bvandeusen
1e3a76eba8
Adapts the existing Fetcher-based MBCAA client to the new Provider abstraction. mbcaaProvider embeds *Fetcher and implements Provider + AlbumCoverProvider + TestableProvider. init() registers a default-config instance; NewMBCAAProviderFromConfig swaps in production config (User-Agent, MinPeriod) at boot. Wrapper approach (rather than reimplementing the HTTP logic) keeps the package compiling during the T4–T8 window: enricher.go and main.go still reference the legacy Fetcher type / NewFetcher constructor / Fetch method, all of which remain unchanged in fetcher.go. A-T8 will consolidate the HTTP logic into this file and delete fetcher.go after the enricher rewrite removes the last legacy call sites. TestConnection hits a hardcoded popular release MBID (Beatles "Abbey Road" UK release) and treats both 200 and 404 as "connection works" — MBCAA needs no auth, so only 5xx / network failures surface. Tests cover ID/DisplayName/Capability metadata, success path, 404→ErrNotFound, disabled-returns-ErrNotFound, Configure toggle, TestConnection variants, and NewMBCAAProviderFromConfig swap.
92 lines
3.2 KiB
Go
92 lines
3.2 KiB
Go
package coverart
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import (
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"context"
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"errors"
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"sync/atomic"
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)
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// mbcaaProvider implements Provider, AlbumCoverProvider, and
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// TestableProvider. It wraps an *Fetcher (the existing
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// MBCAA-specific HTTP client) for the actual fetch logic, adapting
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// the Fetcher's Fetch method to the AlbumCoverProvider interface.
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//
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// The wrapping (rather than reimplementing) is temporary: A-T8 will
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// consolidate fetcher.go's logic into this file and delete fetcher.go.
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// During the T4–T8 window, this struct lets the new provider chain
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// coexist with the legacy Fetcher used by enricher.go and main.go.
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type mbcaaProvider struct {
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fetcher *Fetcher
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enabled atomic.Bool
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}
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// Sample MBID used by TestConnection. The Beatles' "Abbey Road" UK
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// release; verified present on MBCAA at design time. Both 200 (image
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// returned) and 404 (no art for the sample) are treated as "connection
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// works" since MBCAA needs no auth — only network failures surface.
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const mbcaaTestSampleMBID = "f4b3df80-8a6c-3e87-b51e-5c1ee70a78ee"
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func init() {
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// Register with a default-config Fetcher. main.go (in A-T8) will
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// call NewMBCAAProviderFromConfig to swap in the production
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// User-Agent + MinPeriod. Default config values come from
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// FetcherConfig's zero-value handling in NewFetcher.
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Register(&mbcaaProvider{
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fetcher: NewFetcher(FetcherConfig{}),
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})
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}
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// NewMBCAAProviderFromConfig replaces the registered MBCAA provider's
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// internal Fetcher with one built from the supplied config. main.go
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// calls this at boot to set the production User-Agent. Idempotent;
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// safe to call repeatedly.
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func NewMBCAAProviderFromConfig(cfg FetcherConfig) {
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p, err := ProviderByID("mbcaa")
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if err != nil {
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// init() should have registered it; if not, register fresh.
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Register(&mbcaaProvider{fetcher: NewFetcher(cfg)})
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return
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}
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mp, ok := p.(*mbcaaProvider)
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if !ok {
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// Some other provider claimed the "mbcaa" ID — registry bug.
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panic("coverart: provider with ID 'mbcaa' is not *mbcaaProvider")
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}
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mp.fetcher = NewFetcher(cfg)
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}
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func (p *mbcaaProvider) ID() string { return "mbcaa" }
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func (p *mbcaaProvider) DisplayName() string { return "Cover Art Archive" }
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func (p *mbcaaProvider) RequiresAPIKey() bool { return false }
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func (p *mbcaaProvider) DefaultEnabled() bool { return true }
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func (p *mbcaaProvider) Configure(s ProviderSettings) error {
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p.enabled.Store(s.Enabled)
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return nil // MBCAA has no per-operator config beyond enabled
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}
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// FetchAlbumCover delegates to the wrapped Fetcher. The Fetcher's
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// existing Fetch method already returns ErrNotFound / ErrTransient
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// per the contract, so no error mapping is needed.
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func (p *mbcaaProvider) FetchAlbumCover(ctx context.Context, mbid string) ([]byte, error) {
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if !p.enabled.Load() {
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return nil, ErrNotFound // defensive; enricher already filters on enabled
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}
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return p.fetcher.Fetch(ctx, mbid)
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}
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// TestConnection hits the sample MBID's front-500 endpoint. A 200
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// (image bytes) or 404 (no art for sample) both indicate the
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// connection works; 5xx / network errors surface as TestConnection
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// failures.
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func (p *mbcaaProvider) TestConnection(ctx context.Context) error {
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_, err := p.fetcher.Fetch(ctx, mbcaaTestSampleMBID)
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if err == nil {
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return nil
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}
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if errors.Is(err, ErrNotFound) {
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return nil
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}
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return err
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}
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