Files
notarius/internal/modules/dnd/spells/catalog/effective.go

428 lines
14 KiB
Go

package catalog
import (
"bytes"
"crypto/sha256"
"encoding/hex"
"encoding/json"
"fmt"
"io"
"mime"
"sort"
"strings"
"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
)
const (
SpellCatalogReferenceSlot = "spell_catalog"
overlaySchemaVersion = "notarius.dnd.spell-catalog-overlay.v1"
)
// EffectiveCatalog is the immutable spell-name recognition catalog assembled
// from the embedded SRD catalog and an optional set of campaign overlays.
type EffectiveCatalog struct {
baseID string
ruleset string
overlayIDs []string
canonicalNames []string
lookup map[string]string
digest string
}
func (c EffectiveCatalog) BaseID() string { return c.baseID }
func (c EffectiveCatalog) Ruleset() string { return c.ruleset }
func (c EffectiveCatalog) Digest() string { return c.digest }
func (c EffectiveCatalog) OverlayIDs() []string { return append([]string(nil), c.overlayIDs...) }
// CanonicalNames returns the globally sorted canonical spell names without
// exposing the catalog's internal storage.
func (c EffectiveCatalog) CanonicalNames() []string {
return append([]string(nil), c.canonicalNames...)
}
// Lookup matches canonical names and aliases after applying the same
// normalization used by the embedded catalog. The returned string is the
// established canonical display name.
func (c EffectiveCatalog) Lookup(name string) (string, bool) {
canonical, ok := c.lookup[lookupKey(name)]
return canonical, ok
}
// ResolveEffectiveCatalog loads the embedded SRD catalog and applies the
// optional spell-catalog overlay found in the cloned reference set. It does
// not resolve paths or perform filesystem access.
func ResolveEffectiveCatalog(references contracts.ReferenceSet) (EffectiveCatalog, error) {
base, err := LoadSRD5E2014()
if err != nil {
return EffectiveCatalog{}, err
}
cloned := cloneReferenceSet(references)
slot, ok := cloned.Slots[SpellCatalogReferenceSlot]
if !ok || len(slot.Items) == 0 {
return composeEffectiveCatalog(base, nil)
}
if len(slot.Items) != 1 {
return EffectiveCatalog{}, fmt.Errorf("reference slot %q must contain zero or one item", SpellCatalogReferenceSlot)
}
item := slot.Items[0]
mediaType, _, err := mime.ParseMediaType(item.MediaType)
if err != nil {
return EffectiveCatalog{}, fmt.Errorf("reference slot %q item media type %q is invalid: %w", SpellCatalogReferenceSlot, item.MediaType, err)
}
if !strings.EqualFold(mediaType, "application/json") {
return EffectiveCatalog{}, fmt.Errorf("reference slot %q item media type %q must be application/json", SpellCatalogReferenceSlot, item.MediaType)
}
overlays, err := decodeOverlayBundle(item.Content)
if err != nil {
return EffectiveCatalog{}, err
}
return composeEffectiveCatalog(base, overlays)
}
type overlayBundle struct {
SchemaVersion string `json:"schema_version"`
Catalogs []overlayCatalog `json:"catalogs"`
}
type overlayCatalog struct {
ID string `json:"id"`
Ruleset string `json:"ruleset"`
Source overlaySource `json:"source"`
Spells []overlaySpell `json:"spells"`
}
type overlaySource struct {
Title string `json:"title"`
Version json.RawMessage `json:"version"`
URL json.RawMessage `json:"url"`
License json.RawMessage `json:"license"`
}
type overlaySpell struct {
Name string `json:"name"`
Aliases json.RawMessage `json:"aliases,omitempty"`
}
func decodeOverlayBundle(content []byte) ([]overlayCatalog, error) {
decoder := json.NewDecoder(bytes.NewReader(content))
decoder.DisallowUnknownFields()
var bundle overlayBundle
if err := decoder.Decode(&bundle); err != nil {
return nil, fmt.Errorf("decode spell catalog overlay: %w", err)
}
var trailing any
if err := decoder.Decode(&trailing); err != io.EOF {
return nil, fmt.Errorf("decode spell catalog overlay: multiple JSON values")
}
if bundle.SchemaVersion != overlaySchemaVersion {
return nil, fmt.Errorf("spell catalog overlay schema_version %q does not match %q", bundle.SchemaVersion, overlaySchemaVersion)
}
if len(bundle.Catalogs) == 0 {
return nil, fmt.Errorf("spell catalog overlay catalogs must not be empty")
}
seenIDs := make(map[string]struct{}, len(bundle.Catalogs))
for catalogIndex := range bundle.Catalogs {
catalog := &bundle.Catalogs[catalogIndex]
if catalog.ID != strings.TrimSpace(catalog.ID) || catalog.ID == "" {
return nil, fmt.Errorf("catalog[%d] id must be non-empty and trimmed", catalogIndex)
}
if _, exists := seenIDs[catalog.ID]; exists {
return nil, fmt.Errorf("catalog id %q is duplicated", catalog.ID)
}
seenIDs[catalog.ID] = struct{}{}
if catalog.Ruleset != SRD5E2014Ruleset {
return nil, fmt.Errorf("catalog %q ruleset %q does not match %q", catalog.ID, catalog.Ruleset, SRD5E2014Ruleset)
}
if catalog.Source.Title != strings.TrimSpace(catalog.Source.Title) || catalog.Source.Title == "" {
return nil, fmt.Errorf("catalog %q source title must be non-empty and trimmed", catalog.ID)
}
for field, raw := range map[string]json.RawMessage{
"version": catalog.Source.Version,
"url": catalog.Source.URL,
"license": catalog.Source.License,
} {
if _, err := decodeOptionalString(raw); err != nil {
return nil, fmt.Errorf("catalog %q source %s: %w", catalog.ID, field, err)
}
}
if len(catalog.Spells) == 0 {
return nil, fmt.Errorf("catalog %q spells must not be empty", catalog.ID)
}
for spellIndex := range catalog.Spells {
spell := &catalog.Spells[spellIndex]
if spell.Name != strings.TrimSpace(spell.Name) || spell.Name == "" {
return nil, fmt.Errorf("catalog %q spell[%d] name must be non-empty and trimmed", catalog.ID, spellIndex)
}
_, err := decodeAliases(spell.Aliases)
if err != nil {
return nil, fmt.Errorf("catalog %q spell %q aliases: %w", catalog.ID, spell.Name, err)
}
}
}
return bundle.Catalogs, nil
}
func decodeOptionalString(raw json.RawMessage) (string, error) {
if len(raw) == 0 {
return "", nil
}
if bytes.Equal(bytes.TrimSpace(raw), []byte("null")) {
return "", fmt.Errorf("must be a string when present")
}
var value string
if err := json.Unmarshal(raw, &value); err != nil {
return "", fmt.Errorf("must be a string when present: %w", err)
}
return value, nil
}
func decodeAliases(raw json.RawMessage) ([]string, error) {
if len(raw) == 0 {
return nil, nil
}
if bytes.Equal(bytes.TrimSpace(raw), []byte("null")) {
return nil, fmt.Errorf("must be an array when present")
}
var aliases []string
if err := json.Unmarshal(raw, &aliases); err != nil {
return nil, fmt.Errorf("must be an array of strings: %w", err)
}
for index, alias := range aliases {
if alias != strings.TrimSpace(alias) || alias == "" {
return nil, fmt.Errorf("value at index %d must be non-empty and trimmed", index)
}
}
return aliases, nil
}
type effectiveSpell struct {
name string
canonicalKey string
aliases map[string]string
}
type effectiveBuilder struct {
spells map[string]*effectiveSpell
canonicalByKey map[string]string
lookup map[string]string
}
func composeEffectiveCatalog(base Catalog, overlays []overlayCatalog) (EffectiveCatalog, error) {
builder := effectiveBuilder{
spells: make(map[string]*effectiveSpell, len(base.spells)),
canonicalByKey: make(map[string]string, len(base.lookup)),
lookup: make(map[string]string, len(base.lookup)),
}
for _, spell := range base.Spells() {
if err := builder.addCanonical(spell.Name); err != nil {
return EffectiveCatalog{}, fmt.Errorf("base catalog: %w", err)
}
for _, alias := range spell.Aliases {
if err := builder.addAlias(spell.Name, alias); err != nil {
return EffectiveCatalog{}, fmt.Errorf("base catalog: %w", err)
}
}
}
sort.Slice(overlays, func(i, j int) bool { return overlays[i].ID < overlays[j].ID })
overlayIDs := make([]string, len(overlays))
for i, overlay := range overlays {
overlayIDs[i] = overlay.ID
for _, spell := range overlay.Spells {
canonical, err := builder.ensureCanonical(spell.Name)
if err != nil {
return EffectiveCatalog{}, fmt.Errorf("catalog %q: %w", overlay.ID, err)
}
aliases, err := decodeAliases(spell.Aliases)
if err != nil {
return EffectiveCatalog{}, fmt.Errorf("catalog %q spell %q aliases: %w", overlay.ID, spell.Name, err)
}
for _, alias := range aliases {
if err := builder.addAlias(canonical, alias); err != nil {
return EffectiveCatalog{}, fmt.Errorf("catalog %q spell %q: %w", overlay.ID, spell.Name, err)
}
}
}
}
canonicalNames := make([]string, 0, len(builder.spells))
for _, spell := range builder.spells {
canonicalNames = append(canonicalNames, spell.name)
}
sort.Strings(canonicalNames)
digest, err := effectiveDigest(base, overlays, builder, canonicalNames)
if err != nil {
return EffectiveCatalog{}, err
}
return EffectiveCatalog{
baseID: base.ID(),
ruleset: base.Ruleset(),
overlayIDs: overlayIDs,
canonicalNames: canonicalNames,
lookup: cloneStringMap(builder.lookup),
digest: digest,
}, nil
}
func (b *effectiveBuilder) ensureCanonical(name string) (string, error) {
key := lookupKey(name)
if key == "" {
return "", fmt.Errorf("spell %q has an empty lookup key", name)
}
if canonical, exists := b.canonicalByKey[key]; exists {
if canonical != name {
return "", fmt.Errorf("canonical lookup key %q has conflicting display names %q and %q", key, canonical, name)
}
return canonical, nil
}
if canonical, exists := b.lookup[key]; exists {
return "", fmt.Errorf("canonical lookup key %q collides with alias of spell %q", key, canonical)
}
spell := &effectiveSpell{name: name, canonicalKey: key, aliases: make(map[string]string)}
b.spells[name] = spell
b.canonicalByKey[key] = name
b.lookup[key] = name
return name, nil
}
func (b *effectiveBuilder) addCanonical(name string) error {
_, err := b.ensureCanonical(name)
return err
}
func (b *effectiveBuilder) addAlias(canonical string, alias string) error {
key := lookupKey(alias)
if key == "" {
return fmt.Errorf("spell %q has an empty alias lookup key", canonical)
}
if existing, exists := b.lookup[key]; exists && existing != canonical {
return fmt.Errorf("lookup key %q maps to spells %q and %q", key, existing, canonical)
}
spell, exists := b.spells[canonical]
if !exists {
return fmt.Errorf("spell %q is not present", canonical)
}
if key == spell.canonicalKey {
return nil
}
b.lookup[key] = canonical
if previous, exists := spell.aliases[key]; !exists || alias < previous {
spell.aliases[key] = alias
}
return nil
}
type effectiveDigestDocument struct {
BaseID string `json:"base_id"`
BaseRuleset string `json:"base_ruleset"`
BaseSource Source `json:"base_source"`
Overlays []effectiveDigestOverlay `json:"overlays"`
Spells []effectiveDigestSpell `json:"spells"`
}
type effectiveDigestOverlay struct {
ID string `json:"id"`
Ruleset string `json:"ruleset"`
Source struct {
Title string `json:"title"`
Version string `json:"version"`
URL string `json:"url"`
License string `json:"license"`
} `json:"source"`
}
type effectiveDigestSpell struct {
Key string `json:"key"`
Name string `json:"name"`
Aliases []effectiveDigestAlias `json:"aliases,omitempty"`
}
type effectiveDigestAlias struct {
Key string `json:"key"`
Display string `json:"display"`
}
func effectiveDigest(base Catalog, overlays []overlayCatalog, builder effectiveBuilder, canonicalNames []string) (string, error) {
document := effectiveDigestDocument{
BaseID: base.ID(),
BaseRuleset: base.Ruleset(),
BaseSource: base.Source(),
Overlays: make([]effectiveDigestOverlay, len(overlays)),
Spells: make([]effectiveDigestSpell, 0, len(canonicalNames)),
}
for index, overlay := range overlays {
document.Overlays[index].ID = overlay.ID
document.Overlays[index].Ruleset = overlay.Ruleset
version, err := decodeOptionalString(overlay.Source.Version)
if err != nil {
return "", fmt.Errorf("catalog %q source version: %w", overlay.ID, err)
}
url, err := decodeOptionalString(overlay.Source.URL)
if err != nil {
return "", fmt.Errorf("catalog %q source url: %w", overlay.ID, err)
}
license, err := decodeOptionalString(overlay.Source.License)
if err != nil {
return "", fmt.Errorf("catalog %q source license: %w", overlay.ID, err)
}
document.Overlays[index].Source.Title = overlay.Source.Title
document.Overlays[index].Source.Version = version
document.Overlays[index].Source.URL = url
document.Overlays[index].Source.License = license
}
for _, name := range canonicalNames {
spell := builder.spells[name]
digestSpell := effectiveDigestSpell{Key: spell.canonicalKey, Name: spell.name}
keys := make([]string, 0, len(spell.aliases))
for key := range spell.aliases {
keys = append(keys, key)
}
sort.Strings(keys)
for _, key := range keys {
digestSpell.Aliases = append(digestSpell.Aliases, effectiveDigestAlias{Key: key, Display: spell.aliases[key]})
}
document.Spells = append(document.Spells, digestSpell)
}
raw, err := json.Marshal(document)
if err != nil {
return "", fmt.Errorf("encode effective spell catalog digest: %w", err)
}
sum := sha256.Sum256(raw)
return "sha256:" + hex.EncodeToString(sum[:]), nil
}
func cloneStringMap(values map[string]string) map[string]string {
if len(values) == 0 {
return nil
}
out := make(map[string]string, len(values))
for key, value := range values {
out[key] = value
}
return out
}
func cloneReferenceSet(in contracts.ReferenceSet) contracts.ReferenceSet {
if len(in.Slots) == 0 {
return contracts.ReferenceSet{}
}
out := contracts.ReferenceSet{Slots: make(map[string]contracts.ResolvedReferenceSlot, len(in.Slots))}
for name, slot := range in.Slots {
slot.Slot.AcceptedMediaTypes = append([]string(nil), slot.Slot.AcceptedMediaTypes...)
items := make([]contracts.ReferenceItem, len(slot.Items))
for index, item := range slot.Items {
item.Content = append([]byte(nil), item.Content...)
items[index] = item
}
slot.Items = items
out.Slots[name] = slot
}
return out
}