package wanted

import (
	"context"
	"errors"
	"fmt"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"sync/atomic"
	"testing"
	"time"

	"github.com/jackc/pgx/v5/pgtype"
	"github.com/jackc/pgx/v5/pgxpool"

	"git.fabledsword.com/bvandeusen/minstrel/internal/catalogue"
	"git.fabledsword.com/bvandeusen/minstrel/internal/db"
	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
	"git.fabledsword.com/bvandeusen/minstrel/internal/dbtest"
	"git.fabledsword.com/bvandeusen/minstrel/internal/musicbrainz"
	"git.fabledsword.com/bvandeusen/minstrel/internal/tags"
)

func TestPasses_PrimaryListedAndEverySecondaryAllowed(t *testing.T) {
	standard := dbq.ReleaseTypeProfile{PrimaryTypes: []string{"Album", "EP", "Single"}, SecondaryTypes: []string{}}
	withLive := dbq.ReleaseTypeProfile{PrimaryTypes: []string{"Album"}, SecondaryTypes: []string{"Live"}}
	for _, c := range []struct {
		profile   dbq.ReleaseTypeProfile
		title     string
		primary   string
		secondary []string
		want      bool
	}{
		{standard, "Revenge", "Album", nil, true},
		{standard, "Helena", "single", nil, true}, // MusicBrainz's case is not relied on
		{standard, "Live at Koko", "Album", []string{"Live"}, false},
		{standard, "Radio Show", "Broadcast", nil, false},
		{withLive, "Live at Koko", "Album", []string{"Live"}, true},
		{withLive, "Live & Rare", "Album", []string{"Live", "Compilation"}, false},
		{withLive, "Like Phantoms, Forever", "EP", nil, false},
		// MusicBrainz types these plain Singles; their titles say otherwise (#5573).
		{standard, "Common People (Recorded For BBC Radio 1)", "Single", nil, false},
		{standard, "Welcome to the Black Parade (Steve Aoki remix)", "Single", nil, false},
		{standard, "The Five of Us Are Dying (Rough mix)", "Single", nil, false},
		{withLive, "Desolation Row (live at BBC Maida Vale)", "Album", nil, true},
		{withLive, "Helena (acoustic)", "Album", nil, false},
		{standard, "Live Through This", "Album", nil, true},
	} {
		if got := Passes(c.profile, c.title, c.primary, c.secondary); got != c.want {
			t.Errorf("Passes(%v/%v, %q %s %v) = %v, want %v", c.profile.PrimaryTypes, c.profile.SecondaryTypes,
				c.title, c.primary, c.secondary, got, c.want)
		}
	}
}

func TestProfileInput_NormalizesToMusicBrainzTypes(t *testing.T) {
	in, err := ProfileInput{Name: "  Live too ", PrimaryTypes: []string{"single", "Album"}, SecondaryTypes: []string{"live"}}.normalize()
	if err != nil {
		t.Fatal(err)
	}
	if in.Name != "Live too" || fmt.Sprint(in.PrimaryTypes) != "[Album Single]" || fmt.Sprint(in.SecondaryTypes) != "[Live]" {
		t.Errorf("normalized = %+v", in)
	}
	for name, bad := range map[string]ProfileInput{
		"no name":         {PrimaryTypes: []string{"Album"}},
		"no primary type": {Name: "x"},
		"unknown type":    {Name: "x", PrimaryTypes: []string{"Mixtape"}},
	} {
		if _, err := bad.normalize(); !errors.Is(err, ErrProfileInvalid) {
			t.Errorf("%s: err = %v", name, err)
		}
	}
}

func TestRecent_ReadsAPartialDateAsItsLastDay(t *testing.T) {
	s := &Service{}
	baseline := time.Date(2026, 10, 10, 0, 0, 0, 0, time.UTC)
	for date, want := range map[string]bool{
		"":           true, // not yet known: an announced release
		"2026-11-01": true,
		"2026-09-15": true, // inside the grace before the follow
		"2026-08-01": false,
		"2026":       true, // could be December
		"2025":       false,
		"2026-09":    true,
		"1998-04-01": false,
	} {
		if got := s.recent(date, baseline); got != want {
			t.Errorf("recent(%q) = %v, want %v", date, got, want)
		}
	}
}

func TestShortest_PrefersOfficialEditions(t *testing.T) {
	rel := func(status string, n int32) dbq.MbRelease { return dbq.MbRelease{Status: status, TrackCount: n} }
	for _, c := range []struct {
		releases []dbq.MbRelease
		want     int
	}{
		{nil, 0},
		{[]dbq.MbRelease{rel("Official", 14), rel("Official", 12), rel("Promotion", 3)}, 12},
		{[]dbq.MbRelease{rel("Bootleg", 9), rel("", 11)}, 9},
		{[]dbq.MbRelease{rel("Official", 0), rel("Bootleg", 9)}, 9},
	} {
		if got := Shortest(c.releases); got != c.want {
			t.Errorf("Shortest(%v) = %d, want %d", c.releases, got, c.want)
		}
	}
}

func TestAnswers(t *testing.T) {
	album := pgtype.UUID{Bytes: [16]byte{1}, Valid: true}
	other := pgtype.UUID{Bytes: [16]byte{2}, Valid: true}
	missing := dbq.Want{Reason: ReasonMissing, AlbumID: album}
	request := dbq.Want{Reason: ReasonRequest}
	for name, c := range map[string]struct {
		w        dbq.Want
		h        dbq.WantHoldingsRow
		shortest int
		want     bool
	}{
		"nothing on disk":                  {request, dbq.WantHoldingsRow{AlbumID: other, ArrivedSince: true}, 10, false},
		"a full edition":                   {request, dbq.WantHoldingsRow{AlbumID: other, Present: 10}, 10, true},
		"short of every edition":           {request, dbq.WantHoldingsRow{AlbumID: other, Present: 9, ArrivedSince: true}, 10, false},
		"no editions known, an arrival":    {request, dbq.WantHoldingsRow{AlbumID: other, Present: 1, ArrivedSince: true, MissingBefore: true}, 0, true},
		"no editions known, still missing": {request, dbq.WantHoldingsRow{AlbumID: other, Present: 5, MissingBefore: true}, 0, false},
		"the lost album, a gap remains":    {missing, dbq.WantHoldingsRow{AlbumID: album, Present: 12, UncoveredMissing: 1}, 10, false},
		"the lost album, every gap filled": {missing, dbq.WantHoldingsRow{AlbumID: album, Present: 9, UncoveredMissing: 0}, 10, true},
		"another copy of the lost album":   {missing, dbq.WantHoldingsRow{AlbumID: other, Present: 10}, 10, true},
	} {
		if got := Answers(c.w, c.h, c.shortest); got != c.want {
			t.Errorf("%s: Answers = %v, want %v", name, got, c.want)
		}
	}
}

func TestFollowable(t *testing.T) {
	for _, c := range []struct {
		mbid, name string
		want       bool
	}{
		{"a", "Gorillaz", true},
		{variousArtists, "Various Artists", false},
		{"b", "[unknown]", false},
		{"", "Nameless", false},
		{"c", "[ ]Bracketed Band", true},
	} {
		if got := Followable(c.mbid, c.name); got != c.want {
			t.Errorf("Followable(%q, %q) = %v", c.mbid, c.name, got)
		}
	}
}

// --- integration ---

func newPool(t *testing.T) *pgxpool.Pool {
	t.Helper()
	if testing.Short() {
		t.Skip("skipping integration test in -short mode")
	}
	dsn := os.Getenv("MINSTREL_TEST_DATABASE_URL")
	if dsn == "" {
		t.Skip("MINSTREL_TEST_DATABASE_URL not set")
	}
	if err := db.Migrate(dsn, slog.New(slog.NewTextHandler(io.Discard, nil))); err != nil {
		t.Fatalf("migrate: %v", err)
	}
	pool, err := pgxpool.New(context.Background(), dsn)
	if err != nil {
		t.Fatalf("pool: %v", err)
	}
	t.Cleanup(pool.Close)
	dbtest.ResetDB(t, pool)
	return pool
}

const (
	blur        = "ba853904-ae25-4ebb-89d6-c44cfbd71bd2"
	parklife    = "11111111-0000-4000-8000-000000000001" // 1994 album, held
	liveAtWemb  = "11111111-0000-4000-8000-000000000002" // 2009 live album
	theBallad   = "11111111-0000-4000-8000-000000000003" // 2023 album, not held
	newSingle   = "11111111-0000-4000-8000-000000000004" // appears after the baseline
	oldSingle   = "11111111-0000-4000-8000-000000000005" // 1997 single, catalogued late
	bbcSingle   = "11111111-0000-4000-8000-000000000006" // live, typed a plain Single (#5573)
	parkRelease = "22222222-0000-4000-8000-000000000001"
)

// fakeMB is a MusicBrainz holding Blur's discography; added groups appear in
// it after the baseline, and down makes every request a 503.
type fakeMB struct {
	srv   *httptest.Server
	added atomic.Bool
	down  atomic.Bool
}

func newFakeMB(t *testing.T) *fakeMB {
	t.Helper()
	f := &fakeMB{}
	group := func(id, title, primary, secondary, date string) string {
		return fmt.Sprintf(`{"id": %q, "title": %q, "primary-type": %q, "secondary-types": [%s], "first-release-date": %q,
			"artist-credit": [{"name": "Blur", "artist": {"id": %q}}]}`, id, title, primary, secondary, date, blur)
	}
	f.srv = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if f.down.Load() {
			w.WriteHeader(http.StatusServiceUnavailable)
			return
		}
		switch {
		case r.URL.Path == "/artist/"+blur:
			_, _ = fmt.Fprintf(w, `{"id": %q, "name": "Blur", "type": "Group", "country": "GB"}`, blur)
		case r.URL.Path == "/release-group" && r.URL.Query().Get("artist") == blur:
			groups := group(parklife, "Parklife", "Album", "", "1994-04-25") + "," +
				group(liveAtWemb, "Live at Wembley Stadium", "Album", `"Live"`, "2009-07-02") + "," +
				group(theBallad, "The Ballad of Darren", "Album", "", "2023-07-21") + "," +
				group(bbcSingle, "Song 2 (Recorded For BBC Radio 1)", "Single", "", "2023-08-01")
			n := 4
			if f.added.Load() {
				groups += "," + group(newSingle, "New Single", "Single", "", "") +
					"," + group(oldSingle, "Old Single", "Single", "", "1997-02-03")
				n = 6
			}
			_, _ = fmt.Fprintf(w, `{"release-group-count": %d, "release-groups": [%s]}`, n, groups)
		case r.URL.Path == "/release-group/"+theBallad:
			_, _ = fmt.Fprint(w, group(theBallad, "The Ballad of Darren", "Album", "", "2023-07-21"))
		case r.URL.Path == "/release" && r.URL.Query().Get("release-group") == theBallad:
			_, _ = fmt.Fprint(w, `{"release-count": 2, "releases": [
				{"id": "r-ballad-1", "title": "The Ballad of Darren", "status": "Official", "media": [{"position": 1,
				 "tracks": [{"position": 1, "number": "1", "title": "The Ballad", "recording": {"id": "rec-1"}},
				            {"position": 2, "number": "2", "title": "St. Charles Square", "recording": {"id": "rec-2"}}]}]},
				{"id": "r-ballad-2", "title": "The Ballad of Darren", "status": "Official", "media": [{"position": 1,
				 "tracks": [{"position": 1, "number": "1", "title": "The Ballad", "recording": {"id": "rec-1"}},
				            {"position": 2, "number": "2", "title": "St. Charles Square", "recording": {"id": "rec-2"}},
				            {"position": 3, "number": "3", "title": "Bonus", "recording": {"id": "rec-3"}}]}]}]}`)
		case r.URL.Path == "/release":
			_, _ = fmt.Fprint(w, `{"release-count": 0, "releases": []}`)
		case r.URL.Path == "/release-group" && strings.Contains(r.URL.Query().Get("query"), "releasegroup:"):
			// The library listing's search by artist and title (#5569).
			found := ""
			if strings.Contains(r.URL.Query().Get("query"), "Ballad") {
				found = group(theBallad, "The Ballad of Darren", "Album", "", "2023-07-21")
			}
			_, _ = fmt.Fprintf(w, `{"release-groups": [%s]}`, found)
		default:
			w.WriteHeader(http.StatusNotFound)
		}
	}))
	t.Cleanup(f.srv.Close)
	return f
}

func newService(t *testing.T, pool *pgxpool.Pool, f *fakeMB) *Service {
	t.Helper()
	mb := &musicbrainz.Client{BaseURL: f.srv.URL, Pace: &musicbrainz.Pacer{}, Retries: -1}
	s := New(pool, catalogue.New(pool, mb, nil), slog.New(slog.NewTextHandler(io.Discard, nil)))
	// Never the real MusicBrainz from a test.
	s.releaseGroup = func(context.Context, string) (string, error) { return "", tags.ErrNotFound }
	return s
}

// seedHeld puts an album of Blur's in the library with n tracks on disk.
func seedHeld(t *testing.T, q *dbq.Queries, title, release, group string, n int) dbq.Album {
	t.Helper()
	ctx := context.Background()
	mbid := blur
	artist, err := q.UpsertArtist(ctx, dbq.UpsertArtistParams{Name: "Blur", SortName: "Blur", Mbid: &mbid})
	if err != nil {
		t.Fatal(err)
	}
	params := dbq.UpsertAlbumParams{Title: title, SortTitle: title, ArtistID: artist.ID, Mbid: &release}
	if group != "" {
		params.ReleaseGroupMbid = &group
	}
	album, err := q.UpsertAlbum(ctx, params)
	if err != nil {
		t.Fatal(err)
	}
	for i := range n {
		num := int32(i + 1)
		if _, err := q.UpsertTrack(ctx, dbq.UpsertTrackParams{
			Title: fmt.Sprintf("Track %d", i+1), AlbumID: album.ID, ArtistID: artist.ID, TrackNumber: &num,
			DurationMs: 180000, FilePath: fmt.Sprintf("/music/%s/%02d.flac", release, i+1), FileSize: 1, FileFormat: "flac",
		}); err != nil {
			t.Fatal(err)
		}
	}
	return album
}

func TestFollow_BaselineThenOnlyNewReleasesThatPass_Integration(t *testing.T) {
	pool := newPool(t)
	q := dbq.New(pool)
	ctx := context.Background()
	f := newFakeMB(t)
	s := newService(t, pool, f)
	_ = seedHeld(t, q, "Parklife", parkRelease, parklife, 2)

	if _, err := s.Follow(ctx, FollowParams{ArtistMBID: blur, ArtistName: "Blur"}); err != nil {
		t.Fatal(err)
	}
	res, err := s.Pass(ctx)
	if err != nil {
		t.Fatal(err)
	}
	if res.Baselined != 1 || res.Wanted != 0 {
		t.Fatalf("baseline pass = %+v: a follow wants nothing it already lists", res)
	}

	// MusicBrainz gains two singles: one new, one from 1997. A day later the
	// follow reads the discography again.
	f.added.Store(true)
	if _, err := pool.Exec(ctx, `
		UPDATE mb_artists SET discography_refreshed_at = now() - interval '2 days';
		UPDATE follows SET checked_at = now() - interval '2 days'`); err != nil {
		t.Fatal(err)
	}
	if res, err = s.Pass(ctx); err != nil {
		t.Fatal(err)
	}
	if res.Wanted != 1 {
		t.Errorf("second pass wanted %d, want 1 (the new single)", res.Wanted)
	}
	if w, err := q.GetWantByReleaseGroup(ctx, newSingle); err != nil || w.Reason != ReasonFollow || w.PrimaryType != "Single" {
		t.Errorf("new single: %+v, %v", w, err)
	}
	if _, err := q.GetWantByReleaseGroup(ctx, oldSingle); err == nil {
		t.Error("a 1997 single catalogued late is not a new release")
	}
}

func TestFollow_WantExistingWantsWhatPassesAndIsNotHeld_Integration(t *testing.T) {
	pool := newPool(t)
	q := dbq.New(pool)
	ctx := context.Background()
	f := newFakeMB(t)
	s := newService(t, pool, f)
	_ = seedHeld(t, q, "Parklife", parkRelease, parklife, 2)
	// Wanted before the follow read the version a title names (#5573).
	if _, err := WantWith(ctx, q, WantParams{GroupMBID: bbcSingle, ArtistMBID: blur, ArtistName: "Blur",
		Title: "Song 2 (Recorded For BBC Radio 1)", PrimaryType: "Single", Reason: ReasonFollow}); err != nil {
		t.Fatal(err)
	}

	if _, err := s.Follow(ctx, FollowParams{ArtistMBID: blur, ArtistName: "Blur", WantExisting: true}); err != nil {
		t.Fatal(err)
	}
	if _, err := s.Pass(ctx); err != nil {
		t.Fatal(err)
	}
	if _, err := q.GetWantByReleaseGroup(ctx, theBallad); err != nil {
		t.Errorf("the studio album not held should be wanted: %v", err)
	}
	for group, why := range map[string]string{parklife: "held", liveAtWemb: "live, and Standard is studio only",
		bbcSingle: "recorded for the BBC, which its title says, and Standard is studio only"} {
		if _, err := q.GetWantByReleaseGroup(ctx, group); err == nil {
			t.Errorf("%s wanted, but it is %s", group, why)
		}
	}
	if fol, _ := q.GetFollow(ctx, blur); fol.WantExisting || !fol.BaselineAt.Valid {
		t.Errorf("follow = %+v: want_existing applied once, then cleared", fol)
	}

	// A profile that allows live releases, applied with "want what exists".
	live, err := s.CreateProfile(ctx, ProfileInput{Name: "With live", PrimaryTypes: []string{"Album"}, SecondaryTypes: []string{"Live"}})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := s.Follow(ctx, FollowParams{ArtistMBID: blur, ArtistName: "Blur", ProfileID: live.ID, WantExisting: true}); err != nil {
		t.Fatal(err)
	}
	if _, err := s.Pass(ctx); err != nil {
		t.Fatal(err)
	}
	if _, err := q.GetWantByReleaseGroup(ctx, liveAtWemb); err != nil {
		t.Errorf("with live allowed, the live album is wanted: %v", err)
	}
	if err := s.DeleteProfile(ctx, live.ID); !errors.Is(err, ErrProfileInUse) {
		t.Errorf("deleting a profile in use: err = %v", err)
	}
}

func TestSettle_HeldOnceAFullEditionIsOnDisk_Integration(t *testing.T) {
	pool := newPool(t)
	q := dbq.New(pool)
	ctx := context.Background()
	s := newService(t, pool, newFakeMB(t))

	if _, err := WantWith(ctx, q, WantParams{
		GroupMBID: theBallad, ArtistMBID: blur, ArtistName: "Blur", Title: "The Ballad of Darren", Reason: ReasonRequest,
	}); err != nil {
		t.Fatal(err)
	}
	album := seedHeld(t, q, "The Ballad of Darren", "r-ballad-1", theBallad, 1)
	if res, err := s.Pass(ctx); err != nil || res.Held != 0 {
		t.Fatalf("one track of a two-track edition: %+v, %v", res, err)
	}
	_ = seedHeld(t, q, "The Ballad of Darren", "r-ballad-1", theBallad, 2)
	if res, err := s.Pass(ctx); err != nil || res.Held != 1 {
		t.Fatalf("the shortest edition complete: %+v, %v", res, err)
	}
	w, _ := q.GetWantByReleaseGroup(ctx, theBallad)
	if !w.FulfilledAt.Valid || w.AlbumID != album.ID {
		t.Errorf("want = %+v: held by the album", w)
	}
}

func TestSettle_MovesAWantNamedByReleaseIdToItsGroup_Integration(t *testing.T) {
	pool := newPool(t)
	q := dbq.New(pool)
	ctx := context.Background()
	s := newService(t, pool, newFakeMB(t))
	s.releaseGroup = func(_ context.Context, release string) (string, error) {
		if release == "r-ballad-1" {
			return theBallad, nil
		}
		return "", tags.ErrNotFound
	}
	if _, err := WantWith(ctx, q, WantParams{
		GroupMBID: "r-ballad-1", ArtistMBID: blur, ArtistName: "Blur", Title: "The Ballad of Darren", Reason: ReasonRequest,
	}); err != nil {
		t.Fatal(err)
	}
	group := "r-ballad-1"
	if _, err := q.CreateRequest(ctx, dbq.CreateRequestParams{
		UserID: seedUser(t, pool), Kind: dbq.RequestKindAlbum, ArtistMbid: blur, AlbumMbid: &group, ArtistName: "Blur",
	}); err != nil {
		t.Fatal(err)
	}
	if _, err := s.Pass(ctx); err != nil {
		t.Fatal(err)
	}
	if _, err := q.GetWantByReleaseGroup(ctx, theBallad); err != nil {
		t.Errorf("the want should be under its group now: %v", err)
	}
	var moved string
	if err := pool.QueryRow(ctx, "SELECT album_mbid FROM requests").Scan(&moved); err != nil || moved != theBallad {
		t.Errorf("the request should follow its want: %q, %v", moved, err)
	}
}

func TestPass_MusicBrainzDownStopsFollowsButStillSettles_Integration(t *testing.T) {
	pool := newPool(t)
	q := dbq.New(pool)
	ctx := context.Background()
	f := newFakeMB(t)
	s := newService(t, pool, f)
	if _, err := s.Follow(ctx, FollowParams{ArtistMBID: blur, ArtistName: "Blur"}); err != nil {
		t.Fatal(err)
	}
	if _, err := WantWith(ctx, q, WantParams{
		GroupMBID: "some-group", ArtistMBID: blur, ArtistName: "Blur", Title: "Some", Reason: ReasonRequest,
	}); err != nil {
		t.Fatal(err)
	}
	_ = seedHeld(t, q, "Some", "some-release", "some-group", 3)
	f.down.Store(true)
	res, err := s.Pass(ctx)
	if !errors.Is(err, musicbrainz.ErrUnreachable) {
		t.Errorf("err = %v, want ErrUnreachable", err)
	}
	if res.Held != 1 {
		t.Errorf("held = %d: with no editions known, an album that arrived since the want answers it", res.Held)
	}
	if fol, _ := q.GetFollow(ctx, blur); fol.BaselineAt.Valid {
		t.Error("a follow is not baselined without reading its discography")
	}
}

func seedUser(t *testing.T, pool *pgxpool.Pool) pgtype.UUID {
	t.Helper()
	u, err := dbq.New(pool).CreateUser(context.Background(), dbq.CreateUserParams{
		Username: dbtest.TestUserPrefix + "wanter", PasswordHash: "x", ApiTokenHash: "x",
	})
	if err != nil {
		t.Fatal(err)
	}
	return u.ID
}