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|
package main
// Client for the Redacted (Gazelle) API, and the code that mirrors its
// responses into PostgreSQL.
//
// The API is at https://redacted.sh/ajax.php, authenticated by an Authorization
// header, and answers with {"status": "success", "response": ...}. Responses are
// paged; a page count is only present on some endpoints, in which case we assume
// one page.
//
// CAUTION: the JSON stored in redacted.torrents_json.full_json_result is not
// merely a record of the response, it is *input to the database*: the STORED
// generated columns seeding_weight and artist_ids are computed from it (see
// db.go). The normalisation in parseTourGroups below — renaming "snatched" to
// "snatches" and the per-endpoint torrent id field to "torrentId" — is therefore
// load-bearing and must not be "cleaned up".
import (
"context"
"encoding/json"
"fmt"
"io"
"log/slog"
"net/http"
"net/url"
"strconv"
"strings"
"time"
"github.com/jackc/pgx/v5"
"go.opentelemetry.io/otel/trace"
"golang.org/x/sync/errgroup"
)
const redactedHost = "redacted.sh"
// redactedClient talks to the Redacted API.
type redactedClient struct {
apiKey string
http *http.Client
}
func newRedactedClient(apiKey string) *redactedClient {
return &redactedClient{
apiKey: apiKey,
http: &http.Client{Timeout: 60 * time.Second},
}
}
// mkRedactedTorrentLink builds the user-facing link to a torrent group.
func mkRedactedTorrentLink(groupID int) string {
return fmt.Sprintf("https://redacted.sh/torrents.php?id=%d", groupID)
}
// request performs an API call and returns the raw response body.
//
// Rate limiting is handled here: the API answers 429 with a Retry-After header,
// which we honour (clamped to 0..10 seconds, defaulting to 2) and then retry,
// exactly as the Haskell httpJsonWithRateLimit did.
func (c *redactedClient) request(ctx context.Context, action string, args url.Values) ([]byte, error) {
return inSpan1(ctx, "HTTP Request (JSON)", func(ctx context.Context, span trace.Span) ([]byte, error) {
q := url.Values{}
for k, v := range args {
q[k] = v
}
q.Set("action", action)
u := url.URL{
Scheme: "https",
Host: redactedHost,
Path: "/ajax.php",
RawQuery: q.Encode(),
}
attr(span, "http.url", u.String())
attr(span, "redacted.action", action)
for {
req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
if err != nil {
return nil, err
}
req.Header.Set("Authorization", c.apiKey)
resp, err := c.http.Do(req)
if err != nil {
return nil, fmt.Errorf("requesting %s: %w", action, err)
}
body, readErr := io.ReadAll(resp.Body)
resp.Body.Close()
if readErr != nil {
return nil, fmt.Errorf("reading response for %s: %w", action, readErr)
}
attr(span, "http.response.status_code", resp.StatusCode)
switch {
case resp.StatusCode == http.StatusOK:
ct := resp.Header.Get("Content-Type")
if !strings.HasPrefix(ct, "application/json") {
return nil, fmt.Errorf("server returned a non-json body, with content-type %q", ct)
}
return body, nil
case resp.StatusCode == http.StatusTooManyRequests:
wait := retryAfter(resp.Header.Get("Retry-After"))
slog.Info("rate limited by redacted", "action", action, "retry-after", wait)
event(span, "rate limited, waiting")
select {
case <-ctx.Done():
return nil, ctx.Err()
case <-time.After(wait):
}
continue
default:
return nil, fmt.Errorf("server returned a non-200 error code, code %d: %s",
resp.StatusCode, truncate(string(body), 500))
}
}
})
}
// retryAfter parses the Retry-After header, clamped to 0..10s as the Haskell
// version did (an unbounded value would hang the request).
func retryAfter(h string) time.Duration {
n, err := strconv.Atoi(strings.TrimSpace(h))
if err != nil {
return 2 * time.Second
}
if n < 0 {
n = 0
}
if n > 10 {
n = 10
}
return time.Duration(n) * time.Second
}
func truncate(s string, n int) string {
if len(s) <= n {
return s
}
return s[:n] + "…"
}
// redactedReply is the standard envelope.
type redactedReply struct {
Status string `json:"status"`
Error string `json:"error"`
Response json.RawMessage `json:"response"`
}
// requestJSON performs a call and unwraps the standard envelope, returning the
// "response" value and the page count (1 when the endpoint does not page).
func (c *redactedClient) requestJSON(ctx context.Context, action string, args url.Values) (json.RawMessage, int, error) {
body, err := c.request(ctx, action, args)
if err != nil {
return nil, 0, err
}
var reply redactedReply
if err := json.Unmarshal(body, &reply); err != nil {
return nil, 0, fmt.Errorf("response was not valid JSON: %w", err)
}
if reply.Status != "success" {
if reply.Error != "" {
return nil, 0, fmt.Errorf("status was not \"success\", but %s: %s", reply.Status, reply.Error)
}
return nil, 0, fmt.Errorf("status was not \"success\", but %s", reply.Status)
}
// `pages` is optional; when missing there is exactly one page.
var pageInfo struct {
Pages *json.Number `json:"pages"`
}
pages := 1
if err := json.Unmarshal(reply.Response, &pageInfo); err == nil && pageInfo.Pages != nil {
if n, err := pageInfo.Pages.Int64(); err == nil && n > 0 {
pages = int(n)
}
}
return reply.Response, pages, nil
}
// ---------------------------------------------------------------------------
// Tour groups: the shape both `browse` and `artist` return, modulo field names
// ---------------------------------------------------------------------------
// tourGroup is one release group together with its torrents.
type tourGroup struct {
GroupID int
GroupName string
FullJSONResult json.RawMessage
Torrents []tourGroupTorrent
}
type tourGroupTorrent struct {
TorrentID int
FullJSONResult json.RawMessage
}
// tourGroupFieldNames captures the two ways the API names the same things.
//
// action=browse returns groups with a "torrents" array whose elements have
// "torrentId"; action=artist returns "torrentgroup" entries with a "torrent"
// array whose elements have "id".
type tourGroupFieldNames struct {
torrentField string // "torrents" or "torrent"
torrentIDKey string // "torrentId" or "id"
}
var (
searchFieldNames = tourGroupFieldNames{torrentField: "torrents", torrentIDKey: "torrentId"}
artistFieldNames = tourGroupFieldNames{torrentField: "torrent", torrentIDKey: "id"}
)
// parseTourGroups extracts release groups from an array of API objects.
//
// Entries without the torrent field are skipped: the API also returns
// non-torrent items (e.g. guitar tabs, see Dream Theater "Systematic Chaos").
//
// The normalisation applied to each torrent object is load-bearing, see the
// warning at the top of this file:
// - "snatched" is renamed to "snatches", because some endpoints use the former
// while calc_seeding_weight reads the latter;
// - the endpoint-specific torrent id key is renamed to "torrentId".
//
// The group object stores everything *except* the torrent array, which is stored
// separately in redacted.torrents_json.
func parseTourGroups(raw json.RawMessage, names tourGroupFieldNames) ([]tourGroup, error) {
var items []map[string]json.RawMessage
if err := json.Unmarshal(raw, &items); err != nil {
return nil, fmt.Errorf("expected an array of torrent groups: %w", err)
}
groups := make([]tourGroup, 0, len(items))
for _, item := range items {
torrentsRaw, ok := item[names.torrentField]
if !ok {
// Not a torrent group.
continue
}
groupID, err := jsonInt(item["groupId"])
if err != nil {
return nil, fmt.Errorf("groupId: %w", err)
}
var groupName string
if err := json.Unmarshal(item["groupName"], &groupName); err != nil {
return nil, fmt.Errorf("groupName: %w", err)
}
// The stored group JSON excludes the torrents.
groupJSON := make(map[string]json.RawMessage, len(item))
for k, v := range item {
if k == names.torrentField {
continue
}
groupJSON[k] = v
}
groupBytes, err := json.Marshal(groupJSON)
if err != nil {
return nil, err
}
var torrentObjs []map[string]json.RawMessage
if err := json.Unmarshal(torrentsRaw, &torrentObjs); err != nil {
return nil, fmt.Errorf("torrent array of group %d: %w", groupID, err)
}
torrents := make([]tourGroupTorrent, 0, len(torrentObjs))
for _, t := range torrentObjs {
normalised := make(map[string]json.RawMessage, len(t))
for k, v := range t {
switch k {
case "snatched":
// Some torrent objects use “snatched” instead of “snatches”.
normalised["snatches"] = v
case names.torrentIDKey:
normalised["torrentId"] = v
default:
normalised[k] = v
}
}
torrentID, err := jsonInt(normalised["torrentId"])
if err != nil {
return nil, fmt.Errorf("torrent id of group %d: %w", groupID, err)
}
b, err := json.Marshal(normalised)
if err != nil {
return nil, err
}
torrents = append(torrents, tourGroupTorrent{TorrentID: torrentID, FullJSONResult: b})
}
groups = append(groups, tourGroup{
GroupID: groupID,
GroupName: groupName,
FullJSONResult: groupBytes,
Torrents: torrents,
})
}
return groups, nil
}
// jsonInt reads an integer that the API may encode as a number or a string.
func jsonInt(raw json.RawMessage) (int, error) {
if len(raw) == 0 {
return 0, fmt.Errorf("missing value")
}
var n json.Number
if err := json.Unmarshal(raw, &n); err == nil {
i, err := n.Int64()
if err != nil {
return 0, err
}
return int(i), nil
}
var s string
if err := json.Unmarshal(raw, &s); err == nil {
return strconv.Atoi(s)
}
return 0, fmt.Errorf("not an integer: %s", truncate(string(raw), 60))
}
// ---------------------------------------------------------------------------
// Paged search and insert
// ---------------------------------------------------------------------------
// pagedFetchBatchSize bounds how many API pages are in flight at once.
//
// The Haskell version used a QSem of 5 around a conduit; errgroup.SetLimit is
// the direct equivalent.
const pagedFetchBatchSize = 5
// searchAndInsert runs a `browse` search and stores every page of results.
//
// maxPages == 0 means "all pages", as in the Haskell version.
func (a *app) searchAndInsert(ctx context.Context, args url.Values, maxPages int) ([]int, error) {
return a.pagedSearchAndInsert(ctx, maxPages, searchFieldNames,
func(ctx context.Context, page int) (json.RawMessage, int, error) {
q := url.Values{}
for k, v := range args {
q[k] = v
}
if page > 0 {
q.Set("page", strconv.Itoa(page))
}
raw, pages, err := a.redacted.requestJSON(ctx, "browse", q)
if err != nil {
return nil, 0, err
}
// The groups live under "results".
var wrapper struct {
Results json.RawMessage `json:"results"`
}
if err := json.Unmarshal(raw, &wrapper); err != nil {
return nil, 0, err
}
return wrapper.Results, pages, nil
})
}
// refreshArtist re-fetches an artist's whole discography and stores it.
func (a *app) refreshArtist(ctx context.Context, artistID int) ([]int, error) {
return a.pagedSearchAndInsert(ctx, 0, artistFieldNames,
func(ctx context.Context, page int) (json.RawMessage, int, error) {
q := url.Values{}
q.Set("id", strconv.Itoa(artistID))
if page > 0 {
q.Set("page", strconv.Itoa(page))
}
raw, pages, err := a.redacted.requestJSON(ctx, "artist", q)
if err != nil {
return nil, 0, err
}
var wrapper struct {
TorrentGroup json.RawMessage `json:"torrentgroup"`
}
if err := json.Unmarshal(raw, &wrapper); err != nil {
return nil, 0, err
}
return wrapper.TorrentGroup, pages, nil
})
}
// pagedSearchAndInsert fetches page 1 to learn the page count, then fetches the
// remaining pages with bounded concurrency and inserts everything.
//
// Returns the ids of all torrents seen.
func (a *app) pagedSearchAndInsert(
ctx context.Context,
maxPages int,
names tourGroupFieldNames,
fetch func(ctx context.Context, page int) (json.RawMessage, int, error),
) ([]int, error) {
return inSpan1(ctx, "Redacted paged search and insert", func(ctx context.Context, span trace.Span) ([]int, error) {
firstRaw, pages, err := fetch(ctx, 0)
if err != nil {
return nil, err
}
total := pages
if maxPages > 0 && maxPages < total {
total = maxPages
}
attr(span, "search.pages.available", pages)
attr(span, "search.pages.fetching", total)
slog.Info("got the first page", "more_pages", total-1)
// Page results in order: page 1 first, then 2..total.
raws := make([]json.RawMessage, total)
raws[0] = firstRaw
if total > 1 {
g, gctx := errgroup.WithContext(ctx)
g.SetLimit(pagedFetchBatchSize)
for p := 2; p <= total; p++ {
p := p
g.Go(func() error {
raw, _, err := fetch(gctx, p)
if err != nil {
return fmt.Errorf("page %d: %w", p, err)
}
raws[p-1] = raw
return nil
})
}
if err := g.Wait(); err != nil {
return nil, err
}
}
var allGroups []tourGroup
for _, raw := range raws {
if len(raw) == 0 {
continue
}
groups, err := parseTourGroups(raw, names)
if err != nil {
return nil, err
}
allGroups = append(allGroups, groups...)
}
if len(allGroups) == 0 {
return nil, nil
}
var torrentIDs []int
err = withTx(ctx, a.pool, func(ctx context.Context, tx pgx.Tx) error {
ids, err := insertTourGroupsAndTorrents(ctx, tx, allGroups)
torrentIDs = ids
return err
})
if err != nil {
return nil, err
}
attr(span, "search.torrents.inserted", len(torrentIDs))
return torrentIDs, nil
})
}
// insertTourGroupsAndTorrents writes groups, their torrents and the artists
// mentioned by either.
//
// Groups and torrents are deleted before insertion, matching the Haskell
// version: a re-fetch is authoritative, and the delete also drops torrents that
// disappeared upstream.
func insertTourGroupsAndTorrents(ctx context.Context, tx pgx.Tx, groups []tourGroup) ([]int, error) {
// Deduplicate groups by id: the same group can appear on several pages, and
// ON CONFLICT cannot handle a conflict target twice in one statement.
seenGroup := map[int]bool{}
deduped := make([]tourGroup, 0, len(groups))
for _, g := range groups {
if seenGroup[g.GroupID] {
continue
}
seenGroup[g.GroupID] = true
deduped = append(deduped, g)
}
groupIDs := make([]int, len(deduped))
groupNames := make([]string, len(deduped))
groupJSONs := make([][]byte, len(deduped))
for i, g := range deduped {
groupIDs[i] = g.GroupID
groupNames[i] = g.GroupName
groupJSONs[i] = g.FullJSONResult
}
if _, err := tx.Exec(ctx,
`DELETE FROM redacted.torrent_groups WHERE group_id = ANY ($1::integer[])`,
groupIDs); err != nil {
return nil, fmt.Errorf("deleting torrent groups: %w", err)
}
// Insert groups, keeping the mapping group_id -> primary key.
rows, err := tx.Query(ctx, `
INSERT INTO redacted.torrent_groups (group_id, group_name, full_json_result)
SELECT * FROM UNNEST($1::integer[], $2::text[], $3::jsonb[])
ON CONFLICT (group_id) DO UPDATE SET
group_id = excluded.group_id,
group_name = excluded.group_name,
full_json_result = excluded.full_json_result
RETURNING group_id, id`,
groupIDs, groupNames, groupJSONs)
if err != nil {
return nil, fmt.Errorf("inserting torrent groups: %w", err)
}
pgIDByGroupID := map[int]int{}
for rows.Next() {
var groupID, pgID int
if err := rows.Scan(&groupID, &pgID); err != nil {
rows.Close()
return nil, err
}
pgIDByGroupID[groupID] = pgID
}
rows.Close()
if err := rows.Err(); err != nil {
return nil, err
}
// Torrents, deduplicated by torrent id for the same reason as above.
var (
torrentGroupPGIDs []int
torrentIDs []int
torrentJSONs [][]byte
)
seenTorrent := map[int]bool{}
for _, g := range deduped {
pgID, ok := pgIDByGroupID[g.GroupID]
if !ok {
return nil, fmt.Errorf("no primary key for group %d after insert", g.GroupID)
}
for _, t := range g.Torrents {
if seenTorrent[t.TorrentID] {
continue
}
seenTorrent[t.TorrentID] = true
torrentGroupPGIDs = append(torrentGroupPGIDs, pgID)
torrentIDs = append(torrentIDs, t.TorrentID)
torrentJSONs = append(torrentJSONs, t.FullJSONResult)
}
}
if len(torrentIDs) > 0 {
if _, err := tx.Exec(ctx,
`DELETE FROM redacted.torrents_json WHERE torrent_id = ANY ($1::integer[])`,
torrentIDs); err != nil {
return nil, fmt.Errorf("deleting torrents: %w", err)
}
if _, err := tx.Exec(ctx, `
INSERT INTO redacted.torrents_json (torrent_group, torrent_id, full_json_result)
SELECT * FROM UNNEST($1::integer[], $2::integer[], $3::jsonb[])`,
torrentGroupPGIDs, torrentIDs, torrentJSONs); err != nil {
return nil, fmt.Errorf("inserting torrents: %w", err)
}
}
// Artists are extracted from both group and torrent JSON.
var jsons [][]byte
for _, g := range deduped {
jsons = append(jsons, g.FullJSONResult)
for _, t := range g.Torrents {
jsons = append(jsons, t.FullJSONResult)
}
}
if err := insertArtists(ctx, tx, jsons); err != nil {
return nil, err
}
return torrentIDs, nil
}
// artistRef is an (id, name) pair as it appears in the API's "artists" arrays.
type artistRef struct {
ID int `json:"id"`
Name string `json:"name"`
}
// insertArtists maintains the artist id -> name lookup table.
//
// The first name seen for an id wins, matching the Haskell version's use of
// Map.fromList.
func insertArtists(ctx context.Context, tx pgx.Tx, jsons [][]byte) error {
byID := map[int]string{}
var order []int
for _, raw := range jsons {
var obj struct {
Artists []artistRef `json:"artists"`
}
if err := json.Unmarshal(raw, &obj); err != nil {
// Not every object has an artists array; that is not an error.
continue
}
for _, ar := range obj.Artists {
if ar.ID == 0 || ar.Name == "" {
continue
}
if _, seen := byID[ar.ID]; !seen {
byID[ar.ID] = ar.Name
order = append(order, ar.ID)
}
}
}
if len(order) == 0 {
return nil
}
ids := make([]int, len(order))
names := make([]string, len(order))
for i, id := range order {
ids[i] = id
names[i] = byID[id]
}
if _, err := tx.Exec(ctx, `
INSERT INTO redacted.artists (artist_id, artist_name)
SELECT * FROM UNNEST($1::integer[], $2::text[])
ON CONFLICT (artist_id) DO UPDATE SET
artist_name = EXCLUDED.artist_name,
updated_at = NOW()`,
ids, names); err != nil {
return fmt.Errorf("inserting artists: %w", err)
}
slog.Info("inserted/updated artists", "count", len(ids))
return nil
}
// ---------------------------------------------------------------------------
// Torrent files
// ---------------------------------------------------------------------------
// freeleechStatus reports whether a download consumed a freeleech token.
type freeleechStatus int
const (
freeleechPossible freeleechStatus = iota
noTokensRemaining
)
// getTorrentFile downloads a .torrent, using a freeleech token when that seems
// worthwhile.
//
// Token handling, ported as-is: tokens are used unless they were found to be
// exhausted less than 24 hours ago. If the API rejects the request because no
// tokens are left, we retry immediately without a token and report that back so
// the caller can record the exhaustion.
func (a *app) getTorrentFile(ctx context.Context, torrentID int, exhaustedAt *time.Time) ([]byte, freeleechStatus, error) {
type result struct {
file []byte
status freeleechStatus
}
r, err := inSpan1(ctx, "Redacted Get Torrent File", func(ctx context.Context, span trace.Span) (result, error) {
attr(span, "torrent.id", torrentID)
useTokens := true
if exhaustedAt != nil {
if time.Since(*exhaustedAt) < 24*time.Hour {
useTokens = false
} else {
event(span, "Testing freeleech tokens (24+ hours since exhaustion)")
}
}
attr(span, "freeleech.use_tokens", useTokens)
file, exhausted, err := a.downloadTorrent(ctx, torrentID, useTokens)
if err != nil {
return result{}, err
}
if !exhausted {
return result{file: file, status: freeleechPossible}, nil
}
event(span, "Freeleech tokens exhausted, retrying without tokens")
file, exhausted, err = a.downloadTorrent(ctx, torrentID, false)
if err != nil {
return result{}, err
}
if exhausted {
return result{}, fmt.Errorf("unexpected token exhaustion error on retry without tokens")
}
return result{file: file, status: noTokensRemaining}, nil
})
return r.file, r.status, err
}
// downloadTorrent performs one download attempt.
//
// The second return value reports the specific "no freeleech tokens left"
// failure, which the API signals with a 400 and a JSON error message.
func (a *app) downloadTorrent(ctx context.Context, torrentID int, useToken bool) ([]byte, bool, error) {
q := url.Values{}
q.Set("action", "download")
q.Set("id", strconv.Itoa(torrentID))
if useToken {
q.Set("usetoken", "1")
}
u := url.URL{Scheme: "https", Host: redactedHost, Path: "/ajax.php", RawQuery: q.Encode()}
req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
if err != nil {
return nil, false, err
}
req.Header.Set("Authorization", a.redacted.apiKey)
resp, err := a.redacted.http.Do(req)
if err != nil {
return nil, false, err
}
defer resp.Body.Close()
body, err := io.ReadAll(resp.Body)
if err != nil {
return nil, false, err
}
ct := resp.Header.Get("Content-Type")
switch {
case resp.StatusCode == http.StatusOK && strings.HasPrefix(ct, "application/x-bittorrent"):
return body, false, nil
case resp.StatusCode == http.StatusOK && ct != "":
return nil, false, fmt.Errorf("redacted returned a non-torrent body, with content-type %q", ct)
case resp.StatusCode == http.StatusOK:
return nil, false, fmt.Errorf("redacted returned a body with unspecified content type")
case resp.StatusCode == http.StatusBadRequest:
var errReply struct {
Error string `json:"error"`
}
if err := json.Unmarshal(body, &errReply); err == nil &&
strings.Contains(errReply.Error, "You do not have any freeleech tokens left") {
return nil, true, nil
}
return nil, false, fmt.Errorf("redacted returned a 400 error: %s", truncate(string(body), 300))
default:
return nil, false, fmt.Errorf("redacted returned a non-200 error code, code %d", resp.StatusCode)
}
}
// getTorrentFileAndInsert downloads a torrent file and stores it.
func (a *app) getTorrentFileAndInsert(ctx context.Context, torrentID int, exhaustedAt *time.Time) ([]byte, freeleechStatus, error) {
file, status, err := a.getTorrentFile(ctx, torrentID, exhaustedAt)
if err != nil {
return nil, 0, err
}
tag, err := a.pool.Exec(ctx, `
UPDATE redacted.torrents_json
SET torrent_file = $1::bytea
WHERE torrent_id = $2::integer`,
file, torrentID)
if err != nil {
return nil, 0, fmt.Errorf("storing torrent file: %w", err)
}
if err := assertOneUpdated("getTorrentFileAndInsert", tag.RowsAffected()); err != nil {
return nil, 0, err
}
return file, status, nil
}
// getTorrentFileByID returns a previously downloaded torrent file, if any.
func (a *app) getTorrentFileByID(ctx context.Context, torrentID int) ([]byte, error) {
var file []byte
err := a.pool.QueryRow(ctx, `
SELECT torrent_file FROM redacted.torrents
WHERE torrent_id = $1::integer`, torrentID).Scan(&file)
if err == pgx.ErrNoRows {
return nil, nil
}
if err != nil {
return nil, err
}
return file, nil
}
// updateTransmissionTorrentHashByID records which Transmission torrent
// corresponds to a Redacted torrent.
func (a *app) updateTransmissionTorrentHashByID(ctx context.Context, torrentID int, hash string) error {
_, err := a.pool.Exec(ctx, `
UPDATE redacted.torrents_json
SET transmission_torrent_hash = $1::text
WHERE torrent_id = $2::integer`, hash, torrentID)
return err
}
// getTorrentByID returns the stored API JSON for a torrent, for the UI's
// "show raw data" toggle.
func (a *app) getTorrentByID(ctx context.Context, torrentID int) (json.RawMessage, error) {
var raw json.RawMessage
err := a.pool.QueryRow(ctx, `
SELECT full_json_result FROM redacted.torrents
WHERE torrent_id = $1::integer`, torrentID).Scan(&raw)
if err != nil {
return nil, err
}
return raw, nil
}
// getArtistNameByID resolves an artist id to a name for page titles.
func (a *app) getArtistNameByID(ctx context.Context, artistID int) (string, error) {
var name string
err := a.pool.QueryRow(ctx, `
SELECT artist_name FROM redacted.artists
WHERE artist_id = $1::int
LIMIT 1`, artistID).Scan(&name)
if err == pgx.ErrNoRows {
return "", nil
}
if err != nil {
return "", err
}
return name, nil
}
// ---------------------------------------------------------------------------
// Similar artists (recommendations)
// ---------------------------------------------------------------------------
type similarArtist struct {
ArtistID int `json:"id"`
ArtistName string `json:"name"`
Score int `json:"score"`
}
// getSimilarArtists asks the API for artists related to the given one.
func (a *app) getSimilarArtists(ctx context.Context, artistID int, limit int) ([]similarArtist, error) {
q := url.Values{}
q.Set("id", strconv.Itoa(artistID))
if limit > 0 {
q.Set("limit", strconv.Itoa(limit))
}
raw, _, err := a.redacted.requestJSON(ctx, "similar_artists", q)
if err != nil {
return nil, err
}
var out []similarArtist
if err := json.Unmarshal(raw, &out); err != nil {
return nil, fmt.Errorf("parsing similar artists: %w", err)
}
return out, nil
}
// insertSimilarArtists replaces the stored recommendations for one artist.
func insertSimilarArtists(ctx context.Context, tx pgx.Tx, artistID int, similar []similarArtist) error {
if _, err := tx.Exec(ctx,
`DELETE FROM redacted.similar_artists WHERE artist_id = $1::integer`, artistID); err != nil {
return err
}
if len(similar) == 0 {
return nil
}
artistIDs := make([]int, len(similar))
similarIDs := make([]int, len(similar))
names := make([]string, len(similar))
scores := make([]int, len(similar))
for i, s := range similar {
artistIDs[i] = artistID
similarIDs[i] = s.ArtistID
names[i] = s.ArtistName
scores[i] = s.Score
}
_, err := tx.Exec(ctx, `
INSERT INTO redacted.similar_artists
(artist_id, similar_artist_id, similar_artist_name, score)
SELECT * FROM UNNEST($1::integer[], $2::integer[], $3::text[], $4::integer[])`,
artistIDs, similarIDs, names, scores)
return err
}
// populateSimilarArtistsForFavourites fetches related artists for every
// favourite artist.
//
// "Favourite" means: an artist we have snatched a torrent of, or one explicitly
// marked by visiting their page.
func (a *app) populateSimilarArtistsForFavourites(ctx context.Context) (int, error) {
return inSpan1(ctx, "Populate Similar Artists for Favorites", func(ctx context.Context, span trace.Span) (int, error) {
rows, err := a.pool.Query(ctx, `
SELECT DISTINCT unnest(artist_ids) as artist_id
FROM redacted.torrents_json
WHERE transmission_torrent_hash IS NOT NULL
UNION
SELECT artist_id
FROM redacted.artist_favourites
ORDER BY artist_id`)
if err != nil {
return 0, err
}
var ids []int
for rows.Next() {
var id int
if err := rows.Scan(&id); err != nil {
rows.Close()
return 0, err
}
ids = append(ids, id)
}
rows.Close()
if err := rows.Err(); err != nil {
return 0, err
}
attr(span, "favorite-artists.count", len(ids))
for _, id := range ids {
similar, err := a.getSimilarArtists(ctx, id, 20)
if err != nil {
return 0, err
}
err = withTx(ctx, a.pool, func(ctx context.Context, tx pgx.Tx) error {
return insertSimilarArtists(ctx, tx, id, similar)
})
if err != nil {
return 0, err
}
slog.Info("populated similar artists", "artist", id, "count", len(similar))
}
return len(ids), nil
})
}
// populateReleasesForSimilarArtists searches for releases by recommended artists
// we have no data for yet, so that recommendations have something to point at.
func (a *app) populateReleasesForSimilarArtists(ctx context.Context) (int, error) {
return inSpan1(ctx, "Populate Releases for Similar Artists", func(ctx context.Context, span trace.Span) (int, error) {
rows, err := a.pool.Query(ctx, `
SELECT DISTINCT sa.similar_artist_id, sa.similar_artist_name
FROM redacted.similar_artists sa
WHERE sa.similar_artist_id NOT IN (
SELECT DISTINCT unnest(artist_ids)
FROM redacted.torrents_json
)
ORDER BY sa.similar_artist_id
LIMIT 20`)
if err != nil {
return 0, err
}
type artist struct {
id int
name string
}
var artists []artist
for rows.Next() {
var ar artist
if err := rows.Scan(&ar.id, &ar.name); err != nil {
rows.Close()
return 0, err
}
artists = append(artists, ar)
}
rows.Close()
if err := rows.Err(); err != nil {
return 0, err
}
attr(span, "similar-artists-to-fetch.count", len(artists))
for _, ar := range artists {
slog.Info("searching for releases by similar artist", "name", ar.name, "id", ar.id)
q := url.Values{}
q.Set("artistname", ar.name)
q.Set("releasetype", releaseTypesOverapproximatedWithout(releaseTypeCompilation))
// Only the first page: enough to suggest a release.
ids, err := a.searchAndInsert(ctx, q, 1)
if err != nil {
return 0, err
}
slog.Info("found new torrents for similar artist", "name", ar.name, "count", len(ids))
}
return len(artists), nil
})
}
// ---------------------------------------------------------------------------
// Settings
// ---------------------------------------------------------------------------
// settings is the small key/value store in redacted.settings.
type settings struct {
// freeleechTokensExhaustedAt is when the API last told us we were out of
// freeleech tokens; nil means "not exhausted".
freeleechTokensExhaustedAt *time.Time
}
func (a *app) getSettings(ctx context.Context) (settings, error) {
return inSpan1(ctx, "Get Settings", func(ctx context.Context, span trace.Span) (settings, error) {
var s settings
rows, err := a.pool.Query(ctx, `SELECT key, value FROM redacted.settings`)
if err != nil {
return s, err
}
defer rows.Close()
for rows.Next() {
var key string
var value []byte
if err := rows.Scan(&key, &value); err != nil {
return s, err
}
if key != "freelechTokensExhaustedAt" {
continue
}
var ts string
// A JSON null means the exhaustion was explicitly cleared. Note
// that unmarshalling null into a string succeeds and yields "", so
// it has to be checked for separately.
if err := json.Unmarshal(value, &ts); err != nil || ts == "" {
continue
}
t, err := parseSettingsTime(ts)
if err != nil {
slog.Warn("ignoring unparseable freeleech timestamp", "value", ts, "err", err)
continue
}
s.freeleechTokensExhaustedAt = &t
}
return s, rows.Err()
})
}
// parseSettingsTime accepts both the Haskell `show`n UTCTime already in the
// database and RFC 3339, so the two implementations can share a database.
func parseSettingsTime(s string) (time.Time, error) {
if t, err := time.Parse(time.RFC3339Nano, s); err == nil {
return t, nil
}
// Haskell's UTCTime Show instance, e.g. "2025-01-09 12:34:56.789 UTC".
for _, layout := range []string{
"2006-01-02 15:04:05.999999999 UTC",
"2006-01-02 15:04:05 UTC",
} {
if t, err := time.Parse(layout, s); err == nil {
return t, nil
}
}
return time.Time{}, fmt.Errorf("unrecognised time format %q", s)
}
// setFreeleechExhausted records or clears the token exhaustion timestamp.
func (a *app) setFreeleechExhausted(ctx context.Context, at *time.Time) error {
var value []byte
if at == nil {
value = []byte("null")
} else {
b, err := json.Marshal(at.UTC().Format(time.RFC3339Nano))
if err != nil {
return err
}
value = b
}
_, err := a.pool.Exec(ctx, `
INSERT INTO redacted.settings (key, value)
VALUES ('freelechTokensExhaustedAt', $1::jsonb)
ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`, value)
return err
}
|