// Package register composes the production D&D module family.
package register

import (
	"fmt"

	"gitea.maximumdirect.net/eric/notarius/internal/framework/llm"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/chunk/scenes"
	npccodec "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/codec/npcs"
	spellcodec "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/codec/spells"
	npcextract "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/extract/npcs"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/extract/spells"
	npcnormalize "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/normalize/npcs"
	spellnormalize "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/normalize/spells"
	npcidentity "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/npcs/identity"
	npcshape "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/npcs/shape"
	npcsourcerefs "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/npcs/source_refs"
	npcrelatedness "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/npcs/source_relatedness"
	spellcatalog "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/spells/catalog"
	spellshape "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/spells/shape"
	spellsourcerefs "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/spells/source_refs"
	spellrelatedness "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/spells/source_relatedness"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/generic/merge/appendorder"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/generic/normalize/noop"
	alwaysaccept "gitea.maximumdirect.net/eric/notarius/internal/modules/generic/validate/always_accept"
	alwaysreject "gitea.maximumdirect.net/eric/notarius/internal/modules/generic/validate/always_reject"
	validjson "gitea.maximumdirect.net/eric/notarius/internal/modules/generic/validate/valid_json"
	validjsonschema "gitea.maximumdirect.net/eric/notarius/internal/modules/generic/validate/valid_json_schema"
)

// Register adds all production D&D modules, validators, policy, and assets.
func Register(registries pipeline.Registries, assets *llm.AssetRegistry) error {
	if err := validateRegistries(registries, assets); err != nil {
		return err
	}
	codec := spellcodec.New()
	registrations := []struct {
		name     string
		register func() error
	}{
		{name: "spells codec", register: func() error { return pipeline.RegisterArtifactCodec(registries.ArtifactCodecs, codec) }},
		{name: "npcs codec", register: func() error { return pipeline.RegisterArtifactCodec(registries.ArtifactCodecs, npccodec.New()) }},
		{name: "scenes chunker", register: func() error { return scenes.Register(registries.Chunkers) }},
		{name: "spells extractor", register: func() error { return spells.Register(registries.Extractors) }},
		{name: "npcs extractor", register: func() error { return npcextract.Register(registries.Extractors) }},
		{name: "spell-list appendorder merger", register: func() error {
			return appendorder.RegisterTyped(registries.Mergers, dnd.SpellListKind, appendSpellLists)
		}},
		{name: "npc-list appendorder merger", register: func() error {
			return appendorder.RegisterTyped(registries.Mergers, dnd.NPCListKind, appendNPCLists)
		}},
		{name: "spells normalizer", register: func() error { return spellnormalize.Register(registries.Normalizers) }},
		{name: "npcs normalizer", register: func() error { return npcnormalize.Register(registries.Normalizers) }},
		{name: "spell-list noop normalizer", register: func() error { return noop.RegisterTyped[dnd.SpellList](registries.Normalizers, dnd.SpellListKind) }},
		{name: "npc-list noop normalizer", register: func() error { return noop.RegisterTyped[dnd.NPCList](registries.Normalizers, dnd.NPCListKind) }},
		{name: "spell shape validator", register: func() error { return spellshape.Register(registries.Validators) }},
		{name: "spell catalog validator", register: func() error { return spellcatalog.Register(registries.Validators) }},
		{name: "spell source references validator", register: func() error { return spellsourcerefs.Register(registries.Validators) }},
		{name: "spell source relatedness validator", register: func() error { return spellrelatedness.Register(registries.Validators) }},
		{name: "npc shape validator", register: func() error { return npcshape.Register(registries.Validators) }},
		{name: "npc identity validator", register: func() error { return npcidentity.Register(registries.Validators) }},
		{name: "npc source references validator", register: func() error { return npcsourcerefs.Register(registries.Validators) }},
		{name: "npc source relatedness validator", register: func() error { return npcrelatedness.Register(registries.Validators) }},
		{name: "spell-list always accept validator", register: func() error {
			return alwaysaccept.RegisterTyped[dnd.SpellList](registries.Validators, dnd.SpellListKind)
		}},
		{name: "spell-list always reject validator", register: func() error {
			return alwaysreject.RegisterTyped[dnd.SpellList](registries.Validators, dnd.SpellListKind)
		}},
		{name: "npc-list always accept validator", register: func() error {
			return alwaysaccept.RegisterTyped[dnd.NPCList](registries.Validators, dnd.NPCListKind)
		}},
		{name: "npc-list always reject validator", register: func() error {
			return alwaysreject.RegisterTyped[dnd.NPCList](registries.Validators, dnd.NPCListKind)
		}},
		{name: "scenes prompt assets", register: func() error { return scenes.RegisterPromptAssets(assets) }},
		{name: "spells prompt assets", register: func() error { return spells.RegisterPromptAssets(assets) }},
		{name: "npcs prompt assets", register: func() error { return npcextract.RegisterPromptAssets(assets) }},
	}
	for _, registration := range registrations {
		if err := registration.register(); err != nil {
			return fmt.Errorf("register dnd %s: %w", registration.name, err)
		}
	}
	if err := registries.ValidatorChains.Register(pipeline.ValidatorChainMapping{
		Stage:  pipeline.StageExtract,
		Module: spells.Key,
		Validators: []pipeline.ModuleBinding{
			pipeline.Binding(validjson.Key),
			pipeline.Binding(validjsonschema.Key),
			pipeline.Binding(spellshape.Key),
			pipeline.Binding(spellcatalog.Key),
			pipeline.Binding(spellsourcerefs.Key),
			pipeline.Binding(spellrelatedness.Key),
		},
	}); err != nil {
		return fmt.Errorf("register dnd spells validator chain: %w", err)
	}
	if err := registries.ValidatorChains.Register(pipeline.ValidatorChainMapping{
		Stage:  pipeline.StageNormalize,
		Module: spellnormalize.Key,
		Validators: []pipeline.ModuleBinding{
			pipeline.Binding(validjson.Key),
			pipeline.Binding(validjsonschema.Key),
			pipeline.Binding(spellshape.Key),
			pipeline.Binding(spellcatalog.Key),
			pipeline.Binding(spellsourcerefs.Key),
			pipeline.Binding(spellrelatedness.Key),
		},
	}); err != nil {
		return fmt.Errorf("register dnd spells normalize validator chain: %w", err)
	}
	if err := registries.ValidatorChains.Register(pipeline.ValidatorChainMapping{
		Stage:  pipeline.StageExtract,
		Module: npcextract.Key,
		Validators: []pipeline.ModuleBinding{
			pipeline.Binding(validjson.Key),
			pipeline.Binding(validjsonschema.Key),
			pipeline.Binding(npcshape.Key),
			pipeline.Binding(npcsourcerefs.Key),
			pipeline.Binding(npcrelatedness.Key),
		},
	}); err != nil {
		return fmt.Errorf("register dnd npcs validator chain: %w", err)
	}
	if err := registries.ValidatorChains.Register(pipeline.ValidatorChainMapping{
		Stage:  pipeline.StageNormalize,
		Module: npcnormalize.Key,
		Validators: []pipeline.ModuleBinding{
			pipeline.Binding(validjson.Key),
			pipeline.Binding(validjsonschema.Key),
			pipeline.Binding(npcshape.Key),
			pipeline.Binding(npcidentity.Key),
			pipeline.Binding(npcsourcerefs.Key),
			pipeline.Binding(npcrelatedness.Key),
		},
	}); err != nil {
		return fmt.Errorf("register dnd npcs normalize validator chain: %w", err)
	}
	return nil
}

func appendSpellLists(values []dnd.SpellList) (dnd.SpellList, error) {
	count := 0
	for _, value := range values {
		count += len(value.SpellCasts)
	}
	combined := dnd.SpellList{SpellCasts: make([]dnd.SpellCast, 0, count)}
	for _, value := range values {
		combined.SpellCasts = append(combined.SpellCasts, value.SpellCasts...)
	}
	return combined, nil
}

func appendNPCLists(values []dnd.NPCList) (dnd.NPCList, error) {
	count := 0
	present := false
	for _, value := range values {
		if value.NPCs != nil {
			present = true
		}
		count += len(value.NPCs)
	}
	if !present {
		return dnd.NPCList{}, nil
	}
	combined := dnd.NPCList{NPCs: make([]dnd.NPC, 0, count)}
	for _, value := range values {
		combined.NPCs = append(combined.NPCs, value.NPCs...)
	}
	return combined, nil
}

func validateRegistries(registries pipeline.Registries, assets *llm.AssetRegistry) error {
	switch {
	case registries.Chunkers == nil:
		return fmt.Errorf("dnd registrar: chunker registry must not be nil")
	case registries.ArtifactCodecs == nil:
		return fmt.Errorf("dnd registrar: artifact codec registry must not be nil")
	case registries.Extractors == nil:
		return fmt.Errorf("dnd registrar: extractor registry must not be nil")
	case registries.Mergers == nil:
		return fmt.Errorf("dnd registrar: merger registry must not be nil")
	case registries.Normalizers == nil:
		return fmt.Errorf("dnd registrar: normalizer registry must not be nil")
	case registries.Validators == nil:
		return fmt.Errorf("dnd registrar: validator registry must not be nil")
	case registries.ValidatorChains == nil:
		return fmt.Errorf("dnd registrar: validator chain registry must not be nil")
	case assets == nil:
		return fmt.Errorf("dnd registrar: asset registry must not be nil")
	default:
		return nil
	}
}