package acquire

import (
	"context"
	"errors"
	"fmt"
	"strings"
	"testing"
	"time"

	"git.fabledsword.com/bvandeusen/minstrel/internal/downloader"
	"git.fabledsword.com/bvandeusen/minstrel/internal/indexer"
	"git.fabledsword.com/bvandeusen/minstrel/internal/release"
)

type fakeSearch struct {
	results []indexer.Result
	err     error
	asked   []indexer.Query
}

func (f *fakeSearch) Search(_ context.Context, q indexer.Query) ([]indexer.Result, error) {
	f.asked = append(f.asked, q)
	return f.results, f.err
}

var ram = Want{Want: release.Want{
	Artist: "Daft Punk", Title: "Random Access Memories", Year: 2013, PrimaryType: "Album",
	MinTracks: 13, MaxTracks: 15,
}}

var anyQuality = release.NewProfile([]string{
	"lossless_hires", "lossless", "lossy_high", "lossy_standard", "lossy_low", "lossy_poor", "lossy_trash",
})

func result(title, hash string, seeders int) indexer.Result {
	return indexer.Result{Title: title, InfoHash: hash, Seeders: seeders, Indexer: "Knaben", Source: "prowlarr",
		Magnet: "magnet:?xt=urn:btih:" + hash}
}

func TestFor_JudgesSortsAndFolds(t *testing.T) {
	search := &fakeSearch{results: []indexer.Result{
		result("Daft Punk - Random Access Memories (2013) [MP3 320]", "aaaa", 40),
		result("Daft Punk Random Access Memories (Drumless Edition 2023) [Flac 24-88]", "bbbb", 90),
		result("Daft Punk - Random Access Memories (2013) [FLAC]", "cccc", 12),
		result("Daft Punk - Random Access Memories (2013) [FLAC]", "CCCC", 30), // the same torrent from another tracker
		result("Daft Punk - Discovery (2001) [FLAC]", "dddd", 50),
	}}
	s := &Service{Search: search, Profile: anyQuality}
	r := s.For(context.Background(), ram)

	if len(search.asked) != 1 || search.asked[0].Text != "Daft Punk Random Access Memories" {
		t.Fatalf("asked %+v", search.asked)
	}
	if r.Considered != 5 || r.Folded != 1 || len(r.Candidates) != 4 {
		t.Fatalf("considered %d folded %d candidates %d", r.Considered, r.Folded, len(r.Candidates))
	}
	// Lossless before high-quality lossy among what can be taken; the
	// folded copy keeps the higher seeder count.
	first, second := r.Candidates[0], r.Candidates[1]
	if first.InfoHash != "cccc" || first.Verdict != Grab || first.Seeders != 30 || first.Tier != release.TierLossless {
		t.Errorf("first = %s %s %d %s", first.Name, first.Verdict, first.Seeders, first.Tier)
	}
	if second.InfoHash != "aaaa" || second.Verdict != Grab {
		t.Errorf("second = %s %s", second.Name, second.Verdict)
	}
	for _, c := range r.Candidates[2:] {
		if c.Verdict != Rejected || len(c.Reasons) != 1 || c.Reasons[0].Kind != Hard {
			t.Errorf("%s: %s %+v", c.Name, c.Verdict, c.Reasons)
		}
	}
	if len(r.Grabbable()) != 2 || !r.ForAPerson() {
		t.Errorf("grabbable %d", len(r.Grabbable()))
	}
}

func TestFor_ProfileSeedersAndDoubt(t *testing.T) {
	search := &fakeSearch{results: []indexer.Result{
		result("Daft Punk - Random Access Memories [MP3 128]", "aaaa", 5),
		result("Daft Punk - Random Access Memories [FLAC]", "bbbb", 0),
		result("Daft Punk - Random Access Memories", "cccc", 9),
	}}
	s := &Service{Search: search, Profile: release.NewProfile([]string{"lossless", "lossy_high"})}
	r := s.For(context.Background(), ram)
	verdicts := map[string]Verdict{}
	for _, c := range r.Candidates {
		verdicts[c.InfoHash] = c.Verdict
	}
	if verdicts["aaaa"] != Refused || verdicts["bbbb"] != Review || verdicts["cccc"] != Refused {
		t.Errorf("verdicts = %v", verdicts)
	}
	if len(r.Grabbable()) != 0 || !r.ForAPerson() {
		t.Error("nothing grabbable, but something for a person")
	}
}

func TestFor_BlockedReleasesAreSetAside(t *testing.T) {
	c := Candidate{Release: release.Parse("Daft Punk - Random Access Memories [FLAC]"), InfoHash: "aaaa", Seeders: 3}
	decide(&c, ram, anyQuality, map[string]string{"aaaa": "You set this release aside."})
	if c.Verdict != Blocked || c.Reason != "You set this release aside." {
		t.Errorf("verdict %s %q", c.Verdict, c.Reason)
	}
}

func TestFor_UnconfiguredAndFailedSearches(t *testing.T) {
	if r := (&Service{}).For(context.Background(), ram); !r.Unconfigured {
		t.Error("no source is unconfigured")
	}
	r := (&Service{Search: &fakeSearch{err: indexer.ErrUnconfigured}}).For(context.Background(), ram)
	if !r.Unconfigured {
		t.Error("ErrUnconfigured is unconfigured")
	}
	r = (&Service{Search: &fakeSearch{err: errors.New("dial tcp: refused")}}).For(context.Background(), ram)
	if r.Error == "" {
		t.Error("a failed search says so")
	}
}

func TestFanout_ANarrowedSearchKeepsWhatAnswered(t *testing.T) {
	up := &fakeSearch{results: []indexer.Result{result("Daft Punk - Random Access Memories [FLAC]", "aaaa", 3)}}
	down := &fakeSearch{err: indexer.ErrUnreachable}
	f := &Fanout{Sources: []Source{{Code: "prowlarr", Label: "Prowlarr", Search: up}, {Code: "torznab", Label: "Feed", Search: down}}}
	r := (&Service{Search: f, Profile: anyQuality}).For(context.Background(), ram)
	if r.Error != "" || len(r.Candidates) != 1 || len(r.Narrowed) != 1 || r.Narrowed[0].Source != "torznab" {
		t.Errorf("narrowed search: error %q, %d candidates, narrowed %+v", r.Error, len(r.Candidates), r.Narrowed)
	}
	f.Sources = f.Sources[1:]
	if r := (&Service{Search: f}).For(context.Background(), ram); r.Error == "" {
		t.Error("every source down is a failed search")
	}
}

func TestPacer_SpacesSearchesAndHoldsAfterA429(t *testing.T) {
	now := time.Unix(0, 0)
	var slept time.Duration
	p := &Pacer{Now: func() time.Time { return now }, Sleep: func(_ context.Context, d time.Duration) error { slept += d; return nil }}
	src := []Source{{Code: "prowlarr", PerHour: 120, Search: &fakeSearch{}}}
	p.spend(src[0])
	if !p.Wait(context.Background(), src, now.Add(time.Hour)) || slept != 30*time.Second {
		t.Errorf("slept %s, want 30s", slept)
	}
	if p.Wait(context.Background(), src, now.Add(time.Second)) {
		t.Error("waited past the deadline")
	}
	p.hold("prowlarr", &indexer.RateLimited{RetryAfter: 5 * time.Minute})
	if at := p.readyAt(src); at.Sub(now) != 5*time.Minute {
		t.Errorf("held until %s", at.Sub(now))
	}
}

type fakeClient struct {
	downloader.Driver
	added    []downloader.Add
	addErr   error
	deleted  []string
	progress float64
	// elsewhere: the client holds it but does not list it for Minstrel.
	elsewhere bool
}

func (c *fakeClient) AddTorrent(_ context.Context, a downloader.Add) error {
	c.added = append(c.added, a)
	return c.addErr
}

func (c *fakeClient) Torrents(_ context.Context, hashes ...string) ([]downloader.Torrent, error) {
	if c.elsewhere {
		return nil, nil
	}
	return []downloader.Torrent{{Hash: hashes[0], Progress: c.progress}}, nil
}

func (c *fakeClient) Delete(_ context.Context, _ bool, hashes ...string) error {
	c.deleted = append(c.deleted, hashes...)
	return nil
}

func TestGrab_AddsAMagnetToItsOwnFolder(t *testing.T) {
	client := &fakeClient{}
	s := &Service{Search: &fakeSearch{results: []indexer.Result{
		result("Daft Punk - Random Access Memories (2013) [FLAC]", "ABCD", 8),
	}}, Profile: anyQuality, Grabber: &Downloader{Client: client, Code: "qbittorrent", Landing: "/downloads"}}
	r := s.For(context.Background(), ram)
	took := s.Grab(context.Background(), ram, &r.Candidates[0], r.Candidates, false, Origin{By: OriginSchedule})
	if !took.Added || took.SavePath != "/downloads/abcd" {
		t.Fatalf("took %+v", took)
	}
	if len(client.added) != 1 || !strings.Contains(strings.ToLower(client.added[0].Magnet), "abcd") || client.added[0].Tags[0] != Tag {
		t.Errorf("added %+v", client.added)
	}
}

func TestGrab_RefusesWhatTheVerdictWouldNotTake(t *testing.T) {
	client := &fakeClient{}
	s := &Service{Grabber: &Downloader{Client: client, Landing: "/downloads"}}
	review := Candidate{Verdict: Review, InfoHash: "aaaa", Source: indexer.Result{Magnet: "magnet:?xt=urn:btih:aaaa"}}
	if took := s.Grab(context.Background(), ram, &review, nil, false, Origin{By: OriginSchedule}); !took.Refused {
		t.Error("a review was taken unforced")
	}
	if took := s.Grab(context.Background(), ram, &review, nil, true, Origin{By: OriginOperator}); !took.Added {
		t.Errorf("a forced review was not taken: %+v", took)
	}
	blocked := Candidate{Verdict: Blocked, InfoHash: "bbbb"}
	if took := s.Grab(context.Background(), ram, &blocked, nil, true, Origin{By: OriginOperator}); !took.Refused {
		t.Error("forcing took a release set aside")
	}
	if took := (&Service{}).Grab(context.Background(), ram, &review, nil, true, Origin{}); !took.Unconfigured || took.Missing != MissingClient {
		t.Errorf("no client: %+v", took)
	}
}

func TestGrab_AClientThatAlreadyHasItCounts(t *testing.T) {
	client := &fakeClient{addErr: downloader.ErrDuplicate}
	s := &Service{Grabber: &Downloader{Client: client, Landing: "/downloads"}}
	c := Candidate{Verdict: Grab, InfoHash: "aaaa", Source: indexer.Result{Magnet: "magnet:?xt=urn:btih:aaaa"}}
	if took := s.Grab(context.Background(), ram, &c, nil, false, Origin{By: OriginSchedule}); !took.Added {
		t.Errorf("a duplicate: %+v", took)
	}
}

// A duplicate the client does not list for Minstrel sits under another
// category, where it would read as gone half an hour later (#6176). It is set
// aside rather than taken; forced, it is refused with the client's reason.
func TestGrab_ADuplicateHeldOutsideMinstrelIsNotTaken(t *testing.T) {
	client := &fakeClient{addErr: fmt.Errorf("%w: already downloading Ohio Players (lidarr)", downloader.ErrDuplicate), elsewhere: true}
	s := &Service{Grabber: &Downloader{Client: client, Landing: "/downloads"}}
	c := Candidate{Verdict: Grab, InfoHash: "aaaa", Source: indexer.Result{Magnet: "magnet:?xt=urn:btih:aaaa"}}
	took := s.Grab(context.Background(), ram, &c, nil, false, Origin{By: OriginSchedule})
	if took.Added || !took.Refused {
		t.Fatalf("took %+v", took)
	}
	if c.Verdict != Blocked || !strings.Contains(c.Reason, "(already downloading Ohio Players (lidarr))") {
		t.Errorf("candidate %s: %q", c.Verdict, c.Reason)
	}

	forced := Candidate{Verdict: Grab, InfoHash: "aaaa", Source: indexer.Result{Magnet: "magnet:?xt=urn:btih:aaaa"}}
	took = s.Grab(context.Background(), ram, &forced, nil, true, Origin{By: OriginOperator})
	if took.Added || !strings.Contains(took.Error, "outside Minstrel's category") {
		t.Errorf("forced: %+v", took)
	}
}

func TestBetter_QualityThenSeedersThenYear(t *testing.T) {
	flac := Candidate{Verdict: Grab, Tier: release.TierLossless, Seeders: 2}
	mp3 := Candidate{Verdict: Grab, Tier: release.TierLossyHigh, Seeders: 90}
	if !better(flac, mp3) || better(mp3, flac) {
		t.Error("quality first among grabs")
	}
	busy := Candidate{Verdict: Grab, Tier: release.TierLossless, Seeders: 20}
	if !better(busy, flac) {
		t.Error("then seeders")
	}
	dated := Candidate{Verdict: Grab, Tier: release.TierLossless, Seeders: 2, YearAgrees: true}
	if !better(dated, flac) {
		t.Error("then the year")
	}
	if better(Candidate{Verdict: Review}, flac) || !better(flac, Candidate{Verdict: Review}) {
		t.Error("a grab ranks above a review")
	}
}

func TestLandingFor_OneFolderPerTorrent(t *testing.T) {
	if got := landingFor("/downloads", "abcd", "x"); got != "/downloads/abcd" {
		t.Error(got)
	}
	if got := landingFor("/downloads", "", "Daft Punk: R.A.M. [FLAC]"); got != "/downloads/daft-punk-r-a-m--flac" {
		t.Error(got)
	}
}

func TestDecide_AnUpgradeTakesOnlyABetterCopy(t *testing.T) {
	up := ram
	up.Floor, up.Held = release.TierLossyLow, "MP3, about 192 kbps"
	same := Candidate{Release: release.Parse("Daft Punk - Random Access Memories [MP3 192]"), InfoHash: "aaaa", Seeders: 3}
	decide(&same, up, anyQuality, nil)
	if same.Verdict != Refused || same.Reasons[0].Code != CodeNotBetter ||
		same.Reason != "No better than the copy you have (MP3, about 192 kbps)." {
		t.Errorf("same quality: %s %q", same.Verdict, same.Reason)
	}
	flac := Candidate{Release: release.Parse("Daft Punk - Random Access Memories [FLAC]"), InfoHash: "bbbb", Seeders: 3}
	decide(&flac, up, anyQuality, nil)
	if flac.Verdict != Grab {
		t.Errorf("a FLAC over a 192 MP3: %s %q", flac.Verdict, flac.Reason)
	}
	// A video rip has no floor: any clean copy is better.
	rip := ram
	decide(&same, rip, anyQuality, nil)
	if same.Verdict != Grab {
		t.Errorf("no floor: %s %q", same.Verdict, same.Reason)
	}
}