suite.AddStep(`^the CMS API is available$`, theAPIIsAvailable)
	suite.AddStep(`^the Discovery API is available$`, theDiscoveryAPIIsAvailable)
	suite.AddStep(`^I have requested an upload slot for "(.*)" of type "(.*)"$`, requestUploadSlot)
	suite.AddStep(`^I have uploaded the file to the upload URL$`, uploadTheFile)
	suite.AddStep(`^I have registered the uploaded video titled "(.*)" under categories "(.*)"$`, registerUploadedVideo)

	// When — the action under test.
	suite.AddStep(`^I ask the CMS for the list of categories$`, askForCategories)
	suite.AddStep(`^I request an upload slot for "(.*)" of type "(.*)"$`, requestUploadSlot)
	suite.AddStep(`^I upload the file to the upload URL$`, uploadTheFile)
	suite.AddStep(`^I send malformed JSON to the upload slot endpoint$`, sendMalformedJSON)
	suite.AddStep(`^I ask the CMS for that video$`, askForThatVideo)
	suite.AddStep(`^I ask the CMS for the video with id "(.*)"$`, askForVideoWithID)
	suite.AddStep(`^I have registered a video that is being transcoded$`, registerVideoBeingTranscoded)
	suite.AddStep(`^I have registered a video being transcoded under categories "(.*)"$`, registerVideoBeingTranscodedUnder)
	suite.AddStep(`^I have registered a video$`, registerVideoBeingTranscoded)
	suite.AddStep(`^I ask the CMS for that video with its id written (.*)$`, askForThatVideoWrittenAs)
	suite.AddStep(`^MediaConvert reports that the job reached "(.*)"$`, mediaConvertReportsState)
	suite.AddStep(`^MediaConvert reports that the job reached "(.*)" without a playlist$`, mediaConvertReportsStateWithoutPlaylist)
	suite.AddStep(`^MediaConvert reports that the job "(.*)" reached "(.*)"$`, mediaConvertReportsStateForJob)
	suite.AddStep(`^the video eventually has status "(.*)"$`, theVideoEventuallyHasStatus)
	suite.AddStep(`^the video keeps status "(.*)"$`, theVideoKeepsStatus)
	suite.AddStep(`^the video has a playback URL for its HLS playlist$`, theVideoHasAPlaybackURL)
	suite.AddStep(`^the video has no playback URL$`, theVideoHasNoPlaybackURL)
	suite.AddStep(`^the catalogue is told about the video$`, theCatalogueIsToldAboutTheVideo)
	suite.AddStep(`^the catalogue is told nothing about the video$`, theCatalogueIsToldNothingAboutTheVideo)
	suite.AddStep(`^the announcement carries the video's title, playback URL and categories$`, theAnnouncementCarriesTheVideosDetails)
	suite.AddStep(`^the announcement files it under "(.*)"$`, theAnnouncementFilesItUnder)
	suite.AddStep(`^the catalogue eventually holds that video$`, theCatalogueEventuallyHoldsThatVideo)
	suite.AddStep(`^the catalogue does not hold that video$`, theCatalogueDoesNotHoldThatVideo)
	suite.AddStep(`^the catalogue eventually holds that video with no playback URL$`, theCatalogueEventuallyHoldsThatVideoWithNoPlaybackURL)
	suite.AddStep(`^the catalogue's copy carries its title, playback URL and categories$`, theCataloguesCopyCarriesTheDetails)
	suite.AddStep(`^the catalogue holds a video titled "([^"]*)"$`, theCatalogueHoldsAVideoTitled)
	suite.AddStep(`^I search the catalogue for that video's title$`, searchTheCatalogueForThatTitle)
	suite.AddStep(`^I search the catalogue for "([^"]*)"$`, searchTheCatalogueFor)
	suite.AddStep(`^the catalogue holds a video titled "([^"]*)" filed under "([^"]*)"$`, theCatalogueHoldsAVideoTitledUnder)
	suite.AddStep(`^I search the catalogue for that video's title in category "([^"]*)"$`, searchTheCatalogueForThatTitleInCategory)
	suite.AddStep(`^I search the catalogue for that video's title in categories "([^"]*)"$`, searchTheCatalogueForThatTitleInCategories)
	suite.AddStep(`^the catalogue holds (\d+) videos titled "([^"]*)"$`, theCatalogueHoldsVideosTitled)
	suite.AddStep(`^I search the catalogue for that title (\d+) at a time$`, searchTheCatalogueForThatTitleAPageAtATime)
	suite.AddStep(`^I search the whole catalogue (\d+) at a time$`, searchTheWholeCatalogue)
	suite.AddStep(`^I follow the cursor$`, followTheCursor)
	suite.AddStep(`^I search the catalogue for that video's title from the cursor "([^"]*)"$`, searchTheCatalogueFromCursor)
	suite.AddStep(`^the search returns (\d+) videos?$`, theSearchReturnsNVideos)
	suite.AddStep(`^the search returns at most (\d+) videos$`, theSearchReturnsAtMostNVideos)
	suite.AddStep(`^the search offers a cursor to the next page$`, theSearchOffersACursor)
	suite.AddStep(`^the search offers no further cursor$`, theSearchOffersNoFurtherCursor)
	suite.AddStep(`^the pages together hold every one of those videos exactly once$`, thePagesTileTheCohort)
	suite.AddStep(`^the search does not return that video$`, theSearchDoesNotReturnThatVideo)
	suite.AddStep(`^the search returns that video$`, theSearchReturnsThatVideo)
	suite.AddStep(`^I register the uploaded video titled "(.*)" under categories "(.*)"$`, registerUploadedVideo)
	suite.AddStep(`^I register the uploaded video titled "(.*)" under category id (\d+)$`, registerUnderCategoryID)
	suite.AddStep(`^I register a video titled "(.*)" with the key "(.*)" under categories "(.*)"$`, registerWithKey)

	// Then — assertions on the last exchange.
	suite.AddStep(`^the request succeeds with status (\d+)$`, theRequestSucceedsWith)
	suite.AddStep(`^the request is rejected with status (\d+)$`, theRequestIsRejectedWith)
	suite.AddStep(`^the problem title is "(.*)"$`, theProblemTitleIs)
	suite.AddStep(`^the category list is not empty$`, theCategoryListIsNotEmpty)
	suite.AddStep(`^every category has an id and a name$`, everyCategoryHasAnIDAndAName)
	suite.AddStep(`^I am given an upload URL$`, iAmGivenAnUploadURL)
	suite.AddStep(`^the storage key is under "(.*)" and ends with "(.*)"$`, theStorageKeyIs)
	suite.AddStep(`^the video is registered with status "(.*)"$`, theVideoIsRegisteredWithStatus)
	suite.AddStep(`^the video has an id$`, theVideoHasAnID)
	suite.AddStep(`^the video is stored under the key from the upload slot$`, theVideoIsStoredUnderTheSlotKey)
	suite.AddStep(`^the video has a transcoding job id$`, theVideoHasATranscodingJobID)
	suite.AddStep(`^the video is filed under categories "(.*)"$`, theVideoIsFiledUnder)
	suite.AddStep(`^the video keeps the metadata I sent$`, theVideoKeepsTheMetadataISent)

	suite.Run()
}